U.S. patent application number 13/543128 was filed with the patent office on 2013-01-10 for method for elevating prolactin in mammals.
This patent application is currently assigned to CARA THERAPEUTICS, INC.. Invention is credited to Derek T. Chalmers, Michael E. Lewis, Frederique Menzaghi.
Application Number | 20130012431 13/543128 |
Document ID | / |
Family ID | 38654611 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130012431 |
Kind Code |
A1 |
Menzaghi; Frederique ; et
al. |
January 10, 2013 |
Method For Elevating Prolactin In Mammals
Abstract
Methods for elevating and stabilizing prolactin levels in a
mammal including methods of treating disorders and conditions
associated with reduced serum levels of prolactin are provided.
Also provided are methods of using certain synthetic tetrapeptide
amides which are peripherally selective kappa opioid receptor
agonists to elevate or stabilize serum prolactin levels.
Inventors: |
Menzaghi; Frederique; (Rye,
NY) ; Lewis; Michael E.; (West Chester, PA) ;
Chalmers; Derek T.; (Riverside, CT) |
Assignee: |
CARA THERAPEUTICS, INC.
Shelton
CT
|
Family ID: |
38654611 |
Appl. No.: |
13/543128 |
Filed: |
July 6, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12300595 |
Apr 22, 2009 |
8217000 |
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PCT/US2007/012285 |
May 22, 2007 |
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13543128 |
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60808677 |
May 26, 2006 |
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Current U.S.
Class: |
514/4.7 ;
514/17.7; 514/21.9; 514/7.3; 604/20 |
Current CPC
Class: |
A61P 25/00 20180101;
A61P 3/10 20180101; A61P 43/00 20180101; A61K 45/06 20130101; A61P
15/00 20180101; A61P 15/14 20180101; A61K 38/07 20130101; A61K
38/095 20190101; A61P 5/06 20180101; A61P 5/02 20180101; A61K 31/00
20130101 |
Class at
Publication: |
514/4.7 ;
514/21.9; 514/7.3; 514/17.7; 604/20 |
International
Class: |
A61K 38/07 20060101
A61K038/07; A61M 37/00 20060101 A61M037/00; A61P 25/00 20060101
A61P025/00; A61P 15/14 20060101 A61P015/14; A61P 15/00 20060101
A61P015/00; A61P 3/10 20060101 A61P003/10 |
Claims
1. A method of elevating levels of serum prolactin in a mammal in
need of elevated or stabilized levels of serum prolactin,
comprising administering to said mammal an amount of a peripherally
selective kappa opioid receptor agonist, a salt thereof or a
pro-drug thereof effective to elevate or stabilize levels of serum
prolactin in the mammal.
2. The method of claim 1, wherein said peripherally, selective
kappa opioid receptor agonist, a salt thereof or a pro-drug thereof
comprises a peptide.
3. The method of claim 2, wherein said peptide has a binding
affinity for the kappa opioid receptor that is 10 times greater,
100 times greater, 1,000 times greater, or more than its binding
affinity for non-kappa opioid receptors.
4. The method of claim 2, wherein said peptide has the formula:
H-Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-Q; and wherein Xaa.sub.1
is (A)D-Phe, (C.sup.alpha Me)D-Phe, D-Tyr, D-Tic or
D-Ala(cyclopentyl or thienyl), with A being H, NO.sub.2, F, C.sub.1
or CH.sub.3; Xaa.sub.2 is (A')D-Phe, D-1Nal, D-2Nal, D-Tyr or
D-Trp, with A' being A or 3,4Cl.sub.2; Xaa.sub.3 is D-Nle,
(B)D-Leu, D-Hle, D-Met, D-Val, D-Phe or D-Ala(cyclopentyl) with B
being H or C.sup.alpha Me; Xaa.sub.4 is D-Arg, D-Har, D-nArg,
D-Lys, D-Lys(Ipr), D-Arg(Et.sub.2), D-Har(Et.sub.2), D-Amf(G),
D-Dbu, (B)D-Orn or D-Orn(Ipr), with G being H or amidino; and Q is
NR.sub.1R.sub.2, morpholinyl, thiomorpholinyl, (C)piperidinyl,
piperazinyl, 4-mono- or 4,4-di-substituted piperazinyl or
delta-ornithinyl, with R.sub.1 being lower alkyl, substituted lower
alkyl, benzyl, substituted benzyl, aminocyclohexyl, 2-thiazolyl,
2-picolyl, 3-picolyl or 4-picolyl, R.sub.2 being H or lower alkyl;
and C being H, 4-hydroxy or 4-oxo.
5. The method of claim 4, wherein Q is morpholinyl or
thiomorpholinyl.
6. The method of claim 4, wherein Q is NHR.sub.1 and R.sub.1 is
4-picolyl.
7. The method of claim 2, wherein said peptide has the formula:
H-Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-Q; and wherein Xaa.sub.1
is D-Phe (unsubstituted or substituted by C.sup.alpha, Me, 2F, 4F
or 4Cl) or D-Ala(cyclopentyl or thienyl); Xaa.sub.2 is (A')D-Phe,
D-1Nal, D-2Nal or D-Trp, with A' being H, 4F, 40, 4NO.sub.2 or
3,4Cl.sub.2; Xaa.sub.3 is D-Nle, D-Leu, D-CML, D-Met or D-Acp;
Xaa.sub.4 is D-Arg, D-Arg(Et.sub.2), D-Lys, D-Ily, D-Har,
D-Har(Et.sub.2), D-nArg, D-Orn, D-Ior, D-Dbu, D-Amf, and
D-Amf(Amd); and Q is NR.sub.1, R.sub.2, Mor, Tmo, Pip, 4-Hyp, OxP
or Ppz, with R.sub.1 being Me, Et, Pr, Bu, hEt, Cyp, Bzl or
4-picolyl, and R.sub.2 being H or Et.
8. The method of claim 7, wherein Xaa.sub.2 is D-Phe, Xaa.sub.3 is
D-Nle and Xaa.sub.4 is D-Arg.
9. The method of claim 7, wherein Q is morpholinyl or
thiomorpholinyl.
10. The method of claim 7, wherein Q is NHR.sub.1 and R.sub.1 is
4-picolyl.
11. The method of claim 7, wherein Xaa.sub.3 is D-Nle or D-Leu and
Q is morpholinyl.
12. The method of claim 7, wherein Xaa.sub.1 is D-Phe, D-4Fpa,
D-2Fpa, D-Acp or D-Ala(2Thi); Xaa.sub.2 is (A)D-Phe, D-1Nal, D-2Nal
or D-Trp, with A being 4F or 4Cl; Xaa.sub.3 is D-Nle, D-Met or
D-Leu; Xaa.sub.4 is D-Arg, D-Har, D-nArg, D-Lys, D-Orn or
D-Amf(Amd); and Q is NHR.sub.1, Mor, Tmo, Pip or Ppz, with R.sub.1
being Et, Pr or 4Pic.
13. The method of claim 2, wherein said peptide has the formula:
H-D-Phe-D-Phe-D-Nle-D-Arg-NHEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-picolyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHPr,
H-D-Phe-D-Phe-D-Nle-D-Arg-thiomorpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-Net.sub.2,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHMe,
H-D-Phe-D-Phe-D-Leu-D-Orn-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHhEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-cyclopropyl, H-D-Ala(2Thi)-D-4
Cpa-D-Leu-D-Arg-morpholinyl, H-D-Phe-D-Phe-D-Nle-D-Arg-piperidinyl,
H-D-Phe-D-Phe-D-Leu-D-Orn-NHEt,
H-D-Phe-D-Phe-D-Leu-D-Lys-morpholinyl, or
H-D-Phe-D-Phe-D-Nle-D-Arg-piperazinyl.
14. The method of claim 1, wherein said peripherally selective
kappa opioid receptor agonist, when administered peripherally, does
not substantially cross the blood-brain barrier.
15. The method of claim 1, wherein said administration comprises
intravenous, subcutaneous, intramuscular, intranasal, oral, or
transdermal administration.
16. The method of claim 15, wherein said transdermal administration
is provided by an electrotransport device.
17. The method of claim 16, wherein said administration comprises:
(a) providing a first electrode; (b) providing a second electrode;
(c) providing a power source electrically connected to said first
and said second electrodes; (d) providing at least one donor
reservoir having the peripherally selective kappa opioid receptor
agonist, wherein said donor reservoir is associated with said first
or second electrode; and (e) delivering a therapeutically effective
amount of said peripherally selective kappa opioid receptor agonist
through said body surface.
18. A method of treating a mammal in need of elevated or stabilized
prolactin levels, said method comprising administering to said
mammal an amount of a peripherally selective kappa opioid receptor
agonist or a salt thereof or a pro-drug thereof, and administering,
either separately or in combination with said peripherally
selective kappa opioid receptor agonist or a salt thereof or a
pro-drug thereof, an amount of an additional prolactin elevating
compound, effective to treat the mammal.
19. The method of claim 18, wherein the prolactin-elevating agent
is a D2 dopamine receptor antagonist or a mu opioid receptor
agonist.
20. A method for treating reduced sperm motility, an age-related
disorder, type 1 diabetes, insomnia, or inadequate REM sleep,
insufficient or inadequate lactation, or for preventing
insufficient or inadequate lactation, in a mammal, comprising
administering an amount of a peripherally selective kappa opioid
receptor agonist or a salt thereof or a pro-drug thereof, effective
to treat or prevent insufficient or inadequate lactation, or to
treat reduced sperm motility, age-related disorder, type 1
diabetes, insomnia, or inadequate REM sleep in the mammal.
21. The method of claim 20, wherein such amount of a peripherally
selective kappa opioid receptor agonist or a salt thereof or a
pro-drug thereof is administered to said mammal prior to or after
childbirth in conjunction with a lactation enhancer or stabilizer
effective to treat said mammal.
22. The method of claim 21, wherein the lactation enhancer
comprises oxytocin.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and incorporates by
reference herein U.S. Provisional Application Ser. No. 60/808,677
filed May 26, 2006 and entitled "METHOD FOR ELEVATING PROLACTIN IN
MAMMALS."
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to the use of peripherally selective
kappa opioid receptor agonists to elevate serum levels of prolactin
for the benefit of a mammal in need of such elevation.
BACKGROUND
[0003] Prolactin is a 198 amino acid polypeptide synthesized in
pituitary lactotrophs, which constitute about 20 percent of
adenohypophysial cells (for review, see Harrison's Principles of
Internal Medicine, 16th Ed., p. 2084; also Freeman M E et al.
Prolactin: Structure, function, and regulation of secretion.
Physiol. Rev. 80: 1523 1631, 2000). Prolactin is also referred to
in the art as Galactin, Lactogen, Lactoropin, LMTH, LTH,
Luteomammotrophic Hormone, Luteotrophic Hormone, Luteotropin, and
Mammotrophin, although these names are now obsolete. The best
studied effects of prolactin are on the mammary gland, and include
growth and development of the mammary gland (mammogenesis),
synthesis of milk (lactogenesis), and maintenance of milk secretion
(galactopoiesis). The endocrine control of lactation involves
multiple complex physiological mechanisms since mammogenesis,
lactogenesis, galactopoiesis, and galactokinesis are all essential
for proper lactation. Prolactin is the key hormone of lactation and
is believed to be the single most important galactopoietic hormone.
Oxytocin, serotonin, opioid peptides, histamine, substance P, and
other physiological substances modulate prolactin release by means
of an autocrine/paracrine mechanism at the level of the
hypothalamus, whereas estrogen and progesterone hormones can act at
the hypothalamic and adenohypophysial levels. Human placental
lactogen and growth factors play an essential role in successful
lactation during pregnancy, with oxytocin functioning as a key
galactokinetic hormone.
[0004] Normal adult serum prolactin levels are about 10 25 ng/ml in
women and 10 20 ng/ml in men. Prolactin is secreted in an episodic
manner with a distinct 24 hour pattern. Circulating prolactin
levels are lowest at midday, and a modest increase occurs during
the afternoon. Prolactin levels increase shortly after onset of
sleep, peaking in the early morning. Serum prolactin levels rise
substantially during pregnancy (150 200 ng/ml) and decline rapidly
within two weeks of parturition. Breastfeeding will normally cause
prolactin levels to remain elevated, due to suckling induced
activation of neural reflexes that that induce prolactin release.
However, inadequate activation of prolactin release will interfere
with breastfeeding, with a variety of potentially deleterious
psychological and physiological consequences, e.g., a failure of
mother infant bonding and a failure to transmit maternal protective
antibodies to the infant (American Academy of Pediatrics, Section
on Breastfeeding. Breastfeeding and the use of human milk.
Pediatrics 115: 496 506, 2005). According to the American Academy
of Pediatrics, in this most current version of their guidance on
breastfeeding, "Extensive research using improved epidemiologic
methods and modern laboratory techniques documents diverse and
compelling advantages for infants, mothers, families, and society
from breastfeeding and use of human milk for infant feeding. These
advantages include health, nutritional, immunologic, developmental,
psychologic, social, economic, and environmental benefits." Because
of the well documented benefits of breastfeeding, insufficient
lactation is now viewed as an important medical problem.
[0005] There are numerous risk factors for insufficient lactation,
including:
[0006] (i) restarting lactation after termination, e.g., to care
for a sick infant (Thompson N Relactation in a newborn intensive
care setting. J. Hum. Lact. 12: 233-235, 1996)
[0007] (ii) physical abnormality of the breast (Neifert M R et al.
Lactation failure due to insufficient glandular development of the
breast. Pediatrics 76:823-828, 1985)
[0008] (iii) absence of breast enlargement during pregnancy (Moon J
et al. Breast engorgement: contributing variables and variables
amenable to nursing intervention. J. Obstet. Gynecol. Neonatal
Nurs. 18: 309-315, 1989).
[0009] (iv) history of breast surgery (Widdice L The effects of
breast reduction and breast augmentation surgery on lactation: An
annotated bibliography. J. Hum. Lact. 9:161-163, 1993).
[0010] (v) first time delivery of infant (Dewey K G et al. Risk
factors for suboptimal infant breastfeeding behavior, delayed onset
of lactation, and excess neonatal weight loss. Pediatrics
112:607-619, 2003).
[0011] (vi) premature delivery of infant (Ehrenkranz R A et al.
Metoclopramide effect on faltering milk production by mothers of
premature infants. Pediatrics; 78:614 20, 1986; Feher S D K et al.
Increasing breast milk production for premature infants with a
relaxation/imagery audiotape. Pediatrics 83:57-60, 1989)
[0012] (vii) delivery of more than one infant (Leonard, L.
Breastfeeding higher order multiples: Enhancing support during the
postpartum hospitalization period. J. Hum. Lact. 18:386-392,
2002).
[0013] (viii) adoption of infant (Cheales Siebenaler, N. Induced
lactation in an adoptive mother. J. Hum. Lact. 15:41-43, 1999).
[0014] (ix) retention of placental fragments (Neifert, M R et al.
Failure of lactogenesis associated with placental retention. Am. J.
Obstet. Gynecol. 140:477-478, 1981)
[0015] (x) use of hormonal birth control (Tankeyoon M et al.
Effects of hormonal contraceptives on milk volume and infant
growth. WHO Special Programme of Research, Development and Research
Training in Human Reproduction Task force on oral contraceptives.
Contraception 30:505-22, 1984)
[0016] (xi) use of certain OTC decongestants (Aljazaf K et al.
Pseudoephedrine: effects on milk production in women and estimation
of infant exposure via breastmilk. Br. J. Clin. Pharmacol.
56:18-24, 2003)
[0017] (xii) cigarette smoking (Andersen A N et al: Suppressed
prolactin but normal neurophysin levels in cigarette smoking breast
feeding women. Clin. Endocrinol. (Oxf.) 17:363-8, 1982.
[0018] (xiii) prepregnant overweight and obesity (Hilson J A et al.
High prepregnant body mass index is associated with poor lactation
outcomes among white, rural women independent of psychosocial and
demographic correlates. J. Hum. Lact. 20:18-29, 2004; Rasmussen K M
et al. Prepregnant overweight and obesity diminish the prolactin
response to suckling in the first week postpartum. Pediatrics
113:465-71, 2004).
[0019] (xiv) Cesarean delivery (Chapman D J et al. Identification
of risk factors for delayed onset of lactation. J. Am. Diet. Assoc.
99:450-454, 1999)
[0020] (xv) insulin dependent maternal diabetes (Neubauer, S H et
al. Delayed lactogenesis in women with insulin dependent diabetes
mellitus. Am. J. Clin. Nutr. 58:54-60, 1993)
[0021] (xvi) medications to treat labor pain (Riordan J et al. The
effect of labor pain relief medication on neonatal suckling and
breastfeeding duration. J. Hum. Lact. 16:7-12, 2000; Ransjo
Arvidson A B et al. Maternal analgesia during labor disturbs
newborn behavior: effects on breastfeeding, temperature, and
crying. Birth 28:5-12; 2001).
[0022] (xvii) stress (Chen D C et al. Stress during labor and
delivery and early lactation performance. Am. J. Clin. Nutr.
68:335-344, 1998; Dewey K. Maternal and fetal stress are associated
with impaired lactogenesis in humans. J. Nutr. 131:3012 S-3015S,
2001)
[0023] Signs of insufficient lactation in a human infant include:
(1) insufficient weight gain in an infant who is receiving food
only by breast feeding, even if the infant appears content; (2)
infant latching on poorly; (3) infant sucking inconsistently; (4)
inconsistency of let down reflex, and (5) evidence of hunger,
indicated by crying soon after feedings.
[0024] Lactation failure in humans is a common clinical event with
serious emotional sequelae. It has been considered to be a
significant problem in 5 to 10% of all lactations. In many
instances this leads to premature initiation of supplements or
total weaning. This is considered to be an inferior child rearing
practice and may be harmful to certain infants with an increased
risk of gastritis and other disorders. Many affected women are
severely emotionally distressed by their perceived inadequacy, thus
affecting the parent child bond. Failure to thrive in infants is
not uncommon if the mother refuses to supplement.
[0025] There has therefore been a long need for a medicament that
can promote human lactation, e.g., when there is insufficient
lactation after the birth of the child. For animal breeders, the
inability of their livestock, e.g., mares, to produce and secrete
milk after giving birth can be a significant problem. Should the
breeding animals not lactate properly, the offspring must then be
bottle fed, which is time consuming, labor intensive, and costly;
thus, there is a need for a medicament to safely and effectively
promote breeding animal lactation. For commercial milk producing
animals like cows and goats, there is an economic need to safely
and effectively increase their milk production above a normal
level.
[0026] A number of causes of reductions in prolactin levels that
are associated with insufficient lactation were noted above.
Certain of these causes are also associated with reduced prolactin
levels in non lacting subjects, e.g., cigarette smoking (Fuxe K et
al. Neuroendocrine actions of nicotine and of exposure to cigarette
smoke: medical implications. Psychoneuroendocrinology 14: 1.9-41,
1989). Other causes of low prolactin levels (hypoprolactinemia)
include the use of various therapeutic agents, such as L deprenyl
for the treatment of migraine (Fanciullacci M et al. Dopamine
involvement in the migraine attack. Funct Neurol. 15 Suppl
3:171-81, 2000). Hypoprolactinemia of unknown origin has also been
associated with poor sperm motility in adult men (Gonzales G F et
al. Hypoprolactinemia as related to seminal quality and serum
testosterone. Arch. Androl. 23:259-65, 1989), a finding that is
supported by the observation that pharmacological suppression of
prolactin release for several weeks in young men decreased
subsequent hCG stimulated testosterone secretion (Oseko F et al.
Effects of chronic bromocriptine induced hypoprolactinemia on
plasma testosterone responses to human chorionic gonadotropin
stimulation in normal men. Fertil. Steril. 55:355-357, 1991).
