Background: In EMBARK (NCT02319837), enzalutamide (ENZ) + leuprolide (L) or ENZ (ENZ mono) delayed metastasis-free survival vs placebo (P) + L while maintaining high quality of life (QoL) in high-risk biochemically recurrent nonmetastatic hormone-sensitive prostate cancer. SA (a composite score from European Organization for Research and Treatment [Tx] of Cancer QoL Questionnaire-Prostate 25 [QLQ-PR25]) was better preserved with ENZ mono vs P + L with no difference between ENZ + L vs P + L. To better understand effect on SA in relevant subgroups, we examined SA in pts who were sexually active or interested in sex at BL. Methods: QoL was assessed (BL, every 12 weeks) until metastasis/death. Cox regression was used to examine time to confirmed deterioration (TTCD) (confirmed at next visit) defined by one category change for sexual interest, activity, satisfaction, erectile function, and feeling like a man using QLQ-PR25 and FACT-P items (Table).Intent-to-treat analysis was applied. Results: Among pts interested in sex (n=694) or sexually active (n=437) at BL, TTCD in QLQ-PR25 SA domain, items 50 (interest), 51 (activity), GS7 (satisfaction), and BL5 (erectile function) were significantly delayed with ENZ mono vs P + L. In contrast, TTCD in BL5 (erectile function) was shorter with ENZ + L vs. P + L (Table). Conclusions: Among pts who were interested in sex or sexually active at BL, ENZ mono better preserved SA vs P + L in terms of SA domain, interest, activity, satisfaction, and maintaining erection. Adding ENZ to L had no impact on interest, activity, or satisfaction but may adversely affect erectile function, though differences in the median TTCD were clinically non-significant (0.06 months [1.8 days] and 0.09 months [2.7 days] in pts interested in sex and sexually active at BL, respectively). Clinical trial information: NCT02319837.

CI: confidence interval; HR, hazard ratio.