Clinical outcomes by sex with atezolizumab (atezo) monotherapy in patients (pts) with locally advanced/metastatic urothelial carcinoma (mUC)

Abstract

Background: In this study, we investigated whether outcomes with atezo (anti‐PD‐L1) monotherapy in mUC varied between women and men across Phase (Ph) 1‐3 trials in different treatment settings. Methods: In this post hoc analysis, we assessed baseline characteristics, objective response rate (ORR; RECIST 1.1) and overall survival (OS) outcomes by sex in pts with previously treated mUC (Ph 1, PCD4898g; Ph 2, IMvigor210 Cohort 2; Ph 3, IMvigor211; Ph 3b, SAUL) and cisplatin‐ineligible, untreated mUC (Ph 2, IMvigor210 Cohort 1). Results: Across cohorts, 2459 pts were evaluated (including 464 in the IMvigor211 chemo arm); 22% were female (Table). Age was generally similar by sex, except in IMvigor210 Cohort 1 (median age: female, 77 y; male, 72 y). Median body mass index (BMI) was also similar by sex, except in PCD4898g (female, 23 kg/m2; male, 28 kg/m2). ECOG PS varied by sex across studies, but no consistent trend was seen. Median treatment duration was similar in females vs males, except in PCD4989g (44 d vs 108 d) and IMvigor210 Cohort 1 (123 d vs 106 d). ORR tended to be numerically higher in males (except in IMvigor210 Cohort 1; Table), although no statistically significant differences in ORR were seen except in IMvigor210 Cohort 2. Follow‐up (Table) and treatment discontinuation varied by trial but were similar by sex. Median OS was similar by sex across studies; in the only randomised study, IMvigor211, no significant difference in OS benefit with atezo (vs chemo) by sex was seen (HR [95% CI]: female, 0.87 [0.64, 1.18]; male, 0.83 [0.69, 0.98]; P=0.7462). Data evaluating disease and treatment characteristics by sex and outcomes accounting for potential confounders will be presented. Conclusions: No significant OS differences by sex were seen across all Ph 1‐3 atezo mUC studies. ORR was numerically higher in male pts with previously treated mUC, with less‐pronounced differences in larger studies (e.g., IMvigor211, SAUL). (Table Presented).