Hypoprolactinemia could also contribute to age related changes in
physiological functions. Serum prolactin concentrations tend to
fall with age, e.g. in older men and estrogen unreplaced
postmenopausal women (Maddox P et al. Bioactive and immunoactive
prolactin levels after TRH stimulation in the sera of normal women.
Horm. Metab. Res. 24:181-184, 1992; Maddox P et al. Basal prolactin
and total lactogenic hormone levels by microbioassay and
immunoassay in normal human sera. Acta Endocrinol. (Copenh.)
125:621-627, 1991). Remarkably, a comparable quantitative reduction
in prolactin secretion occurs in critically ill individuals (Van
den Berghe G et al. Thyrotropin and prolactin release in prolonged
critical illness--dynamics of spontaneous secretion and effects of
growth hormone secretagogues. Clin. Endocrinol. (Oxf.) 47:599-612,
1998) as well as in patients with poorly controlled type I diabetes
mellitus (Iranmanesh A et al. Attenuated pulsatile release of
prolactin in men with insulin dependent diabetes mellitus. J. Clin.
Endocrinol. Metab. 71:73-78, 1990). Hypoprolactinemia is also
reported to be a risk factor for prolonged lymphopenia and
apoptosis associated depletion of lymphoid organs in nosocomial
sepsis related death in critically ill children (Felmet K A et al.
Prolonged lymphopenia, lymphoid depletion, and hypoprolactinemia in
children with nosocomial sepsis and multiple organ failure. J.
Immunol. 174:3765-72, 2005). The findings reviewed above indicate
that prolactin deficiency may contribute to impaired testosterone
dependent functioning and age related changes as well as
vulnerability to illness.
[0027] In addition to the apparent roles of prolactin discussed
above, there is evidence that prolactin is important for
maintenance of rapid eye movement sleep (REM sleep), which is
essential for normal brain function. After observing that pregnancy
associated sleep enhancement is correlated with the daily surges of
prolactin, investigators found that administration of prolactin to
female rats significantly increased REM sleep (Zhang S Q et al.
Effects of prolactin on sleep in cyclic rats. Psychiatry Clin.
Neurosci. 53:101-3, 1999). Consistent with these findings,
induction of experimental hypoprolactinemia in male rats was found
to decrease REM sleep (Obal Jr F et al. Antiserum to prolactin
decreases rapid eye movement sleep (REM sleep) in the male rat.
Physiol. Behav. 52:1063-1068, 1992). These findings indicate that
subjects experiencing insufficient REM sleep could benefit from
elevations in prolactin.
[0028] Based on the findings reviewed above, there is a need for a
medicament that can safely and effectively elevate prolactin level
in a variety of subjects with functional hypoprolactinemia,
particularly including females experiencing insufficient lactation,
but also males experiencing insufficient testosterone related
functions, and both females and males who are suffering from the
effects of severe illness, including type I diabetes, or who are
suffering the effects of insufficient REM sleep, e.g., due to
insomnia.
[0029] The citation of any reference herein should not be construed
as an admission that such reference is available as "Prior Art" to
the instant application.
SUMMARY OF THE INVENTION
[0030] In general, the invention provides methods for treating a
subject suffering from insufficient or inadequate serum prolactin,
such as functional hypoprolactinemia and the disorders disclosed
herein and known in the art associated with insufficient or
inadequate serum prolactin, as well as methods for treating a
subject in need of elevated or stabilized levels of prolactin. In
one embodiment, a method employs a peripherally selective kappa
opioid receptor agonist compound, optionally in a pharmaceutically
acceptable vehicle for local, regional or systemic administration,
said compound possessing prolactin elevating, increasing or
stabilizing activity, optionally administered without causing a
severe or a clinically significant side effect, such as CNS effects
or diuretic effects.
[0031] In another embodiment, the invention features a method of
treating functional hypoprolactinemia in a subject with a
formulation of a peripherally selective kappa opioid receptor
agonist, optionally suitable for incorporation into a controlled
drug delivery device. In a particular aspect, a controlled drug
delivery device is applied to the skin of a subject. In certain
embodiments, a controlled drug delivery device is applied to the
skin of a subject and optionally further utilizes iontophoresis to
increase transdermal drug delivery.
[0032] In certain embodiments, a formulation is a solid or liquid
or gel.
[0033] In certain embodiments, a formulation includes a liquid
carrier.
[0034] In certain embodiments, a therapeutically effective dose of
a peripherally selective kappa opioid receptor agonist is selected
to produce elevated, increased or stabilized serum prolactin levels
without producing severe or significant diuresis and/or a CNS side
effect.
[0035] In certain embodiments, a peripherally selective kappa
opioid, receptor agonist produces pharmacologically insignificant
or physiologically tolerable levels of said agonist in the plasma
of an infant consuming the breast milk from or produced by a
subject treated with said agonist.
[0036] In certain embodiments, the peripherally selective kappa
opioid receptor agonist is selected to avoid producing a severe or
a clinically significant side effect in an infant consuming the
breast milk from or produced by a subject treated with said
agonist.
[0037] In certain aspects, the invention features methods of
elevating, increasing or stabilizing plasma levels of prolactin to
a subject in need of elevated, increased or stabilized prolactin.
In one embodiment, a method includes administration of a
therapeutically effective dose of a peripherally selective kappa
opioid receptor agonist to the subject. In another embodiment, a
method includes administration of a therapeutically effective dose
of a peripherally selective kappa opioid receptor agonist to the
subject, in combination with a prolactin elevating-increasing or
-stabilizing dose of a second compound selected from a D2 dopamine
receptor antagonist, mu opioid receptor agonist, or prolactin.
[0038] In various embodiments a subject is: a person, e.g., a human
patient, in need of elevated prolactin levels. E.g., the subject
can be: a person in need of stimulation of lactation or
stabilization of lactation, e.g., a mother.
[0039] The invention features methods for treatment and/or
prevention of lactational failure, which can be diagnosed by
various criteria, including:
[0040] a) baby is dissatisfied and irritable after breast
feeding;
[0041] b) poor infant weight gain in relation to age/length;
[0042] c) lack of breast engorgement/leaking if feeding is
missed;
[0043] d) baby is satisfied by supplemental feeding following
breast feeding;
[0044] e) milk secretion of less than 500 ml/day.
[0045] These methods involve systemic administration of
compositions that contain one or more compounds that exert
prolactin elevating, increasing or stabilizing activity via kappa
opiate receptors, but that do not exhibit a severe or significant
side effect, such as a CNS or diuretic effect at effective
dosages.
[0046] In various embodiments, methods use compositions containing
peripherally selective kappa opioid receptor agonists that do not,
upon systemic administration, evoke severe or clinically
significant diuresis or CNS effects, as defined herein,
particularly at the prolactin elevating dosage. Compositions that
contain a peripherally selective kappa opioid receptor agonist
together with other prolactin elevating compounds are also
provided.
[0047] Typically, compounds intended for use in the compositions
and methods herein possess prolactin elevating, increasing or
stabilizing activity and reduced or tolerable CNS effects, as
defined herein, because, without being bound by any theory, they do
not substantially cross the blood brain barrier. A relative or
complete absence of substantial crossing of the blood brain barrier
lessens the occurrence of CNS systemic effects. Kappa opioid
receptors agonists that readily cross the blood brain barrier could
be effective as prolactin elevating agents, but permeability
through the blood brain barrier can result in severe or intolerable
side effects, such as dysphoria and hallucinations.
[0048] Peripherally selective kappa opioid receptor agonists
include kappa opioid receptor agonists that do not substantially
cross the blood brain barrier as assessed by, assays described
herein or known in the art. The peripherally selective kappa opioid
receptor agonists for use in the methods and compositions provided
herein also include any compound that by virtue of its interaction,
either directly or indirectly, with peripheral kappa opioid
receptor receptors ameliorates failure of lactation, or elevates,
increases or stabilizes levels of serum prolactin, without
exhibiting medically severe or significant CNS effects, such as
dysphoria and hallucinations, at effective doses.
[0049] As used herein, the term "peripherally selective," when used
in reference to a "kappa opioid receptor agonist" refers to a
chemical compound having a reduced ability to cross (traverse) the
blood-brain barrier, or that exhibits little or substantially no
crossing of the blood-brain barrier when not administered to the
CNS (brain and spinal cord). As a consequence of a reduced ability
or inability to cross (traverse) the blood-brain barrier, a
peripherally selective kappa opioid receptor agonist typically
exhibits fewer or less severe (minor or tolerable) side effects in
the CNS, such as dysphoria, hallucinations, or sedation.
[0050] Various measures of the ability of a compound to cross
(traverse) the blood-brain barrier are known in the art and can be
used to measure the amount or rate (kinetics) of blood-brain
barrier crossing (traversal). One non-limiting example is to
compare the ability of a compound to elicit peripheral effects
versus the ability of the compound to elicit central effects
following treatment with a particular compound (e.g., kappa opioid
receptor agonist). Peripheral effects can be measured using the
mouse writhing test (WT) and central effects, due to action of
kappa opioid receptors located in the brain and spinal cord, can be
measured using the mouse tail-flick test (TF).
[0051] In brief, the mouse writhing test (WT) test (described in
Bentley et al., Br. J. Phamac., 73:325 (1981)) employs conscious
male ICR mice (available from Harlan) weighing about 20 to 30
grams. Mice are fasted for about 12 to 16 hours prior to the test
and writhing is induced by intraperitoneal administration of dilute
acetic acid (10 ml of 0.6% aqueous acetic acid/kg body weight).
Writhing is scored during the 15 minutes following acetic acid
administration. Compounds (e.g., kappa opioid receptor agonists)
are typically tested at 3 to 4 increasing doses, given by
intravenous route, and at a unique pretreatment time (e.g., -5
minutes before acetic acid injection). This step is used to
determine the potency (WT-ED.sub.50) as well as a submaximal
effective dose (about 80-90% antinociception). In a second step, a
submaximal effective dose for each specific compound is
administered at various pretreatment times (e.g., -5 minutes, -60
minutes, -120 minutes and -180 minutes) prior to the administration
of the acetic acid in order to determine the duration of action.
Throughout the test, a control group of mice are used which are
administered only the vehicle without the compound. The number of
writhes are counted over a 15-minute period, starting from the time
of acetic acid injection, and bioactivity, i.e. antinociception, is
expressed as a percentage, and is calculated as follows:
100.times.(writhes in control group-writhes in treated
group)/writhes in control group
[0052] Because each submaximal dose likely varies so as not to be
directly comparable, results are normalized mathematically, to
provide comparable values. Values higher than 100% indicate greater
antinociception than at the beginning of the study. Compounds
effective at reducing writhing by at least about 25% at a time of 1
hour are considered to have long duration of in vivo action.
[0053] In addition to using the writhing test to determine duration
of antinociceptive activity, it is also used to measure the in vivo
biopotency (short term) of the peptide. This value is represented
as WT-ED.sub.50 in milligrams per kg of body weight, a measure of
the dosage necessary to reduce the number of writhes in the mouse
being tested by 50% (as compared to a control mouse) over a period
of 15 minutes.
[0054] The tail-flick test (TF) is an assay of acute somatic pain,
designed to evaluate potency and duration of action of centrally
acting analgesics (described, for example, in Vanderah, et al., J.
Pharm. Exper. Therapeutics, 262:190 (1992)). Nociception induced by
tail-dip into hot water (52.degree. C.) results in a rapid tail
withdrawal, or a "tail-flick." Centrally acting compounds are
expected to increase, in a dose-related manner, the latency for
tail withdrawal.
[0055] "Brain Penetration Index" (BPI) can be used to provide a
numerical representation of whether a compound functions centrally
or peripherally. BPI is defined as: BPI=TF-ED.sub.50/WT-ED.sub.50;
where the ED.sub.50 values are the doses that produce half maximal
effect in the mouse writhing test (WT-ED.sub.50) and the mouse
tail-flick test (TF-ED.sub.50), respectively, when administered
intravenously. A high BPI value reflects low brain penetration and,
therefore, a compound that is less likely to substantially cross
the blood-brain barrier or produce severe CNS side effects. BPI
values lower than 5 indicate significant or substantial brain
penetration, and, therefore, a compound that is likely to
substantially cross the blood-brain barrier, which can result in
severe side effects (e.g., dysphoria, hallucinations and sedation)
when used clinically. Accordingly, compounds useful in the
invention have BPI values typically greater than 5, or more, for
example, BPI values of 10, 15, 20, 25, 30, 40, 45, 50, 60, 75, 100,
125, 150, 175, 200, 225, 250, 275, 300, 400, 500, 600, 700, 800,
900, 1000, 1500, 2000, or more.
[0056] Particular non-limiting compounds of the invention are
disclosed in U.S. Pat. No. 5,965,701, are sequences of four
D-isomer amino acid residues having a C-terminus which is a mono or
di-substituted amide. Representative compounds, which have an
affinity for the kappa opioid receptor at least 1,000 times their
affinity for the mu opioid receptor and an ED.sub.50 of not greater
than about 0.5 mg/kg, include H-D-Phe-D-Phe-D-Nle-D-Arg-NHEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-picolyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHPr,
H-D-Phe-D-Phe-D-Nle-D-Arg-thiomorpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NEt.sub.2,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHMe,
H-D-Phe-D-Phe-D-Leu-D-Orn-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHhEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-cyclopropyl, H-D-Ala(2Thi)-D-4
Cpa-D-Leu-D-Arg-morpholinyl, H-D-Phe-D-Phe-D-Nle-D-Arg-piperidinyl,
H-D-Phe-D-Phe-D-Leu-D-Orn-NHEt,
H-D-Phe-D-Phe-D-Leu-D-Lys-morpholinyl, and
H-D-Phe-D-Phe-D-Nle-D-Arg-piperazinyl.
[0057] Peripherally selective kappa opioid receptor agonists of the
invention can be peptides, such as those containing D-amino acids
instead of L-amino acids, and which optionally can have little to
no sequence homology with known mammalian endogenous opioid
peptides, e.g., the enkephalins, endorphins, and dynorphins. A
peripherally selective kappa opioid receptor agonist can comprise a
tetrapeptide D-amino acid sequence. Peptides that are encompassed
by the criteria of the invention are any of the known mammalian
endogenous opioid peptides, e.g., as identified in Akil et al
(1984), such as dynorphin A(1-17), including naturally occurring,
processed forms of these peptides, e.g., dynorphin A(1-13) and
dynorphin A (1-8).
[0058] The invention, among other things, relates to the use of
peripherally selective kappa opioid receptor agonists alone or in
conjunction with lactational enhancers, elevators, or stabilizers
for the treatment of lactation failure, or inadequate or
insufficient lactation in a subject.
[0059] The invention also relates to the use of peripherally
selective kappa opioid agonists, alone or in conjunction with
lactational enhancers elevators, or stabilizers for the manufacture
of a medicament in treatment of lactation failure or inadequate or
insufficient lactation in a subject.
[0060] Lactational enhancers, elevators, or stabilizers can be
chosen from among D2 dopamine receptor antagonists, mu opioid
receptor agonists, prolactin, or oxytocin, for example.
[0061] The invention further relates to a method for the treatment
of lactation failure, or inadequate or insufficient lactation in a
subject, characterized in that a peripherally selective kappa
opioid receptor agonist, alone or in conjunction with a lactational
enhancer, elevator, or stabilizer is administered to a female
subject. Non-limiting administration methods include subcutaneous,
intravenous, intramuscular, nasal, oral or transdermal
administration.
[0062] The invention moreover relates to a composition comprising
peripherally selective kappa opioid receptor agonist in conjunction
with a lactational enhancer, elevators, or stabilizers, optionally
including a pharmaceutically acceptable carrier. These and other
compositions set forth herein can be used in methods for the
treatment of lactation failure, or inadequate or insufficient
lactation in a subject, in accordance with the invention, as well
as a method for the manufacture of these compositions.
[0063] By lactation failure is here meant both when a female has no
or insufficient amount of milk or is at risk for none or
insufficient amount of milk.
[0064] Lactation can be promoted and, therefore, lactation failure,
or inadequate or insufficient lactation in a subject, methods are
provided in the following situations:
[0065] i) Normalize lactation volumes in women with lactational
failure;
[0066] ii) Maintain/enhance, increase lactation in females of
premature babies who are being cared for in a neonatal unit;
[0067] iii) Enhance lactational performance in females with twins
and triplets;
[0068] iv) Promote and prolong (frequency or duration) lactation in
females with offspring at risk of developing lactose intolerance or
other milk allergies if formula milk was used;
[0069] v) Promote/prolong lactation in females where adverse
hygiene conditions would make the use of formula undesirable;
[0070] vi) Enhance, increase or stabilize lactation in females
where suckling frequency is diminished during part of the day, e.g.
working mothers;
[0071] vii) To treat females prophylactically if they are at risk
for having an insufficient or inadequate amount of milk
production.
[0072] Certain embodiments of the invention involve peptides,
optionally tetrapeptides containing four D-isomer amino acid
residues, which bind to kappa opioid receptor receptors, which do
not substantially cross the blood brain barrier and enter the
brain, which exhibit high affinity for the kappa opioid receptor
versus the mu opioid receptor, which have high potency and
efficacy, and can exhibit a relative long duration of action in
vivo.
[0073] It is an object herein to provide peripherally selective
kappa opioid receptor agonists for systemic application that have
tolerable, minimal or few if any CNS or diuretic effects at dosages
that are sufficient to elevate, increase or stabilize prolactin and
thereby produce a benefit, such as increased lactation or prevent
significant reductions, or decreases in lactation, in a subject in
need thereof.
[0074] Mammals are defined herein as all animals, including humans,
primates, and ungulates, for which the females of the species have
mammary glands and produce milk.
[0075] As used herein, a "dairy animal" refers to a milk producing
animal. In certain embodiments, the dairy animal produces large
volumes of milk and has a long period of lactation, e.g., cows or
goats.
[0076] The term "pharmaceutically acceptable composition" refers to
compositions which comprise a therapeutically effective amount of
peripherally selective kappa opioid receptor agonist, formulated
together with one or more pharmaceutically acceptable
carrier(s).
[0077] As used herein, the term "formulation" refers to a
composition in solid, e.g., powder, or liquid form, which includes
a peripherally selective kappa opioid receptor agonist.
Formulations can provide therapeutic benefits. These formulations
may contain a preservative to prevent growth of microorganisms.
[0078] By "therapeutically effective" amount is meant a tolerable
(e.g., does not produce a severe side effect, which can be
relatively, substantially, or completely nontoxic) amount of an
active agent to provide the desired therapeutic effect.
[0079] By "transdermal" drug delivery is meant administration of a
drug to the skin surface of an individual so that the drug passes
through the skin tissue and into the individual's blood stream,
thereby providing a systemic effect. The term "transdermal" is
intended to include "transmucosal" drug administration, i.e.,
administration of a drug to the mucosal (e.g., sublingual, buccal,
vaginal, rectal) surface of an individual so that the drug passes
through the mucosal tissue and into the individual's blood
stream.
[0080] The term "body surface" is used to refer to skin or mucosal
tissue.
[0081] By "predetermined area" of skin or mucosal tissue, which
refers to the area of skin or mucosal tissue through which a drug
enhancer formulation is delivered, is intended a defined area of
intact unbroken living skin or mucosal tissue. That area will
usually be in the range of about 5 cm.sup.2 to about 200 cm.sup.2,
more usually in the range of about 5 cm.sup.2 to about 100
cm.sup.2, typically in the range of about 20 cm.sup.2 to about 60
cm.sup.2. However, it will be appreciated by those skilled in the
art of drug delivery that the area of skin or mucosal tissue
through which drug is administered may vary significantly,
depending on patch configuration, dose, and the like.
[0082] "Penetration enhancement" or "permeation enhancement" as
used herein relates to an increase in the permeability of the skin
or mucosal tissue to a selected pharmacologically active agent,
i.e., so that the rate at which the agent permeates therethrough
(i.e., the "flux" of the agent through the body surface) is
increased relative to the rate that would be obtained in the
absence of permeation enhancement. The enhanced permeation effected
through the use of such enhancers can be observed by measuring the
rate of diffusion of drug through animal or human skin using, for
example a Franz diffusion apparatus as known in the art and as
employed in the Examples herein.
