The researchers measured patients' overall survival, whether their cancer progressed, and the drug's safety and tolerability. They also conducted studies of biomarkers to better understand how tasquinimod stimulates the immune system.
Armstrong and his colleagues found that men taking tasquinimod saw no cancer progression for an average of 7.6 months, compared with 3.3 months for placebo. Men whose cancer had already metastasized to their bones and took tasquinimod remained progression-free for even longer 8.8 months, compared with 3.4 months for placebo.
"By delaying the onset of symptoms or growth of metastatic tumors, tasquinimod may allow men to put off other treatments, such as chemotherapy, and maintain a high quality of life," Armstrong said. "That's an important goal for many patients and providers."
Men taking tasquinimod survived 33.4 months on average, versus 30.4 months with placebo. However, those whose cancer had already metastasized to their bones survived an average of 34.2 months, compared with 27.1 months for placebo, a seven-month difference. This improvement in survival with tasquinimod persisted when statistical adjustments were made for other factors such as PSA level, PSA doubling time, lactate dehydrogenase (LDH) levels, and the presence of anemia, each of which were important prognostic factors.
The researchers also identified certain predictors of who would benefit most from tasquinimod, such as lower baseline PSA levels or other biomarkers.
The treatment was considered safe with low to moderate side effects, which included mild gastrointestinal issues, muscle and joint pains, and fatigue.
Based on results from the phase II clinical trial, tasquinimod is now being evaluated in an international phase III trial focusing on men whose prostate cancer has spread to their bones and become resistant to hormonal therapies.
|Contact: Rachel Harrison|
Duke University Medical Center