Camrelizumab combined with concurrent chemoradiotherapy versus chemoradiotherapy alone in locoregionally advanced nasopharyngeal carcinoma: A retrospective cohort study in central China.

Abstract

e18083 Background: Immune checkpoint inhibitors have demonstrated efficacy in recurrent or metastatic nasopharyngeal carcinoma (NPC). Additionally, adjuvant PD-1 blockade with camrelizumab has improved survival in locoregionally advanced NPC from endemic regions. However, its role in concurrent chemoradiotherapy (CCRT) for locoregionally advanced NPC remains unclear, particularly in non-endemic areas where evidence is scarce. This study assessed the efficacy and safety of camrelizumab plus CCRT in patients with locoregionally advanced NPC from Central China, a non-endemic region. Methods: In this retrospective cohort study, patients with stage III-IVa NPC from Central China were included. The camrelizumab group received two to three cycles of induction chemotherapy (docetaxel 75 mg/m² and cisplatin 75 mg/m²), followed by CCRT with intensity-modulated radiotherapy, concurrent cisplatin (40 mg/m² weekly for five to seven cycles), and two cycles of camrelizumab (200 mg). Maintenance camrelizumab was administered for 6-12 cycles post-CCRT. The control group received identical treatment without camrelizumab. The primary endpoint was the 3-year disease-free survival (DFS) rate. Results: Between January 2019 and October 2022, 103 patients were enrolled (48 in the camrelizumab group and 55 in the control group). With a median follow-up of 37 months, the 3-year DFS rate was 81.3% (39/48) in the camrelizumab group versus 69.1% (38/55) in the control group. Corresponding 3-year rates for locoregional recurrence-free survival, distant metastasis-free survival, and overall survival were 89.6% (43/48), 85.4% (41/48), and 83.3% (40/48) in the camrelizumab group, compared with 87.3% (48/55), 76.4% (42/55), and 72.7% (40/55) in the control group. Grade 3 or 4 treatment-related adverse events occurred in 14.6% (7/48) of patients in the camrelizumab group and 3.6% (2/55) in the control group. Reactive capillary endothelial proliferation, a camrelizumab-specific event, affected 83.3% (40/48) of patients (mostly grade 1-2; 4.2% [2/48] grade 3-4). Common grade 3-4 events included leukopenia, neutropenia, and weight loss. Conclusions: Camrelizumab combined with CCRT demonstrated promising antitumor activity and a manageable safety profile in locoregionally advanced NPC from non-endemic areas. These findings warrant validation in prospective randomized trials. Limitations include the retrospective design and small sample size.