Azedra
Azedra is one of our two lead radiotherapeutic product candidates under development for the treatment of cancer. Formerly known as Ultratrace MIBG, or I-131-metaiodobenzylguanidine, Azedra consists of an MIBG molecule radiolabeled by chemically binding to a radioactive iodine isotope through our proprietary Ultratrace technology. The iodine isotope, depending on the particular isotope selected, acts either diagnostically for imaging disease or therapeutically to deliver targeted radiation to the tumor site. Azedra incorporates an iodine isotope, targets specific tumor cells and does not contain unwanted carrier molecules, or cold contaminants. Cold contaminants are avoided using our proprietary Ultratrace technology. We believe cold contaminants provide no therapeutic benefits, may provide unwanted side effects and compete with therapeutic MIBG for binding on target receptor sites, potentially affecting efficacy. I-123 MIBG containing cold contaminants is marketed in Europe and Japan for diagnostic imaging, but is not an FDA-approved product in the United States. I-131 MIBG containing cold contaminants is commercially available for therapeutic use in Europe but is not approved in the United States. We believe that our Ultratrace technology provides Azedra with potential significant advantages over currently marketed I-131 MIBG containing cold contaminants. Our Ultratrace technology enables Azedra to be an ultrapure compound, or a compound that is devoid of unnecessary cold contaminants.

Azedra has received Orphan Drug status and a Fast Track designation by the FDA. We are currently conducting a Phase 1 clinical trial with Azedra in adults at Duke University, with data from nine of an anticipated twelve patients received. This Phase 1 dosimetry trial is designed to evaluate the safety, tolerability and distribution of Azedra in adult patients with one of two forms of neuroendocrine cancer - either carcinoid or pheochromocytoma. Neuroendocrine cancer is a tumor of the neuroendocrine system, a diffuse system involving the nervous system and the endocrine glands. Upon input from the FDA, we expect to begin a Phase 1/2 safety, dose ranging and efficacy clinical trial with Azedra in adults in the first half of 2007, with an estimated 12 patients at four to six U.S. centers. If results of these ongoing and anticipated trials are positive, we believe that the resulting data together with data from our previous clinical trials will provide a basis for us to file for regulatory approval in the United States. The initial target market for Azedra is the treatment of metastatic neuroendocrine tumors such as pheochromocytoma, carcinoid and neuroblastoma that are not amenable to treatment with surgery or conventional chemotherapy. Metastatic tumors are tumors that spread to other organs or parts of the body. There are currently no approved treatments in the United States for metastatic neuroendocrine tumors.

Onalta
Onalta is our other lead radiotherapeutic product candidate under development for the treatment of cancer. Formerly known as OctreoTher, Onalta is our brand name for edotreotide, an yttrium-90 radiolabeled somatostatin peptide analog that we recently in-licensed from Novartis Pharma AG, or Novartis. Somatostatin is a hormone distributed throughout the body that acts as a regulator of endocrine and nervous system function by inhibiting the secretion of several other hormones such as growth hormones, insulin and gastrin. We are developing Onalta for the radiotherapeutic treatment of metastatic carcinoid and pancreatic neuroendocrine cancer in patients whose symptoms are not controlled by conventional somatostatin analog therapy. Somatostatin analog therapy (or octreotide or sandostatin) is used to alleviate the symptoms associated with carcinoid syndrome.

Onalta has been granted Orphan Drug status by the FDA. Novartis conducted three Phase 1 and three Phase 2 clinical trials involving more than 300 patients. Published data from a Phase 1 clinical study suggest that OctreoTher demonstrated longer overall survival as compared with historic controls. We are currently in discussions with the FDA on the clinical investigation plan and path to approval for Onalta with the goal of marketing the first therapy approved for reducing tumors, alleviating symptoms and improving quality of life for patients with metastatic carcinoid and pancreatic neuroendocrine cancer whose symptoms are not controlled by conventional somatostatin analog therapy.