The fast-acting erectile dysfunction medication avanafil was approved by the Food and Drug Administration April 30 on the basis of findings from multiple phase-III trials demonstrating the safety and efficacy of the phosphodiesterase type 5 inhibitor, according to a statement from the agency.
The first new entry in the erectile dysfunction (ED) marketplace in nearly 10 years, avanafil (Stendra) joins the ranks of other PDE5 inhibitors approved for the treatment of ED and is expected to be a formidable competitor in the marketplace because it is a faster-acting agent associated with fewer side effects than the currently available options, including sildenafil citrate (Viagra), vardenafil (Levitra), and tadalafil (Cialis), according to Dr. Irwin Goldstein, director of the sexual medicine program at Alvarado Hospital in San Diego.
Dr. Goldstein was the lead investigator of the pivotal phase-III Research Evaluating an Investigational Medication for Erectile Dysfunction (REVIVE) trial in which 646 men with a history of ED for at least 6 months were randomized to 50-mg, 100-mg, or 200-mg of avanafil or placebo (J. Sex. Med. 2012;9:1122-33).
"We observed significant improvements in erectile function and low rates of side effects common to [the PDE5] drug class," Dr. Goldstein said in an interview. "Importantly, the majority of patients who attempted intercourse within 15 minutes of dosing were successful at all dosage levels," he said, noting that successful attempts were reported 64%, 67%, and 71% of the time with 50-mg, 100-mg, and 200-mg doses, respectively, compared with 27% for placebo.
In addition to the REVIVE trial, the avanafil development program included the REVIVE-Diabetes trial comprising 390 men with ED and diabetes and the REVIVE-RP trial comprising 298 men with ED following radical prostatectomy, as well as a year-long safety study of 712 continuation patients from the REVIVE and REVIVE-Diabetes trials, according to a statement issued by Vivus, manufacturer of the drug.
The combined highlights of the various studies showed statistically significant improvements relative to placebo in measures of erectile function, vaginal penetration, and successful intercourse at all three dosages, according the FDA.
The most common side effects, reported in more than 2% of the patients, were headache, facial flushing, nasal congestion, and back pain; there were no drug-related serious adverse events reported, the FDA said.
In the continuation study of patients who received up to 40 additional weeks of treatment, initially at the 100-mg dose and eventually maintained, increased, or decreased based on individual patient response, the side effects did not appear to worsen over time.
Dr. Goldstein disclosed financial relationships with BioSante, Boehringer Ingelheim, Medtronic, Pfizer, VIVUS, Alagin, Shionogi, Slate, Abbott, Ascend, Auxilium, Coloplast, and Warner Chilcott.