Molecular Insight Pharmaceuticals, Inc. Presents Azedra(TM) (Ultratrace(TM) MIBG) Preclinical Data at Society of Nuclear Medicine Meeting - Early Data on Molecular Imaging Pharmaceutical for Chronic Heart Failure Also Presented.

CAMBRIDGE, Mass. -- Researchers at Molecular Insight Pharmaceuticals announced today the presentation of preclinical data on Azedra(TM) (Ultratrace(TM) iobenguane I 131, or Ultratrace MIBG), the company's lead oncology product candidate for the treatment of neuroendocrine tumors. The studies, presented at the 53rd Annual Meeting of the Society of Nuclear Medicine in San Diego, CA, were conducted in support of Azedra's initial clinical trials in adult patients with neuroendocrine tumors. Azedra is a designated Orphan Drug under development for the treatment of neuroendocrine tumors such as carcinoid, neuroblastoma and pheochromocytoma.

Azedra is a targeted radiopharmaceutical designed to maximize delivery of therapeutic radiolabeled MIBG molecules so that neuroendocrine tumors can be effectively diagnosed and treated, and to minimize the amount of non-radioactive MIBG molecules that are delivered to the patient. The compound targets the norepinephrine transporter, which is over-expressed in certain diseases such as in neuroendocrine cancers. The product candidate is based on Molecular Insight's proprietary Ultratrace technology, which greatly reduces the amount of non-radioactive MIBG molecules, or cold contaminants, by several orders of magnitude.

Azedra data presented in a poster evaluated the pharmacokinetics, tissue distribution and efficacy of Azedra compared with currently available 131I-MIBG. In the preclinical efficacy studies, data suggested that Azedra showed comparable efficacy to conventional 131I-MIBG in inhibiting tumor growth in a xenograft model of neuroblastoma. Over a range of doses commonly seen in the clinic, there was a demonstrable improvement in the dose response curve at all doses tested. Azedra demonstrated improved delays in tumor growth (i.e. no tumor growth for more than 47 days), while the conventional MIBG preparation inhibited tumor growth by 20 days. Tissue distribution studies suggested that Azedra had increased uptake compared with conventional MIBG in tissues that express the norepinephrine transporter. Pharmacokinetic parameters of both preparations were comparable in normal tissues. In a separate oral presentation, the company described the performance of the proprietary solid phase technology that underlies the method for producing Azedra.

Molecular Insight also presented preliminary data on MIP-190, its preclinical cardiovascular candidate to target cardiac angiotensin converting enzyme (ACE) for the potential assessment and monitoring of congestive heart failure. ACE is elevated during heart failure and inhibiting the enzyme is an established therapeutic approach to treating the disease. Researchers believe that an ACE-based imaging product with the ability to map ACE uptake in the heart would be of value in assisting physicians in assessing the extent of cardiac disease and in optimizing therapeutic options without having to wait for further clinical signs of disease progression. In the poster, researchers described the synthesis and initial evaluation of imaging compounds based on a potent ACE inhibitor, lisinopril. The studies suggested that the lead candidate compound in the MIP-190 series retains its ACE targeting activity in vivo. Additional studies are underway to evaluate this compound in models of heart failure.

The Azedra studies are entitled, "Impact of Cold Carrier MIBG on Pharmacokinetics, Tissue Distribution Tumor Uptake and Efficacy of 131I-MIBG," and "Process Development and Robustness of Producing High Specific Activity I-131-MIBG for Radiotherapy Using the Solid State Ultratrace Technology." Authors on the first study are J.A. Barrett, Ph.D., J.L. Joyal, Ph.D., K.P. Maresca, Ph.D., S. Hillier, Ph.D., D. Keith, F.J. Femia, Ph.D., and J.W. Babich, Ph.D., of Molecular Insight, R.J. Mairs, Ph.D. and M. Boyd, Ph.D., of Cancer Research UK Laboratories (Glasgow, Scotland), and M.R. Zalutsky, Ph.D., of Duke University. The authors on the second study are H. Mok, Ph.D., N.S. Lee, D.H. Hunter, Ph.D., J.Qi, Ph.D., K.P. Maresca, Ph.D., J.F. Kronauge, Ph.D., and J.W. Babich, Ph.D. of Molecular Insight, and D. H. Hunter, Ph.D. and X.R. Zhu, Ph.D., of the University of Western Ontario.

The ACE poster on molecular imaging is entitled, "Synthesis and Evaluation of M(CO)3+ (M= Tc, Re) Lisinopril Complexes for Imaging Angiotensin Converting Enzyme." Authors are: F.J. Femia, Ph.D., K.P. Maresca, Ph.D., J.L. Joyal, Ph.D., J.A. Barrett, Ph.D., W.C. Eckelman, Ph.D. and J.W. Babich, Ph.D. of Molecular Insight, and T. Coleman, M.D., O. Aras, M.D., S.A. Messina, M.D., and V. Dilsizian, M.D., of the University of Maryland.

About Molecular Insight Pharmaceuticals, Inc.

Molecular Insight Pharmaceuticals is a biopharmaceutical company focused on the research, development and commercialization of innovative molecular imaging pharmaceuticals and targeted radiotherapeutics. The company's product candidates target markets with significant unmet needs in cardiology, oncology, and neurology. Molecular Insight's lead product candidate, Zemiva (iodofiltic acid I 123) is a radiolabeled fatty acid analog that is in development as a molecular imaging pharmaceutical for the diagnosis of insufficient blood flow to the heart, or cardiac ischemia. The company's second lead product candidate, Azedra (Ultratrace MIBG), is in development for the diagnosis and treatment of neuroendocrine tumors. Molecular Insight Pharmaceuticals is based in Cambridge, Massachusetts. The company's Website is www.molecularinsight.com.