Efficacy and toxicity of aflibercept and bevacizumab in combination with FOLFIRI in second‑line therapy for metastatic colon cancer: a retrospective multicenter study

Objective: to compare the efficacy and toxicity of aflibercept and bevacizumab in combination with fOLfIRI in secondline therapy for patients with metastatic colon cancer.Materials and methods. we performed a retrospective analysis of data on patients with metastatic colon cancer treated in 9 clinics in the Russian federation. The inclusion criteria were as follows: metastatic or locally advanced colon cancer; treatment with bevacizumab or aflibercept plus fOLfIRI in the second-line therapy. The primary outcome measure was progression-free survival (PfS). Secondary outcome measures included objective response rate and incidence of adverse events.Results. A total of 271 patients with metastatic colon cancer who received second-line therapy with bevacizumab (n = 81) or aflibercept (n = 190) between 2014 and 2018 were selected for this study. Study groups were matched for main prognostic signs. The objective response rate was 18.1 % in the bevacizumab group and 20.5 % in the aflibercept group (p = 0.7). The median PfS was 5 months (95 % confidence interval 3.8–6.1) in the aflibercept group and 7 months (95 % confidence interval 0.81–2.1) in the bevacizumab group (hazard ratio 1.4; 95 % confidence interval 0.99–2.1; p = 0.04). multivariate regression analysis demonstrated that the type of the targeted drug independently had no effect on PfS (hazard ratio 1.3; 95 % confidence interval 0.9–1.9; p = 0.2). we observed no statistically significant differences in the incidence of complications of any grades between the groups (58 % vs 72 %, p = 0.1). Patients receiving aflibercept were more likely to develop grade III–Iv arterial hypertension (2 % vs 9.5 %) and diarrhea (0 % vs 5.4 %), whereas thrombotic complications were more common in the bevacizumab group (10 % vs 1.8 %).Conclusion. we observed no significant differences in objective response rate and PfS between patients with metastatic colon cancer receiving bevacizumab or aflibercept in combination with fOLfIRI as second-line therapy. The toxicity profiles were different. Our findings can be used for choosing an optimal targeted drug for second-line treatment.