U.S. patent application number 13/648946 was filed with the patent office on 2013-04-11 for use of aminolevulinic acid and derivatives thereof.
This patent application is currently assigned to Photocure ASA. The applicant listed for this patent is Photocure ASA. Invention is credited to Aslak Godal, Jo Klaveness, Hans Christian WULF.
Application Number | 20130090592 13/648946 |
Document ID | / |
Family ID | 37809842 |
Filed Date | 2013-04-11 |
United States Patent
Application |
20130090592 |
Kind Code |
A1 |
WULF; Hans Christian ; et
al. |
April 11, 2013 |
USE OF AMINOLEVULINIC ACID AND DERIVATIVES THEREOF
Abstract
The invention provides the use of a photosensitiser which is
5-aminolevulinic acid (5-ALA) or a derivative (e.g. an ester) of
5-ALA, or a pharmaceutically acceptable salt thereof, in the
manufacture of a composition for use in methods of photodynamic
therapy (PDT) on an animal, wherein said PDT comprises: (a)
administering to said animal a composition comprising said
photosensitiser; and (b) photoactivating said photosensitiser, and
wherein side-effects (e.g. pain and/or erythema) of said PDT are
prevented or reduced by use of one or more of (i)-(iv): (i) said
composition comprises said photosensitiser in a concentration of
less than 10% wt (e.g. 0.5 to 8% wt), (ii) said composition is
administered for less than 2 hours (e.g. 30 minutes to 90 minutes)
prior to said photoactivation, (iii) said photoactivation is
carried out with a light source having a fluence rate of less than
50 mW/cm.sup.2 (e.g. 5 to 40 mW/cm.sup.2), (iv) said
photoactivation is carried out with sunlight. Preferably,
side-effects of PDT are prevented or reduced by using (iii) or (iv)
in combination with (i) and/or (ii).
Inventors: |
WULF; Hans Christian;
(Espergerde, DK) ; Godal; Aslak; (Oslo, NO)
; Klaveness; Jo; (Oslo, NO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Photocure ASA; |
Oslo |
|
NO |
|
|
Assignee: |
Photocure ASA
Oslo
NO
|
Family ID: |
37809842 |
Appl. No.: |
13/648946 |
Filed: |
October 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12523048 |
Jan 12, 2010 |
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PCT/GB2008/000086 |
Jan 11, 2008 |
|
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13648946 |
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Current U.S.
Class: |
604/20 |
Current CPC
Class: |
A61K 31/221 20130101;
A61P 31/04 20180101; A61P 17/06 20180101; A61P 35/00 20180101; A61P
29/00 20180101; A61P 31/22 20180101; A61P 31/10 20180101; A61N
2005/0662 20130101; A61P 17/00 20180101; A61P 15/02 20180101; A61N
2005/0663 20130101; A61N 5/062 20130101; A61N 5/0616 20130101; A61P
31/00 20180101; A61P 17/10 20180101; A61N 2005/0652 20130101; A61P
31/12 20180101; A61P 17/02 20180101; A61K 41/0061 20130101 |
Class at
Publication: |
604/20 |
International
Class: |
A61K 41/00 20060101
A61K041/00; A61N 5/06 20060101 A61N005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2007 |
GB |
0700580.4 |
Claims
1.-44. (canceled)
45. A method of reducing or preventing side-effects in the
photodynamic treatment of acne comprising: (a) administering to an
area characterized by acne on a patient in need of such treatment a
composition comprising methyl ALA ester at a concentration of less
than 10%, or the equivalent concentration of a pharmaceutically
acceptable salt, for a period of less than 2 hours, and (b)
administering photoactivating light to the affected area.
46. The method of claim 45, wherein the administered compound is
methyl ALA ester hydrochloride salt.
47. The method of claim 45, wherein the concentration of methyl ALA
ester is in the range from 0.5 to 8%, or the equivalent
concentration of a pharmaceutically acceptable salt.
48. The method of claim 47, wherein the concentration of methyl ALA
ester is in the range from 2 to 8%, or the equivalent concentration
of a pharmaceutically acceptable salt.
49. The method of claim 48, wherein the concentration of methyl ALA
ester is 8%, or the equivalent concentration of a pharmaceutically
acceptable salt.
50. The method of claim 45, wherein the administered compound is
methyl ALA ester hydrochloride salt.
51. The method of claim 45, wherein the composition is a cream.
52. The method of claim 45, wherein the composition is administered
for a period of 5 to 90 minutes.
53. The method of claim 52, wherein the composition is administered
for a period of 30 to 90 minutes.
54. The method of claim 53, wherein the composition is administered
for a period of 90 minutes.
55. The method of claim 45, wherein the photoactivating light has a
peak wavelength in the range 631 to 637 nm.
56. The method of claim 45, wherein the total light dosage is about
37 J/cm.sup.2.
57. The method of claim 45, wherein the photoactivating light has a
fluence rate of about 21 to about 74 mW/cm.sup.2.
58. The method of claim 45, wherein the light is provided by an LED
lamp.
Description
[0001] This invention relates to photodynamic therapy (PDT), and in
particular to the use of 5-aminolevulinic acid (5-ALA) and
derivatives of 5-ALA in PDT wherein the side-effects (e.g. pain
and/or erythema) of PDT are prevented or reduced.
[0002] PDT, or photochemotherapy as it is also known, is a
technique for the treatment of various abnormalities or disorders
of the skin or other epithelial organs or mucosa, especially
cancers or pre-cancerous lesions, as well as certain non-malignant
lesions (e.g. skin complaints such as psoriasis, actinic keratoses
(AK) and acne). PDT involves the application of photosensitizing
(photochemotherapeutic) agents to the affected area of the body,
followed by exposure to photoactivating light in order to activate
the photosensitizing agents and convert them into cytotoxic form,
whereby the affected cells are killed or their proliferative
potential diminished.
[0003] A range of photosensitizing agents are known, including the
psoralens, the porphyrins (e.g. Photofrin.RTM.), the chlorins and
the phthalocyanins. Amongst the most clinically useful
photosensitizing agents known in the art, however, are
5-aminolevulinic acid and its derivatives, for example esters such
as 5-ALA esters.
[0004] Although PDT with 5-ALA and 5-ALA derivatives is clinically
useful in the treatment of a wide range of diseases, a major draw
back of such treatment is the concomitant side-effects,
particularly at the treatment site. These often include pain,
erythema, swelling, edema, burning, itching, exfoliation,
hyperpigmentation and prolonged irritation and hypersensitivity
after treatment. Such side-effects are particularly undesirable
when the treatment site is the face, scalp or neck. This is
frequently the case when the PDT is for the treatment of lesions.
(e.g. acne, basal cell carcinoma, actinic keratosis, squamous cell
carcinoma).
[0005] The occurrence of such side effects is recognised in
WO2006/051269 which discloses use of 5-ALA esters in PDT for the
treatment of acne. WO2006/051269 describes a study wherein a cream
comprising 16% wt methyl ALA ester is applied to the faces of
subjects for 3 hours followed by exposure of the subjects' faces to
non-coherent red light (light dose 37 Jcm.sup.-2). The treatment
was then repeated 2 weeks later. Although the results confirmed
that PDT with methyl ALA ester is effective in the treatment of
acne, the subjects also indicated that the treatment caused some
pain.
