Real-world Data Study of the Efficacy and Toxicity of Nivolumabvs. Cetuximab and Predictors of Response to Nivolumab in Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck in a European Population

Background/Aim: This study aimed to assess the effectiveness and safety of nivolumab versus cetuximab in patients with Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck (R/M HNSCC), as well as to analyze possible prognostic factors for response to treatment with nivolumab. Patients and Methods: We conducted an observational, retrospective, descriptive study of patients with R/M HNSCC who initiated treatment with nivolumab or cetuximab monotherapy in two periods of equivalent duration. Overall efficacy was measured in terms of progression-free survival (PFS) and overall survival (OS). Safety was evaluated using the Common Terminology Criteria for Adverse Events classification version 5.0 of the National Cancer Institute. Results: Median OS was 9.1 months with nivolumab (n=34) and 6.3 months with cetuximab (n=12). PFS was 4.3 months for nivolumab and 4.65 months for cetuximab. Any grade adverse events (AEs) were reported in 97% and 100% of the patients treated with nivolumab and cetuximab. Serious AEs were observed in 26% and 58% of the patients, respectively. Elevated albumin values, lymphocytosis, neutropenia, and elevated neutrophil/lymphocyte ratio values were found to have positive prognostic value on the response to nivolumab in R/M HNSCC. Conclusion: Effectiveness of nivolumab in terms of OS remains superior to cetuximab. OS, PFS and severe or any grade AEs were superior in both arms of our study compared to those in clinical trials. The AEs profile of nivolumab differed in our study from that in the clinical trials' observations. We have identified four statistically significant prognostic variables on the response to nivolumab in R/M HNSCC.