Efficacy and Safety of DA-8010, a Novel M3 Antagonist, in Patients With Overactive Bladder: A Randomized, Double-Blind Phase 2 Study

Purpose: DA-8010 is a novel muscarinic M3 receptor antagonist with significant selectivity for bladder over salivary gland in preclinical studies. We evaluated the clinical efficacy and safety of DA-8010 in overactive bladder (OAB) patients. Methods: This phase 2, randomized, double-blind, parallel-group, active reference- and placebo-controlled trial was conducted at 12 centers in South Korea (NCT03566134). Patients aged ≥ 19 years with OAB symptoms for ≥ 3 months were enrolled. Three hundred six patients (30.07% male) were randomized to 12 weeks of treatment among 4 groups; 2 experimental groups (DA-8010 2.5 or 5 mg), an active reference group (solifenacin 5 mg), and a placebo group. The change from the baseline of (= ∆) 24-hour frequency at 12 weeks (primary endpoint), episodes of urgency, overall/urgency urinary incontinence, average/maximum voided volume, nocturia, and patients' subjective responses were analyzed. Results: In the full analysis set, the mean (standard deviation) [median] values for ∆ 24-hour frequency at 12 weeks were -1.01 (2.44) [-1.33] for placebo, -1.22 (2.05) [-1.33] for DA-8010 2.5 mg, and -1.67 (2.25) [-1.67] for DA-8010 5 mg; DA-8010 5 mg showed a significant decrease compared with placebo (P = 0.0413). At 4 and 8 weeks, both DA-8010 2.5 mg (P = 0.0391 at 4 weeks, P = 0.0335 at 8 weeks) and DA-8010 5 mg (P = 0.0001 at 4 weeks, P = 0.0210 at 8 weeks) showed significant decrease in ∆ 24-hour frequency compared with placebo. DA-8010 5 mg achieved a significant decrease in ∆ number of urgency episodes, compared with placebo at 4 (P = 0.0278) and 8 (P = 0.0092) weeks. Adverse drug reactions (ADRs) were observed in 3.95% of placebo, 6.67% of DA-8010 2.5 mg, 18.42% of DA-8010 5 mg, and 17.33% of solifenacin 5 mg groups. No serious ADRs were observed in any patient. Conclusions: Both DA-8010 2.5 mg and 5 mg showed therapeutic efficacy for OAB without serious ADRs. Therefore, both dosages of DA-8010 can advance to a subsequent large-scale phase 3 trial.