First data on Bayer's oral Raf kinase inhibitor

Onyx Pharmaceuticals and Bayer have reported Phase I clinical resultswith BAY-43-9006, claimed to be the first orally-active Raf kinase inhibitor to undergo clinical testing. The drug blocks the Ras signaling pathway in cells, which is believed to play a role in around 30% of all human tumors. The 12-patient study looked at single, escalating doses of the drug, ranging from 50mg to 400mg given once-weekly, and found no significant toxicities. Preclinical data have shown that the drug can inhibit a wide range of tumor xenograft models.