MIAMI – Psoriasis often presents differently in skin of color patients, but an unanswered question remains: Does response to treatment with an agent like a fixed-dose combination foam also differ by ethnicity?

Researchers at Mount Sinai St. Luke’s Hospital in New York addressed this question using phase 2 and 3 study data for 1,104 people with psoriasis, about half of whom were randomized to topical treatment with calcipotriene and betamethasone dipropionate foam 0.005%/0.064% (Enstilar); the rest received a single component or vehicle only. The data were obtained from LEO Pharma, the product’s manufacturer.

“We were very interested in knowing if there was any difference in efficacy between the specific ethnic groups – the skin of color and non–skin of color patients,” said Bridget Kaufman, MD, a dermatopharmacology fellow at Mount Sinai St. Luke’s Hospital. “So we went back to look at the data to see if there was any difference in side effects or efficacy between ethnic groups.”

Strength in numbers?

The three randomized, pooled clinical studies included many ethnic groups. However, only 6.5% of participants were black and even fewer were Asian, American Indian, or native Hawaiian, Dr. Kaufman said. “It’s hard to see meaningful differences when you don’t have a substantial skin of color population.”

As a result, no significant associations emerged from the pooled data. “That is the main take-home message of this study: We don’t have a great understanding now of the difference in efficacy between white and nonwhite ethnic groups,” Dr. Kaufman said.

The researchers defined treatment success at 4 weeks as a two-point improvement to “clear” or “almost clear” on the Investigator Global Assessment of psoriasis. Of the adult participants with chronic plaque psoriasis randomized to the combination foam product, 54% of the white patients; 30% of black patients; 69% of Asian patients; and one of the two Hawaiian/Pacific Islander patients achieved treatment success after 4 weeks of topical treatment.

“All subgroups analyzed had a good response to treatment at 4 weeks. Numerically it appears African Americans in particular did not do quite as well, but we can’t [definitively] draw that conclusion,” Dr. Kaufman said in an interview.

More data, please

The study is just the first step in investigating the efficacy of this particular product in diverse ethnic groups, Dr. Kaufman added. “That really emphasizes the importance of studying these medications in skin of color populations in particular.”

More guidance on psoriasis in skin of color patients is available in a published review article by Dr. Kaufman and Andrew F. Alexis, MD, director of the Skin of Color Center at Mount Sinai St. Luke’s and Mount Sinai West, New York (Am J Clin Dermatol. 2017 Dec 5. doi: 10.1007/s40257-017-0332-7).

Enstilar manufacturer LEO Pharma supplied the clinical data but did not fund the study. Dr. Kaufman had no relevant financial disclosures.

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SOURCE: Kaufman B et al. ODAC 2018

Study highlights need to investigate psoriasis treatment outcomes in skin of color patients