Overall survival subgroup analyses for prior taxane use in the phase 3 ROSELLA trial of relacorilant plus nab-paclitaxel versus nab-paclitaxel monotherapy in patients with platinum-resistant ovarian cancer (GOG-3073, ENGOT-ov72, APGOT-Ov10, LACOG-022

5503 Background: Relacorilant is a first-in-class, selective glucocorticoid receptor antagonist that increases tumor sensitivity to chemotherapy-induced apoptosis. The phase 3 ROSELLA trial of relacorilant plus nab-paclitaxel in patients with platinum-resistant ovarian cancer (PROC) recently reported statistically significant results for the dual primary endpoints of progression-free survival (PFS) and overall survival (OS). The relacorilant combination was well tolerated and the safety profile was similar to nab-paclitaxel monotherapy. Here we present final OS subgroup analyses for prior taxane use. Methods: Patients (n = 381) were randomized 1:1 to relacorilant (150 mg PO the day before, of, and after nab-paclitaxel) plus nab-paclitaxel (80 mg/m 2 IV on days 1, 8, and 15 of each 28-day cycle) or nab-paclitaxel alone (100 mg/m 2 IV on the same schedule). The final OS analysis was performed after 288 deaths had been reported (76% maturity). The hazard ratio (HR) was estimated with a Cox regression model with treatment group as the main effect and stratification factors at randomization as covariates. Kaplan-Meier methods were used to estimate medians and generate survival curves. Results: At a median follow-up of 24.8 months, the addition of relacorilant to nab-paclitaxel resulted in a statistically and clinically significant improvement in OS (HR 0.65; 95% confidence interval [CI], 0.51 to 0.83; P = 0.0004). Median OS in the relacorilant combination arm was extended by 4.1 months compared with the nab-paclitaxel monotherapy arm (16.0 vs 11.9 months). Prior taxane use was almost universal (n = 379/381, 99.5%). A consistent OS benefit was observed irrespective of the taxane-free interval: taxane-free interval ≤6 months (n = 55, HR 0.60 [95% CI, 0.31 to 1.15], median difference 5.7 months) and taxane-free interval > 6 months (n = 324, HR 0.66 [95% CI, 0.51 to 0.86], median difference 3.6 months). Moreover, a consistent OS benefit was observed irrespective of whether a taxane was used in the most recent regimen: taxane in the last regimen (n = 73, HR 0.67 [95% CI, 0.38 to 1.19], median difference 3.9 months) and no taxane in the last regimen (n = 308, HR 0.63 [95% CI, 0.48 to 0.82], median difference 4.2 months). Additional safety data will be presented. Conclusions: ROSELLA met both dual primary endpoints. Relacorilant plus nab-paclitaxel demonstrated a statistically and clinically significant OS benefit in patients with PROC compared to a weekly taxane, the most efficacious chemotherapy. Subgroup analyses for OS showed a consistent benefit favoring the addition of relacorilant to nab-paclitaxel irrespective of prior taxane use. Clinical trial information: NCT05257408 .