(025) Efficacy and Safety of Tunodafil Hydrochloride for Men with Erectile Dysfunction: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Phase III Trial

Introduction Tunodafil hydrochloride is a novel, highly selective, and potent oral phosphodiesterase type 5 inhibitor developed for the treatment of erectile dysfunction (ED). Objective To evaluate the efficacy and safety of tunodafil in men with ED. Methods This multicenter, randomized, double-blind, placebo-controlled Phase III trial enrolled men aged 18–65 years with ED (IIEF-5 ≤21; duration ≥6 months). Subjects were randomly assigned (1:1:1) to receive on-demand tunodafil 50 mg, tunodafil 100 mg, or placebo for 12 weeks. Primary efficacy endpoints were (i) change from baseline in the International Index of Erectile Function–Erectile Function (IIEF-EF) domain score and (ii) the proportions of “Yes” responses to Sexual Encounter Profile (SEP) Questions 2 (successful penetration) and 3 (successful intercourse). Secondary endpoints included the proportion achieving IIEF-EF ≥26, changes in other IIEF domain scores. Safety was monitored throughout via treatment-emergent adverse events (TEAEs), vital signs, clinical laboratory tests, and electrocardiograms. Results Of 780 randomized men, 727 (93.2%) completed treatment. After 12 weeks of treatment, the mean changes from baseline in IIEF-EF were 6.7 (placebo), 9.5 (50 mg), and 10.8 (100 mg) (both P < 0.001 vs placebo). Increases from baseline in the proportion of affirmative responses were 22.43%, 31.16%, and 35.34% for SEP Q2 and 38.14%, 53.03%, and 59.57% for SEP Q3 in the placebo, 50 mg, and 100 mg groups, respectively (all P < 0.001). The proportion achieving normal erectile function (IIEF-EF ≥26) was 52.4% with 50 mg and 61.0% with 100 mg, both higher than placebo (both P < 0.001). Other IIEF domain scores, including orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction, also improved with tunodafil versus placebo (all P < 0.001). The most frequently reported drug-related TEAEs (incidence ≥2%) included dizziness, headache, flushing, palpitations, dry mouth, nasal congestion, and elevations in ALT or AST levels. Most adverse events were mild or transient and resolved without intervention. Conclusions Tunodafil significantly improved erectile function and sexual satisfaction with good tolerability and no serious adverse events, supporting its use as a safe and effective on-demand treatment for ED. Registered at the Chinese Clinical Trial Registry (ChiCTR): CTR20211201. Disclosure Yes, this is sponsored by industry/sponsor: Yangtze River Pharmaceutical Group Co, Ltd., Taizhou, China Clarification: Industry initiated, executed and funded study