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.