[0006] WO02/13788 discloses a similar study on use of ALA acid in
PDT for the treatment of acne. In this case 20% ALA acid was
applied to the backs of the subjects for 3 hours and then the
subjects were exposed to 150 J/cm.sup.2 broad band light. Again the
results confirmed that PDT with ALA is effective for the treatment
of acne, but the subjects also reported a plethora of undesirable
side effects. For example, WO02/13788 reports that erythema,
hyperpigmentation and exfoliation were often seen after PDT
treatment and states that in some cases a subsequent treatment even
had to be postponed. Reports of pain, burning and itching during
and after treatment were also common.
[0007] WO02/13788 describes the above-described treatment regime as
a "high dose, high energy" regime and it is said to provide a
permanent improvement to acne. WO02/13788 additionally discloses a
"low dose, low energy" regime that is said to be designed to
provide relief from acne. In this treatment 0.1 to 10% wt ALA acid
is applied, and after waiting for the ALA acid to penetrate the
skin, is followed by irradiation with a light dose of 1 to 20
J/cm.sup.2. WO02/13788 suggests that this regime be used in
occasional multiple treatments to alleviate acne and be repeated as
necessary to maintain diminishment thereof. Although it is
recognised that use of such a regime may be pain free, the
implication in WO02/13788 is that the therapeutic effect of this
treatment regime is less than the high dose, high energy regime it
describes and exemplifies.
[0008] A need still therefore exists for alternative PDT methods
that are free from undesirable side effects (e.g. pain) but which
have high therapeutic efficacy.
[0009] It has now surprisingly been found that substantially pain
free (e.g. pain free), therapeutically acceptable, PDT can be
achieved by modifying the photosensitiser-composition used in the
PDT and/or altering the PDT procedure.
[0010] Thus viewed from a first aspect the invention provides the
use of a photosensitiser which is 5-aminolevulinic acid (5-ALA) or
a derivative (e.g. an ester) of 5-ALA, or a pharmaceutically
acceptable salt thereof, in the manufacture of a composition for
use in photodynamic therapy (PDT) on an animal, wherein said PDT
comprises: [0011] (a) administering to said animal a composition
comprising said photosensitiser; and [0012] (b) photoactivating
said photosensitiser, and side-effects (e.g. pain and/or erythema)
of said PDT are prevented or reduced by use of one or more of
(i)-(iv): [0013] (i) said composition comprises said
photosensitiser in a concentration of less than 10% wt (e.g. 0.5 to
8% wt), [0014] (ii) said composition is administered for less than
2 hours (e.g. 30 minutes to 90 minutes) prior to said
photoactivation, [0015] (iii) said photoactivation is carried out
with a light source having a fluence rate of less than 50
mW/cm.sup.2 (e.g. 5 to 40 mW/cm.sup.2), [0016] (iv) said
photoactivation is carried out with sunlight.
[0017] Viewed from a further aspect, the invention provides a
method of preventing or reducing side-effects (e.g. pain and/or
erythema) of photodynamic therapy (PDT) in an animal, wherein said
PDT comprises: [0018] (a) administering to said animal a
composition comprising a photosensitiser as hereinbefore defined;
and [0019] (b) photoactivating said photosensitiser, and
side-effects of said PDT are prevented or reduced by use of one or
more of (i)-(iv): [0020] (i) said composition comprises said
photosensitiser in a concentration of less than 10% wt (e.g. 0.5 to
8% wt), [0021] (ii) said composition is administered for less than
2 hours (e.g. 30 minutes to 90 minutes) prior to said
photoactivation, [0022] (iii) said photoactivation is carried out
with a light source having a fluence rate of less than 50
mW/cm.sup.2 (e.g. 5 to 40 mW/cm.sup.2), [0023] (iv) said
photoactivation is carried out with sunlight.
[0024] In a particularly preferred aspect of the invention,
side-effects of PDT are prevented or reduced by use of (iii) or
(iv) in combination with one or both of (i) and (ii).
[0025] In preferred uses and methods of the invention, the PDT has
substantially the same therapeutic effect as the corresponding
standard PDT treatment.
[0026] By the term "animal" is meant herein any human or non-human
being. Preferred animals for treatment in accordance with the
invention are humans.
[0027] The use of 5-ALA and derivatives of 5-ALA
(5-amino-4-oxo-pentanoic acid, otherwise known as 5-aminolevulinic
acid) in PDT is well known in the scientific and patent literature
(see, for example, J. C. Kennedy et al., J. Clin. Laser Med. Surg.
(1996) 14: 289-304, U.S. Pat. No. 5,079,262, U.S. Pat. No.
5,211,938, U.S. Pat. No. 5,234,940, U.S. Pat. No. 5,422,093, U.S.
Pat. No. 6,034,267, WO91/01727, WO96/28412, WO2005/092838 and
WO2006/051269, the contents of which are incorporated herein by
reference). 5-ALA and all such derivatives of 5-ALA, as well as
their pharmaceutically acceptable salts, are suitable for the uses
and methods herein described.
[0028] The 5-ALA derivatives useful in accordance with the
invention maybe any derivative of 5-ALA capable of forming
protoporphyrin IX (PpIX) or any other photosensitiser (e.g. a PpIX
derivative) in vivo. Typically, such derivatives will be a
precursor of PpIX or of a PpIX derivative (e.g. a PpIX ester) in
the biosynthetic pathway for haem and which are therefore capable
of inducing an accumulation of PpIX at the site to be treated
following administration in vivo. Suitable precursors of PpIX or
PpIX derivatives include 5-ALA prodrugs which might be able to form
5-ALA in vivo as an intermediate in the biosynthesis of PpIX or
which may be converted (e.g. enzymatically) to porphyrins without
forming 5-ALA as an intermediate. 5-ALA esters are among the
preferred compounds for use in the methods herein described.
[0029] Esters of 5-aminolevulinic acid and N-substituted
derivatives thereof are preferred photosensitisers for use in the
invention. Those compounds in which the 5-amino group is
unsubstituted (i.e. the ALA esters) are particularly preferred.
Such compounds are generally known and described in the literature
(see, for example, WO96/28412, WO02/10120 and WO2005/092838 to
PhotoCure ASA, the contents of which are incorporated herein by
reference).
[0030] Esters of 5-aminolevulinic acid with substituted or
unsubstituted alkanols, i.e. alkyl esters are especially preferred
photosensitisers for use in the invention. Examples of such
compounds include those of general formula I:
R.sup.2.sub.2N--CH.sub.2COCH.sub.2--CH.sub.2CO--OR.sup.1 (I)
(wherein R.sup.1 represents a substituted or unsubstituted
straight-chained, branched or cyclic alkyl group (e.g. a
substituted or unsubstituted straight-chained alkyl group); and
each R.sup.2 independently represents a hydrogen atom or an
optionally substituted alkyl group, e.g. a group R.sup.1) and
pharmaceutically acceptable salts thereof.
[0031] As used herein, the term "alkyl", unless stated otherwise,
includes any long or short chain, cyclic, straight-chained or
branched aliphatic saturated or unsaturated hydrocarbon group. The
unsaturated alkyl groups may be mono- or polyunsaturated and
include both alkenyl and alkynyl groups. Unless stated otherwise,
such groups may contain up to 40 atoms. However, alkyl groups
containing up to 30, preferably up to 10, particularly preferably
up to 8, especially preferably up to 6, e.g. up to 4 carbon atoms
are preferred.
