Limited Systemic Exposure with Topical Glycopyrronium Tosylate in Primary Axillary Hyperhidrosis.

BACKGROUND: Glycopyrronium tosylate (GT; Qbrexza® [glycopyrronium] cloth, 2.4%) is a topical anticholinergic approved (USA) for primary axillary hyperhidrosis in patients aged ≥ 9 years. OBJECTIVE: The objective of this study was to compare the pharmacokinetics and safety of GT to oral glycopyrrolate (phase I study) and assess the relationship between glycopyrronium pharmacokinetics and anticholinergic-related adverse events or efficacy with population pharmacokinetics using data from two phase II studies. METHODS: In the phase I study, study staff applied GT to axillae of patients with primary axillary hyperhidrosis (aged 9-65 years) once daily (5 days); oral glycopyrrolate was administered to healthy adults (aged 18-65 years) every 8 hours (15 days). In the phase II studies (NCT02016885 [20 December, 2013], NCT02129660 [2 May, 2014]), adults with primary axillary hyperhidrosis applied topical glycopyrronium (0.8-3.2%) or vehicle to axillae once daily (4 weeks). Pharmacokinetic and adverse event data were collected in all studies. RESULTS: Glycopyrronium pharmacokinetic parameters were similar between adult and pediatric patients treated with GT; there was no evidence of accumulation. Systemic absorption of glycopyrronium was lower with GT vs oral glycopyrrolate. No anticholinergic-related adverse events occurred with GT in the phase I study, while dry mouth and nasal dryness occurred with oral glycopyrrolate; anticholinergic adverse events occurred in the phase II studies. In the population pharmacokinetic analysis, frequency/severity of anticholinergic-related adverse events increased with higher glycopyrronium concentration; no relationship was observed between efficacy and pharmacokinetic measures. CONCLUSIONS: These studies indicate limited absorption of GT compared to oral glycopyrrolate and a low risk of anticholinergic adverse events with proper GT administration when following instructions for use (wipe each underarm once with same cloth, wash hands, avoid ocular contact).

A 44-Week Open-Label Study Evaluating Safety and Efficacy of Topical Glycopyrronium Tosylate in Patients with Primary Axillary Hyperhidrosis.

BACKGROUND: Glycopyrronium tosylate is a topical anticholinergic approved in the USA for primary axillary hyperhidrosis in patients aged ≥ 9 years (Qbrexza™ [glycopyrronium] cloth, 2.4%). OBJECTIVE: This 44-week open-label extension study assessed glycopyrronium tosylate safety and descriptive efficacy in patients completing one of two, phase III, double-blind, vehicle-controlled, 4-week trials (NCT02530281; NCT02530294). METHODS: Patients aged ≥ 9 years with primary axillary hyperhidrosis were randomized 2:1 (glycopyrronium tosylate: vehicle, once daily) in the double-blind trials. Completers could receive open-label glycopyrronium tosylate for up to an additional 44 weeks. Treatment-emergent adverse events and local skin reactions were assessed. Descriptive efficacy assessments were gravimetrically measured sweat production, Hyperhidrosis Disease Severity Scale responder rate (≥ 2 grade improvement), and Dermatology Life Quality Index/children's Dermatology Life Quality Index. RESULTS: Of 651 patients completing the double-blind trials, 564 (86.6%) entered the open-label extension; 550 were analyzed. Most patients experiencing treatment-emergent adverse events had mild or moderate events (> 90%). Discontinuation because of treatment-emergent adverse events remained low and relatively stable, with a cumulative rate of 8.0% (44/550) over 44 weeks. Common treatment-emergent adverse events (> 5%) were dry mouth (16.9%), vision blurred (6.7%), application-site pain (6.4%), nasopharyngitis (5.8%), and mydriasis (5.3%). Most patients (67.5%) had no local skin reactions; those occurring were predominantly mild/moderate. Glycopyrronium tosylate efficacy was maintained throughout the trial; at week 44, the Hyperhidrosis Disease Severity Scale responder rate was 63.2%, and improvements from baseline (double blind) in sweat production were - 71.3% and 8.7 ± 6.2/6.2 ± 4.9 for Dermatology Life Quality Index/children's Dermatology Life Quality Index. CONCLUSIONS: Daily long-term application of glycopyrronium tosylate for up to 48 weeks (double blind plus open label) was generally well tolerated and efficacy was maintained. No new safety signals emerged. TRIAL REGISTRY: Clinicaltrials.gov NCT02553798.