Effective topical treatment options for patients with primary axillary hyperhidrosis are limited. Recent phase 1 trial showed promising results regarding efficacy and safety for topical cream containing glycopyrronium bromide (GPB).To assess efficacy, safety and tolerability of a 4-week topical treatment with 1% GPB cream in subjects with primary axillary hyperhidrosis compared to placebo.171 patients (84 placebo; 87 1% GPB) with primary axillary hyperhidrosis were included in this 4 week, multicenter, randomised, double-blind, placebo-controlled Phase 3a part of the pivotal study. Sweat production was measured by gravimetry. Patients rated disease impact using the Hyperhidrosis Disease Severity Scale (HDSS) and Hyperhidrosis Quality of Life Index (HidroQoL© ).Absolute change in sweat production from baseline to day 29 in logarithmic values was significantly larger in the 1% GPB group than in the placebo group (p=0.0038). The improvement in HidroQoL© exceeded minimal clinically important difference of 4. The proportion of responders was two-fold higher than for placebo for sweat reduction, HDSS and HidroQoL© (-197.08 mg GPB vs. -83.49 mg placebo; 23% GPB vs 11.9% placebo and 59.8% GPB vs. 26.2% placebo respectively). Treatment was safe, most TEAEs were mild or moderate and transient. Local tolerability was very good with 9.2% of patients having only mild or moderate application site reactions. The most reported ADR was dry mouth (16.1%), an expected anticholinergic effect of the treatment.1% GPB cream may provide an effective new treatment option exhibiting a good safety profile for patients with primary axillary hyperhidrosis. The long-term open-label part (Phase 3b) is ongoing.