Efficacy of Immune Checkpoint Inhibitor Combinations in Locally Advanced Head and Neck Squamous Cell Carcinoma: Phase II Trial
Abstract
Background
Locally advanced head and neck squamous cell carcinoma (LA-HNSCC) carries a poor prognosis with standard chemoradiation. The combination of PD-1 and CTLA-4 inhibition has shown promise in melanoma but data in HNSCC from South Asian populations is lacking.
Methods
Open-label Phase II trial enrolling 56 treatment-naive patients with Stage III/IV HNSCC. Patients received nivolumab (3 mg/kg) + ipilimumab (1 mg/kg) every 3 weeks for 4 cycles, followed by concurrent chemoradiation (cisplatin 40 mg/m² weekly + 70 Gy in 35 fractions). Primary endpoint: complete response (CR) rate at 3 months post-treatment. Secondary: progression-free survival (PFS), overall survival (OS), and toxicity profile.
Results
CR rate was 58.9% (33/56 patients). Median PFS was 18.4 months (95% CI: 14.2–22.6). Median OS was not reached at 24-month follow-up. Grade 3/4 immune-related adverse events occurred in 21.4% of patients; hypothyroidism (17.9%) and colitis (8.9%) were most common. No treatment-related deaths observed.
Conclusion
Dual immune checkpoint blockade combined with chemoradiation shows promising efficacy and manageable toxicity in LA-HNSCC. These data support advancement to a Phase III trial in the South Asian setting.
Conflict of Interest
Research grant received from Bristol Myers Squibb (India) for study medication supply only. No financial conflicts.