PULSE PHOTODYNAMIC TREATMENT OF ACNE

Abstract

A pulse photodynamic therapy (or pulse PDT) treatment of acne is described herein.

Claims

1. A method of treating acne in an animal, the method comprising treating the acne by photodynamic therapy (PDT), wherein a photosensitizer is applied to the skin of the animal after a pretreatment of the skin.

2. The method according to claim 1, wherein the photosensitizer is applied for a duration of from 4 minutes to 4 hours.

3. The method according to claim 2, wherein the duration is from 15 minutes to 3 hours.

4. The method according to claim 1, wherein the photosensitizer is applied for a short period of time.

5. The method according to claim 4, wherein the short period of time is from 5 minutes to 120 minutes.

6. The method according to claim 4, wherein the short period of time is from 15 minutes to 60 minutes.

7. The method according to claim 4, wherein the short period of time is from 20 minutes to 40 minutes.

8. The method according to claim 4, wherein the short period of time is selected from the group consisting of 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 and 35 minutes.

9. A method of treating acne in an animal, the method comprising treating the acne by photodynamic therapy (PDT), wherein a photosensitizer is applied for a short period of time.

10. The method according to claim 9, wherein the short period of time is from 5 minutes to 120 minutes.

11. The method according to claim 9, wherein the short period of time is from 15 minutes to 60 minutes.

12. The method according to claim 9, wherein the short period of time is from 20 minutes to 40 minutes.

13. The method according to claim 9, wherein the short period of time is selected from the group consisting of 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 and 35 minutes.

14. The method according to claim 1, wherein the method reduces side effects associated with PDT.

15. The method according to claim 1, wherein the PDT includes a photoactivation achieved by a natural light source.

16. The method according to claim 15, wherein the PDT includes a photoactivation for a duration of from 0.5 hour to 3 hours with the natural light source.

17. The method according to claim 15, wherein the natural light source is sunlight.

18. The method according to claim 1, wherein the PDT comprises: a) subjecting the skin of the animal to a pretreatment; b) administering to the animal a composition comprising the photosensitizer for a duration of from 5 minutes to 120 minutes; and c) photoactivating the photosensitizer for a duration of from 0.5 hour to 3 hours with natural light.

19. The method according to claim 18, wherein the pretreatment is mechanical or chemical pretreatment.

20. The method according to claim 1, wherein the PDT comprises: a) subjecting the skin of the animal to a pretreatment; b) administering to the animal a composition comprising the photosensitizer for a duration of about 30 minutes; c) removing the photosensitizer; and d) photoactivating the photosensitizer 2.5 hours later for a duration of at least 2 hours with natural light.

21. The method according to claim 20, wherein the pretreatment is mechanical or chemical pretreatment.

22. The method according to claim 21, wherein the pretreatment is sandpaper.

23. The method according to claim 20, wherein the photosensitizer is administered for a duration selected from the group consisting of 27, 28, 29, 30, 31 and 32 minutes.

24. The method according to claim 23, wherein the duration is 30 minutes.

25. The method according to claim 1, wherein the photosensitizer is selected from the group consisting of 5-ALA, 5-ALA derivatives, 5-MAL derivatives, and compounds covered by general formula I:
R.sup.2.sub.2NCH.sub.2COCH.sub.2CH.sub.2COOR.sup.1(I) wherein: R.sup.1 represents a substituted or unsubstituted straight, branched or cyclic alkyl group; and each R.sup.2 independently represents a hydrogen atom or an optionally substituted alkyl group; and pharmaceutically acceptable salts thereof.

26. The method according to claim 25, wherein R.sup.1 is a substituted or unsubstituted straight-chained alkyl group.

27. The method according to claim 1, wherein the photosensitizer is 5-ALA or 5-methyl ALA ester.

28. The method according to claim 1, wherein administering to the animal of a composition comprising the photosensitizer is carried out with or without occlusion.

29. The method according to claim 28, wherein the administration of the photosensitizer is carried out with occlusion.

30. The method according to claim 1, wherein the pretreatment is selected from the group consisting of mechanical pretreatment and chemical pretreatment.

31. The method according to claim 30, wherein the mechanical pretreatment is dermoabrasion or microneedling.

32. The method according to claim 30, wherein the chemical pretreatment is peeling.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0097] FIG. 1 is a graph showing the inflammation vs. response rate (3 months) of AK on the face.

[0098] FIG. 2 is a graph showing the mean increased redness the day after PDT.

[0099] FIG. 3 is a graph reporting the visual redness 1 day after PDT with different treatment protocols.

[0100] FIG. 4 is a graph showing the pain scale after different treatments.

[0101] FIG. 5 is a graph showing the cure rate after different treatments.

