Vivus, Inc. announced positive results from a phase 3, placebo-controlled clinical trial of the investigational drug avanafil for the treatment of erectile dysfunction (ED) in patients following a radical prostatectomy. The study (REVIVE-RP, TA-303) met all primary endpoints by demonstrating improvement from baseline in erectile function as measured by the Sexual Encounter Profile (both SEP2 and SEP3) and improvements in the International Index of Erectile Function (IIEF). The detailed results of the study will be presented on June 17, 2011 at the Cancer Survivorship and Sexual Health Symposium in Washington, DC.
"Patients who have undergone a radical prostatectomy often have significant erectile dysfunction. Despite advancements in surgery, it can take several months or years to normalize erections. Radical prostatectomy patients are difficult to treat but the positive results of avanafil in these patients suggest that, if approved, avanafil could be an attractive treatment option," commented John Mulhall, M.D., director, Male Sexual & Reproductive Medicine Program, Memorial Sloan Kettering Cancer Center and an investigator in the study. "The trial met all the primary endpoints and detailed results of the study will be presented during the upcoming Cancer Survivorship Symposium to be held in Washington DC."
Consistent with other avanafil clinical studies, successful intercourse as measured by SEP 3 was observed as early as 15 minutes after the administration of avanafil. The most common side effects were headache, flushing and nasopharyngitis, and dropouts due to adverse events were low. There were no serious adverse events reported in the study.
The results of the TA-303 study are not required for the avanafil New Drug Application (NDA), but the final study report will be submitted to the FDA upon completion. Vivus expects to file the NDA for avanafil in the second quarter of 2011.
TA-303 was a randomized, double-blind, placebo-controlled, parallel group, multicenter study of the safety and efficacy of avanafil in the treatment of erectile dysfunction following bilateral, nerve-sparing, radical prostatectomy in 298 men with ED. On average, subjects entering the study were 58 years old, 19 months past their surgery dates and diagnosed with severe ED. Subjects were randomized to 100mg or 200mg avanafil or placebo and were instructed to take one dose of study drug 30 minutes prior to initiation of sexual activity. The study had a four-week run-in period followed by 12 weeks of treatment. The primary endpoints of the study were improvement in erectile function as measured by the SEP2 and SEP3 and improvements in the EF-Domain of the IIEF score; secondary endpoints included patient satisfaction with erections and with sexual experience.
In addition to TA-303, the avanafil phase 3 programme consists of three pivotal studies: TA-301 (REVIVE), TA-302 (REVIVE-Diabetes), and TA-314. TA-301 and TA-302 were randomized, double-blind, placebo-controlled phase 3 studies of avanafil in 646 and 390 men, respectively, with a history of ED for at least six months. Each of these trials had a similar trial design with patients undergoing a four-week, non-treatment run-in period followed by 12 weeks of treatment. Primary endpoints of the studies are improvement in erectile function as measured by the Sexual Encounter Profile (SEP) and improvements in the EF Domain score of the International Index of Erectile Function (IIEF). In both the TA-301 and TA-302 studies, all doses of avanafil met the primary endpoints, with successful intercourse achieved by some subjects as early as 15 minutes after dosing. TA-314 was an open label, long-term safety and efficacy study required as part of the NDA. In TA-314, patients also had significant improvement in erectile function that was maintained for up to 52 weeks as measured by SEP2, SEP3 and the IIEF. In total, the phase 3 avanafil clinical programme randomized approximately 1,350 subjects.
Avanafil is an investigational oral medication being developed for the treatment of erectile dysfunction. Avanafil is a highly selective phosphodiesterase type 5 (PDE5) inhibitor licensed from Mitsubishi Tanabe Pharma Corporation. With the exception of certain Asian Pacific Rim countries, Vivus owns worldwide development and commercial rights to avanafil for the treatment of sexual dysfunction.
Vivus is a biopharmaceutical company developing therapies to address obesity, sleep apnea, diabetes and male sexual health. The company's lead investigational product in clinical development, Qnexa, has completed phase 3 clinical trials for the treatment of obesity and is currently being considered for approval by US and EU regulators.