Emerging Challenges of Prostate Cancer Drug Development
Summary
The annual meeting of the American Society of Clinical Oncology (ASCO) attracted over 30,000 attendees to hear leading experts on the latest in cancer drug development.From what I heard at ASCO, biotechnology and pharmaceutical companies with new prostate cancer products in development or those seeking to enter this increasingly crowded market will face a number of challenges.Overall survival (OS), i.e. whether will men live longer, is still the endpoint expected by regulatory agencies for marketing approval With the exception of the COU-AA-302 trial for Johnson & Johnson’s abiraterone acetate (Zytiga) that was presented at ASCO this year, all the recent Phase III trials in metastatic castration-resistant prostate cancer—a form of disease that has spread and no longer responds to traditional chemical castration therapies—have shown a significant overall survival advantage.At ASCO in an education session on castration-resistant prostate cancer, Dr. Andrew J. Armstrong, an associate professor of medicine at Duke University, illustrated examples of why certain surrogate markers in clinical trials—which researchers use to gauge whether a drug is working before long-term survival data is available—aren’t always reliable.In the case of prostate cancer, measurements of disease progression (PFS) did not correlate in the end with overall survival (OS) in many clinical trials, Armstrong said.