International randomized phase III study of capecitabine (Cap), bevacizumab (Bev), and mitomycin C (MMC) in first-line metastatic colorectal cancer (mCRC): Final results of the AGITG MAX trial

Abstract

4023 Background: The addition of Bev to oxaliplatin or irinotecan based doublet chemotherapy has shown benefit in mCRC. Cap± MMC are alternate chemotherapy regimens suitable for patients (pts) who are either unfit for or who do not require initial oxaliplatin/irinotecan. This phase III study compared Cap with Cap Bev and Cap Bev MMC. The aim was to develop a low toxicity regimen suitable for a broad population of pts with mCRC. Methods: Previously untreated pts with unresectable mCRC considered suitable for Cap monotherapy were randomised to arm A Cap (Cap 2000mg/m2/d or 2500mg/m2 d1–14 q21d), arm B Cap Bev (Bev 7.5mg/kg q3w) or arm C Cap Bev MMC (MMC 7mg/m2 q6w). Primary endpoint: PFS, secondary endpoints: RR, toxicity, OS, QoL . Randomisation was stratified by age, PS, centre and Cap dose. Response was assessed every 6w. The study was designed to detect an increase in the median PFS from 5.5m (arm A) to 8m (arm B or C) at p<0.025 with 80% power. Results: A total of 471 pts were randomised from July 2005-June 2007. Outcomes were evaluated on an intention to treat basis and included 15 ineligible pts. Baseline demographics were well balanced between arms with median age 67y (range 31–86y). Toxicity was reported: ASCO 2008 abstr 4029. The most common grade 3/4 toxicities were PPE (16%, 26%, 28%) and diarrhoea (11%, 17%, 16%) for arms (A,B,C). However, adjusted rates per cycle were similar as arms B & C received more cycles of Cap (A8.3, B10.8, C10.5). Other toxicity rates were generally <10%. The study achieved its primary endpoint with a highly significant improvement in PFS for arms B & C. RR and OS are summarized ( Table ). Conclusions: All treatment regimens were well tolerated in a relatively elderly patient cohort. The addition of Bev±MMC to Cap significantly improved PFS without significant additional toxicity. OS was similar for all arms. Cap Bev±MMC is an active, low toxicity regimen that may be considered as a treatment option for pts with mCRC. [Table: see text] [Table: see text]