Bevacizumab (BEV) plus chemotherapy (CT) continued beyond first progression in patients with metastatic colorectal cancer (mCRC) previously treated with BEV plus CT: Results of a randomized phase III intergroup study (TML study).

Abstract

CRA3503 Background: BEV in combination with fluoropyrimidine-based CT is standard treatment for mCRC in the first-line (1L) and BEV-naïve second-line (2L) settings. This is the first randomized study evaluating the benefit of continuing BEV in combination with standard CT as 2L treatment for patients with mCRC who progressed after receiving a standard BEV-containing regimen in the 1L setting. Methods: Patients with unresectable, histologically confirmed mCRC who progressed within 3 months after discontinuation of 1L BEV + CT were randomised to 2L fluoropyrimidine-based CT ± BEV (2.5 mg/kg/wk equivalent). Choice of oxaliplatin- or irinotecan-based 2L CT was dependent on the regimen used in 1L (crossover) and included as a stratification variable. The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), response rate and safety. Results: 820 patients were randomized from February 2006 to June 2010 (409 to BEV + CT and 411 to CT alone). Baseline patient and disease characteristics were well balanced between arms. The study met its primary endpoint; median OS was 11.2 months for BEV + CT and 9.8 months for CT (HR=0.81; 95% CI 0.69–0.94; unstratified log-rank test, p=0.0062). Median PFS was 5.7 months for BEV + CT and 4.1 months for CT (HR=0.68; 95% CI 0.59–0.78; unstratified log-rank test, p<0.0001). The response rate was 5.4% for BEV + CT and 3.9% for CT (unstratified Chi-Square Test, p=0.3113). The adverse event profile was consistent with previously reported data for BEV + CT. Compared with historical data from BEV treatment in 1L or 2L mCRC, BEV-related adverse events were not increased when continuing BEV beyond progression. Conclusions: This is the first randomized study to prospectively investigate the impact of continuing BEV treatment in 2L mCRC for patients who progressed after receiving a BEV-containing regimen in 1L. Our findings demonstrate that BEV + CT (crossed over from 1L regimen) continued beyond progression significantly prolongs OS and PFS in 2L mCRC. Additional analysis (including biomarker evaluation) is ongoing.