This is a prospective, exploratory, non-registration, multi-center clinical study to evaluate the efficacy and safety of becotatug vedotin (EGFR-ADC) combined with putlimab and radiotherapy in the perioperative treatment of locally advanced resectable head and neck squamous cell carcinoma (HNSCC).
\*\*Neoadjuvant Phase\*\* (3-week cycle, 2 cycles):
* Putlimab (HX008): 200 mg, Q3W, D1, IV * Becotatug vedotin (MRG003): 2.0 mg/kg, Q3W, D1, IV
\*\*Adjuvant/Maintenance Phase:\*\* Surgery within 2-4 weeks post-neoadjuvant; surgical approach at investigator discretion.
\*\*Group A (Postoperative pCR):\*\*
* Putlimab (HX008): 200 mg, Q3W, D1, IV, up to 1 year * Adjuvant RT: 40 Gy/5 weeks
\*\*Group B (Postoperative MPR):\*\*
* Putlimab (HX008): 200 mg, Q3W, D1, IV, up to 1 year * Adjuvant RT: 50 Gy/5 weeks
\*\*Group C (Postoperative Partial/No Response):\*\*
* Low-risk (no extracapsular nodal extension \[ENE\] and negative margins): Putlimab 200 mg Q3W (up to 1 year) + RT 60 Gy/6 weeks * High-risk (ENE and/or positive margins): Putlimab 200 mg Q3W (up to 1 year) + RT 60-66 Gy/6-6.6 weeks + Cisplatin 60 mg/m², Q3W, D1, IV, for 2 cycles
RT timing, field, and fractionation may be adjusted by investigators based on individual disease status.
Imaging assessment every 2 cycles (±7 days) until disease recurrence, initiation of new anti-tumor therapy, withdrawal of informed consent, death, or up to 21 cycles, whichever occurs first. Additional imaging may be performed at any time if clinically indicated.
Diagnosis of any malignancy other than gastric cancer within 5 years prior to the first dose, with the exception of adequately treated cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, and/or radically resected carcinoma in situ;
Known endoscopic evidence of active bleeding in the target lesion;
Concurrent participation in another interventional clinical study, or receipt of any investigational medicinal product or use of investigational device within 4 weeks prior to the first dose;
Prior exposure to any of the following therapies: anti-PD-1, anti-PD-L1, or anti-PD-L2 agents; agents targeting other stimulatory or co-inhibitory T-cell receptors (including but not limited to CTLA-4, OX-40, and CD137); or antibody-drug conjugates (ADCs) with MMAE or MMAF payloads;
Presence of distant metastatic lesions;
History of Grade ≥3 immune-related adverse events or treatment-related adverse events that have not recovered to Grade ≤1;
Receipt of surgery, chemotherapy, targeted small molecule therapy, or radiotherapy for another invasive malignancy within the past 5 years;
Autoimmune disease requiring systemic corticosteroid therapy within the past 3 months, history of clinically significant autoimmune disease, or syndrome requiring systemic corticosteroid therapy;