[0083] An "effective amount" or "an effective permeation enhancing
amount" of a permeation enhancer refers to a nontoxic, nondamaging
but sufficient amount of the enhancer composition to provide the
desired increase in skin permeability and, correspondingly, the
desired depth of penetration, rate of administration, and amount of
drug delivered.
[0084] A genus of peptides has been discovered which exhibit high
selectivity for the kappa opioid receptor and relative long
duration of in vivo action and which can exhibit reduced or
substantially little if any significant brain penetration. These
peptides include sequences in which a sequence of four D-isomer
amino acids having a C-terminus is either a mono or disubstituted
amide. These compounds have the following general formula:
H Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-substituted amide
wherein Xaa.sub.1 is (A)D-Phe, (C.sup.alpha Me)D-Phe, D-Tyr, D-Tic
or D-Ala(cyclopentyl or thienyl), with A being H, NO.sub.2, F, Cl
or CH.sub.3; Xaa.sub.2 is (A')D-Phe, D-1Nal, D-2Nal, D-Tyr or
D-Trp, with A' being A or 3,4Cl.sub.2; Xaa.sub.3 is D-Nle,
(B)D-Leu, D-Hle, D-Met, D-Val, D-Phe or D-Ala(cyclopentyl) with B
being H or C.sup.alpha Me; Xaa.sub.4 is D-Arg, D-Har, D-nArg,
D-Lys, D-Lys(Ipr), D-Arg(Et.sub.2), D-Har(Et.sub.2), D-Amf(G),
D-Dbu, (B)D-Orn or D-Orn(Ipr), and with G being H or amidino.
Non-limiting amides include ethylamide, morpholinylamide,
4-picolylamide, piperazineamide, propyl amide, cyclopropylamide and
diethylamide.
[0085] The invention also provides a method of treating a mammal in
need of elevated prolactin by increasing levels of serum prolactin
of said mammal, comprising administering to said mammal an amount
of a peripherally selective kappa opioid receptor agonist or a salt
thereof or a pro-drug thereof effective to treat the mammal. In
certain embodiments, the method increases or stabilizes levels of
serum prolactin to greater than 25, 50, 75, 100, 125, 150, 175, or
200 ng/ml serum in the mammal. In other embodiments the method the
peripherally selective kappa opioid receptor agonist or salt
thereof or prodrug thereof effective to treat the mammal is a
peptide, or ionizes or is metabolized to form a peptide. The
peptide can comprise a pentapeptide or tetrapeptide, which can
include a sequence of four D-isomer amino acids having a C-terminus
that is either a mono- or di-substituted amide. In certain
embodiments the peptide has a binding affinity for the kappa opioid
receptor that is greater than its binding affinity for non-kappa
opioid receptors. In particular embodiments the peptide has a
binding affinity for the kappa opioid receptor at least 1,000 times
greater than its binding affinity for the mu opioid receptor. In
some of these particular embodiments the peptide has a binding
affinity for the kappa opioid receptor at least 1,000 times greater
than its binding affinity for the mu opioid receptor and in
addition has an ED.sub.50 for elevating prolactin of about 0.5
mg/kg or less.
[0086] Particular compounds useful in the methods of the present
invention include the compound having the formula:
##STR00001##
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-picolyl, or a picolyl N-oxide
thereof, optionally excluding or including an acetate
counterion.
[0087] Another particular compound useful in the methods of the
present invention is the compound having the formula:
##STR00002##
H-D-Phe-D-Phe-D-Leu-D-Orn-Morpholinyl, optionally excluding or
including an acetate counterion.
BRIEF DESCRIPTION OF THE FIGURES
[0088] FIG. 1 is a graph showing the Arithmetic. Mean Changes from
Baseline (Pre dose) in Serum Prolactin Concentrations Following a 1
hour IV Infusion of CR665 at various dosages in Male Subjects (Part
A).
[0089] FIG. 2 is a graph showing the Arithmetic Mean Changes from
Baseline (Pre dose) in Serum Prolactin Concentrations Following a 1
hour IV Infusion of CR665 in Female Subjects (Part A).
[0090] FIG. 3 is a graph showing the Arithmetic Mean Changes from
Baseline (Pre dose) in Serum Prolactin Concentrations Following a 5
minute IV. Infusion of CR665 in Male Subjects (Part B).
[0091] FIG. 4 is a graph showing the Geometric Mean Plasma
Concentrations of CR665 Following a 1 hour IV Infusion of CR665 in
Male Subjects (Part A) (Linear Scale
[0092] FIG. 5 is a graph showing the Geometric Mean Plasma
Concentrations of CR665 Following a 1 hour IV Infusion of CR665 in
Male Subjects (Part A) (Semi logarithmic Scale).
[0093] FIG. 6 is a graph showing the Geometric Mean AUC0 {dot over
(.quadrature.)} or CR665 Versus Dose Level Following a 1 hour IV
Infusion of CR665 in Male Subjects (Part A).
[0094] FIG. 7 is a graph showing the Geometric Mean Plasma
Concentrations of CR665Following a 1 hour IV Infusion of 0.24 mg/kg
CR665 in Female Subjects (Part A) (Linear Scale).
[0095] FIG. 8 is a graph showing the Geometric Mean Plasma
Concentrations of CR665 Following a 1 hour IV Infusion of 0.24
mg/kg CR665 in Female Subjects (Part A) (Semi logarithmic
Scale).
[0096] FIG. 9 is a graph showing the Arithmetic Mean (.+-.SD)
Plasma Concentrations of CR665 Following a 1-hour IV Infusion of
0.24 mg/kg CR665 in Male and Female Subjects (Part A) (Linear
Scale).
[0097] FIG. 10 is a graph showing the Geometric Mean Plasma.
Concentrations of CR665 Following a 5-minute IV Infusion of CR665
in Male and Female Subjects (Part B) (Linear Scale).
[0098] FIG. 11 is a graph showing the Geometric Mean Plasma
Concentrations of CR665 Following a 5-minute IV Infusion of CR665
in Male and Female Subjects (Part B) (Semi logarithmic Scale).
[0099] FIG. 12 is a graph showing the Geometric Mean AUC.sub.(0 to
infinity) for CR665 Versus Dose Level Following a 5-minute IV
Infusion of CR665 in Male Subjects (Part B).
[0100] FIG. 13 is a graph showing the Relationship Between AUC0 12
h of Changes from Baseline in Serum Prolactin and AUC.sub.(0 to
infinity) of CR665 over the 0.015 to 0.36 mg/kg Dose Range in Male
Subjects (Part A).
[0101] FIG. 14 is a graph showing the Relationship Between Cmax of
Changes from Baseline in Serum Prolactin and Cmax of CR665 over the
0.015 to 0.36 mg/kg Dose. Range in Male Subjects (Part A).
DETAILED DESCRIPTION
[0102] The nomenclature used to define the peptides is specified by
Schroder & Lubke, The Peptides, Academic Press, 1965, wherein,
in accordance with conventional representation, the N-terminus
appears to the left and the C-terminus to the right. Where an amino
acid residue has isomeric forms, it is the L-isomer form of the
amino acid that is being represented herein unless otherwise
indicated.
[0103] The invention provides methods, compositions, or dosage
forms that employ and/or contain compounds, such as peptides, that
are selective for kappa opioid receptor and not only exhibit a
strong affinity for the kappa opioid receptor but exhibit,
optionally, long duration of in vivo prolactin elevating activity
in the absence of a severe or significant side effect, such as CNS
side effects or diuresis. Exemplary kappa selective opioid,
receptor compounds (e.g., agonists) have a Ki against a mammalian
kappa opioid receptor, such as a human kappa opioid receptor, of
less than 1000 nM, or less than 100 nM or less than 10 nM, or less
than 1 nM, optionally having a selectivity for kappa opioid
receptors over other mammalian opioid receptor subtypes greater
than 100, or greater than 1,000 or greater than 10,000 times
greater affinity, measurable in vitro by the ratio of their IC50 or
Ki values against the mammalian, e.g., human mu and delta opioid
receptors, respectively. Kappa opioid receptor agonists can exhibit
both a lack of significant brain penetration and a prolonged
duration of in vivo activity. Therefore, in addition to the above
mentioned kappa opioid receptor affinity and selectivity, compounds
also include those that exhibit no significant brain penetration
while preserving substantial activity for measurable or detectable
period of time, for example, at least about one hour, at least
about two hours, for three hours or longer (e.g., 4, 5, 6, 12, 24,
48 hours or clays, or longer).
[0104] In certain embodiments, the method of the invention can be
practiced using a peripherally selective kappa opioid receptor
agonist, which when administered peripherally, is effective to
increase or stabilize levels of prolactin without substantially
crossing the blood-brain barrier of the subject. In other
embodiments, the amount of the peripherally selective kappa opioid
receptor agonist administered is an amount effective to increase or
stabilize levels of prolactin without causing a severe side effect
in the subject. Alternatively, the amount of the peripherally
selective kappa opioid receptor agonist administered is an amount
effective to increase or stabilize levels of prolactin with minor
or tolerable side effects in the subject. Side effects can include
a neuropsychiatric side effect (such as but not limited to
dysphoria or hallucinations), diuresis or sedation.
[0105] In some embodiments, according to the method of the
invention for elevating levels of serum prolactin in a mammal, the
administered dose of the peripherally selective kappa opioid
receptor agonist is between about 1 microgram/kg of body weight to
about 100 milligrams/kg of body weight of said mammal per hour, or
per day, or per week or per month. The prolactin levels can be
elevated to greater than 10, 15, 20, 25, 50, 75, 100, 125, 150,
175, or 200 ng/ml serum above the baseline level of serum
prolactin.
[0106] In some embodiments, the method of the invention for
treating insufficient or inadequate lactation in a mammal, includes
administering, separately or in combination an amount of a
peripherally selective kappa opioid receptor agonist or a salt
thereof or a pro-drug thereof, and an amount of prolactin effective
to treat insufficient or inadequate lactation in the mammal. In
other embodiments, the invention provides a method for treating
insufficient or inadequate lactation. The method includes
administering an amount of a peripherally selective kappa opioid
receptor agonist or a salt thereof or a pro-drug thereof, to a
mammal, separately or in combination, with (1) another
prolactin-elevating agent, (2) prolactin, or (3) a non-drug
therapy, the method effective to treat insufficient or inadequate
lactation in the mammal. In still other embodiments, the invention
provides a method for treating insufficient or inadequate lactation
in a mammal. The method includes administering separately or in
combination 1) a peripherally selective kappa opioid receptor
agonist or a salt thereof or a pro-drug thereof, and; 2) another
prolactin-elevating agent, said administration in an amount
effective for treating insufficient or inadequate lactation in the
mammal.
[0107] In other embodiments, the invention provides a method of for
treating a mammal exhibiting insufficient or inadequate milk
production or at risk of insufficient or inadequate milk
production. The method includes administering to said mammal an
amount of a peripherally selective kappa opioid receptor agonist or
salt thereof or prodrug thereof effective to treat the mammal. The
peripherally selective kappa opioid receptor agonist or salt
thereof or prodrug thereof can include a peptide, or can ionize or
metabolize to form a peptide. The peptide can include a
tetrapeptide or a pentapeptide.
[0108] In particular embodiments, the prolactin-elevating agent
useful in the methods of the present invention can be administered
with a mu opioid receptor agonist selected from the group
consisting of (i) morphine, (ii) hydromorphone, (iii) oxymorphone,
(iv) levorphanol, (v) methadone, (vi) codeine, (vii) hydrocodone,
(viii) oxycodone, (ix) morphine 6 glucuronide, (x) tramadol, (xi)
meperidine, (xii) diphenoxylate, (xiii) loperamide, (xiv) fentanyl,
(xv) sufentanil, (xvi) alfentanil, (xvii) remifentanil, (xviii)
levomethadyl and (xviv) propoxyphene.
[0109] In certain embodiments of the method, the
prolactin-elevating agent can be a peptide having a binding
affinity for the peripheral kappa opioid receptor that is greater
than its binding affinity for non-peripheral kappa opioid receptor.
Alternatively, the peptide can have a binding affinity for the
peripheral kappa opioid receptor that is 10 times greater, 100
times greater, 1,000 times greater, or more than its binding
affinity for a non-peripheral kappa opioid receptor. For instance
the peptide can have a binding affinity for the kappa opioid
receptor which is at least 1,000 times greater than its binding
affinity for the mu opioid receptor. In certain embodiments, the
peptide has a binding affinity for the kappa opioid receptor which
is at least 1,000 times greater than its binding affinity for the
mu opioid receptor and an ED.sub.50 for elevating prolactin of
about 0.5 mg/kg or less.
[0110] In a particular embodiment, the invention provides a method
of treating a mammal in need of elevated or stabilized prolactin
levels, wherein the method includes administering to said mammal an
amount of a peripherally selective kappa opioid receptor agonist or
a salt thereof or a pro-drug thereof, in conjunction with an amount
of an additional prolactin elevating compound, effective to treat
the mammal. The additional prolactin elevating compound can include
a D2 dopamine receptor antagonist or mu opioid receptor
agonist.
[0111] In one embodiment, the D2 dopamine receptor agonist is
selected from the group consisting of (i) domperidone, (ii)
metoclopramide, (iii) levosulpiride, (iv) sulpiride, (v)
thiethylperazine, (vi) ziprasidone, (vii) zotepine, (viii)
clozapine, (ix) chlorpromazine, (x) acetophenazine, (xi)
carphenazine (xii) chlorprothixene, (xiii) fluphenazine, (xiv)
loxapine, (xv) mesoridazine, (xvi) molindone, (xvii) perphenazine,
(xviii) pimozide, (xviv) piperacetazine, (xx) prochlorperazine,
(xxi) thioridazine, (xxii) thiothixene, (xxiii) trifluoperazine,
(xxiv) triflupromazine, (xxv) pipamperone, (xxvi) amperozide,
(xxvii) quetiapine, (xxviii) melperone, (xxix) remoxipride, (xxx)
haloperidol, (xxxi) rispiridone, (xxxii) olanzepine, (xxxiii)
sertindole, and (xxxiv) prochlorperazine.
[0112] In another embodiment the mu opioid receptor agonist is
selected from the group consisting of (i) morphine, (ii)
hydromorphone, (iii) oxymorphone, (iv) levorphanol, (v) methadone,
(vi) codeine, (vii) hydrocodone, (viii) oxycodone, (ix)
morphine-6-glucuronide, (x) tramadol, (xi) meperidine, (xii)
diphenoxylate, (xiii) loperamide, (xiv) fentanyl, (xv.) sufentanil,
(xvi) alfentanil, (xvii) remifentanil, (xviii) levomethadyl, and
(xviv) propoxyphene.
[0113] As used herein, "prolactin elevating activity" refers to the
pharmacological activity of a compound if it causes an elevation in
circulating plasma or serum levels of prolactin in a subject. A
"prolactin increasing activity" refers to a compound that causes a
measurable or detectable, transient or longer term increase in
circulating plasma or serum levels of prolactin in a subject. A
"prolactin stabilizing activity" refers to a compound that causes a
measurable or detectable, transient or longer term, stabilization
in circulating plasma or serum levels of prolactin in a subject,
e.g., prevents or inhibits a reduction in prolactin levels,
maintains a particular level of prolactin for a measurable period
of time, prevents or inhibits a reduction in prolactin levels below
a certain amount (e.g., below 200, 175, 150, 125, 100, 75, 50, 25
ng/ml serum), etc.
[0114] As used herein, "functional hypoprolactinemia" refers to a
condition in which a subject has insufficient or inadequate levels
of circulating prolactin required to initiate, maintain or enhance
a physiological function, e.g. lactation. The level of circulating
prolactin required for a given physiological function will vary, as
is known in the art, depending upon the function and the gender and
physiological or pathophysiological status of the subject. Thus,
for example, a normal pre pregnancy baseline level of circulating
prolactin would be insufficient to sustain lactation after
delivery. Under these circumstances, the failure of lactation in a
post pregnant female with this level of prolactin would be
characterized as a functional hypoprolactinemia, even though the
circulating level of prolactin would be normal for a non lactating
female.
[0115] As used herein, "CNS side effect" refers to a clinically
significant side effect of a compound in which the symptoms are
psychiatric or neurological, e.g., visual or auditory
hallucinations, delusions, impaired intellectual functioning, or
impaired control of voluntary movements.
[0116] As used herein, the term "subject" is intended to include
human and non human mammals. Subjects include a person, e.g., a
patient, in need of elevated, increased or stabilized levels of
prolactin, e.g., a person in need of stimulation of lactation,
e.g., a female (mother). The term "mammals" includes humans and all
non human mammals, such as non human primates, ungulates and
ruminants.
[0117] As used herein, "effective amount" or "sufficient amount"
refers to an amount of a compound as described herein that may be
therapeutically effective to inhibit, prevent or treat a symptom of
a particular disease, disorder, condition, or side effect. Such
diseases, disorders, conditions, and side effects include those
conditions associated with insufficient, or inadequate circulating
levels of prolactin, wherein the treatment comprises elevating,
increasing, or stabilizing circulating levels of prolactin by
contacting cells, tissues or receptors with compounds as set forth
herein. Thus, for example, an "effective amount", when used in
connection with lactational insufficiency or inadequacy, for
example, refers to an amount of a compound required for treatment
and/or prevention of this condition. An "effective amount", when
used in connection with functional hypoprolactinemia, refers to the
treatment and/or prevention of one or more symptoms, diseases,
disorders, and conditions associated with circulating levels of
prolactin that are undesirably low, for example, to optimally
sustain a physiological function.
[0118] As used herein, "pharmaceutically acceptable" refers to
compounds, materials, compositions, and/or dosage forms which are,
within the scope of sound medical judgment, suitable for contact
with the tissues of human beings and animals without severe
toxicity, irritation, allergic response, or other complications
commensurate with a reasonable benefit/risk ratio.
[0119] As used herein, "in combination with", "combination therapy"
and "combination products" refer, in certain embodiments, to the
concurrent administration to a patient of a peripherally selective
kappa opioid receptor agonist of the invention and either or both
of prolactin and a compound with prolactin elevating, increasing or
stabilizing activity but lacking peripherally selective kappa
opioid receptor agonist activity, e.g., a D2 dopamine receptor
antagonist, e.g., domperidone. When administered in combination,
each component may be administered at the same time or sequentially
in any order at different points in time. Thus, each component may
be administered separately but sufficiently closely in time so as
to provide a desired therapeutic effect.
[0120] As used herein, a "D2 dopamine receptor antagonist" refers
to compounds with a binding affinity (K.sub.D or K.sub.i) for a
mammalian D2 dopamine receptor of less than 10 micromolar,
regardless of binding affinity for other receptors. Where there is
ambiguity or an absence of useful information regarding whether the
binding affinity of a compound for a mammalian D2 dopamine receptor
meets this definition, data from in vitro or in vivo functional
studies, as are commonly employed by those with skill in the art,
can be used to determine whether a compound is a functional
antagonist of a mammalian D2 dopamine receptor.
[0121] As used herein, "mu opioid receptor agonist" refers to
compounds with a binding affinity (K.sub.D or K.sub.i) for a
mammalian mu opioid receptor of less than 10 micromolar, regardless
of binding affinity for other receptors. Where there is ambiguity
or an absence of useful information regarding whether the binding
affinity of a compound for a mammalian mu opioid receptor meets
this definition, data from in vitro or in vivo functional studies,
as are commonly employed by those with skill in the art, can be
used to determine whether a compound is a functional agonist of a
mammalian mu opioid receptor.
