Molecular Insight Pharmaceuticals, Inc. Presents Oncology Data at Society of Nuclear Medicine 2011 Annual Meeting

CAMBRIDGE, MA--(Marketwire - June 13, 2011) - Molecular Insight Pharmaceuticals, Inc. today announced the presentation of preclinical data, based on the Company’s small molecule approach to targeted radiotherapy and imaging of cancer, at the Society of Nuclear Medicine 2011 Annual Meeting held June 4-8 in San Antonio, Texas. The data were presented in three oral sessions and one poster presentation. These scientific presentations are available on the Company’s website, www.molecularinsight.com, under the Molecular Medicine tab, Scientific Presentations.

In a presentation titled “Molecular Imaging of Tumor Carbonic Anhydrase (CA) with a 99mTc-labeled Small Molecule Inhibitor,” (Abstract 243), Dr. Shawn M. Hillier, Senior Scientist, demonstrated the feasibility of in vivo targeting of carbonic anhydrase IX (CA IX), an enzyme that is up-regulated in hypoxic tumors with a small molecular inhibitor of CA IX radiolabeled with 99mTc. This work paves the way to visualizing tumor hypoxia in cancer patients. Hypoxia is a hallmark of most solid tumors and is associated with adverse outcome for a number of cancers. Hypoxia imaging would be used to guide treatment planning or treatment enhancement such as in the case of radiotherapy. This research, conducted under a grant from the National Cancer Institute, represents the development of a novel hypoxia-imaging radiopharmaceutical able to characterize a specific cancer by targeting CA IX, a key hypoxia-regulated enzyme. Additional analogues are being developed that retain and improve tumor uptake and decrease non-target binding to potentially aid in the detection of hypoxic tumors in patients.

A second presentation titled, "[131I] MIP-1375, a Small Molecule Prostate-Specific Membrane Antigen (PSMA) Inhibitor for Targeted Therapy of Prostate Cancer (PCa),” (Abstract 361), reported by Dr. Hillier, described the preliminary evaluation of the Company’s prostate cancer radiation targeting platform based on small molecule inhibitors of the enzyme prostate-specific membrane antigen (PSMA), for reducing the growth of human prostate tumors in a mouse xenograft model. [131I] MIP-1375 inhibited tumor growth in a dose-dependent manner at radioactivity doses that are clinically relevant and the treatment was dependent upon specific binding to tumor associated PSMA. The therapy was well tolerated as evidenced by no changes in body weight. The positive results with [131I] MIP-1375 provide impetus for further evaluation of this series of compounds to optimize tumor targeting and optimal anti-tumor effects.

Dr. John W. Babich, President and Chief Scientific Officer of Molecular Insight, noted, “In the U.S., prostate cancer is the second leading cause of cancer-related deaths in men. We need to provide better ways of treating late stage disease in men with prostate cancer. We have successfully demonstrated the ability of our PSMA targeting platform to successfully visualize metastatic prostate cancer in both soft tissue and bone metastases, opening up the potential of these molecules to deliver therapeutic radiation to metastatic prostate cancer when labeled with beta emitting radionuclides such as iodine-131, yttrium-90, and lutetium-177. There are no effective drugs which offer prolonged survival in late stage prostate cancer. Our targeted radiotherapy approach, either as a single agent or in combination with tumor specific radiation sensitizers may offer the potential to provide a significant impact on this deadly cancer in terms of survival and palliation of symptoms.”

A third presentation titled, “Comparison of SSTR2 Agonist and Antagonist Peptides Incorporating a Novel 99mTc-Chelator for Targeting Neuroendocrine Tumors,” (Abstract 472), presented by Senior Scientist, John C. Marquis, described the evaluation of a series of novel radiolabeled peptides incorporating the Company’s second generation radiolabeling technology for the targeting of neuroendocrine tumors via the somatostatin receptor. The data demonstrated that the inclusion of Molecular Insight’s novel SAAC, (Single Amino Acid Chelate) technology significantly improved the localization of both the agonist and antagonist peptides tested, compared to the respective control peptides radiolabeled using standard methods. The research concluded that the high tumor uptake in vivo, excellent pharmacokinetics, and rapid normal tissue clearance make these attractive candidates for clinical evaluation in patients with neuroendocrine tumors. Carcinoid and other neuroendocrine tumors are currently detected clinically by nuclear imaging with 111In-Octreoscan. A 99m Tc-labeled peptide would be preferable over current detection methods with the advantages of improved image quality, reduced radiation dose, reduced cost, and widespread availability.

In a scientific poster presentation titled, “Formulation and Human Distribution Comparison of AdreView and Ultratrace™ Iobenguane I 123,” (Abstract 1445), the research conclusions highlighted were that AdreView (GE Medical) and Ultratrace Iobenguane I 123 (Molecular Insight Pharmaceuticals) demonstrate dramatic differences in concentration of active ingredient and specific activities. While imaging studies show that they have similar normal organ distribution, and excretion and tissue radiation dosimetry, the ratio of heart to mediastinum indicate that Ultratrace images of the twelve healthy subjects provide significantly more contrast between target organ (heart) uptake and background tissues.

About Molecular Insight Pharmaceuticals, Inc.
Molecular Insight Pharmaceuticals is a clinical-stage biopharmaceutical company and pioneer in molecular medicine. The Company is focused on the discovery, development, and commercialization of targeted therapeutic and imaging radiopharmaceuticals for use in oncology. For further information, please visit the Company’s website: www.molecularinsight.com.