FDA Approval Summary: Durvalumab for the Treatment of Adult Patients with Muscle-Invasive Bladder Cancer

On March 28, 2025, the Food and Drug Administration approved durvalumab (Imfinzi, AstraZeneca) with gemcitabine and cisplatin as neoadjuvant treatment, followed by single agent durvalumab as adjuvant treatment following radical cystectomy (RC), for adults with muscle invasive bladder cancer (MIBC). Substantial evidence of effectiveness was obtained from NIAGARA (NCT03732677), a randomized, phase 3, open-label trial in cisplatin-eligible patients with MIBC who had not received prior systemic chemotherapy or immunotherapy. A total of 1063 patients were randomized (1:1) to receive neoadjuvant durvalumab + gemcitabine and cisplatin prior to RC, followed by adjuvant durvalumab (GC-D), or neoadjuvant gemcitabine and cisplatin (GC) prior to RC, with no subsequent adjuvant treatment. The dual primary endpoints were event free survival (EFS) and pathologic complete response (pCR), both per blinded independent central review (BICR). The key secondary endpoint (alpha-controlled) was overall survival (OS). GC-D demonstrated a statistically significant improvement in EFS compared to GC at the second interim analysis (IA2), with a hazard ratio (HR) of 0.68 (95% CI: 0.56 - 0.82; p < 0.0001). Median EFS was not reached (NR) for GC-D and was 46.1 months (95% CI: 32.3, NR) for GC. There was no statistically significant difference in pCR rate between the arms. A statistically significant improvement in OS was observed for GC-D compared with G+C, with a HR of 0.75 (95% CI: 0.59 - 0.93; 2-sided p = 0.0106). Median OS was NR in both arms. Safety appeared consistent with the safety profile demonstrated in prior trials of durvalumab in combination with platinum-based chemotherapy.