Objective: Therapeutic regimens are relatively scarce among patients with treatment-refractory metastatic colorectal cancer (CRC). This study aimed to determine the feasibility and tolerability of anlotinib plus PD-1 blockades in patients with treatment-refractory metastatic CRC retrospectively.
Methods: A total of 68 patients with previously treated metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in this study retrospectively. Demographic and clinical characteristics of the patients, therapeutic outcomes and safety profile during administration were collected and briefly analyzed. All subjects were followed up regularly. Therapeutic outcomes, including drug response and prognosis, were presented, and a safety profile was depicted to illustrate the adverse reactions.
Results: A total of 68 patients with treatment-refractory metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in the final analysis. Best therapeutic response during treatment indicated that partial response was observed in 11 patients, stable disease was noted in 41 patients, and progressive disease was found in 16 patients, producing an objective response rate of 16.2% (95% CI: 8.4%– 27.1%) and a disease control rate of 76.5% (95% CI: 64.6%– 85.9%). Prognostic analysis suggested that the median progression-free survival (PFS) of the 68 patients was 5.3 months (95% CI: 3.01– 7.59), and the median overall survival (OS) was 12.5 months (95% CI: 9.40– 15.60). Of the 11 patients who responded, the median duration of response was 6.7 months (95% CI: 2.89– 10.53). Safety profile during treatment showed that patients experienced adverse reactions regardless of grade, and grade ≥ 3 adverse reactions were found in 61 patients (89.7%) and 41 patients (60.3%), respectively. Common adverse reactions were hypertension, myelosuppression (including leukopenia, neutropenia, thrombocytopenia, and anemia), fatigue, and hand-foot syndrome.
Conclusion: Anlotinib plus PD-1 blockades demonstrated encouraging efficacy and acceptable safety profile in patients with treatment-refractory metastatic CRC preliminarily in clinical practice. This conclusion should be confirmed in prospective clinical trials.

Keywords: colorectal cancer, anlotinib, PD-1 blockades, efficacy, safety