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Pharmaceutical industry

Cougar Biotechnology Announces Positive Phase I Data for Prostate Cancer Drug CB7630

Strategic Insights

— 2 min read

Presented today at the National Cancer Research Institute (NCRI) Cancer Conference in Birmingham, UK, Cougar Biotechnology's prostate cancer drug CB7630 (abiraterone acetate) has demonstrated promising results in a Phase I trial. The data, presented by Dr. Johann S. deBono, shows that CB7630 was well-tolerated at high doses, with minimal toxicity, and resulted in significant declines in prostate-specific antigen (PSA) levels in 8 out of 12 evaluable patients (67%). Additionally, 6 out of 14 patients (43%) experienced a confirmed decline in PSA levels of greater than 90%. The study also showed that treatment with CB7630 resulted in partial radiological responses in 3 out of 5 evaluable patients with measurable tumor lesions.

Key Takeaways:

  • The Phase I trial of CB7630, a targeted inhibitor of the 17-alpha hydroxylase/c17,20 lyase enzyme, was conducted in chemotherapy-naive patients with castration-refractory prostate cancer (CRPC).
  • In the 14 patients tested, CB7630 was well-tolerated at doses as high as 2000 mg/day with minimal toxicity, and no dose-limiting toxicity was observed.
  • 8 out of 12 evaluable patients (67%) experienced a confirmed decline in PSA levels of greater than 50%, and 6 out of 14 patients (43%) experienced PSA declines of greater than 90%.
  • Treatment with CB7630 resulted in partial radiological responses in 3 out of 5 evaluable patients with measurable tumor lesions.
  • Individual patients treated with CB7630 experienced radiographic regression of bone metastases and improvement in pain.
  • Circulating tumor cells (CTC) were detected in 6 of 14 patients and changes in CTC counts correlated with changes in PSA.
  • 10 out of 14 patients (71%) continue on treatment with CB7630, with some patients having been on the drug for over 9 months.
  • Dr. Arie Belldegrun, MD, FACS, Vice Chairman of the Board of Directors of Cougar Biotechnology, stated that "Improved understanding of the basic biology leading to CRPC now offers new opportunities for drug development. We continue to believe that CB7630 has strong potential as a second-line hormonal therapy for patients with advanced prostate cancer who fail first-line hormonal treatment."

Statistics:

  • 8 out of 12 evaluable patients (67%) experienced a confirmed decline in PSA levels of greater than 50%.
  • 6 out of 14 patients (43%) experienced PSA declines of greater than 90%.
  • 3 out of 5 evaluable patients (60%) with measurable tumor lesions experienced partial radiological responses.
  • 10 out of 14 patients (71%) continue on treatment with CB7630.

Sources:

  • Cougar Biotechnology, Inc. (2006). "Cougar Biotechnology Announces Positive Phase I Data on CB7630 for Prostate Cancer." Press Release.
  • National Cancer Research Institute (NCRI) Cancer Conference (2006). Presentation: "Inhibition of androgen synthesis by an oral, irreversible, inhibitor of CYP450c17 appears safe and results in a high, durable, response rate in castration refractory prostate cancer (CRPC) patients." Dr. Johann S. deBono, MSc, PhD, MD, FRCP.

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