[0122] As used herein, "dosage unit" refers to a physically
discrete unit suited as unitary dosages for a particular individual
or condition to be treated. Each unit may contain a predetermined
quantity of active compound(s) calculated to produce the desired
therapeutic effect(s), optionally in association with a
pharmaceutical carrier. The specification for the dosage unit forms
may be dictated by (a) the unique characteristics of the active
compound(s) and the particular therapeutic effect(s) to be
achieved, and (b) the limitations inherent in the art of
compounding such active compound(s).
[0123] As used herein, "pharmaceutically acceptable salts" refer to
derivatives of compounds wherein the parent compound is modified by
making acid or base salts thereof. Examples of pharmaceutically
acceptable salts include, but are not limited to, mineral or
organic acid salts of basic residues such as amines; alkali or
organic salts of acidic residues such as carboxylic acids; and the
like. The pharmaceutically acceptable salts include the
conventional non toxic salts or the quaternary ammonium salts of
the parent compound formed, for example, from non toxic inorganic
or organic acids. For example, such conventional non toxic salts
include those derived from inorganic acids such as hydrochloric,
hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like;
and the salts prepared from organic acids such as acetic,
propionic, succinic, glycolic, stearic, lactic, malic, tartaric,
citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic,
glutamic, benzoic, salicylic, sulfanilic, 2 acetoxybenzoic,
fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic,
oxalic, isethionic, and the like. These physiologically acceptable
salts are prepared by methods known in the art, e.g., by dissolving
the free amine bases with an excess of the acid in aqueous alcohol,
or neutralizing a free carboxylic acid with an alkali metal base
such as a hydroxide, or with an amine.
[0124] Compounds described herein, can be used or prepared in
alternate forms. For example, many amino containing compounds can
be used or prepared as an acid addition salt. Often such salts
improve isolation and handling properties of the compound. For
example, depending on the reagents, reaction conditions and the
like, compounds as described herein can be used or prepared, for
example, as their hydrochloride or tosylate salts. Isomorphic
crystalline forms, all chiral and racemic forms, N-oxide, hydrates,
solvates, and acid salt hydrates, are also contemplated to be
within the scope of the present invention.
[0125] Certain acidic or basic compounds of the present invention
may exist as zwitterions. All forms of the compounds, including
free acid, free base and zwitterions, are contemplated to be within
the scope of the present invention. It is well known in the art
that compounds containing both amino and carboxyl groups often
exist in equilibrium with their zwitterionic forms. Thus, any of
the compounds described herein throughout that contain, for
example, both amino and carboxyl groups, also include reference to
their corresponding zwitterions.
Pharmaceutical Compositions
[0126] A peripherally selective kappa opioid receptor agonist of
the invention can be incorporated into a pharmaceutical composition
to ameliorate functional hypoprolactinemia in a subject, e.g., a
subject presenting with a deficiency, inadequacy or insufficiency
in lactation associated with insufficient or inadequate plasma
levels of prolactin. The compositions should contain an effective
amount of a peripherally selective kappa opioid receptor agonist,
in a pharmaceutically acceptable carrier.
[0127] The pharmaceutical carrier can be any compatible, non toxic
substance suitable to deliver the peripherally selective kappa
opioid receptor agonist to the subject. Sterile water, alcohol,
fats, waxes, and inert solids may be used as the carrier.
Pharmaceutically acceptable adjuvants, buffering agents, dispersing
agents, and the like, may also be incorporated into the
pharmaceutical compositions. The concentration of peripherally
selective kappa opioid receptor agonist or other active agent in
the pharmaceutical composition can vary widely, i.e., from less
than about 0.01% by weight, usually being at least about 1% weight
to as much as 50% by weight or more.
[0128] For oral administration, an active ingredient can be
administered in solid dosage forms, such as capsules, tablets, and
powders, or in liquid dosage forms, such as elixirs, syrups, and
suspensions. Active component(s) can be encapsulated in gelatin
capsules together with inactive ingredients and powdered carriers,
such as glucose, lactose, sucrose, mannitol, starch, cellulose or
cellulose derivatives, magnesium stearate, stearic acid, sodium
saccharin, talcum, magnesium carbonate and the like. Examples of
additional inactive ingredients that may be added to provide
desirable color, taste, stability, buffering capacity, dispersion
or other known desirable features are red iron oxide, silica gel,
sodium lauryl sulfate, titanium dioxide, edible white ink and the
like. Similar diluents can be used to make compressed tablets. Both
tablets and capsules can be manufactured as sustained release
products to provide for continuous release of medication over a
period of hours. Compressed tablets can be sugar coated or film
coated to mask any unpleasant taste and protect the tablet from the
atmosphere, or enteric coated for selective disintegration in the
gastrointestinal tract. Liquid dosage forms for oral administration
can contain coloring and flavoring to increase patient acceptance.
To facilitate drug stability and absorption, peptides of the
invention can be released from a capsule after passing through the
harsh proteolytic environment of the stomach. Methods for enhancing
peptide stability and absorption after oral administration are well
known in the art (e.g., Mahato R I. Emerging trends in oral
delivery of peptide and protein drugs. Critical Reviews in
Therapeutic Drug Carrier Systems. 20:153-214, 2003). In addition,
oral delivery of compounds of the invention can be optimized
through the use of remote controlled capsules as disclosed by
Wilding and Prior in Critical Reviews in Therapeutic Drug Carrier
Systems 20:405-431 (2003).
[0129] For nasal administration, the peripherally selective kappa
opioid receptor agonists can be formulated as aerosols. The term
"aerosol" includes any gas-borne suspended phase of the compounds
of the instant invention which is capable of being inhaled into the
bronchioles or nasal passages. Specifically, aerosol includes a
gas-borne suspension of droplets of the compounds of the instant
invention, as may be produced in a metered dose inhaler or
nebulizer, or in a mist sprayer. Aerosol also includes a dry powder
composition of a compound of the instant invention suspended in air
or other carrier gas, which may be delivered by insufflation from
an inhaler device, for example. See Ganderton & Jones, Drug
Delivery to the Respiratory Tract, Ellis Horwood (1987); Gonda
(1990) Critical Reviews in Therapeutic Drug Carrier Systems
6:273-313; and Raeburn et al. (1992) J. Pharmacol. Toxicol. Methods
27:143-159.
[0130] Parenteral administration of the formulations of the present
invention includes intravenous, subcutaneous, intramuscular and
transdermal administrations.
[0131] Preparations for parenteral administration include sterile
solutions ready for injection, sterile dry soluble products ready
to be combined with a solvent just prior to use, including
hypodermic tablets, sterile suspensions ready for injection,
sterile dry insoluble products ready to be combined with a vehicle
just prior to use and sterile emulsions. The solutions may be
either aqueous or nonaqueous, and thereby formulated for delivery
by injection, infusion, or using implantable pumps. For
intravenous, subcutaneous, and intramuscular administration, useful
formulations of the invention include microcapsule preparations
with controlled release properties (R. Pwar et al. Protein and
peptide parenteral controlled delivery. Expert Opin Biol Ther.
4(8):1203-12, 2004) or encapsulation in liposomes, with an
exemplary form being polyethylene coated liposomes, which are known
in the art to have an extended circulation time in the vasculature
(e.g. Koppal, T. "Drug delivery technologies are right on target",
Drug Discov. Dev. 6, 49-50, 2003).
[0132] Preparations for transdermal delivery are incorporated into
a device suitable for said delivery, said device utilizing, e.g.,
iontophoresis (Kalia Y N et al. Iontophoretic drug delivery. Adv
Drug Deliv Rev. 56:619-58, 2004) or a dermis penetrating surface
(Prausnitz M R. Microneedles for transdermal drug delivery. Adv
Drug Deliv Rev. 56:581-7, 2004), such as are known in the art to be
useful for improving the transdermal delivery of drugs. An
electrotransport device and methods of operating same are disclosed
in U.S. Pat. No. 6,718,201. Methods for the use of iontophoresis to
promote transdermal delivery of peptides are disclosed in U.S. Pat.
No. 6,313,092 and U.S. Pat. No. 6,743,432. Herein the terms
"electrotransport", "iontophoresis", and "iontophoretic" are used
to refer to the delivery through a body surface (e.g., skin or
mucosa) of one or more pharmaceutically active compounds by means
of an applied electromotive force to an agent containing reservoir.
The compound may be delivered by electromigration, electroporation,
electroosmosis or any combination thereof. Electroosmosis has also
been referred to as electrohydrokinesis, electro convection, and
electrically induced osmosis. In general, electroosmosis of a
compound into a tissue results from the migration of solvent in
which the compound is contained, as a result of the application of
electromotive force to the therapeutic species reservoir, i.e.,
solvent flow induced by electromigration of other ionic species.
During the electrotransport process, certain modifications or
alterations of the skin may occur such as the formation of
transiently existing pores in the skin, also referred to as
"electroporation." Any electrically assisted transport of species
enhanced by modifications or alterations to the body surface (e.g.,
formation of pores in the skin) are also included in the term
"electrotransport" as used herein. Thus, as used herein, applied to
the compounds of the instant invention, the terms
"electrotransport", "iontophoresis" and "iontophoretic" refer to
(1) the delivery of charged agents by electromigration, (2) the
delivery of uncharged agents by the process of electroosmosis, (3)
the delivery of charged or uncharged agents by electroporation, (4)
the delivery of charged agents by the combined processes of
electromigration and electroosmosis, and/or (5) the delivery of a
mixture of charged and uncharged agents by the combined processes
of electromigration and electroosmosis. Electrotransport devices
generally employ two electrodes, both of which are positioned in
close electrical contact with some portion of the skin of the body.
One electrode, called the active or donor electrode, is the
electrode from which the therapeutic agent is delivered into the
body. The other electrode, called the counter or return electrode,
serves to close the electrical circuit through the body. In
conjunction with the patient's skin, the circuit is completed by
connection of the electrodes to a source of electrical energy,
e.g., a battery, and usually to circuitry capable of controlling
current passing through the device.
[0133] Depending upon the electrical charge of the compound to be
delivered transdermally, either the anode or cathode may be the
active or donor electrode. Thus, if the compound to be transported
is positively charged, e.g., the compound exemplified in Example 1
herein, then the positive electrode (the anode) will be the active
electrode and the negative electrode (the cathode) will serve as
the counter electrode, completing the circuit. However, if the
compound to be delivered is negatively charged, then the cathodic
electrode will be the active electrode and the anodic electrode
will be the counter electrode. Electrotransport devices
additionally require a reservoir or source of the therapeutic agent
that is to be delivered into the body. Such drug reservoirs are
connected to the anode or the cathode of the electrotransport
device to provide a fixed or renewable source of one or more
desired species or agents. Each electrode assembly is comprised of
an electrically conductive electrode in ion-transmitting relation
with an ionically conductive liquid reservoir which in use is
placed in contact with the patient's skin. Gel reservoirs such as
those described in Webster (U.S. Pat. No. 4,383,529) are one form
of reservoir since hydrated gels are easier to handle and
manufacture than liquid-filled containers. Water is one liquid
solvent that can be used in such reservoirs, in part because the
salts of the peptide compounds of the invention are water soluble
and in part because water is non-irritating to the skin, thereby
enabling prolonged contact between the hydrogel reservoir and the
skin. Examples of reservoirs and sources include a pouch as
described in U.S. Pat. No. 4,250,878, a pre-formed gel body as
disclosed in U.S. Pat. No. 4,382,529, and a glass or plastic
container holding a liquid solution of the drug, as disclosed in
the figures of U.S. Pat. No. 4,722,726. For electrotransport,
compounds (e.g., peptides) the invention can be formulated with
flux enhancers such as ionic surfactants (e.g., U.S. Pat. No.
4,722,726) or cosolvents other than water (e.g., European Patent
Application 278,473). Alternatively the outer layer (i.e., the
stratum corneum) of the skin can be mechanically disrupted prior to
electrotransport delivery therethrough (e.g., U.S. Pat. No.
5,250,023).
[0134] Peripherally selective kappa opioid receptor agonists that
are well suited for electrotransport can be selected, by measuring
their electrotransport flux through the body surface (e.g., the
skin or mucosa), e.g., as compared to a standardized test peptide
with known electrotransport flux characteristics, e.g. thyrotropin
releasing hormone (R. Burnette et al. J. Pharm. Sci. (1986) 75:738)
or vasopressin (Nair et al. Pharmacol Res. 48:175-82, 2003).
Transdermal electrotransport flux can be determined using a number
of in vivo or in vitro methods well known in the art. In vitro
methods include clamping a piece of skin of an appropriate mammal
(e.g., human cadaver skin) between the donor and receptor
compartments of an electrotransport flux cell, with the stratum
corneum side of the skin piece facing the donor compartment. A
liquid solution or gel containing the drug to be delivered is
placed in contact with the stratum corneum, and electric current is
applied to electrodes, one electrode in each compartment. The
transdermal flux is calculated by sampling the amount of drug in
the receptor compartment. Two successful models used to optimize
transdermal electrotransport drug delivery are the isolated pig
skin flap model (Heit M C et al. Transdermal iontophoretic peptide
delivery: in vitro and in vivo studies with luteinizing hormone
releasing hormone. J. Pharm. Sci. 82:240 3, 1993), and the use of
isolated hairless skin from hairless rodents or guinea pigs, for
example. See Hadzija B W et al. Effect of freezing on iontophoretic
transport through hairless rat skin. J. Pharm. Pharmacol. 44, 387
390, 1992. Compounds of the invention for transdermal iontophoretic
delivery can have one, or typically, two charged nitrogens, to
facilitate their delivery.
[0135] The scope of the present invention also includes methods of
treating a mammal in need of elevated prolactin wherein the
peripherally selective kappa opioid receptor agonist or a salt
thereof or a pro-drug thereof is administered transdermally, for
instance and without limitation, by an electrotransport device. The
electrotransport device can, in some embodiments, deliver the
peripherally selective kappa opioid receptor agonist or a salt
thereof or a pro-drug thereof through a body surface.
[0136] Other useful transdermal delivery devices employ high
velocity delivery under pressure to achieve skin penetration
without the use of a needle. Transdermal delivery can be improved,
as is known in the art, by the use of chemical enhancers, sometimes
referred to in the art as "permeation enhancers", i.e., compounds
that are administered along with the drug (or in some cases used to
pretreat the skin, prior to drug administration) in order to
increase the permeability of the stratum corneum, and thereby
provide for enhanced penetration of the drug through the skin.
Chemical penetration enhancers are compounds that are innocuous and
serve merely to facilitate diffusion of the drug through the
stratum corneum, whether by passive diffusion or an energy driven
process such as electrotransport. See, for example, Meidan V M et
al. Enhanced iontophoretic delivery of buspirone hydrochloride
across human skin using chemical enhancers. Int. J. Pharm.
264:73-83, 2003.
[0137] Pharmaceutically acceptable carriers used in parenteral
preparations include aqueous vehicles, nonaqueous vehicles,
antimicrobial agents, isotonic agents, buffers, antioxidants, local
anesthetics, suspending and dispersing agents, emulsifying agents,
sequestering or chelating agents and other pharmaceutically
acceptable substances.
[0138] Examples of aqueous vehicles include Sodium Chloride
Injection, Ringers Injection, Isotonic Dextrose Injection, Sterile
Water Injection, Dextrose and Lactated Ringers Injection.
Nonaqueous parenteral vehicles include fixed oils of vegetable
origin, cottonseed oil, corn oil, sesame oil and peanut oil.
Antimicrobial agents in bacteriostatic or fungistatic
concentrations must be added to parenteral preparations packaged in
multiple dose containers which include phenols or cresols,
mercurials, benzyl alcohol, chlorobutanol, methyl and propyl p
hydroxybenzoic acid esters, thimerosal, benzalkonium chloride and
benzethonium chloride. Isotonic agents include sodium chloride and
dextrose. Buffers include phosphate and citrate. Antioxidants
include sodium bisulfate. Local anesthetics include procaine
hydrochloride. Suspending and dispersing agents include sodium
carboxymethylcelluose, hydroxypropyl methylcellulose and
polyvinylpyrrolidone. Emulsifying agents include Polysorbate 80
(Tween 80). A sequestering or chelating agent of metal ions
includes EDTA. Pharmaceutical carriers also include ethyl alcohol,
polyethylene glycol and propylene glycol for water miscible
vehicles and sodium hydroxide, hydrochloric acid, citric acid or
lactic acid for pH adjustment.
[0139] Typically a therapeutically effective amount of a
peripherally selective kappa opioid receptor agonist is at least
about 0.01% w/w up to about 50% w/w or more, or more than 0.1% w/w
of the active compound. The active ingredient may be administered
at once, or may be divided into a number of smaller doses to be
administered at intervals of time, or as a controlled release
formulation. The term "controlled release formulation" encompasses
formulations that allow the continuous delivery of a peripherally
selective kappa opioid receptor agonist to a subject over a period
of time, for example, several days to weeks. Such formulations may
administered subcutaneously or intramuscularly and allow for the
continual steady state release of a predetermined amount of
compound in the subject over time. The controlled release
formulation of peripherally selective kappa opioid receptor agonist
may be, for example, a formulation of drug containing polymeric
microcapsules, such as those described in U.S. Pat. Nos. 4,677,191
and 4,728,721, incorporated herein by reference. The concentration
of the pharmaceutically active compound is adjusted so that
administration provides an effective amount to produce a desired
effect. The exact dose depends on the age, weight and condition of
the patient or animal, as is known in the art. For any particular
subject, specific dosage regimens can be adjusted over time
according to the individual need and the professional judgment of
the person administering or supervising the administration of the
formulations. Thus, the concentration ranges set forth herein are
exemplary only and are not intended to limit the scope or practice
of the claimed invention.
[0140] The unit dose parenteral preparations include packaging in
an ampoule or a syringe with a needle.
[0141] All preparations for parenteral administration are typically
sterile, as is known and practiced in the art.
[0142] Illustratively, intravenous infusion of a sterile aqueous
buffered solution containing an active compound is an effective
mode of administration. Another embodiment is a sterile aqueous or
oily solution or suspension containing an active material injected
as necessary to produce the desired pharmacological effect.
[0143] Compositions and methods of the invention can be delivered
or administered intravenously, transdermally, intranasally,
subcutaneously, intramuscularly, or orally. Compositions can be
administered for prophylactic treatment of individuals suffering
from, or at risk of a disease or a disorder, e.g., a female
experiencing insufficient or inadequate lactation. For therapeutic
applications, a pharmaceutical composition is typically
administered to a subject suffering from a disease or disorder,
e.g., a lactational deficiency, in an amount sufficient to inhibit,
prevent, or ameliorate the disease or disorder. An amount adequate
to accomplish this is defined as a "therapeutically effective
dose."
