Phase II Trial of Enfortumab Vedotin in Patients With Previously Treated Advanced Head and Neck Cancer.

Purpose: Despite advances in immunotherapy, unresectable recurrent/metastatic head and neck cancer (HNC) carries a poor prognosis, and effective treatments are needed. As nectin-4 is widely expressed in HNC, enfortumab vedotin (EV), a nectin-4-directed antibody-drug conjugate, was explored in HNC in EV-202 (ClinicalTrials.gov identifier: NCT04225117).

Methods: This open-label, multicohort, phase II study evaluated intravenous EV 1.25 mg/kg on days 1, 8, and 15 of each 28-day cycle. In the HNC cohort, eligible patients had recurrent/metastatic HNC and had received platinum-based therapy for locally advanced/metastatic disease and a PD-1/PD-L1 inhibitor. The primary end point was investigator-assessed confirmed objective response rate (ORR) per RECIST version 1.1. Secondary end points were investigator-assessed duration of response (DOR), disease control rate (DCR), and progression-free survival (PFS); overall survival (OS); and safety.

Results: The primary analysis included 46 patients; all received EV (median follow-up, 9.3 months). Most patients (52.2%) had ≥3 previous lines of systemic therapy in the metastatic setting. Confirmed ORR was 23.9%, DCR was 56.5%, and median DOR was not reached (median DOR was 9.4 months at a later data cutoff [median follow-up, 11.3 months]). Median PFS and OS were 3.9 and 6.0 months, respectively. Treatment-related adverse events (TRAEs) occurring in >20% of patients were alopecia (28.3%), fatigue (26.1%), and peripheral sensory neuropathy (23.9%). Sixteen patients (34.8%) experienced grade ≥3 TRAEs; anemia and decreased neutrophil count occurred in ≥1 patient (both n = 2; 4.3%).

Conclusion: EV demonstrated antitumor activity in heavily pretreated HNC. Safety was consistent with the known safety profile of EV; no new safety signals were identified. These data support further evaluation of EV for advanced HNC not amenable to definitive local therapy.