[0032] The substituted alkyl R.sup.1 and R.sup.2 groups may be mono
or poly-substituted. Suitable substituents may be selected from
hydroxy, alkoxy, acyloxy, alkoxycarbonyloxy, amino, aryl, nitro,
oxo, fluoro, --SR.sub.3, --NR.sup.3.sub.2 and --PR.sup.3.sub.2
groups, and each alkyl group may be optionally interrupted by one
or more --O--, --NR.sub.3--, --S-- or --PR.sub.3-- groups, in which
R.sup.3 is a hydrogen atom or a C.sub.1-6 alkyl group).
[0033] Preferred substituted alkyl R.sup.1 groups include those
carrying one or more oxo groups, preferably straight-chained
C.sub.4-12 alkyl (e.g. C.sub.8-10 alkyl) groups substituted by one,
two or three (preferably two or three) oxo groups. Examples of such
groups include 3,6-dioxa-1-octyl and 3,6,9-trioxa-1-decyl
groups.
[0034] Particularly preferred for use in the invention are those
compounds of formula I in which at least one R.sup.2 represents a
hydrogen atom. In especially preferred compounds each R.sup.2
represents a hydrogen atom.
[0035] Compounds of formula I in which R.sup.1 represents an
unsubstituted alkyl group (preferably C.sub.1-8 alkyl, e.g.
C.sub.1-6 alkyl) or an alkyl group (e.g. C.sub.1-2 alkyl,
especially C.sub.1 alkyl) substituted by a substituent as
hereinbefore defined (e.g. by an aryl group such as phenyl or by an
alkoxy group such as methoxy) are also preferred.
[0036] Unsubstituted alkyl groups which may be used in the
invention include both branched and straight-chained hydrocarbon
groups. Compounds of formula I in which R.sup.1 is a C.sub.4-8
preferably a C.sub.5-8, straight chain alkyl group which is
branched by one or more C.sub.1-6 (e.g. C.sub.1-2 alkyl) groups are
preferred. Representative examples of suitable unsubstituted
branched alkyl groups include 2-methylpentyl, 4-methylpentyl,
1-ethylbutyl and 3,3-dimethyl-1-butyl. 4-methylpentyl is
particularly preferred.
[0037] Compounds of formula I in which R.sup.1 is a C.sub.1-10
straight-chained alkyl group are also preferred. Representative
examples of suitable unsubstituted alkyl groups include methyl,
ethyl, propyl, butyl, pentyl, hexyl and octyl (e.g. n-propyl,
n-butyl, n-pentyl, n-hexyl and n-octyl). Hexyl, especially n-hexyl,
is a particularly preferred group. Methyl is also particularly
preferred.
[0038] Also preferred for use in the invention are those compounds
of formula I in which R.sup.1 represents a C.sub.1-2 alkyl group
(preferably a C.sub.1 alkyl group) optionally substituted by an
aryl group.
[0039] Still further preferred for use in the invention are those
compounds of formula I in which R.sup.1 represents an alkyl group
(e.g. C.sub.1-2 alkyl, especially C.sub.1 alkyl) substituted by an
aryl group (e.g. phenyl). Preferred substituted alkyl R.sup.1
groups which may be present in compounds of formula I include
C.sub.1-6 alkyl, preferably C.sub.1-4 alkyl, particularly
preferably C.sub.1 or C.sub.2 alkyl (e.g. C.sub.1 alkyl)
substituted (preferably terminally substituted) by an optionally
substituted aryl group.
[0040] By an "aryl group" is meant a group which is aromatic.
Preferred aryl groups comprise up to 20 carbon atoms, more
preferably up to 12 carbon atoms, for example, 10 or 6 carbon
atoms.
[0041] Aryl groups which may be present in the compounds of the
invention may be heteroaromatic (e.g. 5-7 membered heteroaromatics)
but are preferably non-heteroaromatic. By "non-heteroaromatic" is
meant an aryl group having an aromatic system comprising electrons
originating solely from carbon atoms. Preferred aryl groups include
phenyl and napthyl, especially phenyl. In preferred compounds for
use in the invention one or two aryl groups may be present,
preferably one.
[0042] Aryl groups which may be present in the compounds of the
invention may optionally be substituted by one or more (e.g. 1 to
5), more preferably one or two, groups (e.g. one group). Preferably
the aryl group is substituted at the meta or para position, most
preferably the para position. Suitable substituent groups may
include haloalkyl (e.g. trifluoromethyl), alkoxy (i.e. --OR groups
wherein R is preferably a C.sub.1-6 alkyl group), halo (e.g. iodo,
bromo, more especially chloro and fluoro), nitro and C.sub.1-6
alkyl (preferably C.sub.1-4 alkyl). Preferred C.sub.1-6 alkyl
groups include methyl, isopropyl and t-butyl, particularly methyl.
Particularly preferred substituent groups include chloro and nitro.
Still more preferably the aryl group is unsubstituted.
[0043] In a further preferred aspect the invention provides the use
of a photo sensitiser which is a compound of formula I wherein
R.sup.1 represents an aryl substituted C.sub.1-4 alkyl group
(preferably C.sub.1-2, e.g. C.sub.1), preferably wherein said aryl
group comprises up to 20 carbon atoms (e.g. up to 12 carbon atoms,
especially 6 carbon atoms) and is itself optionally substituted,
and each R.sup.2 is as hereinbefore defined (e.g. each R.sup.2 is
hydrogen), or a pharmaceutically acceptable salt thereof in the
manufacture of a medicament for use in PDT.
[0044] Preferred compounds for use in the invention include methyl
ALA ester, ethyl ALA ester, propyl ALA ester, butyl ALA ester,
pentyl ALA ester, hexyl ALA ester, octyl ALA ester, 2-methoxyethyl
ALA ester, 2-methylpentyl ALA ester, 4-methylpentyl ALA ester,
1-ethylbutyl ALA ester, 3,3-dimethyl-1-butyl ALA ester, benzyl ALA
ester, 4-isopropylbenzyl ALA ester, 4-methylbenzyl ALA ester,
2-methylbenzyl ALA ester, 3-methylbenzyl ALA ester,
4-[t-butyl]benzyl ALA ester, 4-[trifluoromethyl]benzyl ALA ester,
4-methoxybenzyl ALA ester, 3,4-[di-chloro]benzyl ALA ester,
4-chlorobenzyl ALA ester, 4-fluorobenzyl ALA ester, 2-fluorobenzyl
ALA ester, 3-fluorobenzyl ALA ester, 2,3,4,5,6-pentafluorobenzyl
ALA ester, 3-nitrobenzyl ALA ester, 4-nitrobenzyl ALA ester,
2-phenylethyl ALA ester, 4-phenylbutyl ALA ester,
3-pyridinyl-methyl ALA ester, 4-diphenyl-methyl ALA ester and
benzyl-5-[(1-acetyloxyethoxy)-carbonyl]amino levulinate.
