Acne trial suggests strategies for enhancing outcomes with blue light

Data were reported in a poster presentation at the annual meeting of the American Academy of Dermatology for the study that compared blue light treatment with broad area, short contact application of aminolevulinic acid (ALA, Levulan Kerastick; DUSA Pharmaceuticals) or vehicle in 72 subjects with moderate-to-severe acne. The subjects were divided into three cohorts to receive varying incubation times for vehicle or ALA (15, 60 or 120 minutes); within each of those cohorts, subjects were randomized 3:1 to treatment with ALA or vehicle.

Prior to application of the topical study agent, the face on all subjects was prepared with an acetone scrub. All subjects received 500 seconds (5 J/cm² ) of BLU-U light. Patients received a total of up to four of their assigned treatments administered at two-week intervals.

Further analyses showed that within the subgroup of patients with severe acne, there was a benefit for the ALA PDT regimen compared with blue light plus vehicle. In addition, the improvements achieved with blue light plus vehicle exceeded those reported in previous studies of blue light phototherapy for acne. The latter more favorable outcomes included marked reductions in noninflammatory lesion counts, as well as in inflammatory lesions and occurred despite delivery of fewer treatments relative to earlier trials.

"For patients with severe acne who might have fewer alternatives, the results of this study suggest PDT with blue light and ALA may be a promising new modality. Therefore, we look forward to results of future studies that will help to better define its role," says Diane S. Berson, M.D., a clinical investigator in the study and assistant professor of dermatology at the Weill Medical College of Cornell University, New York.

"We were very pleased to find this study suggested efficacy for blue light-ALA PDT in the treatment of severe acne, and we will be investigating that further in another study. However, the results were also exciting because they suggested a way to improve responses achieved using blue light phototherapy for moderate acne," says Stuart Marcus, M.D., Ph.D, chief medical officer, DUSA Pharmaceuticals, Valhalla, N.Y.

"Currently, it is recommended that the blue light be delivered as two treatments a week for four weeks, and previous studies using that approach have shown that it primarily reduced inflammatory lesions. The greater benefit achieved in this study using only four treatments and including an effect on noninflammatory lesions was unexpected and is thought to reflect the addition of the acetone scrub. Hopefully, this approach might improve the efficacy of blue light treatment for moderate acne to an extent that could further reduce patient dependence on antibiotics and other agents," Dr. Marcus notes.

Study subjects

The study enrolled males and females older than 16 years of age who had at least 20 noninflammatory lesions and at least 20 inflammatory lesions.

Based on severity ratings using a grading scale of 0 (normal, clear skin) to 5 (highly inflammatory lesions predominate), the majority of study participants, 60 percent, were categorized as having grade 3 acne. All of the remaining subjects had an acne severity score of "4" (39 percent) with the exception of one patient whose acne severity was categorized as "5".

Across the six treatment groups representing ALA or vehicle treatment for one of the three incubation times, median total lesion counts were decreased nearly 40 percent to 80 percent. Median decreases in noninflammatory lesion counts ranged from 27 to 98 percent and there were 28 to 73 percent median reductions in inflammatory lesions.