Second-line chemotherapy after early disease progression during first-line chemotherapy containing bevacizumab for patients with metastatic colorectal cancer

Background The ML18174 study, which showed benefits of bevacizumab (BEV) continuation beyond progression (BBP) for metastatic colorectal cancer (mCRC), excluded patients with first-line progression-free survival (PFS) shorter than 3 months. The present study was conducted to evaluate the efficacy of second-line chemotherapy after early disease progression during first-line chemotherapy containing bevacizumab. Methods The subjects of this study were mCRC patients who experienced disease progression < 100 days from commencement of first-line chemotherapy containing BEV initiated between Apr 2007 and Dec 2016. Second-line chemotherapy regimens were classified into two groups with and without BEV/other anti-angiogenic agents (BBP and non-BBP) and efficacy and safety were compared using univariate and multivariate analysis. Results Sixty-one patients were identified as subjects of this study. Baseline characteristics were numerically different between BBP (n = 37) and non-BBP (n = 25) groups, such as performance status (0-1/> 2/unknown: 89/8/3 and 56/40/4%), RAS status (wild/mutant/unknown: 32/54/16 and 76/16/8%). Response rate was 8.6% in BBP group and 9.1% in non-BBP group (p = 1.00). Median PFS was 3.9 months in BBP group and 2.8 months in non-BBP group (HR [95%CI]: 0.79 [0.46-1.34], p = 0.373, adjusted HR: 0.87 [0.41-1.82], p = 0.707). Median overall survival was 8.5 months in BBP group and 5.4 months in non-BBP group (HR 0.66 [0.38-1.12], p = 0.125, adjusted HR 0.53 [0.27-1.07], p = 0.078). Conclusion In mCRC patients who experienced early progression in first-line chemotherapy, second-line chemotherapy showed poor clinical outcomes regardless use of anti-angiogenic agents.

Automated summary

This study found that in mCRC patients, those who experienced early progression in first-line chemotherapy showed poor clinical outcomes with second-line chemotherapy regardless of the use of anti-angiogenic agents.