Apatinib Monotherapy for Chemotherapy-Refractory Metastatic Colorectal Cancer: A Multi-centre, Single-Arm, Prospective Study

Angiogenesis inhibitors are of considerable interest for treating metastatic colorectal cancer (mCRC). This trial evaluated the efficacy and safety of apatinib in chemotherapy-refractory mCRC. Apatinib 500mg was administered daily to patients who had progressed after two or more lines of standard fluorouracil-based chemotherapy. Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and toxicity. Overall, 48 patients were enrolled. ORR and DCR were 8.3% (4/48) and 68.8% (33/48), respectively. Median PFS and OS were 4.8 (95% confidence interval [CI], 3.653-5.887) and 9.1 months (95% CI, 5.155-13.045), respectively, and did not differ between subgroups stratified by previous anti-angiogenic therapies. The most prevalent grade 3-4 adverse events were hypertension (12.5%), hand-foot syndrome (HFS, 10.4%), thrombocytopenia (10.4%), and proteinuria (8.3%). Low baseline neutrophil/lymphocyte ratio (NLR, hazard ratios [HR], 0.619; P=0.027), early carbohydrate antigen 19-9 (CA19-9) decrease (HR, 1.654; P=0.016), and HFS (HR, 2.087; P=0.007) were associated with improved PFS. In conclusion, apatinib monotherapy demonstrated encouraging efficacy with manageable toxicities in chemotherapy-refractory mCRC. Previous anti-angiogenic therapies did not influence outcomes. Baseline NLR, early CA19-9 decrease, and HFS could predict the efficacy of apatinib.