[0102] FIG. 6 is a graph showing the increase in erythema percentage one day after treatment with different protocols.

[0103] FIG. 7 is a graph showing erythema scale after treatment with different protocols.

[0104] FIG. 8 is a graph showing the mean photobleaching in the standard treatment and a different pulse treatment.

[0105] FIG. 9 is a graph showing the inflammation (erythema)/PpIX formation relationship.

[0106] FIG. 10 is a graph showing the values of fluorescence by IMP and pre-treatment at 405 nm

[0107] FIG. 11 is a graph showing the values of fluorescence by IMP and pre-treatment at 632 nm

[0108] FIG. 12 is a graph showing TEWL detailed by occlusion and pre-treatment

EXAMPLES

Example 1Comparison of Mechanical Penetration Enhancers on Photosensitizer Skin Penetration

[0109] The effect on the product skin penetration of different mechanical penetration enhancement techniques (occlusion, microneedles, ablative fractional laser) has been evaluated.

[0110] 10 healthy volunteers have been treated according to the following protocol: [0111] pretreatment with either micro-needles (Dermaroller) or ablative fractional laser (CO.sub.2 laser fraxel repair (SOLTA)), or no pretreatment; [0112] application of Metvix; [0113] 3 hours of incubation with or without occlusion. [0114] Penetration was quantified during incubation using measurement of photo fluorescence of PpIX at 30 minutes, 1 hour, 2 hours, and 3 hours after product application.

[0115] Both Dermaroller and laser similarly increased Metvix penetration in surface and deeper skin as measured by blue (405 nm) (see FIG. 10) and red (632 nm) (see FIG. 11) photo fluorescence as compared to no pretreatment without occlusion and no pretreatment with occlusion.

[0116] No difference was observed with or with occlusion before 3 hours.

[0117] In addition, laser pretreatment was found to be more painful and more irritant than Dermaroller, and laser pretreatment has more impact in lowering skin barrier function as observed by measuring transepidermal water loss. (see FIG. 12)

[0118] Therefore, the inventors have surprisingly shown that mechanical pretreatment with a device such as micro-needle device is as efficient as a laser pretreatment to increase product skin penetration but with less adverse events and is therefore more adapted to the PDT treatment of acne.

Example 2PDT Procedure Change to Minimize Inflammation in PDT

[0119] According to the just mentioned theory it would be preferable to keep PPIX and cellular enzymes away from the extracellular compartment, thereby avoiding inflammation.

[0120] The purpose of this project is therefore to keep the PPIX formation within the mitochondria and avoid excess amounts of PPIX to be formed. Simultaneously PPIX should be allowed to be formed for such a long time that most unnormal cells will be affected.

[0121] So the purpose of PDT is to kill unnormal cells, preferably by apoptosis. The ideal situation would be to keep PPIX inside the cell and to destroy the mitochondria only, thereby inhibiting the ATP formation necessary for cell functions. That should result in cell death by apoptosis.

[0122] One possible way to achieve this would be to give a short 5-MAL pulse treatment to get a high concentration of 5-MAL in the cells initially and then diminish further access to 5-MAL by removing 5-MAL from the skin surface.

[0123] This could be done by only exposing the skin to 5-MAL for a short time, after which all 5-MAL is removed from the skin surface. If the right pulse time can be found it might ensure high cellular PPIX and low extracellular PPIX. Excess amounts of PPIX formation during and after the end of the treatment would thus be avoided.

[0124] The result shows less inflammation with unchanged efficacy and thus mitochondria destruction seems to be the most important factor in PDT.

[0125] To estimate the preferable Metvix pulse time a separate investigation was performed (Method B) on 24 healthy volunteers. The pulse time was 20 min., 40 min., 60 min., and the conventional 180 min, after which excess amounts of Metvix was removed from the skin.

[0126] The formation of PPIX after 3 hours is seen in FIG. 8, and the relation to inflammation is seen in FIG. 9. It is seen that PPIX concentration speeds up between 20-40 min. of pulse exposure, and so we have chosen 30 min. as the minimum pulse exposure time in the following (Method A) investigation of efficacy and inflammation by this method change. The results are illustrated in Column 3 in FIGS. 4, 5, 6, and 7. The procedure change clearly diminishes inflammation (erythema), without affecting the cure rate (FIG. 5). Pain level is not changed. PPIX concentration is clearly lower than for the conventional 3-hour exposure to Metvix (FIG. 8).

