GlaxoSmithKline (NYSE:GSK) is adding to its cancer drug discovery capabilities by picking up the epigenetics research program from drug partner Astex Pharmaceuticals (Nasdaq:ASTX).

Oncology drug discovery and development company Astex will end its work on the the “Climb” collaboration and transfer the research work and assets to British pharma giant GSK, which has its U.S. headquarters in Research Triangle Park.

The GSK-Astex collaboration dates to 2009, when GSK entered into a licensing agreement with Astex predecessor company SuperGen. SuperGen received $5 million up front, including a $3 million equity investment in the deal. SuperGen stood to gain more than $375 million in additional milestones for progress reached during the collaboration.

GSK collaborated with SuperGen on its Climb platform technology, which screens libraries of compounds with computational chemistry in order to speed up the drug discovery process. The technology was being used for cancer drug discovery work.

Last April, SuperGen merged with Astex Therapeutics, another California pharmaceutical company. Dublin, California-based Astex said that the decision to transfer the drug discovery program to GSK followed a review of its own pipeline and drug discovery programs following the merger that formed Astex. The transfer of Climb to GSK ends Astex obligations to conduct additional research in that program. But Astex remains eligible to receive milestones and royalties if Climb yields successful drugs. GSK and Astex will continue their R&D collaboration on a separate drug platform called Pyramid. Pyramid was included in the 2009 agreement.

About half of GSK’s early-stage drug pipeline is partnered. Like other pharmaceutical companies trying to broaden their reach beyond internal R&D, GSK has sought out partnerships to generate new drug candidates. But if the Climb platform proves successful, GSK could be producing its own cancer candidates from the technology.

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