AstraZeneca has announced positive interim results from the Phase III VOLGA trial evaluating perioperative durvalumab (Imfinzi) in combination with neoadjuvant enfortumab vedotin (EV) in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for or have declined cisplatin-based chemotherapy. The regimen demonstrated statistically significant and clinically meaningful improvements in event-free survival (EFS) and overall survival (OS) compared with standard surgical management, supporting a potential new perioperative treatment approach in this high-risk population.

Clinical Takeaway

The Phase III VOLGA trial suggests perioperative durvalumab plus enfortumab vedotin may provide a new treatment option for patients with cisplatin-ineligible MIBC, a population historically treated with surgery alone and associated with high recurrence risk.

Drug Profiles & Mechanisms

  • Agent & Mechanism of Action:
    • durvalumab (Imfinzi): Human IgG1 monoclonal antibody targeting PD-L1, restoring antitumor T-cell activity by blocking PD-L1-mediated immune evasion
    • enfortumab vedotin (EV): Nectin-4-directed antibody-drug conjugate delivering a microtubule-disrupting cytotoxic payload
    • tremelimumab (Imjudo): CTLA-4 inhibitor that enhances T-cell activation and proliferation
  • Route of Administration & Dosing Schedule:
    • durvalumab: 1500 mg IV every 4 weeks in the perioperative setting
    • enfortumab vedotin: IV during neoadjuvant treatment cycles
    • tremelimumab: Limited perioperative dosing in combination with durvalumab

Target Population

  • Patients with muscle-invasive bladder cancer (MIBC)
  • Cisplatin-ineligible or patients who declined cisplatin-based therapy
  • Candidates for radical cystectomy in a curative-intent setting

VOLGA Study Design (NCT04960709)

  • Study Type: Phase III, randomized, open-label, multi-center trial
  • Population: 695 patients with MIBC undergoing radical cystectomy who are ineligible for or have declined cisplatin-based chemotherapy
  • Randomization: 1:1:1
    • Arm 1: Neoadjuvant durvalumab + enfortumab vedotin + tremelimumab, followed by adjuvant durvalumab + tremelimumab
    • Arm 2: Neoadjuvant durvalumab + enfortumab vedotin, followed by adjuvant durvalumab
    • Arm 3: Radical cystectomy with or without approved adjuvant therapy
  • Follow-Up Duration:
    • Interim analysis (maturity not yet fully reported)
  • Primary completion: April 30, 2026 (final data collection date for primary outcome measure)
  • Estimated Study Completion: September 9, 2028 (estimated)

Endpoints

  • Primary Endpoint:
    • Event-free survival (EFS)
  • Secondary Endpoints:
    • Overall survival (OS)
    • Pathologic complete response
    • Disease-free survival
    • Pathologic downstaging

Efficacy Outcomes

  • Primary Endpoint Results:
    • Durvalumab + Enfortumab Vedotin (Doublet):
      • Statistically significant improvement in EFS
      • Statistically significant improvement in OS
    • Durvalumab + Enfortumab Vedotin + Tremelimumab (Triplet):
      • Statistically significant improvement in EFS
      • Favorable trend in overall survival, not statistically significant at interim analysis
    • Findings support meaningful clinical benefit of perioperative immunotherapy-based strategies in cisplatin-ineligible MIBC

Safety

  • Overall Safety Profile: Consistent with known safety profiles of individual agents
  • Grade ≥3 Events: Not fully detailed in interim release
  • Treatment discontinuation: Not specified
  • Notable toxicity patterns:
    • Immune-related adverse events consistent with checkpoint inhibition
    • Peripheral neuropathy and skin reactions consistent with enfortumab vedotin

No new or unexpected safety signals were identified, and adverse events were generally manageable with standard supportive care and dose modifications.

Regulatory Milestones

  • Approval Status: Not currently approved in this setting
  • Current Standard of Care:
    • Cisplatin-based neoadjuvant chemotherapy + radical cystectomy (eligible patients)
    • Radical cystectomy alone for cisplatin-ineligible patients
  • Regulatory Pathway: Data expected to be presented at upcoming medical meetings and submitted to regulatory authorities

Key Clinical Implications

✔ Provides a perioperative systemic therapy option for cisplatin-ineligible MIBC patients

✔ Demonstrates overall survival benefit with the doublet regimen

✔ Supports enfortumab vedotin + immunotherapy combinations in earlier-stage disease

✔ Reinforces durvalumab as a backbone immunotherapy across bladder cancer settings

✔ Signals a potential shift in standard of care for a large, previously underserved population

Bottom Line

Interim results from the Phase III VOLGA trial demonstrate that perioperative durvalumab combined with enfortumab vedotin significantly improves EFS and OS in cisplatin-ineligible MIBC. This approach may represent a meaningful advancement in curative-intent treatment for patients historically limited to surgery alone.

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