Impact of age, race, and medication use on efficacy endpoints in a randomized controlled trial of topical sildenafil cream for the treatment of female sexual arousal disorder

Background: A study of topical Sildenafil Cream 3.6% was completed among healthy premenopausal women with female sexual arousal disorder. Aims: To compare efficacy endpoints based on product use in pre-planned and post-hoc subsets of age, race, and medication use. Methods: Phase 2b, exploratory, randomized, placebo-controlled, double-blind study of Sildenafil Cream, 3.6% among healthy premenopausal women with female sexual arousal disorder (FSAD). Eligible participants were randomized 1:1 to Sildenafil versus Placebo Cream and used investigational product for 12 weeks. Outcomes: The co-primary efficacy endpoints were the change from baseline, at week 12, in the Arousal Sensation (AS) domain of the Sexual Function Questionnaire (SFQ28) and Question 14 (Q14) of the Female Sexual Distress Scale - Desire, Arousal, Orgasm (FSDS-DAO). The secondary efficacy endpoint was the change from baseline at week 12 in the mean number of satisfactory sexual events (SSEs) reported in a daily diary. Exploratory efficacy endpoints included the Desire and Orgasm domains of the SFQ28. Results: Age group (>= 18 years and <= 45 years versus >45 years), race group (White versus non-White), and baseline use/non-use of hormonal contraception did not significantly affect the co-primary endpoints of the SFQ28 AS domain and FSDS-DAO Q14 (P values >0.11). Non-White Sildenafil Cream users had an increase in SSEs at week 12 (0.7 +/- 0.63) while non-white Placebo Cream users reported a decrease (-1.5 +/- 0.58) (P = .02). Daily psychiatric medication use among women assigned to either Placebo or Sildenafil Cream resulted in lower SFQ28 Desire domain scores compared to non-users of these medications. Women who used study product only in un-partnered events had a larger improvement in their SFQ28 Orgasm domain scores at week 12 (2.39 +/- 0.95) with Sildenafil Cream use compared to Placebo (-0.19 +/- 0.75) (P = .06). Non-White women represented a higher proportion of un-partnered women and women who used IP only during un-partnered sexual events compared to White women (P < .01). Clinical Implications: These pre-planned subset analyses will help refine target populations in future studies of Sildenafil Cream, 3.6% for the treatment of FSAD. Strengths and Limitations Subset analyses focused on variables pertinent to future target populations. The current study population was primarily educated non-Hispanic White women. Conclusion: Age and hormonal contraceptive use did not impact the efficacy of topical Sildenafil Cream. Daily psychiatric medication use decreased sexual desire in active and placebo users.