[0045] Still further preferred compounds for use in the invention
include methyl ALA ester, ethyl ALA ester, 2-methoxyethyl ALA
ester, benzyl ALA ester, 4-isopropylbenzyl ALA ester,
4-methylbenzyl ALA ester, 2-methylbenzyl ALA ester, 3-methylbenzyl
ALA ester, 4-[t-butyl]benzyl ALA ester, 4-[trifluoromethyl]benzyl
ALA ester, 4-methoxybenzyl ALA ester, 3,4-[di-chloro]benzyl ALA
ester, 4-chlorobenzyl ALA ester, 4-fluorobenzyl ALA ester,
2-fluorobenzyl ALA ester, 3-fluorobenzyl ALA ester,
2,3,4,5,6-pentafluorobenzyl ALA ester, 3-nitrobenzyl ALA ester,
4-nitrobenzyl ALA ester, 2-phenylethyl ALA ester, 4-phenylbutyl ALA
ester, 3-pyridinyl-methyl ALA ester, 4-diphenyl-methyl ALA ester
and benzyl-5-[(1-acetyloxyethoxy)-carbonyl]amino levulinate
[0046] Particularly preferred compounds for use in the invention
include methyl ALA ester, hexyl ALA ester and benzyl ALA ester,
especially methyl ALA ester.
[0047] The compounds for use in the invention may be prepared by
any conventional procedure available in the art (e.g. as described
in WO02/10120 to PhotoCure ASA). For example, esters of 5-ALA may
be prepared by reaction of 5-ALA with the appropriate alcohol in
the presence of acid. Alternatively compounds for use in the
invention may be available commercially (e.g. from Photocure ASA,
Norway).
[0048] The compounds for use according to the invention may be in
the form of a free amine (e.g. --NH.sub.2, --NHR.sup.2 or
--NR.sup.2R.sup.2) or preferably in the form of a physiologically
acceptable salt. Such salts preferably are acid addition salts with
physiologically acceptable organic or inorganic acids. Suitable
acids include, for example, hydrochloric, nitric, hydrobromic,
phosphoric, sulphuric, sulphonic and sulphonic acid derivatives.
Hydroiodic acids may also be suitable. Particularly preferred salts
are acid addition salts with hydrochloric acid and sulphonic acid
derivatives (e.g. mesylate or tosylate) as described in
WO2005/092838 to PhotoCure ASA, the entire contents of which are
incorporated herein by reference. Procedures for salt formation are
conventional in the art.
[0049] In the uses and methods of the invention a single
photosensitiser as hereinbefore defined (i.e. 5-ALA or a derivative
of 5-ALA) may be used alone in PDT. Alternatively, a combination of
two or more, preferably two, photosensitisers may be used wherein
at least one of the photosensitisers is selected from 5-ALA and
derivatives of 5-ALA, or a pharmaceutically acceptable salt
thereof.
[0050] Other photosensitisers which may be formulated with 5-ALA or
a derivative of 5-ALA (e.g. a 5-ALA ester) or co-administered in
accordance with the invention include:
[0051] Hematoporphyrin derivative (HpD);
[0052] Hematoporphyrins such as Photofrin.RTM. (Quadra Logic
Technologies Inc., Vancouver, Canada) and Hematoporphyrin IX
(HpIX);
[0053] Photosan III (Seehof Laboratorium GmbH, Seehof,
Wesselburenerkoog, Germany);
[0054] Chlorins such as tetra(m-hydroxyphenyl)chlorins (m-THPC) and
their bacteriochlorins (Scotia Pharmaceuticals Ltd, Surrey, UK),
mono-L-aspartyl chlorin e6 (NPe6) (Nippon Petrochemical Co., CA,
USA), chlorin e6 (Porphyrin Products Inc.), benzoporphyrins (Quadra
Logic Technologies Inc., Vancouver, Canada) (e.g. benzoporphyrin
derivative monoacid ring A, BPD-MA) and purpurines (PDT
Pharmaceuticals Inc., CA, USA) (e.g. tin-ethyl etiopurpurin,
SnET2);
[0055] phthalocyanines (e.g. zinc-(Quadra Logic Technologies Inc.,
Vancouver, Canada), some aluminium- or silicon phthalocyanines,
which may be sulfonated, in particular sulfonated phthalocyanines
such as aluminium phthalocyanine di-sulfonate (A1PcS.sub.2a) or
aluminium phthalocyanine tetra-sulfonate (Al PcS.sub.4));
[0056] porphycenes;
[0057] hypocrellins;
[0058] Protoporphyrin IX (PpIX);
[0059] Hematoporphyrin di-ethers;
[0060] Uroporphyrins;
[0061] Coproporphyrins;
[0062] Deuteroporphyrin;
[0063] Polyhematoporphyrin (PHP), and precursors and derivatives
thereof; and
[0064] antibiotics such as tetracycline (e.g. Topicycline.RTM.,
Shire).
[0065] Preferably the second photosensitiser will be a
Hematoporphyrin (e.g. Photofrin.RTM.), a chlorin (particularly
m-THPC or chlorin e6) or a sulphonated phthalocyanine (particularly
aluminium phthalocyanine di-sulfonate or aluminium phthalocyanine
tetra-sulfonate).
[0066] If a second photosensitiser is used together with 5-ALA or
5-ALA derivatives according to the uses and methods of the present
invention, the PDT conditions still preferably ensure that few, if
any, side effects of treatment occur. This may be achieved by use
of at least one of (i)-(iv) as hereinbefore described and
optionally a low dose (e.g. sub-therapeutic dose) of the second
photosensitiser.
[0067] Thus in a further aspect the invention provides the use of a
first photosensitiser which is 5-ALA or a derivative of 5-ALA as
hereinbefore defined, or a pharmaceutically acceptable salt
thereof, together with a second photosensitiser in the manufacture
of a composition for use in PDT as hereinbefore defined.
[0068] Furthermore the compounds for use according to the invention
may be formulated and/or administered with other active components
which are able to increase the photosensitizing effect and thus
enhance the PDT. For example, chelating agents may beneficially be
included and/or co-administered in order to enhance the
accumulation of Pp; the chelation of iron by the chelating agent
prevents its incorporation into Pp to form haem by the action of
the enzyme ferrochelatase, thereby leading to a build-up of Pp. The
photosensitizing effect is thus enhanced.
[0069] Suitable chelating agents include aminopolycarboxylic acids,
including any of the chelants described in the literature for metal
detoxification or for the chelation of paramagnetic metal ions in
magnetic resonance imaging contrast agents. Particular mention
maybe made of EDTA, CDTA (cyclohexane diamine tetraacetic acid),
DTPA and DOTA and well known derivatives/analogues thereof EDTA and
DTPA are particularly preferred. To achieve the iron-chelating
effect, desferrioxamine and other siderophores may also be used,
e.g. in conjunction with aminopolycarboxylic acid chelating agents
such as EDTA.
[0070] Where present, the chelating agent may conveniently be used
at a concentration of 0.05 to 20%, e.g. 0.1 to 10% (w/w).
