Efficacy and safety of secukinumab treatment in adults with extensive alopecia areata

Alopecia areata (AA) is a common form of non-scarring hair loss. The pathogenesis of AA is believed to involve multiple inflammatory cytokines, including possibly IL-17A. To assess the efficacy and safety of the IL-17A antagonist secukinumab in AA, we conducted a double-blinded, randomized prospective pilot study in which 11 subjects were treated with either secukinumab (n = 7) or placebo (n = 4) subcutaneously at weeks 0, 1, 2, 3, 4 and every 4 weeks thereafter until (inclusive of) week 20. The primary endpoint for the study was the percentage of patients achieving SALT50 at 24 weeks. A total of three subjects out of 11 completed the study through the primary endpoint, and therefore, we used the last observation carried forward method to analyze the missing data. At the primary endpoint or last completed observation, 0% (0/7) of the secukinumab-treated subjects achieved a 50% reduction in SALT score (SALT50), and likewise, 0% (0/4) of the placebo-treated subjects achieved SALT50. In the secukinumab group, one (14.3%) subject had some hair regrowth, one (14.3%) subject had worsening hair loss, and five (71.4%) subjects had no change in response to treatment. No adverse events attributable to the study drug were observed. The lack of a treatment response to most of our treated patients suggests that the TH17/IL-17 axis likely has no pathogenic role in AA and an alternative therapeutic approach should be considered for this disease. However, due to the low statistical power of this study, future studies may be required to corroborate these findings.