Becotatug Vedotin in Patients with Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck: A Multicenter, Phase IIa Trial

PURPOSE: This multicenter, phase IIa trial (NCT04868162) investigated the efficacy and safety of becotatug vedotin, an anti-epidermal growth factor receptor (EGFR) antibody-drug conjugate, in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) who have limited therapeutic options. PATIENTS AND METHODS: Patients with R/M SCCHN who progressed after platinum-based chemotherapy and/or programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors, including those with multiple lines of prior therapy, were administered intravenous becotatug vedotin at either 2 or 2.3 mg/kg every 3 weeks. The primary endpoint was the objective response rate (ORR). RESULTS: Sixty-seven patients were enrolled (35 received 2 mg/kg and 32 received 2.3 mg/kg). The ORR was 20.9% [14/67, 95% confidence interval (CI), 11.9-32.6], with a median duration of response (DoR) of 10.9 months (95% CI, 2.6-15.1). The median progression-free survival (PFS) was 2.9 months (95% CI, 1.8-3.9), and the median overall survival (OS) was 6.7 months (95% CI, 5-8.9). Treatment-related adverse events (TRAE) were reported in 91% (61/67) patients, most commonly being rash (26.9%), pruritus (25.4%), constipation (23.9%), and anemia (20.9%). CONCLUSIONS: Becotatug vedotin demonstrated promising antitumor activity with a manageable safety profile in previously heavily treated R/M SCCHN, particularly at the recommended dose of 2.3 mg/kg, among patients who had failed platinum-based chemotherapy and PD-1/PD-L1 inhibitors (≤2 prior lines of therapy).