Bevacizumab (BV) maintenance (M) after first-line chemotherapy (CT) plus BV for metastatic colorectal cancer (mCRC) patients (pts): A meta-analysis of individual pts data (IPD) from three phase III studies.

Abstract

3550 Background: Although CAIRO3 and AIO KRK 0207 trials demonstrated the benefit of BV + fluoropyrimidine as a M regimen after induction CT + BV, the role of BV alone is not clear. Indeed, SAKK 41/06 and PRODIGE 9 trials failed to demonstrate the superiority of BV alone vs no M, while AIO KRK 0207 showed the non-inferiority of BV alone vs combo M. Thus, in order to evaluate the magnitude of the eventual benefit of M with BV alone vs no M, an IPD meta-analysis was performed. Methods: Trials whereas mCRC pts were prospectively randomized to receive BV M or not were considered eligible. Primary end-points were PFS and OS, both from the start of induction and M. Univariate and multivariate analyses for PFS and OS were performed, with the following variables: baseline ECOG PS; age ( > vs ≤ 65 years); RAS and BRAF status; LDH and CEA baseline level; RR (PR or CR vs SD) during induction; induction CT (oxa- vs iri-based); resected primary tumor; primary tumor side; synchronous vs metachronous; adjuvant treatment; number (N) of metastatic sites; liver-only disease. Results: IPD of 1,064 pts enrolled in the PRODIGE 9, AIO KRK 0207 and SAKK 41/06 trials were collected. Considering the different timing of randomization in PRODIGE 9 (at the start of induction) vs AIO KRK 0207 and SAKK 41/06 (at the start of M), IPD of pts not progressed during induction and starting M phase entered the analysis. 909 pts were included, 457 (50%) received BV M. Median PFS from induction start was 9.6 and 8.9 months in BV group vs no M group, respectively (HR 0.78; 95%CI: 0.68-0.89; p < 0.0001). At the multivariate PFS analysis, BV M, resected primary tumor, N of metastatic sites and liver-only disease were significant. No difference in terms of OS between the 2 groups was observed. Conclusions: This is the first IPD meta-analysis investigating the role of BV alone M vs no M after first-line induction CT+BV in mCRC pts. Despite the significant PFS improvement in favor of BV M, the absolute benefit appears limited, and without a clear clinical relevance. On these bases, a predictive nomogram to identify pts most likely to benefit from BV M is under evaluation and will be presented during the Congress.