Molecular Insight Pharmaceuticals, Inc. Presents Clinical Data on Prostate Cancer Diagnostic

Trofex(TM) Demonstrates Potential to Rapidly Detect Prostate Cancer in Soft Tissues and Bone

Molecular Insight Pharmaceuticals, Inc. (NasdaqGM:MIPI) today presented clinical data on a radiolabeled, small-molecule molecular imaging pharmaceutical in development for diagnosis and staging of prostate cancer at the 2009 annual meeting of the Society of Nuclear Medicine (SNM) in Toronto. Trofex(TM), which targets prostate specific membrane antigen (PSMA), a protein highly expressed by prostate tumor cells, has the potential to both detect and, when labeled with a therapeutic isotope, to treat metastatic prostate cancer. This was one of four conference presentations on products and technologies under development at Molecular Insight.

In 2008, Molecular Insight initiated clinical studies of Trofex in patients with documented prostate cancer and confirmed hormone refractory metastatic disease. Two internally developed Trofex compounds, MIP-1072 and MIP-1095, were evaluated for their capacity to visualize the disease and to define their pharmacokinetic profiles. Both agents rapidly detected metastatic prostate cancer lesions in soft tissues and bone, confirming that targeting the extracellular domain of PSMA is a viable approach for the molecular targeting of this cancer. The compounds were uniquely able to detect metastases within one to two hours after injection.

"Based on the potential demonstrated here, to rapidly and clearly image prostate cancer, we have planned additional studies to investigate the performance of these radiolabeled small molecules in patients with metastatic prostate cancer," said John W. Babich, Ph.D., Executive Vice President, Chief Scientific Officer and President of Research and Development at Molecular Insight Pharmaceuticals. "Not only does this data demonstrate the capability to rapidly visualize bone metastasis and soft tissue lesions -- that may be missed by conventional imaging techniques -- imaging can be done in a single day, which is not possible with some of the products currently on the market for imaging recurrent metastatic disease.

"Currently more than 2.5 million American men suffer from prostate cancer," Dr. Babich said. "About 200,000 new cases are diagnosed yearly and there are 30,000 deaths from the disease annually. Conventional imaging technologies lack both sensitivity and specificity for detecting metastatic disease. The targeting compound that we developed for imaging is an Iodine-123 labeled small-molecule candidate. But when the compound is labeled with Iodine-131 we believe we also may have the potential to treat metastatic prostate cancer. We are conducting preclinical studies to assess the potential of Trofex as a therapeutic. Trofex could dramatically change the diagnosis of prostate cancer, as well as the treatment landscape. Our plan for 2009 is to first complete a proof of concept and dosimetry trial for the detection of prostate cancer. Appropriate results in the additional pilot studies could support a request for fast-track development designation for the detection of metastatic disease."

 
Abstract # 522
Abstract Title: Targeting Metastatic Prostate Cancer (PCa) in Patients
                using (123)I-MIP 1072 & (123)I-MIP 1095
Authors:        J.A. Barrett(1); N.D. LaFrance(1); R.E. Coleman(2);
                S.J. Goldsmith(3); J.B. Stubbs(4); N. Petry(2);
                S. Vallabhajosula(3); K.P. Maresca(1); F. Femia(1);
                M. Stabin(4); J.W. Babich(1)
                (1)Molecular Insight Pharmaceuticals, Inc., Cambridge, MA,
                (2)Duke University, Durham, NC,
                (3)Cornell Medical Center, NY, NY,
                (4)Radiation Dosimetry Systems, Inc., Palo Alto, CA

Molecular Insight also presented data on its recent discovery research oncology projects, including those that have focused on the development of radiolabeled small-molecule inhibitors that target the cancer-related enzymes, carbonic anhydrase IX and seprase.

Detecting tumor hypoxia would allow clinicians to select appropriate treatments that are less influenced by tumor oxygen content and potentially lead to improved outcomes

Hypoxia, or reduced oxygen, is a hallmark of most solid tumors and has been shown to be related to poor prognosis. Researchers at Molecular Insight are capitalizing on this observation to develop novel hypoxia imaging radiopharmaceuticals that should allow the characterization of a patient's cancer by targeting a key hypoxia-regulated enzyme, carbonic anhydrase IX, for imaging by single photon emission tomography. Carbonic anhydrase IX is upregulated in hypoxic tumors of the cervix, ovary, kidney, esophagus, lung, breast, and brain, and is constitutively expressed in renal cell carcinoma. The ability to detect tumor hypoxia would allow clinicians to select appropriate treatments that are less influenced by tumor oxygen content and potentially lead to improved outcomes. The Molecular Insight poster presentation highlighted novel (99m)technetium radiolabeled compounds that demonstrated high affinity and excellent selectivity for carbonic anhydrase IX in biochemical and cellular assays.

