Safety and efficacy of bevacizumab (Bev) when added to oxaliplatin/fluoropyrimidine (O/F) regimens as first-line treatment of metastatic colorectal cancer (mCRC): TREE 1 & 2 Studies

3515 Background: Bevacizumab (Bev) added to IFL combination chemotherapy improves survival in mCRC. This randomized study assesses the safety & tolerability of each of three Oxaliplatin plus fluoropyrimidine regimens (bolus (b), infusional or oral fluoropyrimidine) alone in TREE1, and with Bev in TREE2. Methods: Eligibility: age ≥ 18; measurable untreated mCRC; PS ≤1. Primary endpoint: Grade 3/4 toxicities in the 1st 12 weeks (wk) of Rx; secondary endpoints: TTP, OS. Oxali-FU (in mg/m2) regimens consisted of: FOLFOX = O 85, leucovorin (LV) 350mg, 5FU bolus 400 & 2400 CIV x 46 hrs q 2 wk; bFOL = O 85 days (d) 1&15, LV 20 & bolus 5FU 500 d 1,8,15 q 4 wk; CapOx = O130 d 1, Capecitabine 1000 bid (850 for TREE2) for 14 d q 3 wk; Bev was added to each regimen (5 mg/kg q 2 wk or 7.5 mg/kg q 3 wk) in TREE2. Results: 147 pts were entered in TREE1 and 213 pts in TREE2. Selected gr 3/4 toxicity during 1st 12 wks of treatment is shown in table. Addition of B in TREE 2 caused increased gr 3/4 hypertension, impaired wo...