A 12-week phase 2 study of 153 patients with severe facial acne suggests those using photodynamic therapy (PDT) with the investigational topical methyl aminolevulinate, or MAL, (Photocure ASA) had significantly reduced inflammatory acne lesion counts compared to PDT and vehicle.
PDT treatment with the photosensitizer MAL, 80 mg gâ1, reduced acne lesions by an average 15.6 compared to 7.8 in the control group. Thatâs a percentage change of 37.3 percent in the active group, versus 16.2 percent among controls.
The decrease in noninflammatory lesions wasnât significant in the two groups. And PDT/MAL treatment resulted in manageable pain and erythema comparable to the control group, according to the study.
This is a promising finding for patients with moderate to severe acne, according to the studyâs lead author David M. Pariser, M.D., professor of dermatology at Eastern Virginia Medical School, Norfolk, Virginia, and past president of the American Academy of Dermatology.
âThere have been a lot of attempts at using PDT for treatment of acne, particularly the severe acne, which is usually managed by antibiotics or even systemic use of isotretinoin,â he says. âThis is among the first prospective controlled trials of acne treatment versus placebo treatment, where we were really able to demonstrate clearly over placebo the effect of [PDT] treatment.â
While MAL is an investigational drug, not yet available in the United States but widely used in Europe, there are PDT agents that are available in the United States for treatment of actinic keratoses. Levulan (aminolevulinic acid (ALA) HCl, Dusa) is one. And Ameluz (ALA, hydrochloride, Biofrontera Pharma) was FDA approved in May 2016 for treatment of actinic keratoses. The Leverkusen, Germany-based pharma company announced May 11, 2016 that the FDA approved its combination topical prescription drug Ameluz (BF-200 ALA) and medical device BF-RhodoLED for PDT treatment of mild to moderate AK on the face and scalp.
The way a PDT agent works in acne is the drug, when applied to the skinâs surface, is absorbed preferentially in sebaceous glands. When in those cells, it converts to protoporphyrin IX. Then, when exposed to a bright light of a certain wavelength, a photochemical reaction occurs, destroying the cell in which the drug has been absorbed, according to Dr. Pariser.
âThe light, by itself, doesnât do much of anything; the drug, by itself, doesnât do anything. The combination is what works,â Dr. Pariser says.