Tokai Pharmaceuticals commences TOK-001 Phase 1/2 clinical trial for treatment of castration resistant prostate cancer

Nov 10 2009

Tokai Pharmaceuticals, Inc., a biopharmaceutical company focused on developing new treatments for prostate cancer, today announced the initiation of a Phase 1/2 clinical trial of its lead candidate TOK-001 for the treatment of patients with castration resistant prostate cancer (CRPC). TOK-001 is the only compound in development that combines three distinct mechanisms of action for the treatment of CRPC. CRPC is an advanced, difficult-to-treat form of prostate cancer that does not respond to prostate cancer therapies. Nearly all men initially diagnosed with prostate cancer eventually advance to CRPC. Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer related deaths among men in the U.S.

“TOK-001 delivers a three-pronged attack on CRPC cells, and has shown very promising results in preclinical models of prostate cancer,” said Seth Harrison, M.D., chairman and acting chief executive officer of Tokai and managing general partner of Apple Tree Partners. “This proprietary multi-target mechanism marks a novel and promising approach to both treating CRPC and addressing the clear unmet medical need for a safe and effective CRPC therapy. We are looking forward to building upon our promising preclinical safety and efficacy data to establish clinical safety and proof of concept in this tumor type.”

In preclinical studies, TOK-001 demonstrated a novel mechanism of action acting in three distinct ways to treat prostate cancer: as an androgen receptor antagonist, as a CYP17 lyase inhibitor and by decreasing overall androgen receptor levels in prostate cancer tumors. Androgen receptor antagonists have demonstrated clinical effectiveness in the treatment of prostate cancer, with one currently available to patients and another in Phase 3 clinical trials. There is also a CYP17 lyase inhibitor currently in Phase 3 clinical trials and the compound has demonstrated reduction in prostate-specific antigen (PSA) levels. Notably, TOK-001 is the first investigational new drug that decreases androgen receptor levels in prostate cancer cells and the only prostate cancer compound in development in which all three of these distinct mechanisms are combined in one drug. In fact, in preclinical models, TOK-001 has demonstrated improved efficacy compared with any individual therapy or investigational agent in development to treat prostate cancer.

"For patients suffering from advanced castration resistant prostate cancer, chemotherapy is the only option at this point that has been shown to prolong survival. There is an urgent need for new treatments for patients with prostate cancer since these chemotherapeutic agents extend survival for only a few months,” said Philip Kantoff, M.D., chief clinical research officer, chief, division of solid tumor oncology, and director, Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute and professor of medicine, Harvard Medical School. “We now have a better understanding of the unique mechanisms by which prostate cancer tumors survive. Androgen signaling remains critical to the survival of prostate cancer cells even in the castration resistant state. Preclinical studies suggest that TOK-001 can disrupt these unique mechanisms. We look forward to the results from this trial and learning more about the potential role TOK-001 may play for those patients facing castration resistant prostate cancer.”