SoMore trial: Early metabolic response assessment of a sorafenib (SOR) and capecitabine (CAP) combination in chemorefractory metastatic colorectal cancer (mCRC)

524 Background: The SOR-CAP combination has shown clinical activity in several phase I-II trials involving metastatic breast cancer and mCRC patients (pts). SoMore aims to substantiate the combination’s effects in mCRC refractory to all medications and the predictive value of early metabolic response (MR) on survival. Methods: SoMore (EUDRACT 2010-023695-91) has 2 coprimary objectives: 1) to demonstrate an overall survival (OS) rate at 6 months (mths) > 30%, and 2) to compare OS between pts with and without MR. CAP was given at 1700 mg/m²/day (D), 2 weeks out of 3. SOR was administered at 600mg/D for the first cycle, then at 800mg/D until progression or unacceptable toxicity. FDGPET-CT was performed at baseline and before the 2nd cycle. MR analysis was centralized and blinded for the investigators. Results: From February to October 2011, 92 eligible pts were prospectively recruited in 6 Belgian centers: M/F: 54%/46%; ECOG PS 0/1: 55%/45%; median age: 61. A median of 5 treatment cycles were given (0-28+). Grade 3-4 toxic reactions were reported in 61.2%, mainly fatigue (18%), hand-foot skin reaction (14%) and diarrhea (11%), but no toxic death. 6.9% of the pts stopped therapy due to toxicity. 6 mths OS was 71% (95% CI: 61%-79%), significantly >30% (p