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Molecular Insight Pharmaceuticals, Inc. Presents Preclinical Trofex Prostate Cancer Data at AACR

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Oct 25, 2007 - Molecular Insight Pharmaceuticals, Inc. (NASDAQ: MIPI) today announced the presentation of preclinical data from its Trofex development program for two promising molecular imaging pharmaceutical candidates, MIP-1072 and MIP-1095, for potential use in the detection and monitoring of prostate cancer. Both compounds are radiolabeled small molecules that target prostate-specific membrane antigen (PSMA), a protein that is highly expressed by prostate tumor cells. Based on these and other studies, Molecular Insight plans to begin exploratory clinical trials in the first half of 2008 with both compounds to select a candidate for further clinical development and commercialization.

The studies were presented on October 24th in a poster session at the annual "Molecular Targets and Cancer Therapeutics" meeting in San Francisco, California, which was organized by the American Association for Cancer Research, National Cancer Institute, and European Organization for Research and Treatment of Cancer (AACR-NCI-EORTC).

"Prostate cancer is the second leading cause of cancer-related deaths in men in the United States and there is an urgent need for improved methods to diagnose, monitor and stage the disease, particularly for patients with metastatic disease," said Martin G. Pomper, M.D., Ph.D., Professor, Departments of Radiology, Pharmacology and Oncology at Johns Hopkins University School of Medicine and an author on the study. "The ability to use targeted molecular imaging to clearly and specifically identify areas of metastatic prostate cancer in all areas of the body, including bone, would be a tremendous benefit to ensuring that patients receive proper treatment and staging of their disease."

"These data underscore the potential of our innovative technologies and small molecule approach for targeted molecular imaging," said John W. Babich, President and CSO of Molecular Insight and an author on the study. "PSMA represents an excellent target for prostate cancer detection. By targeting cancer using small molecules rather than antibodies, we can design tumor-targeting compounds with enhanced capacity for tumor uptake and faster blood clearance, while minimizing impact on non-cancer tissues. The study demonstrated that our Trofex program's lead candidates, MIP-1072 and MIP-1095, both have high affinity and specificity for PSMA. Both compounds are internalized by PSMA-expressing cells in vitro and display excellent tumor to normal tissue ratios in vivo, which enables high quality imaging of prostate tumors."

Dr. Babich noted that MIP-1072 and MIP-1095 were internally discovered by Molecular Insight. "The Trofex prostate cancer program has moved from concept to designation as development candidates in less than two years," said Dr. Babich. "Our next step will be to file an exploratory Investigational New Drug (IND) application for Trofex with the U.S. Food and Drug Administration to evaluate both candidate compounds in humans and determine which may be the most suitable for further clinical development in determining the localization of metastatic prostate cancer. We plan to begin a Phase 1 dosimetry study under the exploratory IND process in the first half of 2008."

Prostate cancer is the most frequently diagnosed cancer in men in the United States, with 218,000 new cases per year. It is the second leading cause of cancer deaths in men. There is a major unmet need for accurate, rapid and non-invasive diagnostic tools to determine whether the cancer has spread beyond the prostate to other parts of the body and to help guide treatment. Current techniques often do not confirm the presence of cancer in these patients and the tumors may go undetected.

Study Details

MIP-1072 and MIP-1095 are novel 123I-labeled glutamate-urea-lysine analogs which, in laboratory studies, exhibit high affinity binding to PSMA on cancer cells with K(d) values of 3.0 and 0.6 nM, respectively. Both compounds are internalized by PSMA-expressing cells in vitro, which should afford enhanced tumor to background discrimination. In xenograft models, MIP-1072 and MIP-1095 achieved peak uptake of 17% and 34% of the injected dose/gram tumor, respectively, resulting in a tumor to blood ratio of greater than 30 to 1 and a tumor to muscle ratio of greater than 60 to 1. Specificity of the compounds was demonstrated by co-injection with a structurally unrelated inhibitor of PSMA, which reduced tumor uptake by more than 30-fold. SPECT/CT imaging confirmed localization of MIP-1072 to PSMA-expressing tumors but not to tumors lacking PSMA.

The poster, entitled, "Design and Evaluation of Novel Glutamate-Urea Heterodimers That Target PSMA as Molecular Imaging Agents for Prostate Cancer," was presented by Shawn M. Hillier, Ph.D., of Molecular Insight Pharmaceuticals. Co-authors include Kevin P. Maresca, Ph.D.; Frank J. Femia, Ph.D.; Chris Barone; Craig N. Zimmerman, Ph.D.; John L. Joyal, Ph.D.; and John W. Babich, Ph.D., from Molecular Insight Pharmaceuticals, Inc.; and Martin G. Pomper, M.D., Ph.D., and Catherine A. Foss, Ph.D., from Johns Hopkins University.

About Molecular Insight Pharmaceuticals, Inc.

Molecular Insight Pharmaceuticals (NASDAQ: MIPI) is a biopharmaceutical company specializing in the emerging field of molecular medicine, applying innovations in the identification and targeting of disease at the molecular level to improve healthcare for patients with life-threatening diseases. The company is focused on discovering, developing and commercializing innovative and molecular radiotherapeutics and molecular imaging pharmaceuticals with initial applications in the areas of oncology and cardiology. Its lead molecular radiotherapeutic product candidates, Azedra and Onalta, are being developed for detection and treatment of cancer. The company's lead molecular imaging pharmaceutical product candidate, Zemiva, is being developed for the diagnosis of cardiac ischemia, or insufficient blood flow to the heart. In addition, the company has a growing pipeline of product candidates resulting from application of its proprietary platform technologies to new and existing compounds. Molecular Insight Pharmaceuticals is based in Cambridge, Massachusetts and its website address is:

Forward-Looking Statements

Statements in this release that are not strictly historical in nature constitute "forward-looking statements." Such statements may include, without limitation, statements with respect to the Company's plans, objectives, expectations and intentions and other statements identified by words such as "may," "could," "would," "should," "believes," "expects," "anticipates," "estimates," "intends," "plans" or similar expressions. Examples of such statements include, but are not limited to, statements regarding potential uses of Trofex, MIP-1072, or MIP-1095, other statements regarding product candidates, product development programs, the U.S. FDA, or the clinical trial process or its outcomes. Such forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause the actual results of Molecular Insight to be materially different from historical results or from any results expressed or implied by such forward-looking statements. These factors include, but are not limited to, risks and uncertainties related to the progress, timing, cost, and results of clinical trials and product development programs; difficulties or delays in obtaining regulatory approval for product candidates; competition from other pharmaceutical or biotechnology companies; and the additional risks discussed in filings with the Securities and Exchange Commission. All forward-looking statements are qualified in their entirety by this cautionary statement, and Molecular Insight undertakes no obligation to revise or update this news release to reflect events or circumstances after the date hereof.


Molecular Insight Pharmaceuticals, Inc.
Priscilla Harlan, 617-492-5554
Vice President, Corporate Communications & Investor

Posted: October 2007