Objectives: To determine the effect of PSD502 applied topically 5 min before intercourse on the Index of Premature Ejaculation (IPE) and intravaginal ejaculatory latency time (IELT) of men with lifelong premature ejaculation (PE) defined according to the International Society of Sexual Medicine (ISSM) definition; secondary objectives were to evaluate the safety and tolerability of PSD502 in patients with PE, and their sexual partners.
Patients and methods: Men aged >18 years, in stable heterosexual, monogamous relationships, and with lifelong PE diagnosed according to both the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (text revision) criteria and the ISSM definition, consented (together with their partners) to enter the baseline period of the study. Patients who documented an IELT of <or=1 min with two or more of the first three sexual encounters during the 4-week baseline period were randomized, in a 2:1 ratio, to receive double-blind treatment with PSD502 (three actuations of spray each containing 7.5 mg lidocaine and 2.5 mg prilocaine applied 5 min before intercourse) or placebo for 3 months. Patients completed IPE and Premature Ejaculation Profile (PEP) questionnaires at entry and at monthly clinic visits, and recorded stopwatch-timed IELT during each sexual encounter. Patients rated the quality of their orgasms on a 5-point scale at baseline and at the end of the treatment period, and rated the study medication on a 4-point scale. Safety was assessed by collecting adverse event data.
Results: In all, 300 men with PE were randomized from 31 centres in Europe. The geometric mean (range) IELT over the 3-month treatment period increased from a baseline of 0.6 min in both groups to 3.8 (0.3-57.8) and 1.1 (0-15.0) min in the PSD502 and placebo groups, respectively. Adjusting for treatment-group imbalances, this represents a 6.3-fold and 1.7-fold increase in adjusted geometric means. There were significantly greater increases in the scores for the IPE domains of ejaculatory control and sexual satisfaction in the PSD502 group than in the placebo group, with a mean (sem) 7.0 (0.59)-point difference between treatments in change from baseline in the IPE domain for ejaculatory control and a 5.9 (0.57)- point difference in change from baseline in the IPE domain for sexual satisfaction (both P < 0.001). This was supported by improvements in all secondary endpoints. At the end of the treatment period 66% of patients rated PSD502 as 'good' or 'excellent'. PSD502 was well tolerated and no systemic adverse events were reported. Localized treatment-related adverse events were reported by 2.6% and 3.1% of patients and partners, respectively.
Conclusion: PSD502 applied topically 5 min before intercourse improved ejaculatory latency and significantly improved ejaculatory control and sexual satisfaction, factors relevant for acceptance of a PE treatment by both patient/physician and regulatory authorities. PSD502 was well tolerated by both patients and partners, with no systemic side-effects and a low incidence of localized effects, and was rated favourably by most users. PSD502 therefore appears to offer significant advantages over other therapies in development for the treatment of PE.