[0071] Penetration enhancers may also have a beneficial effect in
enhancing the photosensitizing effect of the compounds for use in
the invention. Surface-penetration assisting agents, especially
dialkylsuphoxides such as dimethylsulphoxide (DMSO), may therefore
also be included in the compositions for use in the invention
and/or co-administered. The surface-penetration assisting agent may
be any of the skin-penetration assisting agents described in the
pharmaceutical literature e.g. chelators (e.g. EDTA), surfactants
(e.g. sodium dodecyl sulphate), non-surfactants, bile salts (e.g.
sodium deoxycholate) and fatty acids (e.g. oleic acid). Examples of
appropriate surface penetrating assisting agents include
isopropanol, HPE-101 (available from Hisamitsu), DMSO and other
dialkylsulphoxides, in particular n-decylmethyl-sulphoxide (NDMS),
dimethylsulphacetamide, dimethylformamide (DMFA),
dimethylacetamide, glycols, various pyrrolidone derivatives
(Woodford et al., J. Toxicol. Cut. & Ocular Toxicology, 1986,
5: 167-177), and Azone.RTM. (Stoughton et al., Drug Dpv. Ind.
Pharm. 1983, 9: 725-744), or mixtures thereof.
[0072] The surface penetration agent may conveniently be provided
in a concentration range of 0.2 to 50% (w/w), e.g. about 10%
(w/w).
[0073] The compositions for use in accordance with the invention
may additionally include lubricating agents, wetting agents,
emulsifying agents, suspending agents, preserving agents,
sweetening agents, flavouring agents, adsorption enhancers, e.g.
surface penetrating agents as mentioned below, and the like.
[0074] The compounds for use according to the invention may be
formulated in any conventional manner with one or more
physiologically acceptable carriers or excipients, according to
techniques well known in the art. Where appropriate, compounds or
compositions for use in the invention are sterilized, e.g. by
.gamma.-irradiation, autoclaving or heat sterilization, before or
after the addition of a carrier or excipient where that is present,
to provide sterile formulations. The compositions of the invention
may also be formulated so as to provide quick, sustained or delayed
release of the active ingredient after administration to the
patient by employing procedures well known in the art. Solubilizing
and/or stabilizing agents may, for example, be used, e.g.
cyclodextrins (CD) .alpha., .beta., .gamma. and HP-.beta.
cyclodextrin. Compositions may be in any appropriate dosage form,
for example as an emulsion or in liposomes, niosomes, microspheres,
nanoparticles or the like. The compounds for use in the invention
may then be absorbed to, incorporated in or bound to these
forms.
[0075] The pH in the final composition is preferably in the range
2.5 to 7.4. Slightly acidic pH, for example pH 5-7, is
preferred.
[0076] Compositions may be administered systemically (e.g. orally
or parenterally) or more preferably locally (e.g. by injection or
topically) at or near the affected site. The route of
administration will depend on the severity, nature and location of
the disease to be treated as well as the photosensitiser (or
combination of photosensitisers) used. Generally, however, local
administration, still more preferably, topical application is
preferred. Topical administration to inaccessible sites may be
achieved by techniques known in the art, e.g. by the use of
catheters or other appropriate drug delivery systems.
[0077] Compositions that may be administered systemically include
plain or coated tablets, capsules, suspensions and solutions
containing the active component optionally together with one or
more inert conventional carriers and/or diluents, e.g. with corn
starch, lactose, sucrose, microcrystalline cellulose, magnesium
stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water,
water/ethanol, water/glycerol, water/sorbitol,
water/polyethyleneglycol, propyleneglycol, stearylalcohol,
carboxymethylcellulose or fatty substances such as hard fat or
suitable mixtures thereof.
[0078] Compositions that may be administered locally (e.g.
topically) include gels, creams, ointments, sprays, lotions,
salves, sticks, soaps, powders, pessaries, aerosols, drops,
solutions and any of the other conventional pharmaceutical forms in
the art. Creams, ointments and gels are especially preferred.
[0079] Creams, ointments and gels may be formulated with an aqueous
or oily base with the addition of suitable thickening and/or
gelling agents. Lotions may be formulated with an aqueous or oily
base and will, in general, also contain one or more emulsifying,
dispersing, suspending, thickening or colouring agents. Powders may
be formed with the aid of any suitable powder base. Drops and
solutions may be formulated with an aqueous or non-aqueous base
also comprising one or more dispersing, solubilising or suspending
agents. Aerosol sprays are conveniently delivered from pressurised
packs, with the use of a suitable propellant.
[0080] Particularly preferably the compositions for use in PDT
according to the invention will be in the form of a ready-to-use
composition such as a cream or as a kit as hereinbefore
defined.
[0081] The concentration of the 5-ALA compounds described herein in
the final compositions for PDT will vary depending on several
factors including the chemical nature of the compound, the chemical
composition, mode of administration and nature of the disease to be
treated. Preferably, however, concentration ranges of less than 20%
wt, more preferably less than 10% wt, still more preferably 0.05 to
8% wt, yet more preferably 0.5 to 6% wt, e.g. 1.5 to 4.5% wt or 2
to 4% wt are used. The most preferred concentrations for local
(e.g. topical) administration is in the range 2 to 4% wt.
[0082] Thus viewed from a yet further aspect the invention provides
a pharmaceutical composition comprising a photosensitiser which is
5-ALA or a derivative of 5-ALA as hereinbefore defined and a
pharmaceutically acceptable carrier or excipient, wherein the
concentration of said photosensitiser is 2 to 8% wt (e.g. 2 to 4.5%
wt).
[0083] Viewed from a still further aspect the invention provides a
pharmaceutical composition comprising a photosensitiser which is
5-ALA or a derivative of 5-ALA as hereinbefore defined and a
pharmaceutically acceptable carrier or excipient, wherein the
concentration of said photosensitiser is 2 to 8% wt (e.g. 2 to 4.5%
wt) for use in therapy (e.g. PDT).
[0084] Viewed from a still further aspect the invention provides a
product or kit for use in a method of preventing or reducing
side-effects (e.g. pain and/or erythema) of photodynamic therapy
(PDT) in an animal comprising: [0085] (a) a container containing a
composition as hereinbefore defined (e.g. a composition comprising
a photosensitiser which is 5-ALA or a derivative of 5-ALA at a
concentration of less than 20% wt, e.g. less than 10% wt), and
[0086] (b) instructions for carrying out said PDT as herein
defined.
[0087] In particularly preferred products and kits, the composition
contained in the first container comprises the composition which
itself forms an aspect of the invention (i.e. a composition
comprising a photosensitiser which is 5-ALA or a derivative of
5-ALA as hereinbefore defined in a concentration of 2 to 8% wt
(e.g. 2 to 4.5 wt %)). Further preferred products and kits comprise
a second container containing a second photosensitiser, e.g. as
hereinbefore defined.
[0088] The instructions present in the products and kits of the
invention describe the steps of administering the composition
comprising a photosensitiser to an animal and photoactivating the
photosensitiser. The instructions also preferably describe at least
one of steps (ii), (iii) or (iv) as herein defined.
[0089] PDT is carried out by administering to an animal a
composition comprising a photosensitiser as hereinbefore defined
and photoactivating the photosensitiser. By use of at least one of
(i)-(iv) as hereinbefore defined the side effects of PDT are
prevented or reduced. By "side effects" is meant herein effects,
usually undesirable effects, caused by PDT, other than its desired
therapeutic effect. Representative examples of side effects
commonly associated with PDT include pain, erythema, swelling,
edema, burning, itching, exfoliation, hyperpigmentation and
prolonged irritation and hypersensitivity after treatment. The uses
and methods of the present invention are particularly useful for
preventing or reducing pain and/or erythema, especially pain.
