Apatinib plus 5-fluorouracil as a third or subsequent-line treatment option for metastatic colorectal cancer: a phase-II, single-arm, prospective study

Background: For metastatic colorectal cancer (mCRC) patients for whom at least 2 lines of previous standard therapies have failed, the prognosis is often unfavorable due to very limited subsequent treatment options. We sought to explore the efficacy of apatinib, an oral small-molecule vascular endothelial growth factor receptor-2 inhibitor, plus 5-fluorouracil (5-FU) as a third- or subsequent-line treatment for mCRC. Methods: In this phase-II, single-arm, prospective study, the eligible patients had been histologically confirmed to have adenocarcinoma of the colon or rectum for which at least 2 previous regimens of standard therapies had failed. All the patients were treated with a daily dose of 250 mg of apatinib, in combination with capecitabine, Tegafur Gimeracil Oteracil Potassium Capsule (S-1), or 5-FU, until disease progression, unacceptable toxicity, or consent withdrawal. Results: From June 2017 to April 2018, 16 patients were enrolled in this study. Among them, 4 achieved partial response, 7 had stable disease, and 5 had progression disease, resulting in an objective response rate of 25.00% [95% confidence interval (CI): 7.27-52.38%], and a disease control rate of 68.75% (95% CI: 41.3488.98%). The median progression-free survival (PFS) was 4.83 months (95% CI: 2.17-8.90 months), and the median overall survival (OS) was 9.10 months (95% CI: 5.59-15.18 months). The common treatment-related adverse events (AEs) were hand- foot syndrome (56.25%), hypertension ( 37.50%), proteinuria (37.50%), gingival bleeding (18.75%) and abdominal pain (18.75%). Grade 3 AEs, including hand-foot syndrome (18.75%), hypertension (12.50%), and proteinuria (12.50%), were observed in 7 patients. Conclusions: The combination regimen of apatinib plus 5-FU had encouraging anti-tumor efficacy, and is a feasible third- or subsequent-line treatment option for mCRC.