Exelixis, Inc. announced that GlaxoSmithKline (GSK) has exercised its option to exclusively license XL880 for further development and commercialisation.
XL880 is a small molecule compound currently being evaluated in phase II trials in patients with papillary renal cell carcinoma (PRC), gastric cancer and head and neck cancer. Under the terms of the collaboration between Exelixis and GSK initiated in October 2002 and amended in January 2005, GSK's selection of XL880 entitles Exelixis to a selection milestone of $35 million and additional payments upon the attainment of specific development and commercialisation milestones. The $35 million selection milestone will be applied to repayment of an advance that GSK paid to Exelixis in 2005.
Exelixis is also entitled to receive double-digit royalties on product sales if the compound is approved for marketing and commercialised. Exelixis will have certain co-promotion rights to XL880 in North America.
"XL880 is the first MET inhibitor to be evaluated in phase II trials, and the clinical data generated to date for this compound has been very compelling," said George A Scangos, Ph.D., president and CEO of Exelixis. "We believe that XL880 has substantial potential as a first-in-class therapy, and GSK and Exelixis look forward to the completion of the ongoing XL880 phase II trials and evaluation of pivotal trial options. We are pleased that GSK shares our belief in the significant clinical and commercial potential of this compound. Additionally, we believe that GSK's selection of XL880 validates our strategy of building a franchise in the area of MET inhibition to exploit the potential of this promising target".
"The exercise of the XL880 option confirms GSK's growing status as a world leader in the development of new oncology medicines for use in thetreatment, prevention and supportive care of cancer patients," commented Paolo Paoletti, MD, senior vice president of the Oncology Medicines Development Centre at GSK. "It further strengthens our oncology pipeline and demonstrates our commitment to identifying compounds that have the potential to deliver real benefit to patients. The data we have seen from trials conducted by Exelixis have given us confidence in the potential of XL880 for treating diseases for which there is high unmet medical need."
The collaboration between Exelixis and GSK, which is managed by GSK's Centre of Excellence for External Drug Discovery (CEEDD), covers seven compounds and their back-up and follow-up compounds currently in the Exelixis development pipeline. Under the terms of the collaboration, Exelixis submits the covered compounds to GSK as they achieve clinical proof-of-concept, which is a pre-determined measure of efficacy, generally based on phase II trial data, and GSK has the option to select two compounds, and potentially a third compound, for further clinical development and commercialisation.
However, in the case of XL880, GSK has requested in August 2007 to review the compound's data prior to achievement of proof-of-concept. Exelixis agreed to the request and submitted the XL880 data package to GSK in September 2007.
Dr Scangos noted, "We believe the selection of XL880 is a significant event that reflects the maturation of our pipeline and our discovery and development capabilities. XL880 represents one of many potentially significant compounds in our pipeline that we hope will help people with cancer. We believe that GSK's selection of this novel compound will expedite the development of XL880 and may provide us with additional resources to advance our other compounds into and through clinical development."
XL880 has attractive pharmaceutical properties, with high solubility and oral bioavailability. In preclinical studies, XL880 potently inhibited both MET and VEGFR with nanomolar potency, and retained potent activity against mutationally activated forms of MET found in hereditary papillary renal cell carcinomas.