[0090] In particularly preferred uses and methods of the invention,
the PDT has substantially the same therapeutic effect as the
corresponding standard PDT treatment, whilst preventing or reducing
the side effects of the standard treatment. By the term
"corresponding standard PDT treatment" is meant the PDT treatment
carried out with the same photosensitiser (e.g. the same 5-ALA
ester) and the same light dose (e.g. 37 J/cm.sup.2), but under the
following conditions: [0091] (I) the concentration of the
photosensitiser is at least 15% wt (e.g. 16% wt), [0092] (II) the
photosensitiser is administered for at least 3 hours (e.g. 3 hours)
prior to photoactivation; and [0093] (III) photoactivation is
carried out with a light source having a fluence rate of at least
60 mW/cm.sup.2, e.g. about 70 mW/cm.sup.2.
[0094] Particularly preferred uses and methods of the invention
provide at least 90%, still more preferably at least 95%, e.g. at
least 99% of the therapeutic effect of the corresponding standard
PDT treatment.
[0095] In preferred uses and methods of the invention, side effects
of PDT are prevented or reduced by use of (i) as hereinbefore
described, i.e. use of a composition comprising the photosensitiser
in a concentration of less than 10% wt (e.g. 0.5 to 8% wt).
Particularly preferred compositions comprise photosensitiser in a
concentration of 0.05 to 8% wt, still more preferably 0.5 to 6% wt,
e.g. 1 to 4.5% wt or 2 to 4% wt.
[0096] In further preferred uses and methods of the invention, the
composition comprising the photosensitiser(s) as hereinbefore
described is administered to the animal and a certain time period
is allowed to elapse before the site to be treated is exposed to
light to achieve the desired photosensitizing effect. By the term
"administered" is meant that the composition is delivered to the
animal. This may be achieved, for example, by applying the
composition to the skin and allowing it to permeate therethrough.
Preferably the composition is administered in a single application.
Before light exposure, excess photosensitiser is preferably
removed.
[0097] The length of time following administration at which light
exposure takes place will depend on the nature of the composition,
the condition to be treated and the form of administration. It may
be, for example, about 3 to 6 hours. In preferred uses and methods
of the invention, however, side effects of PDT are prevented or
reduced by use of (ii) as hereinbefore defined, i.e. by
administering the composition for less than 2 hours prior to
photoactivation. Still more preferably the composition is
administered for 0 to 90 minutes (e.g. 5 to 90 minutes, preferably
30 to 90 minutes), more preferably 10 to 50 minutes, still more
preferably 15 to 45 minutes, e.g. 20 to 40 minutes prior to
photoactivation. In a particularly preferred aspect of the
invention, light exposure maybe effected immediately after
administration of the photosensitiser, i.e. the period of
administration may be a matter of only minutes (e.g. up to 10
minutes, more preferably up to 5 minutes) or may effectively be
zero in the case where administration and photoactivation occur
simultaneously.
[0098] In the uses and methods of the invention, photoactivation
may be achieved using light sources known in the art. Methods for
the irradiation of different areas of the body, e.g. by lamps or
lasers are well known in the art (see for example Van den Bergh,
Chemistry in Britain, May 1986 p. 430-439). The wavelength of light
used for irradiation may be selected to achieve a more efficacious
photosensitizing effect. The most effective light is light in the
wavelength range 300-800 nm, typically 400-700 nm. The irradiation
will in general be applied at a dose level of 40 to 200
Joules/cm.sup.2, for example at 100 Joules/cm.sup.2. A light source
having a fluence rate of 60 to 100 mW/cm.sup.2 maybe used.
[0099] In particularly preferred uses and methods of the invention,
side effects of PDT are prevented or reduced by use of (iii) as
hereinbefore described, i.e. by photoactivating with a light source
having a fluence rate of less than 50 mW/cm.sup.2. Still more
preferably photoactivation is carried out with a light source
having a fluence rate of 5 to 40 mW/cm.sup.2, still more preferably
10 to 35 mW/cm.sup.2, e.g. 15 to 35 mW/cm.sup.2.
[0100] Still more preferably the irradiation is applied at a dose
of 10 to 100 J/cm.sup.2, more preferably 20 to 60 J/cm.sup.2, e.g.
about 37 Joules/cm.sup.2 . Penetration of light into tissues
depends on the wavelength used and is deeper for red light than for
blue light. Irradiation is preferably performed for 5 to 30
minutes, preferably for 15 minutes, depending on the light dose and
fluence rate. A single irradiation may be used or alternatively a
light split dose in which the light dose is delivered in a number
of fractions, e.g. a 1 to 10 minutes between irradiations, may be
used.
[0101] In further preferred uses and methods of the invention, side
effects of PDT are prevented or reduced by use of (iv) as
hereinbefore defined, i.e. by photoactivating with sunlight. This
aspect of the invention includes photoactivation with either
natural sunlight or any light source which provides artificial
sunlight (i.e. the entire range from UV to IR). Use of natural
sunlight as the light source has the advantage that the animal
being treated is free to leave the clinical environment where
treatment is normally conducted. Furthermore, as the intensity of
sunlight (whether natural or artificial) is so low, exposure can
commence as soon as administration begins (i.e. the administration
time may effectively be zero). Thus, in a preferred aspect of the
invention, photoactivation by sunlight may be effected immediately
following administration of the photo sensitiser. This is a
particularly preferred form of treatment for skin disorders, e.g.
in the treatment of acne. Moreover, it may also not be necessary to
remove excess photosensitiser prior to photoactivation using
sunlight therefore administration and photoactivation can be
carried out at the same time. Indeed, it may in many cases be
beneficial to retain excess photosensitiser at the site of
administration such that administration essentially continues
during photosensitisation. Since the intensity of natural sunlight
may vary during the illumination period, if necessary, the light
dose received by a subject from sunlight can easily be monitored by
way of a portable photometer. Such photometers are commercially
available from International Light Technologies. These monitor the
total light dose and give a signal to the patient when the desired
light dose has been reached.
[0102] The desired period of exposure to sunlight following
administration of the photosensitiser will depend on various
factors such as the nature of the composition, the condition to be
treated, the form of administration, etc. but may readily be
determined by those skilled in the art. It has, however, been found
that the pain associated with PDT is less during the first 3 hours
or so of exposure to sunlight and that this is sufficient for the
desired therapeutic effects to be achieved. In a preferred aspect
of the invention the period of exposure to sunlight may therefore
be in the range of from 2 to 4 hours, e.g. about 3 hours.
[0103] In particularly preferred uses and methods of the invention,
side effects of PDT are prevented or reduced by use of (i) as
hereinbefore defined in combination with at least one of (ii),
(iii) and (iv). Prevention or reduction of side effects by use of
(i) in combination with (ii) or (iii), especially (ii), is
particularly preferred.
[0104] In other particularly preferred uses and methods of the
invention, side effects of PDT are prevented or reduced by use of
(ii) as hereinbefore defined in combination with at least one of
(iii) and (iv). Prevention or reduction of side effects by use of
(ii) in combination with (iv) is particularly preferred. In these
uses and methods, the photosensitiser is preferably administered
for 15 to 45 minutes (e.g. for 30 minutes) prior to
photoactivation. Preferably excess photosensitiser is not removed
prior to photoactivation so administration may continue during the
activation.
