407MO - Capecitabine combined with PD-1 antibody as maintenance therapy after first-line treatment of recurrent or metastatic nasopharyngeal carcinoma: A propensity score matching study

Background

The objective of this study was to explore the efficacy of PD-1 antibody combined with or without capecitabine maintenance therapy in recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) after first-line gemcitabine plus cisplatin chemotherapy plus PD-1 antibody therapy.

Methods

A total of 301 patients with RM-NPC were included in this study. Patients treated with combined maintenance therapy (PD-1 antibody plus capecitabine) were matched with those treated with PD-1 antibody maintenance therapy through propensity score matching (PSM) method at a ratio of 1:3. Progression free survival (PFS) was the primary endpoint. The association between maintenance therapy and PFS was assessed using the log-rank test and a Cox proportional hazard model.

Results

Among the patients eligible for this study, 58 received combined maintenance therapy after immunochemotherapy. After PSM, 174 patients were included in the PD-1 antibody maintenance group. In the matched cohort, patients treated with combined maintenance therapy achieved a higher 2-year PFS rate than those treated with PD-1 antibody alone (66.8% versus 51.3%, P = 0.0063). In subgroup analysis, patients with pre-treatment EBV DNA level > 12,400 copies/mL and undetectable post-treatment EBV DNA level were more likely to benefit from combined maintenance therapy than PD-1 antibody maintenance therapy (HR = 0.44, 95% CI 0.20-0.96, P = 0.033), whereas combined maintenance therapy failed to prolong PFS in patients with pre-treatment EBV DNA level ≤ 12,400 copies/mL, regardless of post-treatment EBV DNA levels: undetectable (HR = 0.59, 95% CI 0.27-1.27, P = 0.17) or detectable (HR = 0.73, 95% CI 0.31-1.70, P = 0.46).

Conclusions

PD-1 plus capecitabine maintenance therapy could prolong PFS in RM-NPC patients after first-line immunochemotherapy, particularly in those with pretreatment EBV DNA levels > 12,400 copies/mL and post-treatment undetectable EBV DNA levels. The toxicities of combined maintenance therapy were acceptable and manageable.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.