[0144] Although not wishing to be bound by any theory, it is
believed that peripherally selective kappa opioid receptor agonist
administered to subjects stimulates release of the anterior
pituitary hormone prolactin. The compound is typically administered
in an amount sufficient to stimulate secretion of prolactin, or
stabilize or prevent or inhibit reductions or decreases in
prolactin, without causing a severe side effect, such as CNS side
effects or diuresis. A useful dose range of a peripherally
selective kappa opioid receptor agonist can be determined by one of
skill in the art through routine testing. One skilled in the art
recognizes that a dose depends, in part, upon physical
characteristics of the patient to be treated, e.g., body weight, as
well as the route of administration, e.g., intravenous injection or
transdermal delivery, and the bioavailability and plasma clearance
of the compound by that route of administration, as well as the
kappa opioid receptor affinity of the compound. One method of
approximating an effective dose is to titrate the dose to achieve a
plasma concentration of drug that exceeds the affinity constant (Kd
or Ki) of the drug for the kappa opioid receptor, e.g., as
determined by a conventional radioreceptor assay as is routinely
employed in the art. One method is to titrate the dose to effect,
e.g., to employ a dose that is found to effectively elevate
prolactin levels, as measured by an immunoassay selective for
prolactin. In this case, although only two samples of blood, before
and after drug administration, are necessary to compare the basal
prolactin level with the stimulated prolactin level, it is typical
to measure the stimulated hormonal levels at timed intervals so
that the dosing interval can be adjusted to maintain a persistently
elevated prolactin level. Serum prolactin concentrations can be
assessed by any of several, validated methods as are known in the
art, e.g., a prolactin-specific immunoassay, e.g., the IMx
prolactin assay (Abbott Laboratories, Abbott Park, Ill.), a
microparticle enzyme immunoassay used in conjunction with an Abbott
IMx Automated Immunoassay Analyzer. When the desired therapeutic
effect is to increase lactation, an additional method of dose
titration is to employ a prolactin-elevating dose that effectively
increases the amount of milk that can be expressed, for example, to
between about 500 to 1000 ml per day for a nursing human mother,
with the level of milk expression selected according to the needs
of the nursing infant. The needs of the nursing infant can be
assessed by methods known to those with skill in the art, and which
can include evidence for adequate lactation: (1) infant is
satisfied after breast feeding, (2) infant gains weight
appropriately in relation to age/length, (3) breast engorgement
and/or leaking occurs if infant feeding is missed, and (4) milk is
secreted in volumes above 500 ml/day. The volume of milk ingested
by infants is commonly estimated as 150 ml/kg/day.
[0145] The American Academy of Pediatrics has placed an emphasis on
increasing breastfeeding in the United States, and has noted that
most drugs likely to be prescribed to the nursing mother should
have no effect on milk supply or on infant well being (American
Academy of Pediatrics, Committee on Drugs. The Transfer of Drugs
and Other Chemicals Into Human Milk. Pediatrics 108:776-789, 2001).
Methods of the invention therefore include those that minimize
transfer of a compound or compounds of the invention into breast
milk that is fed to an offspring, such as an infant. The transfer
of drugs into breast milk is most commonly described quantitatively
using the milk to plasma (M/P) concentration ratio. The accuracy of
this value is improved if it is based on the area under the
concentration time curves (AUC), of the drug in maternal milk and
plasma.
[0146] The infant daily dose can be estimated with the following
equation:
Estimated Daily Infant Dosage (mg/kg/day)=M/P.times.average
maternal serum concentration.times.150 mL/kg/day
[0147] In this case M/P (milk to plasma ratio) is the ratio of
AUC.sub.milk to AUC.sub.plasma The average maternal serum
concentration refers to AUC after maternal ingestion of a single
dose of drug or at steady state during chronic maternal dosing
(Bennett 1988, 1996). When using this approach to estimate daily
infant dosage, the AUC is either the AUC from time zero to infinity
after maternal ingestion of a single dose of drug or the AUC within
a dosing interval at steady state during chronic maternal dosing.
The volume of milk ingested by infants is commonly estimated as 150
ml/kg/day. The infant dose (mg/kg) can then be expressed as a
percentage of the maternal dose (mg/kg). Compounds of the invention
can result in an infant dose of less than 10% of the maternal dose,
or less than 1% or less than 0.1% of the maternal dose. Since
compounds of the invention include peptides, they can be
formulated, e.g., with polymeric microspheres, to protect them from
degradation and enhance absorption in the gastrointestinal tract
(e.g., Mahato R I. Emerging trends in oral delivery of peptide and
protein drugs. Crit. Rev. Ther. Drug Carrier Syst. 20:153 214,
2003). Microsphere-encapsulated peptides, for example typically do
not survive the maternal gastrointestinal environment and release
free peptide into the circulation, such that peptides would be
orally bioavailable to the offspring through breast milk in
significant amounts, which can be readily confirmed by drug assay
of infant plasma and/or urine.
[0148] The utility of the present invention is not limited to
promoting, elevating, increasing or stabilizing lactation in human
and non human mammals. Although the prolactin receptor is indeed
found in the mammary gland and the ovary, two of the best
characterized sites of prolactin actions in mammals, the receptor
is also found in areas of the brain that are outside the blood
brain barrier, and are therefore accessible to circulating
prolactin (Freeman M E et al. Prolactin: Structure, function, and
regulation of secretion. Physiol. Rev. 80:1523-1631, 2000). In
particular, the prolactin receptor (and/or the mRNA encoding the
prolactin receptor) is found in the choroid plexus the area
postrema, and the mediobasal hypothalamus. Prolactin receptors are
also present in a wide range of peripheral tissues, including the
pituitary gland, heart, lung, thymus, spleen, liver, pancreas,
kidney, adrenal gland, uterus, skeletal muscle, and skin.
Accordingly, it is contemplated that peripherally selective kappa
opioid receptor agonists, as described herein, will be useful in
preventing, ameliorating or modulating conditions associated with
these regions of the brain and periphery, as well. Thus, for
example, elevated circulating prolactin, caused by a compound of
the instant invention, would have access to the mediobasal
hypothalamus, a region outside the blood-brain barrier that
includes the anterior periventricular area, paraventricular
nucleus, and arcuate nucleus (e.g., Merchenthaler I. Neurons with
access to the general circulation in the central nervous system of
the rat: a retrograde tracing study with fluoro gold. Neuroscience
44:655-62, 1991). These hypothalamic nuclei are critical for
neuroendocrine regulation, and contain prolactin receptors, which
would thereby be therapeutically affected, e.g., in neuroendocrine
related disorders, by elevations in circulating prolactin caused by
a compound of the instant invention.
[0149] A variety of assays may be employed to test whether the
compounds of the invention exhibit high affinity and selectivity
for the kappa opioid receptor, long duration of in vivo
bioactivity, lack of CNS side effects, and prolactin elevating
activity. Receptor assays are known in the art and kappa opioid
receptors from several species have been cloned, as have mu and
delta opioid receptors. Kappa opioid receptors as well as mu and
delta opioid receptors are classical, seven transmembrane spanning,
G-protein coupled receptors. Although these cloned receptors
readily allow a particular candidate compound, e.g., a peptide, to
be screened, natural sources of mammalian opioid receptors are also
useful for screening, as is well known in the art (Dooley C T et
al. Selective ligands for the mu, delta, and kappa opioid receptors
identified from a single mixture based tetrapeptide positional
scanning combinatorial library. J. Biol. Chem. 273:18848-56, 1998).
Thus, screening against both kappa and mu opioid receptors, whether
of recombinant or natural origin, may be carried out in order to
determine the selectivity of the compound(s) for the kappa over the
mu opioid receptor. In general, a mammalian form of the opioid
receptor is used for screening; typically, the species source of
the receptors is the same as the species for which the compound of
the invention is being assessed, e.g., human placental tissue as a
source of kappa opioid receptors (Porthe G et al. Kappa opiate
binding sites in human placenta. Biochem. Biophys. Res. Commun.
101:1-6, 1981) for screening if the contemplated use of the
screened compounds is for treatment of a human subject.
[0150] Binding affinity refers to the strength of interaction
between ligand and receptor. To demonstrate binding affinity for
opioid receptors, the compounds of the invention can be evaluated
using competition binding studies. These studies can be performed
using cloned kappa and mu opioid receptors expressed in stable
transfected cell lines or naturally occurring opioid receptors from
a receptor-enriched tissue source, as noted above. In these
studies, the test compounds (unlabeled or cold ligand) are used at
increasing concentrations to displace the specific binding of a
radiolabeled ligand that has high affinity and selectivity for the
receptor studied. Tritiated U-69,593 and DAMGO can be used as
ligands in kappa and mu opioid receptor studies, respectively. Both
ligands are commercially available (NEN-Dupont). DAMGO is an
acronym for [D-Ala.sup.2, MePhe.sup.4, Gly-ol.sup.5]-enkephalin.
The affinity of the radioligands is defined by the concentration of
radioligand that results in half-maximal specific binding (K.sub.D)
in saturation studies. The affinity of the test compound (unlabeled
or cold ligand) is determined in competition binding studies by
calculating the inhibitory constant (K.sub.i) according to the
following formula:
K.sub.i=IC.sub.50/[1+(F/K.sub.D)]
where IC.sub.50=Concentration of the cold ligand that inhibits 50%
of the specific binding of the radioligand F=free radioligand
concentration K.sub.D=affinity of the radioligand determined in
saturation studies.
[0151] When performing these assays under specific conditions with
relatively low concentrations of receptor, the calculated K.sub.i
for the test compound is a good approximation of its dissociation
constant K.sub.D, which represents the concentration of ligand
necessary to occupy one-half (50%) of the binding sites. A low
K.sub.i value in the nanomolar and subnanomolar range is considered
to identify a high affinity ligand in the opioid field. Exemplary
analogs have a K.sub.i for kappa opioid receptor of about 10
nanomolar (nM) or less, and typical analogs have a K.sub.i of about
1 nM or less. High affinity compounds: (1) enable the use of
relatively low doses of drug, which minimizes the likelihood of
side effects due to low affinity interactions, and (2) potentially
reduce the cost of manufacturing a dose since a correspondingly
smaller amount of a higher affinity compound would be required to
produce the desired therapeutic effect, assuming equal absorption,
distribution, metabolism, and excretion.
[0152] These binding assays employing kappa opioid receptors and mu
opioid receptors are straightforward to perform and can be readily
carried out with large numbers of compounds to determine whether
such compounds are kappa opioid receptor selective and have high
affinity. Such binding assays can be carried out in a variety of
ways as well known to one of skill in the art, and one detailed
example of an assay of this general type is set forth in Young E A
et al. [.sup.3H]Dynorphin A binding and kappa selectivity of
prodynorphin peptides in rat, guinea pig and monkey brain. Eur. J.
Pharmacol. 121:355-65, 1986.
[0153] Various abbreviations used herein are as follows:
By D-Nle is meant D-norleucine, and D-Hle represents D-homoleucine.
D-Har represents D-homoarginine, and D-nArg represents
D-norarginine which is one carbon shorter than D-Arg. By D-Nal is
meant the D-isomer of alanine which is substituted by naphthyl on
the .beta.-carbon. Typically, D-2Nal is employed, i.e. the
attachment to naphthalene is at the 2-position on the ring
structure; however, D-1Nal may also be used. The abbreviations
D-Cpa and D-Fpa are used to represent, respectively, chloro-D-Phe
and fluoro-D-Phe, with D-4 Cpa, D-2Fpa, D-3Fpa and D-4Fpa being
typical. D-Npa means nitro-D-Phe, and D-Mpa is used to represent
methyl D-Phe. D-3,4 Cpa means 3,4-dichloro-D-Phe. D-Acp represents
D-Ala(cyclopentyl). D-Orn represents D-ornithine, and D-Dbu
represents alpha, gamma-diamino butyric acid. CML represents
C.sup.alpha methyl Leu, and CMP and CMO represent C.sup.alpha Me
Phe and C.sup.alpha Me Orn. By D-4Amf is meant
D-4(NH.sub.2CH.sub.2)Phe, and by D-Gmf is meant Amf(amidino) which
represents D-Phe where the 4-position is substituted with
CH.sub.2NHC(NH)NH.sub.2. Amd represents amidino, and the symbol
D-Amf(Amd) is also used. By D-Tic is meant
D-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid. In Ala(Thi),
Thi represents the thienyl group, which is typically linked at its
2-position to alanine, although 3-thienyl is an equivalent. By Ily
and Ior are respectively meant isopropyl Lys and isopropyl Orn
where the side chain amino group is alkylated with isopropyl.
[0154] By lower alkyl is meant C.sub.1 to C.sub.6, for example,
C.sub.1-C.sub.4 but including cyclopropyl and cyclobutyl. Me, Et,
Pr, Ipr, Bu, Pn and Bzl are used to represent methyl, ethyl,
propyl, isopropyl, butyl, pentyl and benzyl. By Cyp is meant
cyclopropyl, and by Cyb is meant cyclobutyl. Although the linkage
is typically to one end of an alkyl chain, the linkage may be
elsewhere in the chain, e.g. 3-pentyl which may also be referred to
as ethylpropyl. 4Nbz and 4Abz represent 4-nitrobenzyl and
4-aminobenzyl. By 2-, 3- and 4-picolyl (Pic) are meant
methylpyridine groups with the attachment being via a methylene in
the 2-, 3- or 4-position.
[0155] By Mor is meant morpholinyl,
##STR00003##
and by Tmo is meant thiomorpholinyl,
##STR00004##
Ahx is used to represent 4-aminocyclohexyl, and hEt is used to
represent hydroxyethyl, i.e. --CH.sub.2CH.sub.2OH. Aeb is used to
represent 4-(2-amino-2-carboxyethyl)benzyl, i.e.
##STR00005##
[0156] By Pip is meant piperidinyl, and by 4-HyP and OxP are meant
4-hydroxypiperidinyl and 4-oxo-piperidinyl. By Ppz is meant
piperazinyl. Ecp represents 4-ethylcarbamoylpiperazinyl; quaternary
ammonium moieties, such as 4-dimethyl piperazinyl (Dmp) or other
di-lower alkyl substitutions, may also be used. Substituted benzyl
is typically 4-aminobenzyl, i.e.
##STR00006##
and by 2-Tzl is meant 2-thiazolyl, i.e.
##STR00007##
[0157] By Dor is meant .delta.-ornithinyl where the side chain
amino group of L-ornithine is connected by an amide bond to the
C-terminus.
[0158] D-Phe or substituted D-Phe is an example at the 1-position.
The phenyl ring may be substituted at the 2-, 3- and/or
4-positions, and commonly substitutions by chlorine or fluorine at
the 2 or 4-position are particular examples. The alpha-carbon atom
may also be methylated. Other equivalent residues which resemble
D-Phe may also be used, and these include D-Ala(cyclopentyl),
D-Ala(thienyl), D-Tyr and D-Tic. The 2-position residue can also be
D-Phe or substituted D-Phe with such substitutions including a
substituent on the 4-position carbon of the phenyl ring or the 3-
and 4-positions. Alternatively, D-alanine substituted by naphthyl
can be used, as well as D-Trp and D-Tyr. The 3-position can be
occupied by a residue such as D-Nle, D-Leu, D-CML, D-Hle, D-Met or
D-Val; however, D-Ala(cyclopentyl) or D-Phe may also be used. D-Arg
and D-Har, which may be substituted with diethyl, are examples for
the 4-position; however, D-nArg and other equivalent residues may
be used, such as D-Lys or D-Orn (either of which can have its
omega-amino group alkylated as by isopropyl or have its
.alpha.-carbon group methylated). Moreover, D-Dbu, D-4Amf (which is
typically substituted with amidino), and D-His may also be
used.
Chart of Additional Formula Abbreviations
TABLE-US-00001 [0159] Abbreviation Definition D-Phe D-phenylalanine
D-Tyr D-tyrosine D-Tic D-1,2,3,4-tetrahydroisoquinoline-3carboxylic
acid D-Ala D-alanine D-1Na1 D-Alanine substituted by naphthyl on
the beta carbon with the point of attachment at the 1-position on
the naphthyl ring structure D-2Na1 D-Alanine substituted by
naphthyl on the beta carbon with the point of attachment at the
2-position on the naphthyl ring structure D-Trp D-tryptophan D-Nle
D-norleucine D-Leu D-leucine D-Hle D-homoleucine D-Met D-methionine
D-Val D-valine D-Arg D-arginine D-Har D-homoarginine D-nArg
D-norarginine D-Lys D-lysine D-Ily Isopropyl-D-lysine
D-Arg(Et.sub.2) diethyl-D-arginine D-Har(Et.sub.2)
diethyl-D-homoarginine D-Amf D-(NH.sub.2CH.sub.2)-Phenylalanine
D-Gmf D-(CH.sub.2NHC(NH)NH.sub.2)-Phenylalanine D-Dbu Alpha,
gamma-diamino butyric acid D-Orn D-ornithine D-Ior
Isopropyl-D-ornithine Aeb 4-(2-amino-2-carboxyethyl)benzyl Ppz
piperazinyl Pcp 4-phenyl carbamoyl piperazin-1-yl Aao
8-(acetylamino)-3,6-dioxaoct-1-yl Aoo 8-amino-3,6-dioxaoct-1-yl Hoh
6-(L-hydroorotylamino)-hex-1-yl; L-hydroorotic acid is
C.sub.4N.sub.2H.sub.5(O).sub.2--COOH Ghx 6-(D-gluconylamino)-hexyl
Gao 6-(D-gluconylamino)-3,6-dioxaoct-1-yl D-4Fpa
4-fluoro-D-phenylalanine D-4Cpa 4-chloro-D-phenylalanine D-3,4Cpa
3,4-dichloro-D-phenylalanine D-CML C.sup..alpha.methyl-D-Leucine
D-Acp D-Ala(cyclopentyl) Mor Morpholinyl Tmo thiomorpholinyl Pip
Piperidinyl 4-HyP 4-hydroxy piperidin-1-yl OxP 4-oxo-piperidin-1-yl
Me Methyl Et Ethyl Pr Propyl Bu Butyl HEt Hydroxyethyl (i.e.,
--CH.sub.2CH.sub.2OH) Cyp Cyclopropyl Bzl Benzyl D-2Fpa
2-fluoro-D-phenylalanine D-Ala(2Thi) 2-thienyl-D-alanine 4Pic
4-picolyl C.sup..alpha.methyl Methyl attached to the alpha carbon
of an amino acid
[0160] In one embodiment, the invention provides a method of
treating a mammal exhibiting insufficient or inadequate milk
production or at risk of insufficient or inadequate milk
production; wherein the method includes administering to the mammal
an amount of a peripherally selective kappa opioid receptor agonist
or salt thereof or prodrug thereof effective to treat the mammal,
the peripherally selective kappa opioid receptor agonist or salt
thereof or prodrug thereof being a peptide, or ionizes or is
metabolized to form a peptide having the formula:
H-Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-Q; and
wherein Xaa.sub.1 is (A)D-Phe, (C.sup.alpha Me)D-Phe, D-Tyr, D-Tic
or D-Ala(cyclopentyl or thienyl), with A being H, NO.sub.2, F,
C.sub.1 or CH.sub.3; Xaa.sub.2 is (A')D-Phe, D-1Nal, D-2Nal, D-Tyr
or D-Trp, with A' being A or 3,4Cl.sub.2; Xaa.sub.3 is D-Nle,
(B)D-Leu, D-Hle, D-Met, D-Val, D-Phe or D-Ala(cyclopentyl) with B
being H or C.sup.alpha Me; Xaa.sub.4 is D-Arg, D-Har, D-nArg,
D-Lys, D-Lys(Ipr), D-Arg(Et.sub.2), D-Har(Et.sub.2), D-Amf(G),
D-Dbu, (B)D-Orn or D-Orn(Ipr), with G being H or amidino; and Q is
NR.sub.1R.sub.2, morpholinyl, thiomorpholinyl, (C)piperidinyl,
piperazinyl, 4-mono- or 4,4-di-substituted piperazinyl or
delta-ornithinyl, with R.sub.1 being lower alkyl, substituted lower
alkyl, benzyl, substituted benzyl, aminocyclohexyl, 2-thiazolyl,
2-picolyl, 3-picolyl or 4-picolyl, R.sub.2 being H or lower alkyl;
and C being H, 4-hydroxy or 4-oxo. In a particular embodiment
Xaa.sub.2 is D-Phe, Xaa.sub.3 is D-Nle and Xaa.sub.4 is D-Arg. In
another embodiment Q is NHR.sub.1 and R.sub.1 is ethyl, propyl,
butyl, cyclopropyl or cyclobutyl. In an alternative embodiment, Q
is morpholinyl or thiomorpholinyl; or Q is NHR.sub.1 and R.sub.1 is
4-picolyl. In another embodiment, Xaa.sub.2 is D-Ala(2-thienyl);
alternatively, Xaa.sub.4 is D-4FPhe and Xaa.sub.2 is D-4ClPhe. In
still another embodiment, Xaa.sub.3 is D-Nle or D-Leu and Xaa.sub.4
is D-Orn or D-Amf(Amd). In another embodiment, Xaa.sub.2 is D-Phe,
Xaa.sub.3 is D-Leu or D-CML and Xaa.sub.4 is D-Orn.