[0105] In further particularly preferred uses and methods of the
invention, side effects of PDT are prevented or reduced by use of
at least (i), (ii) and (iii) or (i), (ii) and (iv), e.g. (i), (ii)
and (iii).
[0106] In yet further preferred embodiments of the invention,
side-effects of PDT are prevented or reduced by use of (iii) in
combination with (i) and/or (ii), e.g. by use of (iii) and (i);
(iii) and (ii); or (iii) and (i) and (ii).
[0107] In other yet further preferred embodiments of the invention,
side-effects of PDT are prevented or reduced by use of (iv) in
combination with (i) and/or (ii), e.g. by use of (iv) and (i); (iv)
and (ii); or (iv) and (i) and (ii).
[0108] In the methods and uses of the present invention, multiple
treatments may be given, e.g. daily, weekly or monthly treatment.
Preferably no more than two treatments are required, e.g. for PDT
of acne.
[0109] The methods and uses of the invention may be used to treat
any disease known to be treatable by PDT. Examples of diseases
which may be treated include any malignant, pre-malignant and
non-malignant abnormalities or disorders responsive to
photochemotherapy e.g. cancers (e.g. basal cell carcinoma (bcc),
tumours, squamous cell carcinoma (scc), Bowen's disease), skin
disorders (e.g. psoriasis, actinic keratoses and acne) and
infections (e.g. bacterial, viral or fungal infections, for example
Herpes virus infections). The invention is particularly suited to
the treatment of diseases, disorders or abnormalities where
discrete lesions are formed to which the compositions may be
directly applied (lesions is used here in a broad sense to include
tumours and the like).
[0110] In some embodiments the uses and methods of the present
invention are particularly suited to the treatment of diseases
other than acne.
[0111] The internal and external body surfaces which may be treated
according to the invention include the skin and all other
epithelial and serosal surfaces, including for example mucosa, the
linings of organs e.g. the respiratory, gastro-intestinal and
genito-urinary tracts, and glands with ducts which empty onto such
surfaces (e.g. liver, hair follicles with sebaceous glands, mammary
glands, salivary glands and seminal vesicles). In addition to the
skin, such surfaces include for example the lining of the vagina,
the endometrium and the urothelium. Such surfaces may also include
cavities formed in the body following excision of diseased or
cancerous tissue e.g. brain cavities following the excision of
tumours such as gliomas.
[0112] Exemplary surfaces thus include: (I) skin and conjunctiva;
(2) the lining of the mouth, pharynx, oesophagus, stomach,
intestines and intestinal appendages, rectum, and anal canal; (3)
the lining of the nasal passages, nasal sinuses, nasopharynx,
trachea, bronchi, and bronchioles; (4) the lining of the ureters,
urinary bladder, and urethra; (5) the lining of the vagina, uterine
cervix, and uterus; (6) the parietal and visceral pleura; (7) the
lining of the peritoneal and pelvic cavities, and the surface of
the organs contained within those cavities; (8) the dura mater and
meninges; (9) any tumors in solid tissues that can be made
accessible to photoactivating light e.g. either directly, at time
of surgery, or via an optical fibre inserted through a needle.
[0113] The uses and methods of the invention are particularly
suited, however, to the PDT treatment of diseases of the face,
scalp or neck, especially the face.
[0114] The uses and methods of the present invention are
particularly suited to the treatment of acne. As used herein, the
term "acne" includes both inflammatory and non-inflammatory
diseases of the pilosebaceous unit. Primarily, however, the uses
and methods herein described will be used for treating inflammatory
types of acne where bacterial invasion of the pilosebaceous unit or
follicles has occurred. The compounds described herein are
preferably used for the treatment or prevention (preferably for the
treatment) of acne associated with Propionibacterium bacteria (e.g.
P. acnes, P. granulosum and P. avidum); especially
Propionibacterium acnes.
[0115] Acne is categorised into different forms depending, for
example, on the nature, severity and/or location of the blackheads,
whiteheads, papules, pustules and/or cysts. Representative types of
acne which may be treated according to the invention include acne
vulgaris, acne rosacea, acne conglobate, acne papulosa and
premenstrual acne, preferably acne vulgaris which is a chronic
inflammatory disease of the pilosebaceous apparatus. Acne may occur
on the back, chest, upper arms and/or face; the compounds described
herein may be used for treating any of these areas of the body,
especially the face.
[0116] The uses and methods of the present invention are also
particularly suited to the treatment of cancers. Representative
examples of cancers that may be treated include bcc, tumors, scc
and Bowen's disease.
[0117] The invention will now be described in more detail by way of
the following non-limiting Examples.
EXAMPLES
Example 1
[0118] A clinical Phase II study involving 23 males and 20 females
(age 18 years or more) with facial acne vulgaris (papulo-pustular
acne and at least 15 inflammatory, acne lesions on at least one
side of the face) has been performed.
[0119] This study assessed porphyrin levels, safety and efficacy of
PDT performed after application of three different concentrations
of methylaminolevulinate (MAL) in a cream base. It further assessed
the effect of different time intervals between MAL application and
light exposure.
[0120] Patients were randomized to receive either MAL cream on the
face at a concentration of 160 mg/g (16% wt), 80 mg/g (8% wt)or 40
mg/g (4% wt). Patients had skin biopsies taken on one half of the
face (each patient had a total of two biopsies taken) and the other
half of the face was exposed to red light (37 J/cm.sup.2 using
Photocure's Aktilite 128 LED light source) as indicated in the
table below.
TABLE-US-00001 Half of face Other half of face Concentration of MAL
Skin biopsies taken* Illumination performed* in cream (hrs) (hrs)
160 mg/g.sup.# 0, 3 3 80 mg/g 0, 0.5, 1, 1.5 0.5, 1, 1.5 40 mg/g 0,
1, 1.5 1, 1.5 *Cream applied at 0 hrs. .sup.#Standard PDT
treatment
[0121] Acne lesion counts (inflammatory and non inflammatory
lesions for the half face exposed to red light) was performed at 0
hours as well as at day 14 and day 84 visits by a blinded
evaluator. A Global Acne Severity Assessment was also performed at
day 0, day 14 and day 84.
[0122] In vivo fluorescence spectroscopy was performed at 0 hours
and immediately after red light exposure to measure porphyrin
photobleaching after illumination. Sebum excretion rates were
measured 7 days before day 0, at day 14 and day 84.
[0123] Safety was evaluated by medical questionnaire and adverse
events reporting.
[0124] This study showed a significant difference between treatment
groups in porphyrins levels after MAL application as measured with
in vivo fluorescence spectroscopy. Porphrin levels were highest in
facial skin of acne patients treated with MAL at 160mg/g for 3
hours and 80 mg/g for 1.5 hours. These elevated levels went back to
baseline levels after red light exposure.
[0125] Mean porphyrin levels were highest in sebaceous glands from
biopsies taken 3 hours after application of 160 mg/g but there was
no significant difference between treatment groups in mean
porphyrin levels in sebaceous glands.