[0127] Methods

[0128] Healthy Volunteers

[0129] Twenty-four healthy male volunteers of Scandinavian ancestry were included in the study (mean age 30 years, range 20-51). A treatment area was selected on the inside of both forearms of the volunteer. Each treatment area was divided into four minor treatment fields of the size 25 cm with at least 3 cm between each field using a prefabricated flexible template. In order to imitate skin lesions all fields were tape stripped 10 times with occlusive dressing before treatment (Tegaderm Roll, 3M, Glostrup, Denmark).

[0130] On the left forearm vehicle Unguentum M was applied to the treatment field.

[0131] On the right forearm excess amounts of 5-MAL 16% (Metvix, Photocure, Oslo, Norway) were applied to all four fields of treatment. All fields were covered with light-impermeable, occlusive dressing. After 20 minutes the dressing was removed from the first field and the excess cream gently wiped off. The field was covered again with a thin piece of gauze and light impermeable dressing. After additional 20 and 40 min same procedure was followed with the second and third field. 180 min after application of 5-MAL and vehicle was removed from all five fields, and the excess cream was gently wiped of the last field. All fields were illuminated with red light. Illumination was performed with red LED light 630 nm peak (Aktilite 128; Photocure ASA, Oslo Norway) using a total light dose of 37 J/cm.sup.2 given over 9 min. During and after illumination pain was recorded. The volunteers were equipped with a special diary for recording pain in the days after treatment. Four follow-up visits were performed at day 1, 2, 3 and 8 after treatment.

[0132] PpIX Fluorescence

[0133] 5-MAL-induced PpIX fluorescence was depicted non-invasively using a fluorescence camera (Medeikonos AB, Gothenburg, Sweden). The amount of PpIX fluorescence was calculated from the photographs by the program MatLab (MatLab, MathWorks, Natic, US). The amount of fluorescence was measured before tape stripping and cream application (baseline) and before and after illumination.

[0134] The photo bleaching is then the difference in PpIX fluorescence (AU) calculated from the pre and post illumination images.

[0135] Erythema and Pigmentation

[0136] As an indicator of inflammation erythema was measured. The erythema was assessed by an expert evaluator and measured objectively.

[0137] The objective measurements of erythema and pigmentation were performed using a skin reflectance meter (Optimize Scientific 558, Chromo-Light, Espergaerde, Denmark).

[0138] Erythema % and pigmentation % were measured before treatment, immediately before illumination, immediately after illumination, and at the four follow-up visits.

[0139] Pain Score

[0140] The volunteers scored their pain every minute during illumination, and recorded their pain in the diary every hour after illumination on the treatment day, twice per day the next three days and once a day on the following five days. Since PDT was performed at different times of the day the number of evaluations differed from 3 to 11 the first day. Pain was assessed using a numerical scale ranging from 0 to 10, where 0 is no pain and 10 is worst imaginable pain. To make it easier for the patients to identify the different treated fields, the dairy was supplied with numbered drawings of the fields.

[0141] Randomizing

[0142] The study was designed as an open randomised trial. A statistical adviser made the randomisation. Since the sequence of treatment duration was predefined, randomization was only determining which of the four treatment fields should be the first.

[0143] Statistics

[0144] The sample size was calculated on the bases of data from the literature. We set the minimal clinical relevant difference to 8.8% (50% of the earlier found 17.6%) and choose a power of 0.80 and a significance level of 0.05, 22 volunteers should be included.

[0145] To identify differences in pain score, erythema % and pigmentation % between the treatment fields we used Wilcoxon Signed Ranked Test, since all results were paired.

[0146] For all calculations a p-value <0.05 was considered statistical significant. All analyses were performed with PASW Statistics 19.0 for Windows (SPSS Inc, Chicago, Ill., USA).

Example 3Evaluation of Efficacy of 5-Mal in Daylight (DL)-PDT in Subjects with Moderate to Severe Acne

[0147] 1. Study Objectives and Clinical Hypothesis

[0148] Study Objectives:

[0149] The primary objective of this study is to evaluate the efficacy of 5-MAL cream combined with DL PDT compared to its vehicle in patients with moderate to severe facial acne vulgaris using a randomized, controlled and investigator-blinded study design.

[0150] The secondary objective of this study is to assess the local tolerance of CD06809-41 cream.

[0151] Clinical Hypothesis:

[0152] The hypothesis of the study is that 5-MAL is more efficacious than its vehicle in moderate to severe acne when combined with DL-PDT. In this study, 5-MAL combined with DL-PDT is expected to reduce the total number of inflammatory lesions, which are major symptoms of moderate to severe acne, and also to be associated with less pain.

[0153] 2. Study Design

[0154] This is an exploratory, single-center, randomized, placebo-controlled, investigator-blinded, intra-individual (left versus right comparison) study, involving approximately 16 subjects with moderate to severe acne, meeting specific inclusion/exclusion criteria.

