Efficacy and Safety of Vibegron Add‐On Therapy for Persistent Overactive Bladder Symptoms in Benign Prostatic Hyperplasia Patients With α ₁ ‐Blocker Treatment: A Multi‐Center Prospective Randomized Controlled Study ( VATON Study)

Objectives To evaluate the efficacy and safety of vibegron add‐on therapy for persistent overactive bladder (OAB) symptoms after α 1 ‐blocker monotherapy for benign prostatic hyperplasia (BPH). Methods Eligible patients were aged ≥ 50 years and diagnosed with BPH. All patients had received an α 1 ‐blocker for ≥ 8 weeks, yet had persistent OAB symptoms. Patients were randomized 1:1 to receive add‐on vibegron (50 mg) or to continue α 1 ‐blocker monotherapy. The primary efficacy endpoint was the between‐group difference from baseline (week 0) to week 12 in total overactive bladder symptom score (OABSS). Secondary endpoints included bladder diary parameters, OABSS subscores; International Prostate Symptom Score total, storage/voiding, quality‐of‐life score; and patient satisfaction assessed by the Patient Global Impression. Safety was assessed by recording treatment‐emergent adverse events. Results Overall, 158 patients were randomized into two groups ( n = 79 each). The least‐squares mean change in the primary endpoint (OABSS total score) was −1.9 (95% confidence interval [CI]: −2.4 to −1.5) with α 1 ‐blocker monotherapy and −3.3 (95% CI: −3.8 to −2.9) with vibegron add‐on therapy; the between‐group difference was −1.4 (95% CI: −2.0 to −0.8; p < 0.001), indicating a significant improvement with add‐on therapy. Across the secondary endpoints, favorable outcomes were observed. Higher satisfaction was reported in the vibegron add‐on therapy group than in the α 1 ‐blocker monotherapy group. Vibegron was well tolerated, and no serious drug‐related treatment‐emergent adverse events were observed. Conclusions Vibegron add‐on therapy to an α 1 ‐blocker may be effective and safe for treating BPH with persistent OAB symptoms.