Programmed cell death receptor 1 inhibitors combined with paclitaxel-platinum induction chemotherapy for treating patients with locally advanced nasopharyngeal carcinoma: a real-world retrospective study.

Background: Concurrent chemoradiotherapy (CCRT) combined with induction chemotherapy (IC) is the standard first-line treatment for locally advanced nasopharyngeal carcinoma (LA-NPC). However, treatment-related toxicities and the risk of recurrence or metastasis remain clinical challenges, which have prompted the development of strategies that can improve efficacy while minimizing adverse effects. The integration of programmed cell death receptor 1 (PD-1) inhibitors with IC has demonstrated significant survival benefits in pivotal phase III trials. This study aimed to assess the efficacy and safety of PD-1 inhibitors combined with IC consisting of a paclitaxel-platinum (TP) regimen for LA-NPC in a real-world clinical setting. Methods: This retrospective study enrolled patients diagnosed with stage III or IVA NPC who received treatment between January 2021 and December 2024. Clinical records and radiographic data were systematically reviewed. Based on the administration of PD-1 inhibitor immunotherapy during IC, patients were categorized into a control group and an immunotherapy group. Propensity score matching (PSM) was performed sequentially after IC and again after CCRT to minimize confounding factors. Matching was based on clinically relevant covariates, including age, gender, differentiation, tumor-node-metastasis stage, Epstein-Barr virus DNA level and treatment cycle. Between-group differences in treatment response and adverse events were assessed via Chi-squared tests for categorical variables. The primary endpoint is the disease control rate (DCR) after IC. The secondary endpoints include the objective response rate (ORR) after CCRT, the incidence of adverse events, and their severity. Results: A total of 150 patients with LA-NPC were included, among whom 76 received standard IC, and 74 received combined immunotherapy. In the PSM analysis, 54 patients were matched to each group, and the immunotherapy group demonstrated significantly higher disease control during the IC phase (P=0.004), with a partial response (PR) rate of 94.4% compared to 70.4% in the control group. Following CCRT, 49 patients per group matched by PSM showed no significant differences in complete response (CR) or PR rates (P=0.25). The CR rates were 10.2% and 18.4% in the control group and the immunotherapy group, respectively, while the PR rates were 89.8% and 81.6%, respectively. Furthermore, the groups showed no statistical differences in terms of the incidence of radiotherapy-related adverse events, including oral mucositis (P=0.26), skin reactions (P=0.20), and myelosuppression (P=0.33). No grade 3 or higher immune-related adverse events (irAEs) were reported in the immunotherapy group. Conclusions: This real-world study successfully verified that adding PD-1 inhibitors to IC improves early efficacy without increasing toxicity in LA-NPC, providing external validation of key trial results related to routine clinical practice.