Adebrelimab Combined With Dalpiciclib Isethionate Plus Chemotherapy for Neoadjuvant Treatment of Locally Advanced Head and Neck Squamous Cell Carcinoma

This single-center, open-label Phase II trial aims to evaluate the efficacy and safety of neoadjuvant combination therapy with Adebrelimab (anti-PD-L1), Dalpiciclib Isethionate (CDK4/6 inhibitor), and cisplatin chemotherapy in patients with resectable locally advanced head and neck squamous cell carcinoma (LA-HNSCC). A total of 32 eligible subjects will receive 2 cycles of triplet neoadjuvant treatment prior to radical surgery. The primary endpoint is the pathological complete response (pCR) rate following neoadjuvant therapy; secondary endpoints include major pathological response (MPR), objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), 1-year overall survival (1y-OS), and treatment-related adverse events (TRAEs). The exploratory objectives analyze correlations between biomarkers (oral microbiome, CDKN2A/B deletion, CDK4/6 amplification, and PD-L1 expression) and therapeutic efficacy or prognosis. Subjects will receive long-term tumor and survival follow-up after surgery until disease progression, death, loss to follow-up, or the end of study.