Molecular Insight Pharmaceuticals’ (MIPI) Onalta Phase 2 Data Published in Journal of Clinical Oncology

CAMBRIDGE, MA — (Marketwire) — 04/12/10 — Molecular Insight Pharmaceuticals, Inc. (NASDAQ: MIPI) today announced results from a completed Phase 2 clinical trial of Onalta™ (Yttrium-90 edotreotide) have been published in the Journal of Clinical Oncology (JCO). Results from the Phase 2 clinical trial of 90 patients show that treatment with Onalta improved symptoms associated with metastatic carcinoid tumors.

Patients enrolled in the Phase 2 clinical study suffered from malignant metastatic carcinoid tumors (neuroendocrine tumors of the GI tract and bronchus) and were refractory to conventional treatment with the somatostatin analogue, octreotide. Y-90-edotreotide therapy resulted in objective tumor response or stable disease in 67 (74.4%) of 90 patients with metastatic carcinoid refractory to octreotide therapy. Median progression-free survival and overall survival were 16.3 and 26.9 months, respectively. Furthermore, there appeared to be a correlation with prolongation of the period of progression free survival in those patients who had durable diarrhea improvement (P =.031).

Key improvements in patient symptoms and quality of life related to carcinoid tumors were also noted. Symptoms of patients with carcinoid tumors include severe diarrhea, hot flushes and abdominal pain, among others. Among symptomatic patients, a trend toward improvement for each specified symptom was consistently demonstrated and statistically significant across all symptoms. Quality of life included assessments of anxiety, depression, pain and discomfort, among others. In addition, treatment was well-tolerated and had an acceptable adverse event profile.

David L. Bushnell, Jr., M.D., Professor of Radiology, University of Iowa and Chief, Diagnostic Imaging / Radioisotope Therapy, Iowa City VA Medical Center, led the study. In summarizing the study, he said: “90Y-edotreotide treatment was well-tolerated with an acceptable expected adverse effect profile. It’s clear from this study that symptoms associated with malignant carcinoid tumors improve following this therapy among patients with no treatment alternatives. Furthermore, there was evidence of improved survival in a subpopulation of patients in this study.”

“The patients in this study had incurable, progressive disease refractory to octreotide with severe symptoms which could themselves be life-threatening. In addition to nearly 75% of the patients showing disease stabilization, most tumor associated symptoms showed improvement with that improvement being of a sustained duration,” said Norman LaFrance, M.D., Senior Vice President, Chief Medical Officer of Molecular Insight and an author on the JCO paper. “These findings further support Onalta’s potential to improve outcomes among a refractory, metastatic patient population lacking treatment options.”

The single-arm, multicenter Phase 2 study was conducted in 90 patients at 18 sites in the U.S. and Europe. The primary objective of the study was to evaluate the efficacy of Onalta in relieving symptoms in patients with malignant carcinoid tumors. Quality of life, objective tumor response and other safety and efficacy outcomes were assessed as secondary endpoints. Study treatment consisted of three cycles of 4.4 GBq (120 mCi) 90Y-edotreotide each, once every six weeks.

Nine (10%) of the patients discontinued treatment because of adverse events, five due to GI events. Twelve (13.3%) of the patients experienced adverse events that required a dosage adjustment or interruption of study drug treatment. The majority of adverse events (76 patients; 84.4%) were of a GI nature, with nausea, vomiting and diarrhea most frequently reported. Nausea, vomiting and abdominal pain were typically associated with amino acid infusion concomitant with therapy and these symptoms almost always subsided with cessation of amino acid infusion. Grade 3 to 4 adverse events were reported in 54 (60%) patients with lymphopenia, nausea and vomiting most frequently observed, while 3 (3.3%) patients experienced grade 3 to 4 renal or urinary toxicity of grade 3 oliguria, grade 3 dysuria, and grade 4 renal failure that lasted 6, 42, and 6 days respectively.

The Phase 2 clinical trial results were published in the April 1, 2010 print edition of the American Society of Clinical Oncology’s Journal of Clinical Oncology in a paper titled: 90Y-Edotreotide for Metastatic Carcinoid Refractory to Octreotide. The article is also available online at http://jco.ascopubs.org/cgi/content/abstract/28/10/1652.

About Onalta
Onalta is a novel radiotherapeutic candidate which selectively targets the somatostatin receptor upregulated in metastatic carcinoid and pancreatic neuroendocrine tumors. It has been studied in clinical trials in patients whose symptoms are no longer controlled by conventional somatostatin analogue therapy.

Neuroendocrine tumors are a type of cancer that arises from neuroendocrine cells and can occur in different parts of the body. A somatostatin analogue is a synthetic compound, in this case a peptide, which functions in the body in a manner similar to the hormone somatostatin, which regulates a variety of other metabolic hormonal functions. Onalta binds selectively to the neuroendocrine tumor cells that have somatostatin receptors for the peptide hormone somatostatin. Molecular targeting of these receptors by Onalta to tumor cell surfaces allows the targeted delivery of a lethal dose of radiation to the cancer cells via the delivery and energy deposition (radioactive decay) of yttrium-90.

Molecular Insight licensed the rights to edotreotide (the parent compound of Onalta) from Novartis Pharma AG, which had developed the product through Phase 2 clinical trials, accumulating data from more than 300 patients. In September 2009, the company sub-licensed its Onalta™ brand 90-Y edotreotide radiotherapeutic in certain countries in Europe, the Middle East, North Africa, Russia and Turkey to BioMedica Life Sciences, S.A. The European Medicines Agency has reviewed and accepted Onalta’s Phase 3 clinical trial protocol design and has granted Onalta Orphan Drug Designation. Molecular Insight retains all rights to Onalta in all other markets and territories, including the United States, Japan and Asia. Onalta has also been granted orphan drug status by the U.S. Food and Drug Administration.

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

Forward-Looking Statements
Statements in this release that are not strictly historical in nature constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about the planned Phase 3 clinical trial of Onalta™ by BioMedica Life Sciences, S.A. as approved by the European Medicines Agency. 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. Such factors include, but are not limited to, risks and uncertainties related to the progress, timing, cost, and results of the Phase 3 clinical trial of Onalta; difficulties or delays in such clinical trial process; difficulties or delays in obtaining regulatory approval for initiating next-phase clinical trials; competition from other pharmaceutical or biotechnology companies in their developments of similar products; 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/. 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.