[0126] Surprisingly there was no difference between MAL-PDT
treatment groups in inflammatory or non-inflammatory lesions at
either day 14 or day 84. However a reduction from the start of the
study in inflammatory lesions (between 23% to 44% at Day 84) was
noted for all groups on the MAL-PDT treated side. There was no
difference between treatment groups in Global acne severity scores
or sebum excretion rates at day 14 and day 84 thus showing that all
treatment regimes were equally efficient.
[0127] Mean pain during light exposure was evaluated by patients on
a visual analog scale where 0=no pain, 50=moderate pain and
100=worst possible pain. The results are shown in the Table
below.
TABLE-US-00002 Pain during light exposure Treatment N Mean Std Dev
1 h after MAL (40 mg/g) 8 2 4 1.5 h after MAL (40 mg/g) 8 19 19 0.5
h after MAL (80 mg/g) 6 1 1 1 h after MAL (80 mg/g) 8 9 16 1.5 h
after MAL (80 mg/g) 6 32 32 3 h after MAL (160 mg/g)# 7 64 13
#Standard PDT treatment
[0128] There was a statistically significant difference between
groups in mean pain during light exposure (p=0.0006). Pairwise
comparison between the 160 mg/g 3 h group and all other groups
showed a higher mean pain during light exposure for the 160 mg/g
group except for the comparison with the 80 mg/g 1.5 h group which
was at the limit of significance (p=0.06). In fact, for a few
patients in these two groups the pain was so strong that the light
delivery had to be interrupted (2 patients) or ended (2 patients).
This shows that pain is related to exposure time and MAL
concentration.
[0129] The duration of post-PDT erythema is presented in the Table
below. This information was derived from the journal kept by
patients. The longest mean duration of erythema (14 days) was seen
in patients treated with 160 mg/g for 3 hours and the shortest (0.5
days) was seen in patients treated with 40 mg/g for 1 hour. There
is a significant difference among the 6 groups in the duration of
post PDT erythema (p=0.03).
TABLE-US-00003 Duration of post PDT erythema (in days) Treatment n
Mean Std Dev 1 h after MAL (40 mg/g) 4 4 6.7 1.5 h after MAL (40
mg/g) 6 1.8 1.3 0.5 h after MAL (80 mg/g) 0 -- -- 1 h after MAL (80
mg/g) 5 2.1 2.7 1.5 h after MAL (80 mg/g) 3 3.7 0.6 3 h after MAL
(160 mg/g)# 7 11.9 11.7 #Standard PDT treatment
[0130] This shows that post-PDT erythema is related to exposure
time and MAL concentration.
[0131] The study shows that there was no significant difference in
the therapeutic effect between groups, but there was a significant
difference between groups for the duration of post-PDT erythema,
local tolerance to PDT and pain during light exposure which was
longest, lowest and highest respectively in the 160 mg/g 3 h
group.
Example 2
[0132] A study was performed to evaluate the effect of reducing the
fluence rate during illumination.
[0133] 34 patients with moderate to severe facial acne vulgaris
were treated full-face with Metvix.RTM. (160 mg/g) applied for
three hours under occlusion. The cream was removed, and the
treatment area was illuminated with a total light dose of 37
J/cm.sup.2 using the Aktilite.RTM. 128 lamp (Photocure ASA,
Norway). This lamp consists of 128 light emitting diodes (LEDs) and
has a peak wavelength of 634.+-.3 nm.
[0134] 15 patients had one PDT treatment with no curettage prior to
Metvix.RTM. application and using a fluence rate of 34 mW/cm.sup.2.
The remaining 19 acne patients were supposed to have 2 PDT
treatments and were illuminated with a fluence rate of 68
mW/cm.sup.2 and curettaged before the first treatment. 12 of these
patients had 2 PDT treatments and 7 patients only one
treatment.
[0135] The treatment effect was evaluated as reduction in number of
inflammatory acne lesions from baseline to 12-week control. Pain
during illumination was assessed using a numerical scale ranging
from 0 to 10 in which 0 is no pain and 10 is worst imaginable
pain.
[0136] The results are summarised in the table below:
TABLE-US-00004 Reduction inflammatory FLUENCE Number of acne
lesions RATE patients Median percentage P value 68.5 mW/cm.sup.2 19
70% 0.92 34 mW/cm.sup.2 15 59%
[0137] It is evident from the table that there was no significant
difference between the two groups with respect to treatment
effect.
TABLE-US-00005 FLUENCE Number of Maximal Pain P *Corrected RATE
treatment sessions Median (IQR) value P value 68.5 mW/cm.sup.2 31 8
(6, 10) 0.018 0.009 34 mW/cm.sup.2 15 6 (5, 7) *By correcting the
pain scores for differences in porphyrin fluorescence (measured by
quantitative fluorescence imaging) in the treatment area, we take
into account differences in curettage and treatment number between
the two treatment groups.
Example 3
[0138] A study was performed to demonstrate that illumination with
sunlight is as effective as if a PDT lamp was used.
[0139] Patients with actinic keratosis (23 men and 6 women) median
age 80 years (63-93 years) were included in this study.
[0140] A gentle curettage was performed followed by application of
Metvix.RTM. cream (160 mg/g). The treated area was then occluded.
After 30 minutes the occlusion was removed on half the treatment
area, which was then exposed to sunlight for 2.5 hours.
[0141] The occlusion was then removed on other half followed by
illumination using the Aktilite.RTM. 128 lamp (Photocure ASA,
Norway)--for details see Example 2. Photodynamic treatment was
performed with a total light dose of 37 Joules/cm.sup.2 and a
fluence rate of 68.5 mW/cm.sup.2.
TABLE-US-00006 Sunlight exposure LUX* No. of patients Mean LUX
>80,000 14 92,362 50,000-80,000 9 68,277 <50,000 6 38,296 *1
LUX = 1 lumen/m.sup.2
[0142] The treatment effect was scored by lesion counting before
treatment and 12 weeks after the PDT treatment:
TABLE-US-00007 Treatment effect SUNLIGHT RED LIGHT Median Median p
(range) (range) value* Number of lesions 9 (2-27) 9 (1-32) 0.76
before treatment Number of lesions at 2 (0-8) 3 (0-9) 0.35 12 week
follow up Absolute decrease 7 (1-22) 6 (0-27) 0.58 (number of
lesions) Lesions with complete 81 (43-100) 75 (0-100) 0.19 response
(percent) *Sunlight group vs. red light group
[0143] Pain was scored using a numerical scale ranging from 0 to 10
in which 0 is no pain and 10 is worst imaginable pain.
TABLE-US-00008 Pain Maximal pain Light exposure Median (range) p
value Sunlight 2 (0-6) <0.0001 Red light 7 (2-10)
[0144] It is evident from the table that there was no significant
difference between the two illumination groups with respect to the
absolute decrease in number of lesions or in the percentage of
lesions with a complete response. It can therefore be concluded
that exposure of continuously formed protoporphyrin to sunlight
during 2.5 hours treatment with Metvix.RTM. is as efficient as
illumination with red light after 3 hours of incubation with
Metvix.RTM..
[0145] Pain during light exposure was significantly lower in the
sunlight group. There was no significant correlation between
intensity of the sunlight exposure and the reduction in lesions in
the area treated with Metvix.RTM. and sunlight (p=0.66). Neither
was there any significant correlation between intensity of the
sunlight exposure and pain during exposure (p=0.1036).
* * * * *