A phase I/II multicenter study of ABI-009 (nab-sirolimus) combined with FOLFOX and bevacizumab as first-line (1L) therapy in patients (pts) with metastatic colorectal cancer (mCRC) with or without PTEN loss.

TPS730Background: Very few treatment options are available for pts with mCRC beside the standard of care (SOC), 5-FU based chemotherapy + bevacizumab. Immunotherapy is an option for pts with microsatellite instability (~5% of mCRC). The central role of the PI3K/mTOR pathway in cancer biology, including CRC, suggests that mTOR inhibition along with chemotherapy may improve antitumor activity in the metastatic setting. A recent phase I/II study showed promising antitumor activity of everolimus + SOC as 1L treatment for mCRC (96% progression-free [PF] rate at six months at the maximum tolerated dose (MTD), and 86% ORR for pts with PTEN loss (Gilcrease, ASCO 2012). The goal of this prospective, single arm phase I/II study is to evaluate the efficacy and safety of ABI-009, a novel mTOR inhibitor, + SOC as 1L treatment for mCRC. Methods: Eligible pts have an ECOG performance status of 0-2 and histologically confirmed measurable metastatic disease. PTEN loss (by IHC) and mutational status for PIK3CA, KRAS, NRAS,...