Bayer's Phase III Colorectal Cancer Trial Unblinded After Promising Interim Data

A Phase III study evaluating Bayer HealthCare Pharmaceuticals’ regorafenib (Bay 73-4506) in patients with metastatic colorectal cancer (mCRC) has been unblinded to allow patients in the placebo arm to start receiving the investigational oral multikinase inhibitor. The Correct study is being conducted in 760 mCRC patients whose disease had progressed after approved standard therapy. Patients are randomized to receive either regorafenib plust best supportive care, or placebo plus best supportive care.

A planned interim data analysis has now shown that in comparison with placebo, regorafenib therapy led to a statistically significant improvement in overall survival. In light of the findings, the study’s data monitoring committee recommended unblinding the study.

Regorafenib is designed to inhibit angiogenic, stromal, and oncogenic receptor tyrosine kinases, and it is also undergoing Phase III development for the treatment of gastrointestinal stromal tumors (GIST). The drug has received orphan drug designation in the U.S. for the GIST indication, and FDA fast track designation both for the mCRC indication and for the treatment of metastatic and/or unresectable GIST in patients whose disease has progressed despite having received at least imatinib and sunitinib therapy.

Earlier this month Bayer and Onyx Pharmaceuticals announced a litigation-settling agreement, part of which secured Bayer’s ownership of regorafenib. The firm will in return pay Onyx a royalty on future global sales of the drug in oncology, and contract Onyx’ sales force to promote regorafenib in the U.S. alongside Bayer’s sales representatives.