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.

Abstract

TPS730 Background: 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, BRAF by NGS is evaluated for all pts. ABI-009 is given weekly x3 every four weeks starting at 30 mg/m2and can escalate to 45 and 60 mg/m2 (3+3 design); mFOLFOX6 + bevacizumab is given every two weeks. After six cycles of therapy, cycles may change to 21-days: ABI-009 weekly x2 every three weeks and mFOLFOX6 + bevacizumab every three weeks. Pts are treated until disease progression. Tumor response is assessed by CT at baseline then every eight weeks for one year, then every 12 weeks thereafter. Phase I will enroll up to 18 pts; the primary endpoints are dose-limiting toxicities and MTD, secondary endpoints include disease control rate (DCR). Phase II will enroll 40 pts; the primary endpoint is PF rate at six months, and secondary endpoints are median PF survival, overall survival, duration of response, and DCR in the intent-to-treat population and based on PTEN status. This study is now active, with first pt enrolled. The anticipated enrollment period is 12 months. This prospective phase I/II study may show evidence of efficacy and safety of ABI-009 combined with the SOC in pts with mCRC with or without PTEN loss to warrant a larger clinical study. Results: N/A. Conclusions: N/A. Clinical trial information: NCT03439462.