GenSpera, Inc. (GNSZ-OTC) is one step closer to initiating its planned Phase II human clinical trial of its lead compound, G-202, in prostate cancer patients. On Tuesday, July 31, 2012, GenSpera announced that the U.S. Food and Drug Administration (FDA) cleared its Phase II trial for initiation. The Company expects to commence patient enrollment once it receives approval by the Institutional Review Boards for its six trial sites in the U.S. and the UK. The study could include up to 40 prostate cancer patients who failed previous hormonal therapy. GenSpera expects prostate cancer patients to particularly benefit from G-202 due to the drug’s ability to target slow-growing cancer cells.
Market Opportunity for Prostate Cancer Treatment
Healthcare advisory firm Decision Resources expects global sales of prostate cancer drugs to more than double from nearly $4 billion in 2009 to nearly $9 billion in 2019. Globally, prostate cancer is responsible for 250,000 deaths each year. In the U.S., the American Cancer Society (ACS) anticipates that over 240,000 men will be diagnosed with prostate cancer in 2012—making it the most commonly diagnosed cancer for men in the U.S.—in addition to causing more than 28,000 deaths annually.
Traditionally, prostate cancer patients had two main treatment options: surgery or radiation. However, over the past decade, a number of new technologies have entered the market, including more advanced and targeted surgical options. Although these options are gaining popularity, the ACS cautions that there remains minimal long-term data on many of these treatments, making it difficult to accurately assess their effectiveness and potential side effects over time.
As well, a better understanding of the molecular abnormalities of prostate cancer has led to new approaches, including hormone therapies such as Johnson & Johnson's (JNJ-NYSE) Zytiga®, which blocks the production of testosterone. Additionally, Medivation, Inc. (MDVN-NASDAQ) has filed a New Drug Application (NDA) for enzalutamide (formerly MDV3100) to treat men with castration-resistant prostate cancer previously treated with docetaxel-based chemotherapy after demonstrating an ability to extend median survival by 4.8 months, and was granted Priority Review Designation by the FDA. Enzalutamide interferes with testosterone’s ability to bind to prostate cells. While hormone therapies are becoming more effective, many patients develop resistance to hormone therapies over time and must eventually rely on other forms of treatment (Source: Reuters, Analysis: New drugs drive prostate cancer market, September 19, 2011).
Additionally, Dendreon Corp.’s (DNDN-NASDAQ) Provenge® was the first FDA-approved immunotherapy for prostate cancer. However, Provenge® costs $93,000 per patient and, in clinical studies, was shown to improve median survival by 4.5 months. Despite being on the market for two years, Dendreon continues to report quarterly losses due to slow market adoption (Source: Chicago Tribune, May 7, 2012).
Employing a Novel Mechanism of Action to Treat Prostate Cancer
Despite recent advances, improved therapies are still needed to treat prostate cancer. Although several drugs have recently been approved or are in late-stage development, they offer different mechanisms of action than GenSpera’s G-202, which kills cancer cells independently of androgen (hormone) pathways. GenSpera has spent two decades developing a drug designed to be activated from within a tumor—reducing the potential for adverse side effects in other areas of the body. Greater details concerning the technology that supports G-202 are provided in the Company’s 56-page Executive Informational Overview® (EIO) available here. Additionally, a peer-reviewed research paper, entitled “Engineering a Prostate-Specific Membrane Antigen–Activated Tumor Endothelial Cell Prodrug for Cancer Therapy,” was published in June 2012 in Science Translation Medicine and offers detailed methods and data supporting GenSpera’s G-202 rationale and mechanism of action.