Efficacy and Safety of Azelaic Acid (AzA) Gel 15% in the Treatment of Post-Inflammatory Hyperpigmentation and Acne: A 16-Week, Baseline-Controlled Study

PIH and 20 percent had severe PIH. At week 4, 67 percent of subjects had achieved at least a one-point improvement in IGA scores (Table 6). At the conclusion of the trial (week 16), 100 percent of subjects had at least a 2-point improvement in IGA scores. Of note, 31 percent of subjects had no PIH at all at week 16, 54 percent of subjects had only slight PIH at week 16 and 15 percent of subjects had just mild PIH at week 16. No patients had moderate or severe PIH at week 16 (Table 7).

At week 4, there was a statistically significant 1-point median improvement in distribution scores (P=0.0039). The majority (60%) of subjects had at least a one-grade improvement in distribution scores and 6.7 percent had at least a two-grade improvement. At week 16, 100 percent of subjects had at least a one-grade improvement and 92 percent of subjects had at least a 2-grade improvement in distribution scores. Complete clearance of PIH was noted in 31 percent of subjects at week 16; 54 percent of subjects had only 1-10 percent distribution of PIH (Table 8).

Improvements in PIH severity and distribution were all statistically significant starting at week 4.

Tolerability of AzA gel was good throughout the trial period, with no serious adverse events reported. Erythema at baseline was absent in 55 percent of subjects, trace in 30 percent and mild in 15 percent. At week 4, 86.7 percent of subjects had no erythema, 6.7 percent of the subjects had mild erythema and 6.7 percent had only trace erythema. By week 12, no subject had erythema.

At week 4, 20 percent of the subjects reported trace dryness and 6.7 percent had moderate dryness. Reported rates of dryness remained low until week 16, at which point no subjects reported dryness. Peeling, which was reported as trace in 6.7 percent of subjects and mild in 13.3 percent of subjects at week 4 was not reported by any subjects at week 12 or 16.

The development of PIH secondary to acne is a significant clinical concern for many patients, especially those with darker skin types. In our clinical practice, patients present every day complaining of PIH, which they sometimes report is more disturbing than acne itself. To be able to treat acne and PIH simultaneously is a logical approach to care that may provide enhanced convenience and better outcomes for patients. The use of topical AzA gel 15% for the management of acne in patients with PIH has been demonstrated to be well tolerated and effective. Therefore, AzA gel may be considered for patients at risk for this troubling sequelum of acne.

The limitation of this study is that it was an open-label study with a small number of patients. However, positive findings of this pilot study will hopefully encourage larger, randomized controlled trials of AzA gel 15% for acne and post-inflammatory hyperpigmentation, which is a significant unmet need.

Twice-daily topical application of AzA gel 15% improved all aspects of acne severity and PIH severity measured during this 16-week study. This study revealed early onset of action in both acne and PIH improvement starting at week 4.

In acne, improvement in total, inflammatory and non-inflammatory lesion counts were seen throughout the study, with an impressive 98 percent median reduction in total acne lesions at week 16. IGA scores for acne showed statistically significant improvement by week 4 that continued throughout the trial period. Furthermore, both the severity and distribution of PIH improved throughout the trial period. By the end of the study period, nearly two-thirds of subjects had no PIH, and more than half had only 1-10 percent involvement. AzA Gel 15% was also well tolerated with minimal dryness and erythema. This open label pilot study demonstrated that AzA Gel 15% is a safe and effective treatment for PIH in skin of color patients with acne.

Dr. Leon H. Kircik has served as an investigator, speaker, consultant or advisory board member for Allergan, Amgen, Astellas Pharma US, Colbar, CollaGenex, Connetics Corporation, Ferndale Laboratories, Galderma, Genentech, Intendis, Johnson & Johnson, Leo Pharma, 3M, Nano Bio, Vovartis AG, Onset Therapeutics, OrthoNeutrogena, Promius, PharmaDerm, Skin- Medica, Stiefel, Valeant, Warner-Chilcott; a speaker for Abbott Laboratories, Dermik, Embil, Innovail, Merck Serono and Triax; an investigator for Acambis, Asubio, Bayer HealthCare, Biolife, Biopelle, Breckinridge Pharma, Centocor, Combinatrix, Coria, Dow Pharmaceutical Sciences, Dusa, GSK, Health Point, Medicis, Nucryst, Obagi, QLT, Pfizer, QuatrixTolerRx and UCB; and as a consultant for Laboratory Skin Care, Medical International Technologies and ZAGE.