The efficacy and safety of apatinib plus capecitabine in platinum-refractory metastatic and/or recurrent nasopharyngeal carcinoma: a prospective, phase II trial.

BACKGROUND: Previous studies have shown that monotherapy with apatinib, an oral tyrosine kinase inhibitor, has promising efficacy for treating recurrent or metastatic (RM) nasopharyngeal carcinoma (NPC) patients. In this study, we aimed to assess the efficacy and safety of apatinib combined with capecitabine as a second-line therapy or beyond for treating RM-NPC patients who failed the first-line platinum-based chemotherapy.

METHODS: In this single-arm, phase II study, we enrolled RM-NPC patients who had at least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST v1.1). The sample size was determined using Simon's two-stage design. All patients were administered with apatinib 500 mg once daily and capecitabine 1000 mg/m2 twice per day on days 1-14 of each 21-day cycle. The primary endpoint was the objective response rate (ORR), and the secondary endpoints comprised disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS: We enrolled 64 patients from September 2018 to August 2020. The ORR and DCR were 39.1% (95% CI, 27.1-52.1) and 85.9% (95% CI, 75.0-93.4), respectively. The median DoR was 14.4 months (95% CI, 7.8-21.0). As of April 20, 2021, the median follow-up duration was 12.0 months. The median PFS was 7.5 months (95% CI, 5.0-10.0) and the median OS was 15.7 months (95% CI, 11.3-20.1). The most common toxicities of any grade were anemia (75.0%), hand-foot syndrome (65.6%), and proteinuria (64.0%). Grade 3-4 toxicities were observed in 36 (56.3%) patients, with hypertension (14.1%), mucositis (12.4%), and fatigue (10.9%) most commonly observed.

CONCLUSIONS: Apatinib plus capecitabine shows promising efficacy as a second-line treatment option in pretreated platinum-refractory RM-NPC patients. Dose selection of this combination needs further investigation considering the toxicity.

TRIAL REGISTRATION: Chi-CTR1800017229.