Avanafil, a pill that may permit diabetic men who are experiencing erectile dysfunction to engage in intercourse without the restrictions on food or alcoholic intake associated with other ED treatments, is entering a second phase 3 study-the crucial step before a drug manufacturer seeks FDA or European approval to market.

The drug, produced by the Mountain View, California-based company VIVUS, is described as a fast-acting, selective, oral phosphodiesterase type 5 inhibitor. VIVUS produces drugs aimed at treating obesity and sexual dysfunctions. 

ED is a common affliction among men with diabetes. The inflammatory disease often damages the vascular system, hampering the supply of blood to the penis that allows it to become erect. Data show that at least 50 percent of men with diabetes experience ED and that they are up to three times more likely than nondiabetic men to have ED. 

In the upcoming study, called REVIVE-Diabetes, approximately 375 type 1 and type 2 men who meet the criteria for participation will undergo four weeks of non-treatment followed by 12 weeks of treatment at 30 centers across the United States.

In the previous phase 2 study of Avanafil, 284 patients received the drug or a placebo. The efficacy of the drug was based on measuring the percentage of erections it induced that were sufficient for vaginal penetration and the percentage of erections lasting long enough for successful intercourse.

The drug produced erections sufficient for vaginal penetration 76, 79, 80, and 84 percent of the time with doses of 50, 100, 200, and 300 mg respectively. Erections lasting long enough for successful intercourse occurred in 54, 59, 62, and 64 percent of attempts with the respective doses noted above.

Subjects were asked to attempt intercourse 30 minutes after taking the pill, regardless of what food or alcohol they had consumed. The most common adverse event subjects experienced was headache, and there were no visual side effects from the drug. If the phase 3 trial goes well and Avanafil reaches market, VIVUS may offer it as a twice-daily treatment for men who would like to have intercourse more than once a day.