Molecular Insight Pharmaceuticals: Two Promising Candidates to Battle Prostate Cancer

by: Michael Becker

Prostate cancer is the most common type of cancer found in American men, other than skin cancer. In 2009, the American Cancer Society estimates that there will be nearly 200,000 new cases of prostate cancer in the United States and that about 27,000 men will die from the disease. It is estimated that there are more than 2 million American men currently living with prostate cancer.

As noted in our June 1, 2009 article, investors appear to be gravitating towards biotechnology companies working in the field of prostate cancer. Consider the following:

  • Shares of Dendreon Corporation (NASDAQ:DNDN), which traded in the low single-digits earlier this year, currently trade above $25 following positive Phase 3 results for the company’s prostate cancer vaccine study in April 2009.
  • Shares of Cougar Biotechnology, Inc. (CGRB), a development stage company with an oral prostate cancer treatment being studied in two Phase 3 clinical trials, traded as low as $16.35 over the prior 12-months before the company received a $43.00 tender offer from Johnson & Johnson (NYSE:JNJ) in May 2009.
  • Shares of OncoGenex Pharmaceuticals, Inc. (NASDAQ:OGXI), which were trading around $6.00 at the end of April 2009, recently reached a 52-week high as $27.00 following the presentation of positive Phase 2 trial results for the company’s prostate cancer treatment at the Annual Meeting of the American Society of Clinical Oncology (ASCO).
  • Shares of Poniard Pharmaceuticals, Inc. (NASDAQ:PARD), which traded as low as $1.00 in December 2008, recently reached a 52-week high of $5.50 following the presentation of positive Phase 2 data for the company’s picoplatin product candidate in patients with metastatic hormone-refractory prostate cancer at ASCO.

Therefore, it may not be surprising that shares of Molecular Insight Pharmaceuticals, Inc. (MIPI) nearly doubled over the past month following the presentation of data demonstrating that the company’s investigational imaging agents can rapidly detect the spread of prostate cancer to soft tissues and bone at the recent annual meeting of the Society of Nuclear Medicine. Shares of Molecular Insight Pharmaceuticals, which traded as low as $1.15 in March 2009, nearly reached $8.00 this month on heavy volume.

Currently, simple blood tests to determine the amount of prostate-specific antigen (PSA), a protein produced by the cells of the prostate gland, are used to help initially detect prostate cancer and to monitor patients with a history of prostate cancer to see if the cancer has come back, or recurred. Unfortunately, PSA levels cannot directly identify the extent or location of disease.

Molecular Insight’s two product candidates (MIP-1072 and MIP-1095) are small molecules that target prostate-specific membrane antigen (PSMA), a protein abundantly expressed on the surface of prostate cancer cells. An imaging radioisotope (Iodine-123) is linked to the small molecules, which are administered intravenously into the patient. The small molecules travel through the bloodstream and bind to PSMA. The radioactivity from the isotope that has been attached to the small molecules can be detected from outside the body by camera equipment found in the nuclear medicine departments of most hospitals. The image captured by the camera assists in the identification of the location of the radiolabeled molecules, thus identifying the sites of tumors.

The first commercial molecular imaging agent targeting PSMA was cleared for marketing by the Food and Drug Administration (FDA) in 1996. Unlike Molecular Insight’s small molecule approach, Eusa Pharma’s ProstaScint® (capromab pendetide) consists of a monoclonal antibody directed against PSMA that is linked to the imaging radioisotope Indium-111. Publicly-reported sales of ProstaScint were $9.6 million for the year ended December 31, 2007.

Theoretically, Molecular Insight’s small molecule approach to targeting PSMA represents an advantage over monoclonal antibodies, as the imaging session can be done in a single day. In fact, the company’s compounds were able to detect metastases within one to two hours after injection. This is not possible with current monoclonal antibody approaches, which require that the patient make a second visit for imaging between 72 and 120 hours after infusion.

Molecular Insight’s product candidates may also have the potential to treat metastatic prostate cancer. The company is conducting preclinical studies for product candidates using the same small molecules attached to a therapeutic (as opposed to imaging) radioactive substance called Iodine-131.

Although investors are enthusiastic about biotech companies working in the field of prostate cancer right now, it is worth reminding readers that drug development is a long and expensive process and Molecular Insight’s prostate cancer compounds are in the early stages. According to the company, the plan for 2009 is to complete a proof of concept and dosimetry trial for imaging prostate cancer. Fortunately, Molecular Insight also has later-stage programs in development, including a molecular imaging product candidate for the diagnosis of cardiac ischemia, or insufficient blood flow to the heart.

Disclaimer: This article contains the author’s own opinions, and none of the information contained therein constitutes a recommendation that any particular security, portfolio of securities, transaction, or investment strategy is suitable for any specific person. To the extent any of the information contained in the article may be deemed to be investment advice, such information is impersonal and not tailored to the investment needs of any specific person.

Disclosure: No positions