GlaxoSmithKline and Synta Pharmaceuticals will end their collaborative agreement for the clinical development and commercialization of elesclomol, a chemotherapy adjuvant, by September 10, 2009. Worldwide rights to elesclomol will revert to Synta and Synta may pay GSK a low single-digit royalty on any potential future sales of elesclomol.

“We appreciate GSK’s contributions to this program and understand their decision,” said Safi R. Bahcall, Ph.D., president and chief executive officer of Synta. “We will be meeting with medical and scientific advisors to review the data from the SYMMETRY trial and additional results later this year, and will use this guidance to inform our choices for a path forward for the program. We expect to report more on additional data and plans for the program later this year.”

Dr. Bahcall added that Synta is continuing to evaluate the potential of elesclomol, while also focusing its Resources on other programs in its portfolio, particularly the Hsp90 program. He remarked, “With a strong cash position, a portfolio of first-in-class and best-in-class programs, and a productive discovery engine, we are excited about the potential of our pipeline and are committed to realizing the potential of these programs to benefit patients.”