[0155] This study consists of: [0156] An up to 4-week screening period (within 3 to 30 days prior to Baseline) except for women of childbearing potential for whom a minimum of 2 weeks between the screening visit and the Day 1 visit (Baseline) is required; [0157] A treatment session with DL-PDT during which each subject will receive 5-MAL on one side of the face versus vehicle on the other side, on pre-treated skin using Homecare Dermaroller (expected hole depth about 0.2 mm). [0158] A 3-month follow-up period (endpoint) and an optional second session with DL-PDT during which the side of the face treated by 5-MAL cream will receive placebo and vice-versa. [0159] A 1 week follow-up period.

[0160] The second treatment session is not mandatory: it will only be performed on subjects who request it, and according to Investigator's judgment.

[0161] 3. Results

[0162] As revealed in the tables below the acne lesions (inflammatory and non-inflammatory) in the DL-PDT treated area with Metvix (5-MAL, otherwise referred to as Metvixia) showed better results comparing to the placebo, with a progressive regression observed to 3 months concerning the non-inflammatory lesions. The reduction from baseline was about 59% regarding the inflammatory lesions after one month of treatment and 56% of the non-inflammatory lesions at the 3-month follow-up. The total lesion reduction was around 50%.

TABLE-US-00002 TABLE 9_2_4_1_2 Percent reduction from Baseline in Inflammatory lesion at each evaluation visit METVIXIA PLACEBO METVIXIA PLACEBO p* Week 4/ITT n 15 15 15 Mean +/ sd 54.1 +/ 25.4 35.2 +/ 34.2 18.9 +/ 36.2 Median 58.8 35.3 20.3 0.063 (Min, Max) (13.3, 76.5) (50.0, 90.5) (31.7, 114.7) Week 8/ITT n 14 14 14 Mean +/ sd 51.8 +/ 30.1 32.4 +/ 32.5 19.4 +/ 32.8 Median 55.9 37.1 24.6 0.068 (Min, Max) (26.7, 88.2) (33.3, 81.0) (43.3, 80.4) Week 12/ITT n 7 7 7 Mean +/ sd 35.3 +/ 30.9 22.7 +/ 37.5 12.6 +/ 47.0 Median 33.3 28.6 26.5 0.678 (Min, Max) (3.3, 76.5) (36.7, 69.2) (60.9, 51.5) *p-value by two-sided Wilcoxon rank signed test

TABLE-US-00003 TABLE 9_2_4_1_6 Percent reduction from Baseline in Non inflammatory lesion at each evaluation visit METVIXIA PLACEBO METVIXIA PLACEBO p* Week 4 TT n 15 15 15 Mean +/ sd 37.4 +/ 27.2 30.1 +/ 32.0 7.3 +/ 34.5 Median 38.6 26.7 13.3 0.661 (Min, Max) (25.0, 87.5) (40.0, 81.8) (45.0, 94.5) Week 8 TT n 14 14 14 Mean +/ sd 34.6 +/ 35.0 17.9 +/ 33.1 16.7 +/ 30.4 Median 32.1 19.4 19.4 0.078 (Min, Max) (45.0, 84.6) (60.9, 61.6) (36.0, 64.8) Week 1 TT n 7 7 7 Mean +/ sd 39.7 +/ 37.6 26.4 +/ 40.8 13.4 +/ 9.5 Median 56.3 38.5 11.8 0.031 (Min, Max) (18.2, 64.6) (30.0, 84.6) (0.0, 30.0) *p-value by two-sided Wilcoxon rank signed test indicates data missing or illegible when filed

TABLE-US-00004 TABLE 9_2_4_1_8 Percent reduction from Baseline in Total lesion at each evaluation visit METVIXIA PLACEBO METVIXIA PLACEBO p* Week 4 TT n 15 15 15 Mean +/ sd 47.3 +/ 19.8 34.2 +/ 22.4 13.1 +/ 25.1 Median 52.0 34.5 6.0 0.073 (Min, Max) (0.0, 72.7) (9.5, 78.8) (26.1, 66.0) Week 8 TT n 14 14 14 Mean +/ sd 43.6 +/ 26.9 25.0 +/28.5 18.6 +/27.0 Median 48.0 23.4 20.6 0.030 (Min, Max) (0.0, 87.5) (24.3, 67.9) (15.7, 66.6) Week 12 TT n 7 7 7 Mean +/ sd 38.3 +/ 27.9 25.7 +/ 38.2 12.8 +/24.9 Median 60.0 32.7 17.3 0.219 (Min, Max) (2.9, 71.9) (24.3, 78.6) (28.6, 37.7) *p-value by two sided Wilcoxon rank signed test indicates data missing or illegible when filed