GSK to decide soon on Exelixis drug option

Exelixis has notified partner GlaxoSmithKline that it has achieved proof-of-concept for XL184 under an October 2002 collaboration with the UK drug major. Under the terms of their agreement, GSK has 90 days to review the data and decide whether to exercise its option to select the compound for further development and commercialization.

If XL184 is selected, Exelixis would receive a $55.0 million milestone creditable by GSK against outstanding amounts under the loan facility between the parties, and potentially would receive milestones, royalties on product sales and certain co-promotion rights in North America. Exelixis anticipates a decision from GSK by late October.

XL184 is a small-molecule anticancer compound targeting the MET, RET and VEGFR2 receptor tyrosine kinases. On the basis of encouraging Phase I trial data, Exelixis initiated a late-stage registration trial of XL184 for the potential treatment of medullary thyroid cancer. Based on the anti-tumor activity recently presented at the American Society of Clinical Oncologists, the US firm believes that the agent shows great potential as a new therapy for patients with MTC, for which no standard of care is currently available.