Azelaic acid reduces truncal acne

Despite the high frequency with which truncal acne accompanies facial acne, patients with truncal acne have fewer effective topical treatments. An investigator-initiated pilot study shows that azelaic acid (AzA) 15 percent foam could provide an appropriate off-label option.¹

Azelaic acid foam 15 percent is FDA-approved for rosacea. "On the other hand, azelaic acid 15 percent gel is approved for both rosacea and acne in Europe. And azelaic acid 20 percent cream is approved in the United States for acne," said Leon H. Kircik, M.D., of Indiana University School of Medicine in Indianapolis.

Because there is a foam formulation of azelaic acid, said Dr. Kircik, "I thought it would be prudent to see if it works for acne on the chest and back because foam is good for large body surface areas."

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The difficulty of covering large areas with previous topical vehicles generally left clinicians treating truncal acne to rely on oral therapies because they are assumed to provide greater efficacy, he said.

"While this line of reasoning may hold up with the use of standard creams and gels, it is challenged with the advent of foam formulations," Dr. Kircik and colleagues wrote in a June 2017 issue of the Journal of Drugs in Dermatology.

Acne experts believe that the rapid dispersal and enhanced percutaneous absorption of the new azelaic acid foam formulation versus other vehicle types will improve its pharmacological activity.²

Putting AZA foam to the test

Dr. Kircik and Las Vegas-based James Q. Del Rosso, D.O., of JDR Dermatology Research/Thomas Dermatology, enrolled a total of 20 patients (9 males, 11 females) with moderate truncal acne (Investigator Global Assessment/IGA score of at least three: some to many noninflammatory lesions and possibly some inflammatory lesions; one or zero small nodular lesions). Investigators instructed patients to apply the study medication sparingly to affected areas twice daily for 16 weeks. Patients could also use the product on facial acne if desired. Ultimately, 14 patients completed the study. Results for four patients lost to follow-up were imputed using the last observation carried forward (LOCF) method.

At week 16, 16 of 18 patients (89%) experienced a one-grade reduction in truncal IGA from baseline; initially, all but one patient (who had IGA 4) had an IGA score of 3. At week 16, 8 subjects (44%) were rated as clear or almost clear of truncal acne. Additionally, 9 patients experienced a one-grade improvement from baseline by week 16. Regarding facial acne, 61% of patients were clear or almost clear at week 16.

Among secondary endpoints for truncal acne, said Dr. Kircik, "There were significant reductions in mean lesion counts in the first 4 weeks of treatment, which is important because it tells you about the medication's early onset of action." These reductions persisted throughout the study's duration, he added.

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Versus baseline, mean inflammatory lesion counts fell 36%, 57%, 66% and 71% at weeks four, eight, 12 and 16, respectively (p<0.05 in all analyses). Noninflammatory lesion counts decreased by 30%, 43%, 54% and 60% at the foregoing follow-up visits, and total lesion counts declined 35%, 52%, 63% and 61%, respectively (p<0.05 in all analyses). 

Assessing adverse events

The product also showed high tolerability, said Dr. Kircik. "From baseline through week 16, one patient experienced a trace of erythema." Throughout the study, he said, a total of 10 trace or mild adverse events occurred, and all resolved without treatment by the next visit. Additionally, two patients experienced mild pruritus and burning at week 16. The study medication's high-quality emulsion foam is helpful, he said, because unlike the previously available AzA gel formulation, it very rarely irritates. This fact can improve patient compliance with treatment, he added.

The study also included a comprehensive patient preference questionnaire. Regarding any topical vehicles patients had previously used, results revealed a slight preference for sprays, and roughly equal preference between gel, lotion, cream and ointment. The study medication compared well to these medications, Dr. Kircik said, with average responses ranging from "about the same" to "better."

One limitation of patient preference studies is that typically they require patients to compare a drug only to what they personally have used in the past. "There's always a limitation numerically in comparing what they have used in the past to what they are using now." It can become difficult to amass meaningful numbers, he said, because not everybody in the study had used other formulations. "But when you don't know who used what, you have to ask about everything."

One might criticize the study's small size and open-label design, said Dr. Kircik, but he said the drug's approval for acne in Europe obviates the need for a control group. "We already know that it works." Key study strengths include its 16-week duration, versus the typical 12 weeks for acne studies, he said, and the fact that statistically significant results appeared by week 4 and persisted.

DISCLOSURES

Dr. Kircik has been a consultant, advisor or speaker for Bayer, Galderma, Aqua/Almirall, LaRoche Posay, Dermira, Allergan, Novan, Valeant, Sun Pharma and Promius. Dr. Del Rosso is a researcher, consultant and speaker for Bayer Dermatology and for several companies who develop and/or market acne products including Allergan, Aqua/Almirall, BiopharmX, Cutanea, Dermira, Galderma, Novan, Promius, Sebacia, Sun Pharma and Valeant. This investigator-initiated study was funded by Bayer.

REFERENCES 

1. Hoffman LK, Del Rosso JQ, Kircik LH. The efficacy and safety of azelaic acid 15% foam in the treatment of truncal acne vulgaris. J Drugs Dermatol. 2017;16(6):534-538.

2. Del Rosso JQ. Using a foam vehicle for dermatologic applications. The Dermatologist. 2002;10. (http://www.the-dermatologist.com/article/625).