FDA Extends Review of EPIX Pharmaceuticals' Appeal of Vasovist™ Approvable Letters

Business Wire, July 28, 2006

CAMBRIDGE, Mass. -- EPIX Pharmaceuticals, Inc. (NASDAQ: EPIX), a developer of innovative pharmaceuticals for magnetic resonance imaging (MRI) which recently announced a definitive agreement to merge with Predix Pharmaceuticals Holdings, Inc., today announced that the U.S. Food and Drug Administration (FDA) has advised EPIX that it is extending its review of the formal appeal submitted by the Company on June 30th, 2006. In the appeal, EPIX asked the FDA to approve the Company's novel blood-pool imaging agent Vasovist(TM) and to use an Advisory Committee as part of the appeal process. The FDA indicated that it expects to respond to the appeal in September 2006.

"We appreciate the FDA's willingness to take this additional time to review our appeal of the Vasovist approvable letters," said Andrew Uprichard, M.D., EPIX's President and Chief Operating Officer. "We look forward to hearing the FDA's response to our appeal in September."

About EPIX

EPIX Pharmaceuticals, Inc., based in Cambridge, MA, discovers and develops innovative pharmaceuticals for imaging that are designed to transform the diagnosis, treatment and monitoring of disease. The Company uses its proprietary Target Visualization Technology(TM) to create imaging agents targeted at the molecular level, designed to enable physicians to use Magnetic Resonance Imaging (MRI) to obtain detailed information about specific disease processes. On April 3, 2006, EPIX announced a definitive agreement to merge with Predix Pharmaceuticals to create a specialty pharmaceutical company with capabilities in both therapeutics and imaging. To receive the latest EPIX news and other corporate developments, please visit the EPIX website at www.epixpharma.com.

About Predix

Predix, based in Lexington, MA, is a pharmaceutical company focused on the discovery and development of novel, highly selective, small-molecule drugs that target G-Protein Coupled Receptors (GPCRs) and ion channels. Using its proprietary drug discovery technology and approach, Predix has advanced four internally-discovered drug candidates into clinical trials and has five additional programs in preclinical development and discovery. Predix is expected to complete the first of at least two pivotal Phase III clinical trials for generalized anxiety disorder for its lead drug candidate, PRX-00023, in the second half of 2006. In addition to PRX-00023, Predix has three other clinical-stage drug candidates: PRX-03140 for the treatment of Alzheimer's disease, which is expected to enter Phase IIa later this year; PRX-08066 for the treatment of pulmonary hypertension (PH) and PH associated with chronic obstructive pulmonary disease, which recently completed a Phase Ib trial and is expected to enter Phase IIa in the second half of 2006; and, PRX-07034, which recently entered a Phase I trial and is expected to be developed for the treatment of obesity and for cognitive impairment associated with Alzheimer's disease or schizophrenia. Additional information about Predix can be found on the company's website at www.predixpharm.com.

Additional Information About the Merger And Where To Find It

EPIX has filed a registration statement on Form S-4 with the Securities and Exchange Commission containing a joint proxy statement/prospectus in connection with the proposed merger with Predix Pharmaceuticals. Investors and security holders are advised to read the joint proxy statement/prospectus (including any amendments or supplements thereto) regarding the proposed merger, because it contains important information about EPIX, Predix and the proposed transaction and other related matters. The joint proxy statement/prospectus was mailed on or about July 18, 2006 to stockholders of EPIX and Predix, seeking their approval for the transaction. Investors and security holders may obtain a free copy of the joint proxy statement/prospectus and any amendments or supplements thereto, and other documents filed by EPIX at the Securities and Exchange Commission's web site at www.sec.gov. The joint proxy statement/prospectus and such other documents may also be obtained for free by directing such request to EPIX Pharmaceuticals, Inc., 161 First Street, Cambridge, Massachusetts, Attn: Investor Relations, tel: (617) 250-6000; e-mail: ahedison@epixpharma.com or Predix Pharmaceuticals Holdings, Inc., 4 Maguire Road, Lexington, Massachusetts 02421, Attn: Investor Relations, tel: (781) 372-3260; e-mail: investors@predixpharm.com.

EPIX and Predix and their respective directors, executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies with respect to the adoption of the merger agreement and the transactions associated with the merger. A description of any interests that EPIX and Predix directors and executive officers have in the merger is included in the registration statement containing the joint proxy statement/prospectus filed with the Securities and Exchange Commission and available free of charge as indicated above. Information regarding EPIX's executive officers and directors is also available in EPIX's Form 10-K, as amended, for the year ended December 31, 2005, which was filed with the Securities and Exchange Commission on March 1, 2006 and amended on April 28, 2006. You can obtain free copies of these documents using the contact information above.