PD-1 inhibitors combined with chemotherapy versus chemotherapy alone: efficacy and prognostic analysis in recurrent metastatic nasopharyngeal carcinoma.

Objective: To evaluate the prognostic value of combining PD-1 inhibitors (toripalimab or karelizumab) with chemotherapy for treating recurrent or metastatic nasopharyngeal carcinoma (R/M NPC).

Methods: This study retrospectively analyzed 142 patients with R/M NPC diagnosed from January 2018 to January 2022. Patients were divided into PD-1 inhibitor combined with chemotherapy group (53 patients) and chemotherapy alone group (89 patients) according to the treatment regimen. Objective remission rate (ORR), progression-free survival (PFS), and treatment-related toxicity were evaluated in both groups.

Results: The overall response rate (P=0.006) and objective remission rate (ORR) (P=0.002) were significantly higher in the combination chemotherapy group than in the chemotherapy-alone group. The incidences of hypothyroidism (P<0.001) and reactive capillary hyperplasia (P<0.001) were significantly higher in the combination chemotherapy group than in the chemotherapy-alone group. Cox regression analysis showed that treatment regimen (P<0.001), age (P<0.001), treatment duration (P=0.002), and number of treatment lines (P=0.034) were independent prognostic factors affecting patients' PFS. The prediction model constructed based on these prognostic factors had high accuracy in predicting 1-year and 2-year PFS (AUC 0.746 and 0.760, respectively).

Conclusion: PD-1 inhibitors in combination with chemotherapy significantly improved the ORR and median PFS of patients with R/M NPC, while maintaining a favorable safety profile. Treatment regimen, age, number of lines and cycle of therapy were important independent prognostic factors for improving PFS in patients.