Enfortumab vedotin after PD-1 or PD-L1 inhibitors in cisplatin-ineligible patients with advanced urothelial carcinoma (EV‑201): a multicentre, single-arm, phase 2 trial.

BACKGROUND

Locally advanced or metastatic urothelial carcinoma is generally incurable and has scarce treatment options, especially for cisplatin-ineligible patients previously treated with PD-1 or PD-L1 therapy. Enfortumab vedotin is an antibody-drug conjugate directed at Nectin-4, a protein highly expressed in urothelial carcinoma. We aimed to evaluate the efficacy and safety of enfortumab vedotin in the post-immunotherapy setting in cisplatin-ineligible patients.

METHODS

EV-201 is a multicentre, single-arm, phase 2 study of enfortumab vedotin in patients with locally advanced or metastatic urothelial carcinoma previously treated with PD-1 or PD-L1 inhibitors. Cohort 2 included adults (aged ≥18 years) with an Eastern Cooperative Oncology Group performance status score of 2 or less who were considered ineligible for cisplatin at enrolment and who had not received platinum-containing chemotherapy in the locally advanced or metastatic setting. Enfortumab vedotin was given intravenously at a dose of 1·25 mg/kg on days 1, 8, and 15 of every 28-day cycle. The primary endpoint was confirmed objective response rate per Response Evaluation Criteria in Solid Tumours version 1.1 assessed by blinded independent central review. Efficacy and safety were analysed in all patients who received at least one dose of enfortumab vedotin. EV-201 is an ongoing study and the primary analysis is complete. This study is registered with Clinicaltrials.gov, NCT03219333.

FINDINGS

Between Oct 8, 2017, and Feb 11, 2020, 91 patients were enrolled at 40 sites globally, of whom 89 received treatment. Median follow-up was 13·4 months (IQR 11·3-18·9). At data cutoff (Sept 8, 2020), the confirmed objective response rate was 52% (46 of 89 patients; 95% CI 41-62), with 18 (20%) of 89 patients achieving a complete response and 28 (31%) achieving a partial response. 49 (55%) of 89 patients had grade 3 or worse treatment-related adverse events. The most common grade 3 or 4 treatment-related adverse events were neutropenia (eight [9%] patients), maculopapular rash (seven [8%] patients), and fatigue (six [7%] patients). Treatment-related serious adverse events occurred in 15 (17%) patients. Three (3%) patients died due to acute kidney injury, metabolic acidosis, and multiple organ dysfunction syndrome (one [1%] each) within 30 days of first dose and these deaths were considered by the investigator to be related to treatment; a fourth death from pneumonitis occurred more than 30 days after the last dose and was also considered to be related to treatment.

INTERPRETATION

Treatment with enfortumab vedotin was tolerable and confirmed responses were seen in 52% of cisplatin-ineligible patients with locally advanced or metastatic urothelial carcinoma who were previously treated with PD-1 or PD-L1 inhibitors. These patients have few treatment options, and enfortumab vedotin could be a promising new therapy for a patient population with a high unmet need.

FUNDING

Astellas Pharma Global Development and Seagen.