[0161] The invention further provides a method of treating a mammal
exhibiting insufficient or inadequate milk production or at risk of
insufficient or inadequate milk production; wherein the method
includes administering to the mammal an amount of a peripherally
selective kappa opioid receptor agonist or salt thereof or prodrug
thereof effective to treat the mammal, the peripherally selective
kappa opioid receptor agonist or salt thereof or prodrug thereof
being a peptide, or ionizes or is metabolized to form a peptide
having the formula:
H-Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-Q; and
wherein Xaa.sub.1 is D-Phe (unsubstituted or substituted by
C.sup.alpha, Me, 2F, 4F or 4Cl) or D-Ala(cyclopentyl or thienyl);
Xaa.sub.2 is (A')D-Phe, D-1Nal, D-2Nal or D-Trp, with A' being H,
4F, 4Cl, 4NO.sub.2 or 3,4Cl.sub.2; Xaa.sub.3 is D-Nle, D-Leu,
D-CML, D-Met or D-Acp; Xaa.sub.4 is D-Arg, D-Arg(Et.sub.2), D-Lys,
D-Ily, D-Har, D-Har(Et.sub.2), D-nArg, D-Orn, D-Ior, D-Dbu, D-Amf,
and D-Amf(Amd); and Q is NR.sub.1, R.sub.2, Mor, Tmo, Pip, 4-Hyp,
OxP or Ppz, with R.sub.1 being Me, Et, Pr, Bu, hEt, Cyp, Bzl or
4-picolyl, and R.sub.2 being H or Et. In one embodiment, Xaa.sub.2
is D-Phe, Xaa.sub.3 is D-Nle and Xaa.sub.4 is D-Arg. In another
embodiment, Q is NHR.sub.1 and R.sub.1 is ethyl, propyl, butyl,
cyclopropyl or cyclobutyl. Alternatively, Q can be morpholinyl or
thiomorpholinyl. In a further embodiment, Q is NHR.sub.1 and
R.sub.1 is 4-picolyl. Alternatively, Q is NR.sub.1R.sub.2 and
R.sub.1 is ethyl and R.sub.2 is ethyl. In yet another embodiment,
Xaa.sub.1 is D-Phe or D-Ala(2-thienyl) and Xaa.sub.2 is D-4ClPhe.
In another embodiment, Xaa.sub.3 is D-Nle or D-Leu and Q is
morpholinyl.
[0162] In a particular embodiment, Xaa.sub.1 is D-Phe, D-4Fpa,
D-2Fpa, D-Acp or D-Ala(2Thi); Xaa.sub.2 is (A)D-Phe, D-1Nal, D-2Nal
or D-Trp, with A being 4F or 4Cl; Xaa.sub.3 is D-Nle, D-Met or
D-Leu; Xaa.sub.4 is D-Arg, D-Har, D-nArg, D-Lys, D-Orn or
D-Amf(Amd); and Q is NHR.sub.1, Mor, Tmo, Pip or Ppz, with R.sub.1
being Et, Pr or 4Pic.
[0163] In another particular embodiment, the peptide has the
formula:
H-D-Phe-D-Phe-D-Nle-D-Arg-NHEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-morpholinyl,
[0164] H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-picolyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHPr,
H-D-Phe-D-Phe-D-Nle-D-Arg-thiomorpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-Net.sub.2,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHMe,
H-D-Phe-D-Phe-D-Leu-D-Orn-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-NHhEt,
H-D-Phe-D-Phe-D-Nle-D-Arg-NH-cyclopropyl,
H-D-Ala(2Thi)-D-4 Cpa-D-Leu-D-Arg-morpholinyl,
H-D-Phe-D-Phe-D-Nle-D-Arg-piperidinyl,
H-D-Phe-D-Phe-D-Leu-D-Orn-NHEt,
H-D-Phe-D-Phe-D-Leu-D-Lys-morpholinyl, or
H-D-Phe-D-Phe-D-Nle-D-Arg-piperazinyl.
[0165] Mammals exhibiting insufficient or inadequate milk
production or at risk of insufficient or inadequate milk production
can be treated by a method according to the present invention; the
method includes administering to the mammal an amount of a
peripherally selective kappa opioid receptor agonist or salt
thereof or prodrug thereof effective to treat the mammal, wherein
the administration includes intravenous, subcutaneous,
intramuscular, intranasal, oral, or transdermal administration,
such as for instance by an electrotransport device. In one
embodiment of the method the electrotransport device delivers the
peripherally selective kappa opioid receptor agonist through a body
surface.
[0166] In one particular aspect, the method includes: (a) providing
a first electrode; (b) providing a second electrode; (c) providing
a power source electrically connected to said first and said second
electrodes; (d) providing at least one donor reservoir having the
peripherally selective kappa opioid receptor agonist, wherein said
donor reservoir is associated with said first or second electrode;
and (e) delivering a therapeutically effective amount of said
peripherally selective kappa opioid receptor agonist through said
body surface.
[0167] The peripherally selective kappa opioid receptor agonist can
administered by any of these methods between about 1 microgram/kg
of body weight to about 100 milligrams/kg of body weight of said
mammal per hour, day, week or month. These methods of the invention
delivering the peripherally selective kappa opioid receptor agonist
administered can increase prolactin to levels greater than 10, 15,
20, 25, 50, 75, 100, 125, 150, 175, or 200 ng/ml serum above the
baseline level of serum prolactin. These methods are particularly
advantageous for the treatment of female animal subjects
(particularly a mammal, such as for instance a primate, ungulate,
canine or feline) or human patients, especially pregnant females or
females that have given birth to an offspring within 1, 2, 3, 4, 5,
6, 7, 8, 9, 10, 11, 12, 12-24, 24-26, 36-48 hours, days, weeks, or
months. Suitable primates include an ape, gorilla, monkey, macaque,
chimpanzee, lemur or orangutan. Suitable ungulates include a cow,
pig, sheep, goat or horse.
[0168] The invention further provides a method of treating a mammal
exhibiting an insufficient or inadequate amount of milk production
or at risk of exhibiting an insufficient or inadequate amount of
milk production, wherein the method includes administering to the
subject prior to or after childbirth an amount of a peripherally
selective kappa opioid receptor agonist in conjunction with a
lactation enhancer, such as for instance, oxitocin or a stabilizer
effective to treat the mammal. The oxytocin can be administered
within one or more hours, days, or weeks following childbirth. In a
particular embodiment, the lactation enhancer or stabilizer is
administered within one or more hours, days, or weeks following
childbirth.
[0169] This invention is further illustrated by the following
examples which in no way should be construed as being further
limiting. The contents of all cited references (including
literature references, issued patents, published patent
applications, and co pending patent applications) cited throughout
this application are hereby expressly incorporated by
reference.
Examples
[0170] The safety, tolerability, pharmacokinetics, and
prolactin-elevating activity of ascending single intravenous (IV)
doses of one of the compounds of the instant invention,
D-phenylalanyl-D-phenylalanyl-D-norleucyl-N-(4-pyridinylmethyl)-D-arginin-
amide, acetate salt, herein designated as CR665, was assessed in
healthy male and surgically sterile female human subjects following
1-hour or 5-minute infusions. CR665, also referenced in the
literature as FE 200665, is a peripherally selective kappa opioid
receptor agonist; see U.S. Pat. No. 5,965,701; also Riviere P.
J.-M. et al. Novel D-amino acid tetrapeptides demonstrate
unprecedented k-opioid receptor selectivity and antinociception.
30.sup.th Int. Narcotics Res. Conf. (INRC) 1999, Saratoga Springs,
N.Y., Jul. 10-12, 1999; Wisniewski K et al. Long acting, selective,
peripheral kappa agonists. 26.sup.th European Peptide Symposium,
Montpilier, France, Sep. 11-15, 2000; Binder W et al. Analgesic and
antiinflammatory effects of two novel kappa-opioid peptides.
Anesthesiology. 94:1034-44, 2001; Riviere Peripheral kappa-opioid
receptor agonists for visceral pain. Br J Pharmacol. 141:1331-4,
2004).
Study Design and Procedures
[0171] This clinical study was conducted as a double blind, placebo
controlled, ascending single intravenous (IV) dose, sequential
group study. The results reported herein were obtained with 54 male
and female human subjects in fifteen groups as shown in Table X
below. This study was double blind and placebo controlled in order
to avoid bias in the collection and evaluation of data during its
conduct. Placebo was chosen as the control treatment to assess
whether any observed effects were treatment related or simply
reflected the study conditions. In each group, subjects received
CR665 or placebo. Doses were administered as a single constant rate
IV infusion over 1 hour (part A) or 5 minutes (part B) on the
morning of Day 1. Doses were administered in an escalating manner
following satisfactory review of the safety data and
pharmacokinetic data from the lower dose levels. There was a
minimum of 6 days between dose escalations to allow sufficient time
for an adequate safety review.
[0172] Dose levels were as shown in Table 1:
TABLE-US-00002 TABLE 1 Treatments Infusion Part Group Population
Treatment duration A A1 Males 0.015 mg/kg/placebo 1 hour A2 Males
0.03 mg/kg/placebo 1 hour A3 Males 0.06 mg/kg/placebo 1 hour A4
Males 0.12 mg/kg/placebo 1 hour A5 Males 0.24 mg/kg/placebo 1 hour
A6 Males 0.48 mg/kg/placebo 1 hour A7 Males 0.36 mg/kg/placebo 1
hour A8 Males 0.48 mg/kg/placebo 1 hour A9 Females 0.24
mg/kg/placebo 1 hour A10 Females 0.42 mg/kg/placebo 1 hour A12
Males 0.42 mg/kg/placebo 1 hour B B1 Males 0.03 mg/kg/placebo 5
minutes B2 Females 0.06 mg/kg/placebo 5 minutes B3 Males 0.06
mg/kg/placebo 5 minutes B4 Males 0.09 mg/kg/placebo 5 minutes
[0173] CR665 was prepared according to Good Manufacturing Practice
(GMP) standards and provided as bulk supply in, 2 mL glass vials,
each containing CR665 solution (1.1 mL at a concentration of 10
mg/mL [free base] in isotonic 0.04 M acetate buffer, pH 4.5).
Placebo solution (isotonic 0.04.degree.M acetate buffer, pH 4.5)
for IV administration, of identical appearance, i.e., a clear,
colorless solution, was also prepared. The IV dose solutions were
stored at 2.degree. C. to 8.degree. C.
[0174] The individual intravenous dose for each subject was
prepared from bulk supplies (2 mL vials containing 1.1 mL of CR665
or placebo solution). For each dose preparation, an appropriate
volume of CR665 solution (10 mg/mL) or placebo solution was
withdrawn from one or more vials using a syringe, and injected into
a 60 mL Plastipak polypropylene syringe (Beckton Dickinson S.A.,
Spain) containing an appropriate volume of sterile NaCl buffer.
[0175] For the 1 hour infusions, the final volume prepared was 40
mL, of which 30 mL was infused. The dose calculation was as
follows:
Volume of 10 mg / mL CR 665 required ( mL ) = Dose level ( mg / kg
) .times. body weight ( kg ) .times. * ( [ 40 / 30 ] / 10 )
##EQU00001## Volume of buffer = 40 mL volume of CR 665 required (
mL ) ##EQU00001.2##
Table 2 provides some example dilutions, based on a 70 kg body
weight.
TABLE-US-00003 TABLE 2 CR665 CR665 dose dose to be infused to be
Concentration CR665 NaCl Dose for a 70 kg prepared of dose
solution.sup.a buffer level person (mg/ solution volume volume
(mg/kg) (mg/30 mL) 40 mL) (mg/mL) (mL) (mL) 0.015 1.05 1.40 0.04
0.14 39.86 0.03 2.10 2.80 0.07 0.28 39.72 0.06 4.20 5.60 0.14 0.56
39.44 0.12 8.40 11.20 0.28 1.12 38.88 0.24 16.80 22.40 0.56 2.24
37.76 .sup.aConcentration 10 mg/mL
[0176] The dose was administered via a cannula inserted into a
suitable vein of the forearm in the non dominant arm of the
subject. The dose was infused over a 1 hour period in the morning
between 07:00 and 10:30, using an IMED Gemini PC 1 infusion pump
operating at a constant rate of 0.5 mL/min (30 mL/h). A total of 30
mL of dosing solution (from 40 mL in the syringe) was administered,
and the subjects remained supine throughout the infusion.
[0177] From 24 hours after the start of the infusion, meals were
provided at appropriate times on each day. Other than the fluid
restrictions on Day 1, water was freely available at all times. The
volume of fluid consumed up to 24 hours after the start of the
infusion was recorded as part of the fluid balance assessment.
Subjects fasted from food and beverages (other than water) from
22:00 on Day 1, until the clinical laboratory samples had been
taken on the following day, and for at least 6 hours prior to the
follow up visit.
[0178] On arrival at the clinical study center on Day -1, pre dose
assessments were performed, including testing a urine sample for
the presence of illicit drugs, administering an alcohol breath
test, and the recording of body weight (in underclothes). Subjects
then commenced a 24 hour urine collection for assessment of
creatinine clearance and fluid balance. Vitals signs and 12 lead
ECG were also assessed, and all subjects received a physical
examination.
[0179] The condition of each subject was monitored throughout the
study. In addition, any signs or symptoms were observed and
elicited by open questioning, such as "How have you been feeling
since you were last asked?" at the following times for each part of
the study: Pre dose, 0.5, 1, 3, 12, 24, 36 and 48 hours after the
start of the infusion (up to 24 hours only for Groups A 1 to A4),
and at Follow up assessment.
[0180] Subjects were also encouraged to spontaneously report
adverse events occurring at any other time during the study. Any
adverse events and remedial action required were to be recorded for
each subject. The nature, time of onset, duration and severity were
documented, together with the Project Physician's opinion of the
relationship to drug administration.
[0181] The condition of the dosing cannula site for each subject
was monitored for erythema, pruritus and swelling at the following
times: Pre dose, 0.5, 1, 2 and 24 hours after the start of the
infusion. Subjects were also encouraged to spontaneously report
adverse events relating to the infusion site at any other time
during the study. Any adverse events and observations relating to
the infusion site and remedial action required were to be recorded
for each subject. The nature, time of onset, duration, and severity
were to be documented, together with the Project Physician's
opinion of the relationship to drug administration.
[0182] Supine and standing blood pressure, supine pulse rate and
oral body temperature were measured in duplicate at the following
times: Day 1; Pre dose, 15 minutes (Part B only), 30 minutes, 55
minutes, 1.5, 2, 2.5, 3, 4, 8, 12, 24 and 48 hours after the start
of the infusion (up to 24 hours only for Groups A I to A4); and at
Follow up visit. Supine vital signs only were measured during the
infusion period. Pre dose blood pressure and pulse rate were
measured in triplicate at approximately 2 minute intervals. The
median value was used as the baseline value in the data analysis.
All subsequent measurements were performed singly, but repeated in
duplicate if outside the relevant clinical reference ranges. If
repeated, the median of the three values were used in the data
analysis. Blood pressure and pulse rate were measured using
automated Critikon Dinamap.TM. PRO 400 monitors. Subjects were
required to be supine for at least 5 minutes before blood pressure
and pulse rate measurements. Standing blood pressure and pulse rate
were then measured singly after the subject had been sitting for
approximately 1 minute and then standing for approximately 2
minutes. Oral body temperature was measured singly using an Omron
digital thermometer. To assess drug effects on cardiovascular
function, a 12 lead resting ECG with a 10 second rhythm strip was
recorded on a Marquette MAC5000 ECG machine at the following times,
after the subject has been supine for at least 5 minutes: Day 1;
Pre dose, 50 minutes, 2, 4, 8, 24 and 48 hours after the start of
the infusion (up to 24 hours only for Groups A1 to A4); and at the
follow up visit. The ECG machine computed the PR, QT and QTc
intervals, QRS duration, and heart rate. The QT interval was
corrected for heart rate (QTc) using Bazett's formula. For
continuous ECG measurements, continuous cardiac Hotter monitoring
of each subject, using Reynolds Tracker II Holier monitors, was
performed from 1 hour prior to until 4 hours after the start of the
infusion. Blood and urine samples were collected, after at least a
6 hour fast, for clinical laboratory evaluations at the following
times during the study: Pre dose and 24 hours after the start of
the infusion; and at the follow up visit.
[0183] The following evaluations were performed, as shown in Table
3.
TABLE-US-00004 TABLE 3 Serum biochemistry: Units Hematology: Units
Aspartate IU/L White blood cell count 10.sup.9/L aminotransferase
(AST) (WBC) Alanine IU/L Red blood cell count 10.sup.12/L
aminotransferase (ALT) (RBC) Alkaline phosphatase IU/L Haemoglobin
g/dL Gamma-glutamyl IU/L Haematocrit (PCV) % transferase (GGT) Mean
cell volume (MCV) fL Sodium mmol/L Mean cell pg Potassium mmol/L
haemoglobin (MCH) Chloride mmol/L MCH concentration g/dL Calcium
mmol/L (MCHC) Inorganic phosphate mmol/L Platelet count 10.sup.9/L
Glucose mmol/L Differential WBC 10.sup.9/ Urea mmol/L L & %
Bilirubin (total.sup.a) .mu.mol/L Creatinine .mu.mol/L Total
protein g/L Albumin g/L Urinalysis: Units Serology: Units
Microscopic examination + Hepatitis B surface antigen.sup.b neg/pos
Specific gravity NA (HBsAg) pH NA Hepatitis C antibody.sup.b
neg/pos Protein + HIV antibodies.sup.b neg/pos Glucose + Ketones +
Blood + Urobilinogen + .sup.aDirect bilirubin analyzed only if
total bilirubin is elevated .sup.bAnalyzed at screening only Neg =
Negative Pos = Positive
[0184] Blood samples (2.5 mL) were collected for evaluation of
serum prolactin at the following times: Pre dose (in triplicate,
with at least a 15 minute interval between each of the triplicate
pre dose samples), 15 minutes, 30 minutes, 45 minutes, 1 hour
(immediately prior to the end of infusion), 1 hour 5 minutes, 1
hour 10 minutes, 1 hour 15 minutes, 1.5, 2, 2.5, 3, 4, 6, 8 and 12
hours after the start of the infusion (18 samples).
[0185] Plasma and urine samples for the analysis of CR665 and N
oxide metabolite were prepared by solid phase extraction. The
centrifuged eluates were quantified by liquid chromatography with
tandem mass spectrometric detection (LC MS/MS). The lower limit of
quantification was 1 ng/mL.
[0186] After collection of urine samples, following removal of the
aliquots for drug assay and/or urinalysis, urine was pooled over
the following time intervals: 24 to 0 hours and 0 to 24 hours after
the start of the infusion. A 10 mL aliquot was removed from the
each pooled collection for determination of urinary creatinine.
[0187] An assessment of fluid balance (made by comparison of volume
of fluid consumed and volume of fluid excreted) was made over the
following periods: 24 to 0 hours and 0 to 24 hours after the start
of the infusion. During these periods, the volume of fluid consumed
and the volume of urine excreted was recorded.
[0188] A full physical examination, including a neurological
examination, was performed at the following times: Discharge (Day 2
or 3) and at Follow up visit.
[0189] For pharmacokinetic assessments, blood samples (1.times.3
mL) were taken from the contralateral forearm vein(s) at the
following times: Pre-dose, 15 minutes, 30 minutes, 45 minutes, 1
hour (immediately prior to the end of infusion), 1 hour 5 minutes,
1 hour 10 minutes, 1 hour 15 minutes, 1.5, 2, 2.5, 3, 4, 6, 8, 12,
16, 24, 36 and 48 hours after the start of the infusion). An
indwelling cannula (Venflon.RTM.; BOC Ohmeda AB, Sweden) was used
for all blood collection pre-dose and up to at least 12 hours after
the start of the infusion. Otherwise, samples were collected using
venipuncture. Blood samples were collected into pre-chilled 3 mL
K.sub.3EDTA Vacutainer.TM. tubes (Becton Dickinson UK, Ltd.,
Oxford) and, after mixing, were placed in a cool box containing
crushed ice/water. The samples were centrifuged, within 30 minutes
of collection, at 1500 g for 10 minutes at approximately 4.degree.
