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

On March 28, 2025, the U.S. Food and Drug Administration (FDA) 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 III, open-label trial in cisplatin-eligible patients with MIBC who had not received prior systemic chemotherapy or immunotherapy. A total of 1,063 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. The key secondary endpoint (α-controlled) was overall survival (OS). GC-D demonstrated a statistically significant improvement in EFS compared with GC at the second interim analysis, with a hazard ratio (HR) of 0.68 [95% confidence interval (CI), 0.56-0.82; P < 0.0001]. The median EFS was not reached (NR) for GC-D and was estimated to be 46.1 months (95% CI, 32.3-NR) for GC. There was no statistically significant difference in the pCR rate between the arms. A statistically significant improvement in OS was observed for GC-D compared with G + C, with an HR of 0.75 (95% CI, 0.59-0.93; two-sided P = 0.0106). The median OS was NR in both arms. Safety seemed consistent with the safety profile demonstrated in prior trials of durvalumab in combination with platinum-based chemotherapy.