A phase III, 52‐week, open‐label study to evaluate the safety and efficacy of 5% sofpironium bromide (BBI‐4000) gel in Japanese patients with primary axillary hyperhidrosis

A long‐term study was conducted in Japanese patients with primary axillary hyperhidrosis who completed the preceding 6‐week phase III, confirmatory study of 5% sofpironium bromide gel (hereinafter referred to as sofpironium) to evaluate the safety and efficacy of 52‐week treatment with sofpironium. In the long‐term study, 185 patients who completed the confirmatory study (94 and 91 patients in the vehicle and sofpironium groups, respectively) started to receive sofpironium (switching and extension groups, respectively), and all these patients were included in both the full analysis set (FAS) and the safety analysis set (SAF). In the FAS, there were more females than males (73.0% vs. 27.0%), and median age was 38.0 years. A total of 161 patients (86 and 75 patients in the switching and extension groups, respectively) completed the study at week 52. The proportions of patients with hyperhidrosis disease severity score of 1 or 2 and a 50% or more reduction in total gravimetric weight of sweat were 57.4% in the switching group and 58.2% in the extension group at week 52. The proportions of patients who achieved this efficacy end‐point in the long‐term study were similar to that (53.9%) in the sofpironium group in the confirmatory study. In the SAF, the incidences of adverse events (AEs) were 80.9% in the switching group and 83.5% in the extension group, and the incidences of adverse drug reactions were 39.4% and 45.1%, respectively. AEs that occurred in at least 20% of patients in both treatment groups were application site dermatitis (25.5% and 33.0%, respectively) and nasopharyngitis (31.9% and 23.1%, respectively). Reported AEs were generally mild, and there were no deaths. Serious AEs occurred in three patients, but none were considered related to the study drug. In this study, the efficacy of sofpironium was maintained during 52‐week treatment, and no new safety risk was observed.