Apatinib for the treatment of metastatic or locoregionally recurrent nasopharyngeal carcinoma after failure of chemotherapy: A multicenter, single-arm, prospective phase 2 study

Background The authors aimed to investigate the efficacy and safety of apatinib in patients with metastatic or locoregionally recurrent nasopharyngeal carcinoma (NPC). Methods A multicenter, single-arm, prospective phase 2 study was conducted on patients (18-70 years of age) with metastatic or recurrent NPC who had failed chemotherapy. Patients with recurrent disease involving vascular structure invasion were excluded. All enrolled patients received apatinib (500 mg daily) in continuous 4-week cycles until disease progression or development of unacceptable toxicity. The primary end point of this study was objective response rate (ORR), and the secondary end points were progression-free survival (PFS), overall survival (OS), and toxicity. This study was registered with ClinicalTrials.gov (NCT03130270). Results Between January 2017 and June 2018, 33 patients were enrolled. At the end of the data collection (May 20, 2020), the 33 patients had completed a total of 261.2 cycles of apatinib. Although 12 patients achieved a partial response, no patient achieved a complete response; thus, the ORR in the 33 patients was 36.4% (95% CI, 19.0%-53.7%). At the end of follow-up (median, 30 months; 95% CI, 24.9-35.1), median OS and median PFS were 16 months (95% CI, 14.6-17.4 months) and 5.0 months (95% CI, 3.6-6.4 months), respectively. The most common adverse events (grade 1/2) were hand-foot syndrome (18 [54.5%]), hypertension (14 [42.4%]), oral ulcer (8 [24.2%]), and proteinuria (4 [12.1%]). Two patients (1 with diabetes and 1 with hypertension) developed cerebral infarction. Grade 3/4 toxicities were uncommon. Conclusions Apatinib shows promising activity, with manageable toxicities, in patients with metastatic or locoregionally recurrent NPC. Further evaluation of apatinib in large-scale studies is warranted. Lay summary Clinical studies on vascular endothelial growth factor receptor (VEGFR)-targeted therapy for recurrent or metastatic nasopharyngeal carcinoma (NPC) are limited. A recent preclinical study that evaluated apatinib in models of NPC showed a high objective response rate and a favorable safety profile. Our data further confirmed good efficacy in patients with lung metastasis. Further studies of the efficacy and safety of apatinib combined with immune checkpoint inhibitors or chemotherapy in NPC is warranted.