PRESS RELEASE: EPIX Pharmaceuticals Achieves Discovery Milestone in Collaboration with GlaxoSmithKline

EPIX Pharmaceuticals Achieves Discovery Milestone in Collaboration with GlaxoSmithKline

Three Lead Candidates Identified in First Discovery Program

LEXINGTON, Mass. -- EPIX Pharmaceuticals, Inc. today announced that it has achieved an initial milestone under its collaboration with GlaxoSmithKline related to the first of three discovery stage programs. Using its proprietary, integrated computational-medicinal chemistry approach to drug discovery, EPIX has identified three lead candidates that will move forward into lead optimization in this first collaborative G-protein coupled receptor (GPCR) discovery program. Under the collaboration, EPIX is entitled to receive a $3 million milestone payment from GSK in the next 30 days.

“We are extremely pleased with the progress of our collaboration with GSK,” stated Michael G. Kauffman, M.D., Ph.D., chief executive officer of EPIX. “In addition to our joint focus on developing PRX-03140, our proprietary 5-HT4 agonist, for the treatment of Alzheimer’s disease, EPIX and GSK have agreed upon the three discovery program targets and are making significant progress on each program. We are on-schedule and expect to continue moving forward to achieve key milestones across all of our collaborative programs.”

In December 2006, EPIX and GSK announced a worldwide multi-target strategic collaboration to discover, develop and market novel medicines targeting four G-protein coupled receptors (GPCRs) for the treatment of a variety of diseases, including EPIX’s novel 5-HT4 partial agonist program, PRX-03140, which is in early-stage clinical development for the treatment of Alzheimer's disease. As part of the collaboration, EPIX received total initial payments of $35 million, including $17.5 million through the purchase of its common stock at a premium, and may be eligible to earn up to $1.2 billion in milestones across the four GPCR programs. Under the collaboration, EPIX is also entitled to receive tiered double-digit royalties of sales by GSK on all collaboration-developed product sales. The alliance is conducted through GSK’s Center of Excellence for External Drug Discovery (CEEDD).

“We have been impressed by the quality and efficiency of the lead identification process for this collaborative effort between EPIX and GSK,” said Hugh Cowley, M.D., head of GSK’s Center of Excellence for External Drug Discovery (CEEDD). “In addition to the PRX-03140 program in Alzheimer’s disease, we are moving forward with EPIX to discover and develop GPCR candidates for the treatment of a variety of diseases. This marks an initial milestone in what we expect will be a long and productive collaboration.”

About the GSK CEEDD

GlaxoSmithKline is enhancing the way it discovers and develops drugs by creating a small dedicated team who will feed the GSK pipeline through the efforts of its external collaborations. In essence, the CEEDD (Center of Excellence for External Drug Discovery) will ‘virtualize’ a portion of the GSK pipeline; namely, from Target to Clinical PoC, by forming multiple risk-sharing/reward-sharing alliances.

About EPIX

EPIX Pharmaceuticals is a biopharmaceutical company focused on discovering and developing novel therapeutics through the use of its proprietary and highly efficient in silico drug discovery platform. The company has a deep pipeline of internally-discovered drug candidates currently in clinical development to treat diseases of the central nervous system and lung conditions. EPIX also has collaborations with leading organizations, including GlaxoSmithKline, Amgen, Cystic Fibrosis Foundation Therapeutics, and Bayer Schering Pharma AG, Germany. For more information, please visit the company’s website at www.epixpharma.com.