A 1% glycopyrronium bromide cream for topical treatment of severe primary axillary hyperhidrosis in adolescents: safety, local tolerability, systemic exposure and efficacy from an open‐label phase II study

BACKGROUND AND OBJECTIVES: Primary axillary hyperhidrosis (PAHH) results from dysregulation of the autonomic nervous system and typically begins during puberty. Treatment options for adolescents remain limited. This open-label phase II study evaluated the safety, local tolerability, systemic exposure, and efficacy of 1% GPB cream over 8 weeks in adolescents with severe PAHH. PATIENTS AND METHODS: A total of 42 adolescents (23 male [55%] and 19 female [45%]; aged 12-17 years) applied the cream once daily for the first 4 weeks and thereafter as needed (at least twice weekly but no more than once daily). The primary endpoints assessed adverse drug reactions (ADRs), local tolerability, and systemic glycopyrronium exposure. Changes in sweat production, PAHH severity, and quality of life were assessed in all patients. RESULTS: Two patients experienced mild ADRs (dry eye and increased conjugated bilirubin in one patient each); no serious adverse events occurred. All 40 evaluable patients had a skin reaction score of 0 throughout treatment. Total sweat production decreased significantly from baseline to day 29 (p < 0.001) and day 57 (p < 0.001). Patient-rated hyperhidrosis severity (PRHS) and quality of life, assessed using the Children's Dermatology Life Quality Index (CDLQI), also improved significantly at both time points (all p < 0.001). CONCLUSIONS: 1% GPB cream showed favorable safety and tolerability and improved clinical outcomes in adolescents with severe PAHH, consistent with findings in adults.