 
Abstract # 1561
Abstract Title: Small Molecule Carbonic Anhydrase IX Inhibitors for
                Targeted Molecular Imaging of Cancer by SPECT
Authors:        S.M. Hillier; G. Lu; C. Shay; K.P. Maresca; C. Barone;
                J.C. Marquis; C.N. Zimmerman; W.C. Eckelman; J.L. Joyal;
                J.W. Babich
                All: Molecular Insight Pharmaceuticals, Cambridge, MA

Seprase an attractive target to exploit for noninvasive imaging, targeted radiotherapy

Seprase is an enzyme that is selectively overexpressed in the cancer-associated microenvironment of greater than 90% of human primary epithelial tumors, including breast, lung, colorectal, gastric, cervical and ovarian cancers, making it an attractive target to exploit for noninvasive imaging, as well as targeted radiotherapy. In a poster presentation, Molecular Insight researchers provided data on several novel (123)Iodine labeled inhibitors that demonstrated high affinity and excellent selectivity for seprase in biochemical and cellular assays.

 
Abstract # 1563
Abstract Title: Radiolabeled Inhibitors of Seprase Targeting the Tumor
                Microenvironment
Authors:        J.C. Marquis; J.C. Wang; K.P. Maresca; S.M. Hillier;
                C.N. Zimmerman; W. C. Eckelman; J.L. Joyal; J.W. Babich
                All: Molecular Insight Pharmaceuticals, Inc., Cambridge, MA

Molecular Insight advances its proprietary metal-binding chemistry platform technology

In addition, in an oral presentation, Molecular Insight described advances in the development of single amino acid chelates, SAAC, Molecular Insight's proprietary unique metal-binding chemistry platform technology, which can be incorporated into any peptide sequence through the use of conventional peptide chemistry.

 
Abstract # 146
Abstract Title: Molecular Targeting using Advanced Single Amino Acid
                Chelates (SAAC) for (99m)Tc
Authors:        K.P. Maresca; S.M. Hillier; G. Lu; J.C. Marquis;
                C.N. Zimmerman; W.C. Eckelman; J. L. Joyal; J.W. Babich
                All: Molecular Insight Pharmaceuticals, Cambridge, MA

About Molecular Insight Pharmaceuticals, Inc.

Molecular Insight Pharmaceuticals (NasdaqGM:MIPI - News) is a Cambridge, Massachusetts-based biopharmaceutical company focused on the discovery and development of innovative radiopharmaceuticals in the emerging field of molecular medicine. These novel radiopharmaceuticals will provide important improvements in disease detection and enable the delivery of radiation therapy to widespread metastatic cancers. The Company has focused the initial applications of its proprietary technologies in the areas of cardiology and oncology. Molecular Insight's lead molecular imaging radiopharmaceutical product candidate, Zemiva(TM), is being developed for the diagnosis of cardiac ischemia, or insufficient blood flow to the heart. The Company's imaging candidate, Trofex(TM), is in development for the detection of metastatic prostate cancer. Molecular Insight's lead molecular radiotherapeutic product candidates, Azedra(TM), Onalta(TM), and Solazed(TM), are being developed for detection and treatment of cancer. In addition, the Company's discovery efforts continue to identify early-stage candidates -- a product of its in-house scientific expertise and the application of its proprietary platform technologies. For more information, visit http://www.molecularinsight.com.

Forward-Looking Statements

Statements in this release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, statements about the development of Zemiva™, Trofex™, Azedra™, Onalta™, Solazed(TM), and our other product candidates. 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 (SEC). The Company's SEC filings are available through the SEC's Electronic Data Gathering Analysis and Retrieval system (EDGAR) at http://www.sec.gov. Press releases for Molecular Insight Pharmaceuticals, Inc. are available on our website: http://www.molecularinsight.com. If you would like to receive press releases via e-mail, please contact: This email address is being protected from spambots. You need JavaScript enabled to view it.. All forward-looking statements are qualified in their entirety by this cautionary statement, and Molecular Insight undertakes no obligation to revise or update this release to reflect events or circumstances after the date hereof.

Contact:

     Contact:
     Deborah S. Lorenz
     Senior Director
     Investor Relations and Corporate Communications
     Molecular Insight Pharmaceuticals, Inc.
     (617) 871-6667
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