-- Primary Endpoint: Sustained Hypertension Reduction; MDS Nordion Will Manufacture Azedra for Potential Commercial Use

CAMBRIDGE, MA -- (Marketwire) -- 08/07/09 -- Molecular Insight Pharmaceuticals, Inc. (NASDAQ: MIPI) today announced that it has initiated a pivotal Phase 2 clinical trial for Azedra(TM) (Ultratrace(TM) Iobenguane I 131), its lead oncology candidate for the treatment of malignant pheochromocytoma, a type of neuroendocrine cancer. The single-arm trial will evaluate the efficacy and safety of Azedra in adult patients with malignant relapsed/refractory pheochromocytoma and position Molecular Insight to file a New Drug Application (NDA).

Azedra has been designated as an Orphan Drug with Fast Track status by the U.S. Food and Drug Administration.

Pheochromocytoma tumors are usually found in the adrenal glands, but may arise in other areas of the body. For malignant pheochromocytoma, radiation therapy offers short-term symptomatic relief, but no cure. Chemotherapy trials have failed to produce cures or significant remissions. For patients with this malignant disease, for whom surgery is not an option, the five-year survival rate is less than 50 percent.

Azedra is a targeted radiotherapeutic, which consists of the known iobenguane I 131 molecule (commonly known as I-131-MIBG) radiolabeled using the Company's proprietary Ultratrace technology. If successful, Azedra would be the first anti-cancer therapy in the United States indicated for the treatment of pheochromocytoma. Molecular Insight also is developing Azedra for the treatment of neuroblastoma, a type of neuroendocrine cancer in children.

Daniel L. Peters, President and Chief Executive Officer of Molecular Insight, said, "The launch of this trial marks a significant milestone for our Azedra program, which addresses the clear need for new treatment options for pheochromocytoma. Azedra is a promising candidate. This targeted radiotherapeutic demonstrated high tumor uptake in preclinical studies and favorable pharmacokinetics in completed trials. Azedra's development underscores Molecular Insight's commitment to apply innovative approaches to address unmet patient needs."

In March 2009, Molecular Insight received Special Protocal Assessment approval from the U.S. Federal Drug Administration (FDA) for the Phase 2 trial. Azedra trial IB-12B will be conducted in 58 adults (evaluable) with pheochromocytoma with an expected enrollment of about 75.

Pheochromocytoma tumors cause excess release of the hormones epinephrine and norepinephrine, producing adverse and often severe effects on a patient's heart rate and blood pressure.