N-desmethyl regorafenib N-oxide

M-5 (also known as BAY 81-8752 or N-desmethyl regorafenib N-oxide) is one of the two major active metabolites of regorafenib (Stivarga), an oral multikinase inhibitor developed by Bayer. Formed in vivo primarily via cytochrome P450 3A4 (CYP3A4) metabolism, M-5 exhibits a similar multikinase inhibition profile to its parent compound, regorafenib. It potently inhibits multiple receptor tyrosine kinases involved in tumor angiogenesis (VEGFR1-3, TIE2), oncogenesis (KIT, RET, RAF-1, BRAF), and the tumor microenvironment (PDGFR-beta, FGFR1). At steady state in cancer patients, M-5 achieves systemic exposure levels comparable to regorafenib, thereby significantly contributing to the overall clinical antitumor efficacy of regorafenib in indications such as metastatic colorectal cancer (mCRC), gastrointestinal stromal tumors (GIST), and hepatocellular carcinoma (HCC).

Other names

M-5M5M 5N-desmethyl regorafenib pyridine-N-oxideN-desmethylregorafenib N-oxidedemethylated regorafenib N-oxideregorafenib M5 metaboliteregorafenib metabolite M5