Bayer and US biotechnology partner were cheered this morning on news that they have filed for approval of their widely-anticipated kidney cancer drug, sorafenib, with European drug regulators. In tandem, the German firm also plans to launch a single-arm late-stage trial of sorafenib in previously-treated patients with advanced kidney cancer across 11 European countries.

Bayer and Onyx filed a new drug application with US regulators in July, where it has received fast-track approval [[12/07/05c]], [[07/04/04e]]. The application in Europe and the USA is based on a Phase III trial in which patients with advanced kidney cancer treated with sorafenib survived twice as long as those receiving placebo - the trial is still ongoing.

Analysts predict great things for sorafenib after a dismal few years for Bayer, following the global withdrawal of its cholesterol-lowering drug Lipobay/Baycol (cerivastatin) [[08/08/01a]]. Sorafenib works as a Raf kinase inhibitor, blocking proliferation of a tumour and interfering with its blood supply and starving it of oxygen and nutrients. It has been granted orphan status for the renal cell carcinoma indication in both the US and EU and is also in development as a treatment for advanced melanoma alongside carboplatin [[05/08/04e]]. In 2003, the companies elected not to press ahead with an accelerated filing based on Phase II data, preferring to wait for the Phase III results, causing jitters among investors who see sorafenib as one of the most important new compounds in Bayer's pipeline.