A phase II trial of metformin and fluorouracil (MetFU) for patients (pts) with metastatic colorectal cancer (mCRC) refractory to standard treatment.

601 Background: Pts with mCRC whose disease progressed after 5-FU, oxaliplatin, irinotecan and monoclonal antibodies have an unmet medical need. There is growing evidence suggesting an antitumoral effect of metformin in several tumor types, including CRC. Methods: Our primary objective was to evaluate the efficacy and safety of MetFU in heavily pretreated CRC pts with current progressive disease Last dose of 5-FU was administred at least 4 months prior to enrollment. Efficacy was defined as disease control rate at 8 weeks, using RECIST 1.1. Secondary endpoints were progression free survival, overall survival and tolerability. Single-arm Simon two-stage phase II trial was used. The treatment consisted of metformin 850 mg bid continuously plus 5-FU 425mg/m2 + Leucovorin (LV) 50 mg weekly for 4 weeks until disease progression, unacceptable toxicity or consent withdrawn in pts with mCRC who had progressed to conventional lines of treatment. Results: In the first stage, 22 pts were included: 12 pts (54%) were ...