GlaxoSmithKline (GSK) and OncoMed Pharmaceuticals (OncoMed) have announced a worldwide strategic alliance to discover, develop and market novel antibody therapeutics to target cancer stem cells which are believed to play a key role in the establishment, metastasis and recurrence of cancer.

The alliance with GSK will be conducted through its Center of Excellence for External Drug Discovery (CEEDD).

The alliance leverages OncoMed’s expertise in the discovery and development of cancer stem cell antibody therapeutics and provides GSK with an option to license four product candidates directed at multiple cancer stem cell targets from OncoMed’s broad library of monoclonal antibodies.

OncoMed will receive an undisclosed initial payment comprised of cash as well as an equity investment. In addition, OncoMed is eligible to earn milestone payments up to $1.4 billion from GSK based on the achievement of specified discovery, development, regulatory and commercial milestones. OncoMed will also receive double-digit royalties on all collaboration product sales. Furthermore, GSK will have an option to invest in a future initial public offering by OncoMed.

OncoMed has established a diverse pipeline of monoclonal antibodies to target multiple pathways important in the activity of cancer stem cells. The alliance with GSK includes OncoMed’s lead antibody product candidate, OMP-21M18, a monoclonal antibody, which is scheduled to enter the clinic in 2008.

In the alliance, OncoMed will utilise its proprietary in vivo xenograft cancer stem cell models to identify monoclonal antibodies in a specific, undisclosed cancer stem cell pathway. OncoMed will develop the most promising of these monoclonal antibodies, including OMP-21M18, through clinical proof of concept across multiple indications.

Upon OncoMed’s achievement of clinical proof of concept in an agreed indication, GSK will have an exclusive option to license such monoclonal antibody. GSK would then assume responsibility for funding of further clinical development and commercialisation on a worldwide basis. OncoMed retains the option to participate in development and commercialisation of OMP-21M18 on pre-agreed terms.

“This alliance confirms GSK’s growing status as a world leader in the development of new oncology medicines for use in the treatment, prevention and supportive care of cancer patients and provides us access to an exciting new area of drug discovery. We believe that targeting cancer stem cells has the potential to change the paradigm of how oncology patients are treated and we are very excited to be working with OncoMed to develop novel and innovative medicines in this regard,” said Hugh Cowley, M.D., Senior Vice President and head of the CEEDD.

“We are extremely pleased to be collaborating with GSK given their proven commitment to innovation and their expertise in the development and commercialisation of novel oncology medicines,” said Paul J. Hastings, President and CEO of OncoMed. “This strategic alliance provides important validation of our scientific expertise in the field of cancer stem cell research and drug development. In addition, we gain access to significant non-dilutive financing to support the development of our novel cancer therapeutics, which we believe have the potential to significantly impact the outcome of cancer treatment.”