Bayer and partner Onyx Pharmaceuticals has filed regorafenib in the USA for a second indication, that of gastrointestinal stromal tumours.

Specifically, a New Drug Application has been submitted to the US Food and Drug Administration for regorafenib, an oral multi-kinase inhibitor, for the treatment of GIST in patients whose disease has progressed despite prior treatment. The filing is based on Phase III data which showed that regorafenib plus best supportive care significantly improved progression-free survival compared to placebo plus BSC in patients who were previously treated with Novartis Gleevec/Glivec (imatinib) and Pfizer's Sutent (sunitinib).

Bayer also noted that the FDA recently agreed that the firm can proceed with its expanded access programme to provide regorafenib to patients diagnosed with GIST through qualified clinical sites. In May, the company filed regorafenib for metastatic colorectal cancer and a month later, the FDA granted the drug a priority review in that indication.

The drug was at the centre of a row between Bayer and partner Onyx Pharmaceuticals which was settled in October 2011. Before then, in May 2009, Onyx sued over the rights to the drug, claiming it is a variant of the two firms' Nexavar (sorafenib), while Bayer always insisted that regorafenib is not covered by a collaboration the companies signed in 1994.

The settlement recognised that regorafenib is a Bayer compound, while Onyx will receive a 20% royalty. The US biotech will not have to pay any development and commercialisation costs and has a co-promotion option in the USA.