STENDRA was evaluated in four randomized, double-blind, placebo-controlled, parallel trials of 2 to 3 months in duration. STENDRA was taken as needed at doses of 50 mg, 100 mg, and 200 mg (Study 1) and 100 mg and 200 mg (Study 2, Study 3 and Study 4). Patients were instructed to take 1 dose of study drug approximately 30 minutes (Study 1 and Study 2) or approximately 15 minutes (Study 4) prior to initiation of sexual activity. Food and alcohol intake was not restricted.

In addition, a subset of patients from 2 of these trials were enrolled into an open-label extension trial. In the open-label extension trial, all eligible patients were initially assigned to avanafil 100 mg. At any point during the trial, patients could request to have their dose of avanafil increased to 200 mg or decreased to 50 mg based on their individual response to treatment.

The 3 primary outcome measures in Studies 1, 2 and 3 were the erectile function domain of the International Index of Erectile Function (IIEF) and Questions 2 and 3 from Sexual Encounter Profile (SEP). The IIEF is a 4-week recall questionnaire that was administered at baseline and at 4-week intervals during treatment. The IIEF erectile function domain has a 30-point total score, where the higher scores reflect better erectile function. The SEP included diary-based measures of erectile function. Patients recorded information regarding each sexual attempt made throughout the trial. Question 2 of the SEP asks "Were you able to insert your penis into your partners vagina?" Question 3 of the SEP asks "Did your erection last long enough for you to have successful intercourse?"

In Study 4, the primary efficacy variable was the per-subject proportion of sexual attempts that had an erectogenic effect within approximately 15 minutes following dosing, where an erectogenic effect was defined as an erection sufficient for vaginal penetration and that enabled satisfactory completion of sexual intercourse.

Results are shown from the three, Phase 3, randomized, double-blind, placebo-controlled, parallel studies, one in the general ED population (Study 1), another in the diabetic population with ED (Study 2), and another in the radical prostatectomy population (Study 3).

Results in the General ED Population (Study 1): 

STENDRA was evaluated in 646 men with ED of various etiologies (organic, psychogenic, mixed), in a randomized, double-blinded, parallel, placebo controlled fixed dose trial of 3 months duration. The mean age was 55.7 years (range 23 to 88 years). The population was 85.6% White, 13.2% Black, 0.9% Asian, and 0.3% of other races. The mean duration of ED was approximately 6.5 years. STENDRA at doses of 50 mg, 100 mg, and 200 mg demonstrated statistically significant improvement in all 3 primary efficacy variables relative to placebo (see Table 7).

Results in the ED Population with Diabetes Mellitus (Study 2)

STENDRA was evaluated in ED patients (n=390) with type 1 or type 2 diabetes mellitus in a randomized, double-blind, parallel, placebo-controlled fixed dose trial of 3 months in duration. The mean age was 58 years (range 30 to 78 years). The population was 80.5% White, 17.2% Black, 1.5% Asian, and 0.8% of other races. The mean duration of ED was approximately 6 years. In this trial, STENDRA at doses of 100 mg and 200 mg demonstrated statistically significant improvement in all 3 primary efficacy variables as measured by the erectile function domain of the IIEF questionnaire; SEP2 and SEP3 (see Table 8).

Results in the ED Population following Radical Prostatectomy (Study 3) 

The efficacy of STENDRA was evaluated in Study 3 (NCT00895011), a randomized, double-blind, parallel, placebo-controlled fixed dose trial of 3 months in duration. For study inclusion, patients had to have ED following bilateral, nerve-sparing radical prostatectomy. Patients received STENDRA 100 mg or 200 mg once daily. A total of 286 patients were included in the efficacy population: mean age 58.4 years (range 40 to 70 years), 81.5% White, 18.1% Black and 0.3% of other races. Treatment with STENDRA at doses of 100 mg and 200 mg demonstrated statistically significant improvement in all 3 primary efficacy variables relative to placebo (see Table 9).

Time to Onset of Effect (Study 4)

STENDRA was evaluated in 440 subjects with ED including diabetics (16.4%) and subjects with severe ED (41.4%) in a randomized double-blind, parallel, placebo-controlled study of 2 months duration. The mean age was 58.2 years (range 24 to 86 years). The population was 75.7% White, 21.4% Black, 1.6% Asian, and 1.4% of other races. Subjects were encouraged to attempt intercourse approximately 15 minutes after dosing and used a stopwatch for measurement of time to onset of effect, defined as the time to the first occurrence of an erection sufficient for sexual intercourse.

STENDRA 100 mg and 200 mg demonstrated statistically significant improvements relative to placebo in the primary efficacy variable, percentage of all attempts resulting in an erection sufficient for penetration at approximately 15 minutes after dosing followed by successful intercourse (SEP3) (see Table 10).

*comparison to placebo using rank-ANCOVA model.