C. For each sample, the separated plasma was transferred into two 5
mL suitably labeled polypropylene, tubes, and stored immediately at
approximately -20.degree. C. Plasma samples were analyzed for CR665
using liquid chromatography with tandem mass spectrometric
detection.
[0190] Urine was collected into standard weight polyethylene
containers over the following time intervals: Pre dose (-24 to 0),
0 to 4, 4 to 8, 8 to 12, 12 to 24 and 24 to 48 hours after the
start of the infusion. During each collection period, the
containers were stored in a refrigerator at 2 to 8.degree. C. The
weight (g) of each collection was recorded prior to removal of two
sub samples (each approximately 4 mL) into suitably labeled
polypropylene containers, which were stored within 2 hours of
collection, at approximately -20.degree. C. Additional aliquots
(1.times.100 mL per collection period) were stored for possible
future analyses. Any remaining urine from post close collection
intervals was pooled with the rest of the urine collected during
the 0 to 24 hour collection period, for analysis of creatinine
clearance. A nominal value for specific gravity of 1.018 was used
to calculate urine volume.
[0191] The pharmacokinetic analysis was conducted using WinNonlin
Enterprise Version 4.0.1.
[0192] Pharmacokinetic parameters were determined from the plasma
and urine concentrations of CR665 and the N-oxide metabolite using
non compartmental procedures. The pharmacokinetic parameters
determined are presented in Table 4 below.
TABLE-US-00005 TABLE 4 Pharmacokinetic Parameters Determined for
CR665 and the N-Oxide Metabolite Parameter Definition AUC.sub.0-t
Area under the plasma concentration-time curve from time zero up to
the last quantifiable concentration AUC.sub.0-.infin. Area under
the plasma concentration-time curve from time zero to infinity %
AUC.sub.ex Percentage of AUC that is due to extrapolation from
t.sub.z to infinity C.sub.max Maximum observed plasma concentration
C.sub.inf Plasma concentration at end of the IV infusion t.sub.max
Time of maximum observed plasma concentration t.sub.z Time of last
quantifiable plasma concentration .lamda..sub.z Apparent plasma
terminal elimination rate constant t1/2 Apparent plasma terminal
elimination half-life MRT.sub.int Intrinsic mean residence time CL
Total plasma clearance (CR665 only) V.sub.z Apparent volume of
distribution during the terminal phase (CR665 only) V.sub.ss
Apparent volume of distribution at steady-state (CR665 only)
MR.sub.AUC Metabolic ratio based on AUC (N-oxide metabolite only)
MR.sub.Cmax Metabolic ratio based on C.sub.max (N-oxide metabolite
only) Ae Amount of drug excreted in urine fe Percentage of dose
excreted in urine CL.sub.R Renal clearance
[0193] Dose and body weight normalized values (norm) were
determined for AUC.sub.0-t, AUC.sub.0-.infin., C.sub.inf and
C.sub.max. Body weight normalized values [norm] were determined for
V.sub.z, V.sub.ss, CL and CL.sub.R.
[0194] The pharmacokinetic analysis was conducted using model
independent methods as implemented in WinNonlin software, based on
plasma concentrations of CR665 from those subjects who have
received CR665 and have evaluable plasma concentration-time
profiles.
[0195] The following plasma pharmacokinetic parameters were
determined for CR665: [0196] C.sub.max Maximum plasma concentration
[0197] t.sub.max Time of maximum plasma concentration [0198]
t.sub.1/2z Terminal half-life=ln(2)/.lamda..sub.z [0199]
AUC.sub.0-t Area under the plasma concentration-time curve from
time zero to time t (time of last quantifiable plasma
concentration) [0200] AUC.sub.inf Area under the plasma
concentration-time curve from time zero to infinity calculated as
[AUC.sub.0-t+(C.sub.last/.lamda..sub.z)] where C.sub.last is the
estimated concentration at the last quantifiable concentration
curve. [0201] .lamda..sub.z Terminal-phase rate constant, also
known as K.sub.el [0202] CL Total body clearance=Dose/AUC.sub.inf
[0203] V.sub.z Volume of distribution based on terminal phase
calculated as
[0203] Vz/F=Dose/.lamda..sub.z*AUC.sub.inf
[0204] Individual elapsed sampling times were used in the
pharmacokinetic analysis. C.sub.max and t.sub.max were obtained
directly from the experimental observations. For the purpose of
calculating AUC.sub.0-t, when two consecutive plasma concentrations
below the lower limit of quantification (LLOQ) were encountered
after t.sub.max, all subsequent values were excluded from the
analysis. The exponential rate constant of the terminal-phase,
.lamda..sub.z, was estimated by linear regression of the log
concentration-time data associated with the terminal phase of the
plasma concentration-time profile. The number of data points
included in the regression was determined by visual inspection. A
minimum of 3 data points in the terminal phase, excluding
C.sub.max, was required to estimate .lamda..sub.z.
[0205] An assessment of dose-proportionality of the
pharmacokinetics of CR665 was also performed. Log-transformed
AUC.sub.0-t, AUC.sub.inf and C.sub.max were derived and a model of
the form:
Log(parameter)=Intercept+.beta.*Log(Dose)+Error
where dose is a fixed term was fitted to assess a between-subject
estimate of the slope in order to assess dose-proportionality. A
point estimate of the slope .beta., with 90% confidence intervals,
provides a plausible range for which the true slope occurs. The
interpretation of the slope is such that a conclusion of
dose-proportionality for AUC.sub.0-t, AUC.sub.inf and C.sub.max of
CR665 will be made if the 90% CI for the slope contains the value
1.
[0206] The pharmacodynamic analysis was conducted using WinNonlin
Enterprise Version 4.0.1 (Pharsight Corporation, Mountain View,
Calif., USA). The following pharmacodynamic parameters were
calculated from the serum concentrations of prolactin: [0207]
Change from baseline (mean of triplicate pre-dose values) at each
sampling time [0208] Maximum observed change from baseline
(C.sub.max) [0209] Area under the change from baseline time curve
from 0 to 12 hours (AUC.sub.0-12 h) This study was conducted under
a MHRA Clinical Trials Authorization (CTA) in accordance with: (1)
the relevant articles of the Declaration of Helsinki as adopted by
the 18th World Medical Assembly in 1964 and as revised in Tokyo
(1975), Venice (1983), Hong Kong (1989), South Africa (1996) and
Scotland (2000); and (2) the ICH Good Clinical Practices (GCP)
consolidated guidelines adopted in the EU by CPMP, July 1996,
issued as CPMP/ICH/135/95.
Drug Safety
[0210] All 54 subjects completed the treatment period with no
severe or serious adverse events. In particular, even at the
highest dose levels, there were no signs of the more typical CNS
symptoms (hallucinations or dysphoria) associated with intolerable
dose levels of previously tested kappa opioid receptor agonists.
For the 12-lead ECG evaluations, there were no treatment related
trends, significant clinical changes, or abnormalities in the
morphology of the 12 lead ECG. Similarly, for the clinical
laboratory evaluations, there were no treatment related trends or
significant clinical findings in serum biochemistry, hematology, or
urinalysis parameters. Physical examination of the subjects also
revealed no treatment related findings.
[0211] In Parts A and B of the study, there were no treatment or
close related trends in mean supine and standing systolic and
diastolic blood pressure, supine and standing pulse rate or oral
body temperature. No apparent treatment or dose related trends in
the 12 lead ECG parameters were noted in Parts A and B. In
addition, there were no clinically important findings in the
morphology of the 12 lead ECGs for individual subjects at each dose
level of CR665. There was no evidence of prolongation of QTc
interval (Bazett's and Friedericia's corrected) at each dose level
of CR665 in male and female subjects.
[0212] For Parts A and B, there were no clinically important
changes in creatinine clearance, estimated from serum creatinine,
for any subject during the study. The mean creatinine clearance was
generally similar prior to dosing and at 24 hours after dosing for
each dose level of CR665 and placebo. There were no apparent
treatment or dose related trends in fluid balance (urine
excreted-fluid consumed) over the 0 to 24 hour period after the
start of the infusion. However, an increase in the volume of urine
excreted over the first 4 hours after the start of the infusion was
observed at each dose level of CR655 compared to placebo in male
and female subjects for Parts A and B of the study.
Pharmacodynamics
Time Course of Prolactin Elevation by CR665
[0213] The administration of single IV doses of CR665 caused a
rapid and marked increase in serum concentrations of prolactin
across all dose levels in male and female subjects. Changes from
baseline (pre dose) in serum concentrations of prolactin following
1-hour and 5-minute infusions of placebo and CR665 in male and
female subjects are shown in FIGS. 1 to 3:
[0214] The derived pharmacodynamic parameters for serum prolactin
following 1-hour and 5-minute infusions of placebo and CR665 in
male and female subjects are summarized in Tables 5 to 7:
TABLE-US-00006 TABLE 5 Summary of the Pharmacodynamic Parameters of
Serum Prolactin (Changes from Baseline) Following a 1 hour IV
Infusion in Male Subjects (Part A) Dose of (mg/kg) Placebo 0.015
0.03 0.06 0.12 0.24 0.36 0.42 0.48 [males] [males] [males] [males]
[males] [males] [males] [males] [males] Parameter (N = 17) (N = 4)
(N = 4) (N = 4) (N = 4) (N = 4) (N = 4) (N = 4) (N = 8)
AUC.sub.0-12 h 0.760 30.8 57.4 43.6 89.5 119 140 132 131 (ng h/mL)
(27.5) (87.6) (30.3) (32.2) (38.6) (22.3) (40.0) (51.5) (74.5)
C.sub.max 4.61 22.2 18.8 25.3 39.3 36.3 45.5 44.2 47.2 (ng/mL)
(3.44) (6.44) (1.47) (6.41) (13.9) (17.3) (16.9) (10.8) (27.4)
Arithmetic mean (SD) data are presented N = Number of subjects
studied
TABLE-US-00007 TABLE 6 Summary of the Pharmacodynamic Parameters of
Serum Prolactin (Changes from Baseline) Following a 1 hour IV
Infusion in Female Subjects (Part A) Dose of (mg/kg) Placebo 0.24
[females] [females] Parameter (N = 3) (N = 3) AUC.sub.0-12 h 19.7
209 (ng h/mL) (23.5) (21.1) C.sub.max 3.67 68.2 (ng/mL) (2.27)
(14.3) Arithmetic mean (SD) data are presented N = Number of
subjects studied
TABLE-US-00008 TABLE 7 Summary of the Pharmacodynamic Parameters of
Serum Prolactin (Changes from Baseline) Following a 5 minute IV
Infusion in Male and Female Subjects (Part B) Dose of (mg/kg)
Placebo 0.03 0.06 0.09 0.06 [males] [males] [males] [males]
[females] Parameter (N = 5) (N = 4) (N = 4) (N = 4) (N = 4)
AUC.sub.0-12 h -0.876 24.3 74.3 68.5 96.8 (ng h/mL) (34.1) (35.4)
(44.2) (13.5) (32.9) C.sub.max 4.08 33.6 42.0 37.1 32.3 (ng/mL)
(3.63) (14.3) (22.8) (13.3) (14.8) Arithmetic mean (SD) data are
presented N = Number of subjects studied
[0215] In Part A, following 1-hour infusions of 0.015 to 0.48 mg/kg
CR665 in male subjects, there was a rapid and marked increase in
serum prolactin concentrations. At each dose level, maximum serum
prolactin concentrations generally occurred at 1 hour after the
start of the infusion, i.e. at the end of the infusion. There was
an apparent dose-related increase in mean values for C.sub.max
(maximum changes from baseline in serum prolactin) up to the 0.36
mg/kg dose level. Mean C.sub.max values were generally similar at
the 0.36, 0.42 and 0.48 mg/kg dose levels, with maximum serum
prolactin levels being approximately 5- to 6-fold higher than
baseline (pre-dose) across these dose levels. Mean values for
AUC.sub.0-12 h (changes from baseline) increased up to 0.36 mg/kg,
and thereafter were generally similar over the 0.36 to 0.48 mg/kg
dose range. Following maximum concentrations of prolactin, there
was a dose-related decrease to baseline levels. Mean values had
fallen to close to baseline values by 8 hours at the 0.36, 0.42 and
0.48 mg/kg dose levels.
[0216] In Part A, following 1 hour infusions of 0.24 mg/kg CR665 in
female subjects, maximum serum prolactin concentrations occurred at
1 hour after the start of the infusion. The mean C.sub.max values
(change from baseline) in females were higher than in male
subjects, with maximum serum prolactin levels being approximately
12-fold greater than baseline (pre dose) in females.
[0217] In Part B, following 5-minute infusions of 0.03 to 0.09
mg/kg CR665 in male subjects, maximum serum prolactin
concentrations occurred at 30 minutes after the start of, the
infusion, i.e., 25 minutes after the end of the infusion. Mean
C.sub.max values were generally similar at the 0.03, 0.06 and 0.09
mg/kg dose levels, with maximum serum prolactin levels being
approximately 4- to 6-fold higher than baseline (pre dose) across
these dose levels. In female subjects, maximum serum prolactin
concentrations occurred at 0.5 to 1 hour after the start of the
5-minute infusion of 0.06 mg/kg CR665. The mean C.sub.max value in
females was similar to male subjects, with maximum serum prolactin
levels being approximately 4-fold greater than baseline (pre dose)
in females.
Part A
Pharmacokinetics of CR665 after a One Hour Intravenous Infusion
[0218] The plasma concentrations of CR665 following a 1 hour
infusion in male subjects are shown in FIGS. 4 and 5.
[0219] The pharmacokinetic parameters of CR665 following a 1-hour
infusion in male subjects are summarized in Table 8.
TABLE-US-00009 TABLE 8 Summary of the Pharmacokinetic Parameters
for CR665 Following a 1 hour IV Infusion in Male Subjects (Part A)
Dose of (mg/kg) [males] 0.015 0.03 0.06 0.12 0.24 0.36 0.42 0.48
Parameter (N = 4) (N = 4) (N = 4) (N = 4) (N = 4) (N = 4) (N = 4)
(N = 8) AUC.sub.0-t 30.0 70.0 129 267 474 808 1080 1120 (ng h/mL)
(20.3) (14.2) (30.2) (7.17) (10.4) (8.39) (17.4) (20.5)
AUC.sub.0-.infin. 31.4 72.5 132 270 478 812 1084 1125 (ng h/mL)
(21.7) (15.5) (29.8) (7.11) (10.5) (8.37) (17.5) (20.4) C.sub.max
27.8 65.3 119 231 431 779 943 982 (ng/mL) (15.2) (13.7) (24.8)
(5.87) (8.30) (10.1) (13.7) (15.7) t.sub.max.sup.a 1.00 1.00 0.875
0.750 1.00 1.00 1.00 0.875 (h) (0.750-1.02) (1.00-1.00)
(0.733-1.35) (0.750-1.00) (1.00-1.00) (0.767-1.00) (0.750-1.00)
(0.750-1.00) AUC.sub.0-t 1979 2349 2161 2232 1979 2252 2573 2333
(norm) (20.5) (14.6) (30.1) (7.06) (10.2) (8.40) (17.0) (20.5)
AUC.sub.0-.infin. 2072 2430 2201 2257 1994 2263 2582 2344 (norm)
(22.0) (16.0) (29.7) (7.00) (10.3) (8.38) (17.1) (20.5) C.sub.max
1837 2189 1991 1932 1797 2170 2248 2046 (norm) (15.1) (13.8) (24.7)
(5.86) (8.12) (10.1) (13.2) (15.9) t.sub.1/2 0.691 0.732 0.728 1.65
1.37 1.64 1.78 1.87 (h) (73.2) (50.0) (14.4) (24.0) (17.6) (21.0)
(41.8) (36.4) MRT.sub.int 0.512 0.510 0.563 0.723 0.614 0.623 0.618
0.649 (h) (43.5) (35.8) (25.7) (23.1) (15.6) (19.8) (17.5) (20.8)
CL 560 538 564 533 629 569 504 576 (mL/min) (15.2) (16.0) (17.8)
(8.71) (6.47) (11.5) (21.3) (18.6) V.sub.z 33.5 34.1 35.5 75.9 74.6
80.6 77.9 93.3 (L) (60.2) (42.2) (7.44) (20.9) (15.7) (13.3) (22.3)
(39.1) V.sub.ss 17.2 16.5 19.0 23.1 23.2 21.2 18.7 22.4 (L) (35.4)
(31.3) (32.1) (22.3) (18.0) (16.0) (8.42) (20.3) Geometric mean (CV
%) data are presented .sup.aMedian (min-max) N = Number of subjects
studied (norm) = Normalized for dose and body weight (mg/kg)
[0220] During the IV infusion of CR665 at dose levels of 0.015 to
0.48 mg/kg in male subjects, plasma concentrations increased
rapidly, with maximum concentrations generally occurring at the end
of the 1 hour infusion. Plasma concentrations of CR665 were
generally similar at 45 minutes and 1 hour after the start of the
infusion for individual subjects at each dose level.
[0221] Following the end of the IV infusion, plasma concentrations
of CR665 appeared to decline in an essentially biphasic manner with
the start of the elimination phase occurring between 1.25 and 6.0
hours after the start of the infusion.
[0222] The mean apparent elimination half life was relatively
constant in the 0.015 to 0.06 mg/kg dose range, at about 0.7 hours,
but became longer across the 0.12 to 0.48 mg/kg dose range, varying
from 1.4 to 1.9 hours, with a trend toward longer half life values
at higher doses. For individual subjects across the 0.12 to 0.48
mg/kg dose range, the apparent elimination half life ranged from
1.2 to 3.0 hours. This apparent increase in half life at higher
dose levels is consistent with plasma concentrations of CR665 being
quantifiable for a longer period of time at the higher dose levels,
revealing more of true terminal elimination phase. As a result,
statistical analysis showed that the elimination half life for
CR665 was dose dependent over the entire dose range.
[0223] AUC.sub.0-.infin. and C.sub.max generally appeared to
increase in a dose-proportional manner over the dose range of 0.015
to 0.48 mg/kg. This observation was confirmed by statistical
analysis, with the estimates of the slopes (95% CI) from the
regression analysis for AUC.sub.0-.infin. and C.sub.max being 1.02
(0.978 to 1.06) and 1.02 (0.984 to 1.05). FIG. 6 illustrates the
dose-proportional increase in AUC.sub.0-.infin. for CR665 over the
dose range of 0.015 to 0.48 mg/kg.
[0224] The dose proportionality of the increase in AUC was found to
be almost perfectly linear, as shown in FIG. 6, with an R.sup.2
value of 0.98, meaning that, for this data set, 98% of the
variation in systemic exposure to CR665 is due to variation in the
administered dose of CR665. The importance of this observation is
that it enables the practitioner to predict, with a high degree of
accuracy, what drug exposures will occur with a given dose of drug.
In fact, one skilled in the art can use this information, together
with the calculated pharmacokinetic parameters of the drug (see
Table 6), to accurately estimate the plasma levels of drug that
would result from intravenous infusions of different doses, at what
time a steady state concentration of drug would be achieved, and
how to design individualized dosage regimens to achieve steady
state drug concentrations for a particular patient (Bauer, L. A.
Applied Clinical Pharmacokinetics, Chap. 2, "Clinical
pharmacokinetic equations and calculations", pp. 26 49, 2001).
