乌鸦传媒

WASHINGTON -- The PDE-5 inhibitor class of drugs for erectile dysfunction gained its first new member in a decade with the FDA approval of avanafil (Stendra).

The FDA based its decision largely on results of three randomized, placebo-controlled clinical trials involving a total of 1,267 men with diagnosed erectile dysfunction.

After treatment for 12 weeks, men randomized to the PDE-5 inhibitor had significantly greater improvement in the three principal endpoints of erectile dysfunction, vaginal penetration, and successful intercourse.

"This approval expands the available treatment options to men experiencing erectile dysfunction and enables patients, in consultation with their doctor, to choose the most appropriate treatment for their needs," Victoria Kusiak, MD, of the FDA Center for Drug Evaluation and Research, said in a statement.

Increased receptor selectivity and a shorter half-life are the key features distinguishing avanafil from other members of the PDE-5 (phosphodiesterase type 5) inhibitor class: sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra).

Men take avanafil on an as-needed basis 30 minutes before sexual activity.

Investigators in one of the randomized trials reported that men achieved erections as soon as 15 minutes after taking the drug. The rate of erections sufficient for intercourse increased from less than 15% to as much as 57% with avanafil versus 27% with placebo.

According to the FDA, the most commonly reported side effects in clinical trials of avanafil were headache, flushing, nasal congestion, nasopharyngitis, and back pain. A 40-week extension study involving patients from two of the randomized trials showed no increase in the frequency or severity of adverse effects associated with avanafil.

The drug is marketed by VIVUS of Mountain View, Calif.