EV-301 long-term outcomes: 24-month findings from the phase III trial of enfortumab vedotin versus chemotherapy in patients with previously treated advanced urothelial carcinoma.

INTRODUCTION

This exploratory analysis evaluated efficacy and safety data for enfortumab vedotin versus chemotherapy over a median follow-up of ∼2 years from EV-301.

MATERIALS AND METHODS

Patients with locally advanced/metastatic urothelial carcinoma with prior platinum-containing chemotherapy and disease progression during/after programmed cell death protein 1/ligand 1 inhibitor treatment were randomized to enfortumab vedotin or chemotherapy (docetaxel, paclitaxel, vinflunine). Endpoints were overall survival (primary), progression-free survival (PFS), objective response, and safety.

RESULTS

In total, 608 patients were included (enfortumab vedotin, n = 301; chemotherapy, n = 307). With a median follow-up of 23.75 months, 444 deaths had occurred (enfortumab vedotin, n = 207; chemotherapy, n = 237). Risk of death was reduced by 30% with enfortumab vedotin versus chemotherapy [hazard ratio (HR) 0.70 (95% confidence interval [CI] 0.58-0.85); one-sided, log-rank P = 0.00015]; PFS improved with enfortumab vedotin [HR 0.63 (95% CI 0.53-0.76); one-sided, log-rank P < 0.00001]. Treatment-related adverse event rates were 93.9% for enfortumab vedotin and 91.8% for chemotherapy; grade ≥ 3 event rates were 52.4% and 50.5%, respectively. Grade ≥ 3 treatment-related decreased neutrophil count (14.1% versus 6.1%), decreased white blood cell count (7.2% versus 1.4%), and anemia (7.9% versus 2.7%) were more common with chemotherapy versus enfortumab vedotin; maculopapular rash (7.4% versus 0%), fatigue (6.8% versus 4.5%), and peripheral sensory neuropathy (5.1% versus 2.1%) were more common with enfortumab vedotin. Of special interest adverse events, treatment-related skin reactions occurred in 47.3% of patients receiving enfortumab vedotin and 15.8% of patients receiving chemotherapy; peripheral neuropathy occurred in 48.0% versus 31.6%, respectively, and hyperglycemia in 6.8% versus 0.3%.

CONCLUSIONS

After a median follow-up of ∼2 years, enfortumab vedotin maintained clinically meaningful overall survival benefit versus chemotherapy, consistent with findings from the EV-301 primary analysis; PFS and overall response benefit remained consistent. Adverse events were manageable; no new safety signals were observed.