RICHMOND, Calif., Sept. 4 /PRNewswire-FirstCall/ -- Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX - News) today announced that its partner Bayer Corporation (NYSE: BAY - News) has initiated a single-agent Phase II clinical study of a novel cancer agent, BAY 43-9006, a Raf kinase inhibitor, for the potential treatment of hepatocellular carcinoma. Onyx indicated that initiation of the Phase II program earned a $5 million loan milestone payment for Onyx. The companies advised that additional single-agent Phase II studies are planned. Bayer said separately that a Phase II study in colorectal cancer is expected to begin this quarter.
The preliminary findings of four Phase I studies -- in Canada, the U.S., Belgium and Germany -- provided rationale for undertaking the Phase II study. Preliminary data from Phase I studies were reported at both the American Association for Cancer Research and the American Society of Clinical Oncology meetings earlier this year. Those data were used to determine the safety profile of the small molecule compound. Also presented were data that included two patients with confirmed partial responses; preliminary evidence of tumor shrinkage in five additional patients; and, in a subset of patients treated at higher doses, 45 patients who had disease stabilization. "Since this molecule targets the Ras pathway -- a pathway that data suggest plays a role in cell proliferation -- we are looking forward to the commencement of Phase II studies," commented Chairman and Chief Executive Officer of Onyx, Hollings C. Renton.
In addition to exploring the utility of BAY 43-9006 alone in the hepatocellular Phase II trial, Bayer and Onyx have planned clinical trials in combination with a range of standard chemotherapeutics. Initially, these studies aim to identify regimens of the combined therapy that are sufficiently well tolerated. That would set the stage for follow-up Phase II and III studies to demonstrate the safety and efficacy profiles of the therapy.
BAY 43-9006, an orally active small molecule Raf kinase inhibitor, was discovered and is being co-developed in a collaboration between Onyx and Bayer. Data suggest that BAY 43-9006 selectively blocks signal transduction in the Ras pathway by inhibiting a specific enzyme known as Raf kinase, and is the first orally active compound in this class to undergo clinical testing. The Ras signaling pathway is believed to play an integral role in the genesis of many cancers, and blocking this pathway has been shown to inhibit tumor growth in vivo. Mutations in the Ras gene occur in approximately 30 percent of all human cancers, including 90 percent of pancreatic cancer and 50 percent of colon cancer.
The co-development collaboration with Bayer results in Onyx funding 50 percent of the development costs for BAY 43-9006. In return, Onyx has a 50/50 profit share in the United States where the companies can co-promote the product. Everywhere in the world except Japan, Onyx's share is somewhat less than 50 percent since Bayer has exclusive marketing rights. In Japan, Bayer funds the product, and Onyx gets a royalty... |
