Efficacy of nimotuzumab added to concurrent chemoradiotherapy after induction chemotherapy for patients with locally advanced nasopharyngeal carcinoma.

6024 Background: To investigate the efficacy and toxicities associated with adding nimotuzumab to concurrent chemoradiotherapy (CCRT) in locally advanced nasopharyngeal carcinoma (LANPC) patients who received induction chemotherapy (IC). Methods: Patients with stage III-IVA nasopharyngeal carcinoma who received IC (TPF/TP/GP) and platinum-based CCRT between January 2017 and October 2021 were retrospectively included. We performed propensity score matching (PSM) to balance and control confounding factors, and the matching variables included gender, age, T stage, N stage, and Epstein-Barr virus (EBV) status. Patients were divided into two treatment groups: CCRT+nimotuzumab (200mg iv, weekly for 7 courses) and CCRT alone. Primary endpoints were overall survival (OS) and disease-free survival (DFS), the secondary endpoints were locoregional recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS). Results: We screened 242 patients in the analysis. After PSM, 121 (50.0%) and 121 (50.0%) had CCRT+nimotuzumab and CCRT alone, respectively. The 3-year OS was 95.4% and 88.0% in those with and without nimotuzumab treatment (P=0.041), and the 3-year DFS of the CCRT+nimotuzumab group was significantly better than that in the CCRT alone group (90.3% vs. 77.5%, P=0.003). Similar LRFS was found between those with and without nimotuzumab treatment (96.5% vs. 93.7%, P=0.297). The 3-year DMFS for CCRT+nimotuzumab versus CCRT alone was 92.9% versus 82.5% (P=0.008). No significant differences in major toxicities were found between the two treatment arms including hematologic toxicities, hepatoxicity, nephrotoxicity, gastrointestinal reactions, and mucositis (P>0.05). Conclusions: The addition of nimotuzumab to CCRT after IC in LANPC has shown promising results in treatment outcomes and acceptable toxicities.