Since controlled release formulations (e.g., microspheres) and
devices (e.g., for electrotransport) are intended to provide
prolonged steady state drug concentrations, the skilled
practitioner utilizes this pharmacokinetic information to define
the useful operating characteristics of modes of drug delivery.
[0225] Statistical analysis showed that total plasma clearance of
CR665 (CL) was dose-independent; however MRT.sub.int and the volume
of distribution (V.sub.z and V.sub.ss) were found to be
dose-dependent. This was due to the observed change in the
elimination rate constant (.lamda..sub.z), which was probably due
to the fact that the CR665 was quantifiable for a longer period of
time, post-injection, at the higher dose levels, rather than true
dose-dependency in the kinetics of CR665.
[0226] Geometric mean plasma concentrations of CR665 following a
1-hour infusion of 0.24 mg CR665 in female subjects are summarized
in FIGS. 7 and 8.
[0227] Arithmetic mean plasma concentrations of CR665 following a
1-hour infusion of 0.24 mg/kg CR665 in male and female subjects are
summarized in FIG. 9.
[0228] The pharmacokinetic parameters of CR665 following a 1-hour
infusion of 0.24 mg/kg CR665 in male and female subjects are
summarized in Table 9.
TABLE-US-00010 TABLE 9 Summary of the Pharmacokinetic Parameters
for CR665 Following a 1-hour IV Infusion of 0.24 mg/kg CR665 in
Male and Female Subjects (Part A) 0.24 mg/kg Males Females
Parameter (N = 4) (N = 3) AUC.sub.0-t 474 440 (ng h/mL) (10.4)
(10.2) AUC.sub.0-.infin. 478 442 (ng h/mL) (10.5) (10.1) C.sub.max
431 384 (ng/mL) (8.30) (3.03) t.sub.max.sup.a 1.00 0.750 (h)
(1.00-1.00) (0.750-1.00) AUC.sub.0-t 1979 1846 (norm) (10.2) (9.71)
AUC.sub.0-.infin. 1994 1855 (norm) (10.3) (9.65) C.sub.max 1797
1612 (norm) (8.12) (2.33) t.sub.1/2 1.37 1.16 (h) (17.6) (15.9)
MRT.sub.int 0.614 0.515 (h) (15.6) (12.9) CL 629 557 (mL/min)
(6.47) (9.21) V.sub.z 74.6 55.7 (L) (15.7) (12.4) V.sub.ss 23.2
17.2 (L) (18.0) (13.1) Geometric mean (CV %) data are presented
.sup.aMedian (min-max) N = Number of subjects studied (norm) =
Normalized for dose and body weight (mg/kg)
[0229] Following administration of 0.24 mg/kg CR665 in female
subjects, maximum plasma concentrations were obtained at a similar
time to those observed in males, i.e., close to the end of the IN
infusion. Thereafter, the disposition kinetics of CR655 were
similar in male and female subjects, with a mean terminal
elimination half-life of approximately 1.2 to 1.4 hours. At the
0.24 mg/kg dose level, mean values for AUC.sub.0-.infin.,
AUC.sub.0-.infin. (norm), C.sub.max and C.sub.max (norm) were
generally similar in male and female subjects. The between-subject
variability for AUC.sub.0-.infin. and C.sub.max was low and similar
in male and female subjects at the 0.24 mg/kg dose level. These
findings are important because they confirm the predictability of
the pharmacokinetics of CR665, which assists the skilled
practitioner in the design of alternative dosing regimens that are
intended to achieve particular plasma levels of drug over time.
[0230] The urinary excretion of CR665 following a 1-hour infusion
of 0.24 mg/kg CR665 in male and female subjects is summarized in
Table 10.
TABLE-US-00011 TABLE 10 Summary of the Urinary Excretion of CR665
Following a 1 hour IV Infusion of 0.24 mg/kg CR665 in Male and
Female Subjects (Part A) 0.24 mg/kg Males Females Parameter (N = 4)
(N = 3) Ae.sub.0-24 h 631 446 (.mu.g) (39.1) (30.0) fe.sub.0-24 h
3.50 3.02 (%) (26.2) (23.2) CL.sub.R 0-24 h 22.0 16.8 (mL/min)
(27.9) (22.7) Geometric mean (CV %) data are presented N = Number
of subjects studied
[0231] The fraction of the dose excreted in the urine as unchanged
drug was low in female subjects, and similar to that seen for male
subjects.
Part B
Extrapolation of Part A PK Data to Design Brief IV Infusions of
CR665
[0232] For the Part B studies, five minute infusion dosing
protocols were designed using conventional pharmacokinetic
calculations (e.g., Bauer, L. A. Applied Clinical Pharmacokinetics,
Chap. 2, "Clinical pharmacokinetic equations and calculations", pp.
26 49, 2001), based on the results obtained in the one hour
infusion study (Part A). Doses were calculated to produce systemic
exposures to CR665 similar to those seen in the one hour infusion
study
[0233] Plasma concentrations of CR665 following a 5-minute infusion
in male and female subjects are shown in FIGS. 10 and 11.
[0234] The pharmacokinetic parameters of CR665 following a 5-minute
infusion in male and female subjects are summarized in Table
11.
TABLE-US-00012 TABLE 11 Summary of the Pharmacokinetic Parameters
for CR665 Following a 5-minute IV Infusion in Male and Female
Subjects (Part B) Dose of (mg/kg) 0.03 0.06 0.09 0.06 [males]
[males] [males] [females] Parameter (N = 3) (N = 4) (N = 4) (N = 3)
AUC.sub.0-t 65.9 139 209 120 (ng h/mL) (12.6) (15.8) (16.2) (9.29)
AUC.sub.0-.infin. 68.4 142 213 122 (ng h/mL) (11.8) (16.3) (16.4)
(8.79) C.sub.max 233 624 783 520 (ng/mL) (14.5) (32.2) (19.6)
(18.8) t.sub.max.sup.a 0.0833 0.0833 0.0833 0.0833 (h)
(0.0833-0.100) (0.0833-0.0833) (0.0833-0.0833) (0.0833-0.0833)
AUC.sub.0-t 2192 2327 2318 2013 (norm) (12.3) (16.0) (16.1) (8.92)
AUC.sub.0-.infin. 2273 2372 2369 2044 (norm) (11.6) (16.5) (16.2)
(8.43) C.sub.max 7751 10418 8701 8716 (norm) (14.4) (32.5) (19.8)
(18.4) t.sub.1/2 1.31 1.00 1.14 0.833 (h) (18.3) (13.0) (23.9)
(22.4) MRT.sub.int 0.615 0.502 0.537 0.419 (h) (4.48) (26.3) (21.0)
(24.2) CL 473 553 575 544 (mL/min) (7.06) (15.5) (14.3) (9.47)
V.sub.z 53.6 48.0 56.7 39.2 (L) (14.0) (13.4) (33.5) (21.5)
V.sub.ss 17.4 16.6 18.5 13.7 (L) (3.13) (24.2) (24.3) (18.8)
Geometric mean (CV %) data are presented .sup.aMedian (min-max) N =
Number of subjects studied (norm) = Normalized for dose and body
weight (mg/kg)
[0235] Following the IV infusion of CR665 at dose levels of 0.03 to
0.09 mg/kg in male subjects, plasma concentrations increased
rapidly with maximum concentrations generally occurring at the end
of the 5-minute infusion. Similarly, maximum concentrations of
CR665 following administration of 0.06 mg/kg CR665 in female
subjects were also attained at the end of the 5 minute infusion.
Following the end of the IV infusion, plasma concentrations of
CR665 appeared to decline in an essentially biphasic manner, with
the start of the elimination phase occurring between 1.0 to 2.0
hours after the start of the infusion in both male and female
subjects.
[0236] In male subjects, the mean apparent elimination half life,
about 1.0 to 1.3 hours, was similar across the 0.03 to 0.09 mg/kg
dose range. Statistical analysis confirmed that the elimination
half life for CR665 was independent of dose. The disposition
kinetics of CR655 were similar in male and female subjects, with
the mean terminal elimination half life of CR665 being
approximately 0.8 hours in females at the 0.06 mg/kg dose
level.
[0237] In male subjects, AUC.sub.0-.infin. and C.sub.max generally
appeared to increase in a dose-proportional manner over the dose
range 0.03 to 0.09 mg/kg. This was confirmed by statistical
analysis, with the estimates of the slopes (95% CI) from the
regression analysis for AUC.sub.0-.infin. and C.sub.max being 1.04
(0.853 to 1.22) and 1.12 (0.800 to 1.44). FIG. 12 illustrates the
dose-proportional increase in AUC.sub.0-.infin. for CR665 over the
dose range of 0.03 to 0.09 mg/kg in male subjects.
[0238] At the 0.06 mg/kg dose level, mean values for
AUC.sub.0-.infin., AUC.sub.0-.infin., (norm), C.sub.max and
C.sub.max (norm) were generally similar in male and female subjects
following a 5-minute infusion.
[0239] Mean values for MRT.sub.int, CL, V.sub.z and V.sub.ss were
similar across the 0.03 to 0.09 mg/kg dose range in male subjects,
which was confirmed by statistical analysis. Mean values for each
parameter were also similar for male and female subjects at the
0.06 mg/kg dose level.
[0240] In general, low between-subject variability was noted for
AUC.sub.0-.infin. and C.sub.max in male subjects, with CV % values
ranging from 11.8 to 16.4% and 19.6% to 32.2%, respectively. Across
all doses in male subjects, the pooled between-subject variability
for AUC.sub.0-.infin. and C.sub.max was 15.3% and 24.1%,
respectively. The between-subject variability for AUC.sub.0-.infin.
and C.sub.max was also low in female subjects at the 0.24 mg/kg
dose level, with CV % values of 8.8% and 18.8%, respectively.
[0241] The urinary excretion of CR665 following a 5-minute infusion
in male and female subjects is summarized in Table 12:
TABLE-US-00013 TABLE 12 Summary of the Urinary Excretion of CR665
Following a 5-minute IV Infusion in Male and Female Subjects (Part
B) Dose of (mg/kg) 0.03 0.06 0.09 0.06 [males] [males] [males]
[females] Parameter (N = 3) (N = 4) (N = 4) (N = 3) Ae.sub.0-24 h
70.0 157 262 153 (.mu.g) (27.3) (25.8) (13.5) (16.9) fe.sub.0-24 h
3.60 3.33 3.56 3.83 (%) (29.6) (27.6) (7.29) (24.0) CL.sub.R 0-24 h
17.1 18.4 20.5 20.9 (mL/min) (22.7) (24.6) (12.0) (17.7) Geometric
mean (CV %) data are presented N = Number of subjects studied
[0242] In male subjects, the fraction of the dose excreted in the
urine as unchanged drug was low for all dose levels, with
approximately 3.5% being eliminated up to 24 hours post-dose. The
fraction of unchanged drug excreted in the urine was also low in
female subjects (3.8%), and similar to male subjects.
[0243] The amount of CR665 excreted in the urine increased in a
dose proportional manner over the dose range studied in male
subjects. This was confirmed by statistical analysis, with the
slopes of the regression not being significantly different from
unity. Renal clearance was generally low and similar across all
dose levels, with dose independence being confirmed by statistical
analysis.
[0244] The results of the statistical analyses to assess the effect
of infusion time on the pharmacokinetic parameters of CR665 in male
subjects are presented in Table 13.
TABLE-US-00014 TABLE 13 Statistical Analysis of the Effect of
Infusion Time on the Pharmacokinetic Parameters for CR665 in Male
Subjects (Parts A & B) Geometric least Ratio of squares means
geometric least 5-minute 1-hour squares means 90% CI for the 95% CI
for the Parameter infusion infusion 5-minute:1-hour ratio ratio
AUC.sub.0-t 2286 2238 1.02 0.957 to 1.09 0.944 to 1.11 (norm)
AUC.sub.0-.infin. 2343 2260 1.04 0.971 to 1.11 0.957 to 1.12 (norm)
C.sub.max 9002 2003 4.49 3.98 to 5.08 3.87 to 5.22 (norm) t.sub.1/2
1.28 1.25 1.02 0.804 to 1.29 0.762 to 1.37 (h) MRT.sub.int 0.558
0.605 0.923 0.817 to 1.04 0.794 to 1.07 (h) CL 538 557 0.964 0.903
to 1.03 0.889 to 1.05 (mL/min) V.sub.z 61.0 59.1 1.03 0.825 to 1.29
0.784 to 1.36 (L) V.sub.ss 18.1 20.1 0.900 0.804 to 1.01 0.783 to
1.03 (L) fe.sub.0-24 h 3.48 3.46 1.01 0.908 to 1.12 0.887 to 1.15
(%) (norm) = Normalized for dose and body weight (mg/kg)
[0245] In male subjects, the following pharmacokinetic parameters
for CR665 were similar following an IV infusion time of 1-hour
versus 5-minutes: AUC.sub.0-.infin., AUC.sub.0-t, t.sub.1/2, CL,
V.sub.z, V.sub.ss, and fe.sub.0-24 h, suggesting that the overall
systemic exposure to CR665, based upon AUC and disposition
kinetics, were not affected by the different infusion times. The
only parameter, however, for which the statistical analysis
confirmed a significant difference was C.sub.max, which was, as
expected, approximately 4.5-fold higher for the 5-minute compared
to the 1-hour infusion.
[0246] The statistical analyses of the effect of infusion time on
the pharmacokinetic parameters of CR665 in female subjects are
presented in Table 14.
TABLE-US-00015 TABLE 14 Statistical Analysis of the Effect of
Infusion Time on the Pharmacokinetic Parameters for CR665 in Female
Subjects Geometric least Ratio of squares means geometric least
5-minute 1-hour squares means 90% CI for the 95% CI for the
Parameter infusion infusion 5-minute:1-hour ratio ratio AUC.sub.0-t
2013 1936 1.04 0.918 to 1.18 0.893 to 1.21 (norm) AUC.sub.0-.infin.
2044 1943 1.05 0.928 to 1.19 0.903 to 1.23 (norm) C.sub.max 8716
1655 5.27 4.17 to 6.66 3.96 to 7.01 (norm) t.sub.1/2 0.946 1.05
0.901 0.606 to 1.34 0.554 to 1.47 (h) MRT.sub.int 0.430 0.498 0.864
0.708 to 1.06 0.677 to 1.10 (h) CL 544 573 0.950 0.837 to 1.08
0.813 to 1.11 (mL/min) V.sub.z 45.7 50.2 0.911 0.628 to 1.32 0.577
to 1.44 (L) V.sub.ss 14.1 17.0 0.832 0.692 to 1.00 0.664 to 1.04
(L) fe.sub.0-24 h 3.83 2.70 1.42 1.16 to 1.73 1.11 to 1.81 (%)
(norm) = Normalized for dose and body weight (mg/kg)
[0247] In female subjects, the following pharmacokinetic parameters
for CR665 were similar following an IV infusion time of 1-hour
versus 5-minutes: AUC.sub.0-.infin., AUC.sub.0-t, t.sub.1/2, CL,
V.sub.z, V.sub.ss, and fe.sub.0-24 h suggesting that the overall
systemic exposure to CR665, based upon AUC and disposition
kinetics, were not affected by the different infusion times.
However, as would be expected, C.sub.max was significantly higher
(5.3-fold) for the 5-minute compared to the 1-hour infusion. These
findings reinforce the predictability of the pharmacokinetics of
CR665, which aids the skilled practitioner in the design of drug
administration protocols that are designed to achieve a particular
level of systemic exposure to drug without undue
experimentation.
Pharmacodynamic
Pharmacokinetic Relationship
[0248] The relationship between pharmacodynamic parameters of serum
prolactin (changes from baseline) and pharmacokinetic parameters of
CR665 following IV infusions of 0.015 to 0.36 mg/kg in male
subjects is presented in FIGS. 13 and 14.
[0249] In Part A, there was a direct linear correlation between
serum concentrations of prolactin (based on AUC.sub.0-12 h and
C.sub.max) and the plasma concentration of CR665 (based on
AUC.sub.0-.infin. and C.sub.max) over the 0.015 to 0.36 mg/kg dose
range following a 1-hour infusion in male subjects, with
correlation coefficients of 0.667 and 0.565 for AUC and C.sub.max
values, respectively. The AUC.sub.0-12 h and C.sub.max values for
serum prolactin appeared to plateau at higher AUC.sub.0-.infin. and
C.sub.max values for CR665 associated with dose levels of 0.36 to
0.48 mg/kg, indicating that the maximum increase in serum prolactin
had been achieved by 0.36 mg/kg CR665 administered as a 1-hour
infusion.
[0250] In Part B, there was no apparent correlation between serum
prolactin concentrations and plasma CR665 concentrations in male
subjects following a 5-minute infusion. A likely cause of the
absence of a correlation is the temporal dissociation of
pharmacokinetics and pharmacodynamics in these subjects: while
plasma CR665 concentrations peaked at the end of the 5-minute
infusion and declined thereafter, serum prolactin concentrations
only began to significantly rise at 10 minutes (5 minutes after the
end of the infusion), and continued to rise at 30 minutes, with
substantial but declining levels measured at 60 minutes. Under
these conditions, a correlation between plasma CR665 concentrations
and serum prolactin concentrations would not be expected. However,
with longer (e.g., 1 hour) infusions of CR665, the plasma
concentration of CR665 may better reflect the concentration of
CR665 in the pharmacodynamically relevant compartment (i.e., high
affinity kappa opioid receptors), and thereby yield the significant
linear relationship shown in FIGS. 13 and 14.
[0251] Following administration of 0.015 to 0.48 mg/kg CR665 as a
1-hour infusion in male subjects, AUC.sub.0-.infin. and C.sub.max
increased in a dose-proportional manner over the entire dose range.
The between-subject variability in the pharmacokinetics of CR665
was low in male subjects.
[0252] In female subjects, maximum plasma concentrations of CR665
occurred at the end of the 1-hour infusion period following a 0.24
mg/kg dose, which was similar to male subjects. The systemic
exposure of CR665, based on AUC.sub.0-.infin. and C.sub.max, was
similar in male and female subjects. The disposition of CR665 was
also similar between genders, with a mean terminal elimination
half-life of 1.2 hours in female subjects. Furthermore, similar
between-subject variability was observed in male and female
subjects.
[0253] The duration of infusion had no effect on the overall
systemic exposure to CR665, with AUC.sub.0-.infin. being similar
following the 1-hour and 5-minute infusions in both male and female
subjects. However, maximum plasma concentrations of CR665 were
notably higher following the 5-minute infusion compared to the
1-hour infusion, being approximately 4.5-fold higher in male
subjects and 5.3-fold higher in female subjects. The difference in
C.sub.max was expected because of the higher rate of infusion used
for the 5-minute infusion (360 mL/hour) compared to the 1-hour
infusion (30 mL/hour). The disposition kinetics of CR665 was
similar for the 1-hour and 5-minute infusion, and low
between-subject variability was observed for both infusion
times.
[0254] The apparent volume of distribution at steady state
(V.sub.ss) of CR665 in male subjects ranged from 19 to 23 L over
the 0.12 to 0.48 mg/kg dose range, which is similar to the volume
of extracellular fluid, and is consistent for a peptide with
limited ability to penetrate lipid-containing membranes. This
observation reflects another aspect of the present invention: a
relatively low volume of distribution. The volume of distribution
is a quantitative measure of the extent of distribution of drug
outside the vasculature; it is the apparent volume which would
contain the entire amount of drug in the body at the same
concentration it is present in the blood. In general, a compound
with a low volume of distribution will have physical
characteristics that impede transport across biological membranes.
Thus, a polar compound with a low apparent volume of distribution,
such as CR665, would not be expected to cross the blood-brain
barrier as well as lipid-soluble compounds that typically have a
higher apparent volume of distribution, and a greater propensity to
cross the blood-brain barrier.
[0255] All patents and other references cited herein are hereby
incorporated by reference.
[0256] Other embodiments are within the following claims.
* * * * *