Cetuximab Plus Platinum and Taxane-based Chemotherapy, Followed by Avelumab and Cetuximab, as First-line Treatment for Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma (HNSCC) Patients With a PD-L1 Combined Positive Score (CPS)≥1≤19.

This phase II interventional clinical trial aims to evaluate whether combining cetuximab and avelumab, after three cycles of platinum and taxane-based chemotherapy, can improve treatment outcomes for patients with recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) with a PD-L1 combined positive score (CPS) between 1 and 19. Specifically, the study seeks to determine if this approach can increase the 6-month progression-free survival (PFS) rate from 40% to 55%. The trial will include adult patients with confirmed R/M HNSCC, who have not previously received systemic therapy for their advanced disease. By testing this sequential treatment strategy, researchers hope to improve outcomes for this specific patient population, which has shown poorer responses to existing immunotherapy options compared to those with higher PD-L1 expression levels. Participants will first undergo an induction phase, consisting of three cycles of chemotherapy with paclitaxel, platinum (cisplatin or carboplatin), and cetuximab. After this initial treatment, they will move to a maintenance phase, where they will receive avelumab and cetuximab every two weeks until disease progression or the occurrence of unacceptable side effects. The study aims to answer several key questions: Can this treatment approach improve progression-free survival at 6 months? What impact does it have on overall survival, response rates, and the duration of response? Is this combination therapy safe and well-tolerated? In addition to the treatment itself, participants will be asked to provide blood and tumor tissue samples for translational research, helping scientists better understand how biomarkers influence treatment response. Regular follow-up assessments will also be conducted to monitor disease progression and overall health. By testing this innovative treatment sequence, researchers hope to bridge the gap between different PD-L1 subgroups, potentially offering a more effective and pe