Becotatug Vedotin Combined With Pucotenlimab as Neoadjuvant Therapy for Resectable Recurrent Head and Neck Squamous Cell Carcinoma After Progression on Immunotherapy: A Prospective Phase II Study

Overview

This is a prospective, single-arm, multi-center, Phase II clinical trial evaluating the efficacy and safety of neoadjuvant becotatug vedotin (an anti-EGFR antibody-drug conjugate) combined with pucotenlimab (HX008, an anti-PD-1 monoclonal antibody) in patients with resectable recurrent head and neck squamous cell carcinoma (rHNSCC) who have progressed on prior PD-1/PD-L1 inhibitor and platinum-based therapy. A total of 42 EGFR-positive patients will be enrolled using Simon's two-stage design across 11 centers in China (Stage 1: 25 patients; Stage 2: 17 additional patients with 5% dropout). Enrolled patients will receive 3 cycles of neoadjuvant becotatug vedotin (2.3 mg/kg, IV, Q3W) plus pucotenlimab (3 mg/kg, IV, Q3W), followed by salvage surgery (3-4 weeks later), adjuvant radiotherapy +/- chemotherapy per NCCN/CSCO guidelines, and pucotenlimab maintenance therapy (3 mg/kg, Q3W) for up to 12 cycles or until disease progression or unacceptable toxicity. The primary endpoint is major pathological response (MPR) rate. The null hypothesis MPR rate is 14% (historical data) and the target MPR rate is 30% (alpha=0.05, power=0.8, one-sided). Secondary endpoints include objective response rate (ORR), pathological complete response (pCR), survival outcomes, quality of life, and safety.

Recurrent head and neck squamous cell carcinoma (rHNSCC) remains a significant clinical challenge, with recurrence rates of 40-60% after curative treatment. Salvage surgery is the standard of care, yet approximately 50% of patients experience re-recurrence within 2 years. For patients who have progressed on prior PD-1 inhibitor and platinum-based therapy, effective treatment options are extremely limited. Becotatug vedotin is a novel anti-EGFR antibody-drug conjugate (ADC) that has demonstrated significant anti-tumor activity in HNSCC, with an ORR of 40% in Phase Ia/Ib and 43% in the post-immunotherapy Phase II study. Pucotenlimab (HX008) is a PD-1 inhibitor with an extended half-life (T1/2 = 21.76 days). Phase I/II data showed the combination achieved ORR of 60% in HNSCC with manageable toxicity. This study investigates neoadjuvant becotatug vedotin plus pucotenlimab in resectable rHNSCC after immunotherapy progression. TREATMENT REGIMEN: 1. Neoadjuvant: Becotatug vedotin 2.3 mg/kg IV + Pucotenlimab 3 mg/kg IV, Q3W, 3 cycles 2. Surgery: Salvage surgery 3-4 weeks after neoadjuvant completion 3. Adjuvant: IMRT (60-66 Gy/30f) +/- platinum-based chemotherapy per NCCN/CSCO 4. Maintenance: Pucotenlimab 3 mg/kg IV Q3W for 12 cycles or until progression/toxicity Simon's two-stage design: Stage 1 (25 patients, \>=3 MPR required) to Stage 2 (17 additional, total 42). H0 MPR=14%, H1 MPR=30% (alpha=0.05, power=0.8).