Pan-Asian subgroup analysis of EV-302/KEYNOTE-A39: a phase 3 study to evaluate enfortumab vedotin and pembrolizumab in patients with untreated advanced urothelial carcinoma

BACKGROUND: In the phase 3 EV-302 study, enfortumab vedotin-pembrolizumab (EV + P) significantly prolonged overall survival (OS) and progression-free survival (PFS) versus chemotherapy in patients with untreated locally advanced/metastatic urothelial carcinoma (la/mUC). We present a post hoc analysis in a pan-Asian population. METHODS: Patients from China, Japan, Singapore, South Korea, Taiwan, and Thailand received 3-week cycles of EV (1.25 mg/kg; intravenously; Days 1 and 8) plus P (200 mg; intravenously; Day 1) or chemotherapy (gemcitabine [Days 1 and 8] plus cisplatin/carboplatin [Day 1]). Primary endpoints were PFS and OS. Secondary endpoints included objective response rate (ORR) and safety. RESULTS: Overall, 176 patients were included (EV + P, n = 94; chemotherapy, n = 82). Median follow-up was 28.9 months for EV + P recipients and 26.6 months for chemotherapy recipients. EV + P prolonged PFS and OS versus chemotherapy, reducing the risk of disease progression or death by 63% (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.24-0.57) and death by 67% (HR, 0.33; [95% CI, 0.20-0.54]), respectively. Confirmed ORR was 72.2% versus 35.0%. Grade ≥ 3 treatment-related adverse events occurred in 66.0% of EV + P recipients and 68.4% of chemotherapy recipients. Most commonly maculopapular rash (11.7%) and hyperglycemia (10.6%) for EV + P and neutropenia (25.0%), anemia (19.7%), and neutrophil count decreased (18.4%) for chemotherapy. CONCLUSION: EV + P demonstrated a clinically meaningful survival benefit in Asian patients with untreated la/mUC, with no new safety signals observed, consistent with the global EV-302 study. Results support guideline recommendations for EV + P as preferred first-line therapy in la/mUC. CLINICAL TRIAL REGISTRATION: NCT04223856 (registered January 8, 2020).