Bevacizumab or Aflibercept in Combination with Second-Line FOLFIRI after Progression on FOLFOX Plus Bevacizumab in Metastatic Colorectal Cancer: A Comparative Study.

BACKGROUND

The optimal anti-angiogenic strategy in the second-line treatment of metastatic colorectal cancer (mCRC) after progression on first-line FOLFOX plus bevacizumab remains unclear. We aimed to compare the efficacy and safety of FOLFIRI combined with bevacizumab or aflibercept in this well-defined clinical setting.

METHODS

In this retrospective single-center study, 152 patients with mCRC who progressed after at least four cycles of first-line FOLFOX plus bevacizumab were included. Of these, 92 patients received FOLFIRI plus bevacizumab and 60 received FOLFIRI plus aflibercept as second-line therapy. Stabilized inverse probability of treatment weighting (IPTW) was applied to account for baseline differences between treatment groups. PFS and OS were evaluated using IPTW-weighted Kaplan-Meier and Cox regression analyses.

RESULTS

No statistically significant difference was observed between the bevacizumab and aflibercept groups for PFS (HR: 1.302, 95% CI: 0.929-1.825, p=0.125) or OS (HR: 1.212, 95% CI: 0.846-1.736, p=0.295) in the IPTW-weighted analyses. Treatment type was not independently associated with PFS or OS in multivariate analyses. Grade 3-4 toxicities were observed in both groups, with neutropenia being the most common; thrombocytopenia and neutropenia were numerically more frequent in the aflibercept group.

CONCLUSION

No statistically significant differences in efficacy were observed between FOLFIRI plus bevacizumab and FOLFIRI plus aflibercept in patients with mCRC progressing after first-line FOLFOX plus bevacizumab. Both strategies represent reasonable second-line options in this setting, highlighting the need for prospective studies to define the optimal sequencing of anti-angiogenic therapies.