Efficacy and Safety of Combined PD-1 Inhibitor With Induction Chemotherapy Followed by IMRT Plus Nimotuzumab in Locally Advanced Nasopharyngeal Carcinoma: A Retrospective Analysis.

Background: Induction chemotherapy (IC) is the standard treatment protocol for locally advanced nasopharyngeal carcinoma (LANPC), though concerns persist regarding high rates of recurrence and metastasis. This retrospective study aims to evaluate the efficacy, potential benefits, and safety of combining PD-1 inhibitors with IC, followed by nimotuzumab and intensity-modulated radiation therapy (IMRT).

Methodology: We analyzed data from 103 patients diagnosed with non-keratinizing LANPC (according to WHO criteria) at clinical stages III-IVA. These patients, treated from May 2020 to November 2023, received four cycles of IC combined with PD-1 inhibitors, followed by nimotuzumab and IMRT. Efficacy assessments were conducted according to RECIST v1.1 guidelines, with the primary endpoint being a clinical complete response (CCR), defined as the absence of detectable tumors or mucosal bulges upon nasoendoscopy.

Results: Among the evaluable patients, the CCR rate reached 66% (95% CI, 56-75%), while the objective response rate (ORR) was 97% (95% CI, 92-99%) and the disease control rate (DCR) reached 99% (95% CI, 95-100%). During the median follow-up of 16.1 months, neither the median progression-free survival (PFS) nor median overall survival (OS) was reached. Notably, patients with T4-stage disease exhibited lower CCR rates, highlighting stage-specific variations in treatment responses. The treatment regimen was well-tolerated, with no significant adverse safety events reported.

Conclusion: The combination of PD-1 inhibitors with IC, followed by nimotuzumab and IMRT, shows promising efficacy and safety in the treatment of LANPC.