Safety analysis of regorafenib prior to selective internal radiation therapy (SIRT) using 90Y resin microspheres for the treatment (tx) of patients (pts) with refractory metastatic colorectal cancer (mCRC) with liver metastases (mets).

e15040Background: SIRT (or radioembolization) has been successfully used in the tx of mCRC patients with liver mets who are not surgical candidates. The addition of the multi-kinase inhibitor, regorafenib to SIRT is an attractive option as anti-tumor and maintenance tx for refractory CRC. Here we present the safety analysis of the 1st of 2 cohorts of our Phase II, open-label study comparing the safety of the combination of SIRT and regorafenib where chemotherapy occurs either before or after SIRT. Methods: mCRC pts with evidence of liver mets not treatable by surgical resection or local ablation were tx with 160 mg regorafenib QD PO on days 1-21 of a 28-day cycle followed by a 1 week (wk) washout then SIRT infusion (SIR-Spheres; Sirtex, North Sydney, Australia). Liver function was evaluated 2 wks and 4 wks after SIRT, and regorafenib was re-initiated if liver function was normal. Pts were evaluated for safety, and restaged on wk 6 and 12 following SIRT. The primary objective was to evaluate the safety of ...