Patient-reported outcomes (PROs) from a randomized, phase 3 trial of enfortumab vedotin plus pembrolizumab (EV+P) versus platinum-based chemotherapy (PBC) in previously untreated locally advanced or metastatic urothelial cancer (la/mUC).

108 Background: EV+P nearly doubled median progression-free survival and overall survival vs PBC in patients (pts) with previously untreated la/mUC in the phase 3 EV-302 trial. PROs are reported here. Methods: In EV-302 (NCT04223856) pts were randomized 1:1 to EV+P or PBC (gemcitabine with cisplatin or carboplatin). PRO assessments included the EORTC Quality of Life Questionnaire (EORTC QLQ-C30), and the Brief Pain Inventory Short Form (BPI-SF) completed at baseline, weekly for 12 weeks (wks), then every 3 wks through survival follow-up, inclusive of the time post-progression. Time to pain progression (TTPP) and mean change from baseline in worst pain at wk 26 using the BPI-SF were prespecified analyses statistically tested using a gatekeeping strategy. Mean change from baseline through wk 26 and time to confirmed deterioration (TTCD) of EORTC-QLQ-C30 and BPI-SF domains were prespecified descriptive analyses. TTPP and TTCD were assessed using Kaplan-Meier methods. Results: Of 886 pts randomized, 731 (376 received EV+P; 355 PBC) completed baseline PRO questionnaires. Compliance rates differed between arms and remained >70% through wk 29 for EV+P and through only wk 17 for PBC. Median TTPP was 14.2 months (mos) with EV+P and 10.0 mos with PBC (hazard ratio [HR]=0.92; 95% CI=0.72, 1.17; 2-sided p-value=0.48). The least squares (LS) mean reduction in worst pain at wk 26 was numerically greater with EV+P vs PBC (-0.61 vs -0.03, LS mean difference [95% CI]: -0.58 [-1.05, -0.11] [nominal 2-sided P = 0.015]). Pts with moderate to severe pain at baseline who were treated with EV+P (n=128, 34%) had a meaningful (>2 pt) improvement from baseline in BPI worst pain from wk 3 through 26. In EORTC QLQ-C30 Global Health Status/Quality of Life [GHS/QoL], EV+P demonstrated a transient worsening at week 3 (-6.3) that returned to baseline from weeks 4 through 26, while patients treated with PBC demonstrated deterioration from week 1 through week 17 (range -1.2 to -7.1) where scores returned to baseline. TTCD for EORTC QLQ-C30 GHS/QoL was 5.9 mos with EV+P vs 3.2 mos with PBC (HR = 0.98 [95% CI]: 0.79 – 1.2). Conclusions: Pts treated with EV+P have improved survival compared with PBC without detriment to quality of life and functioning, further supporting the value of EV+P for pts with la/mUC. Compliance, especially after progression, was lower than expected (particularly in the PBC arm) and may have impacted the results. Clinical trial information: NCT04223856 .