A clinical trial has shown that combining the chemotherapy drug docetaxel with other treatments can improve clinical outcomes in patients with bony metastatic castrate-refractory prostate cancer (CRPC).
The prognoses for patients with CRPC—prostate cancer that has stopped responding to treatment and metastasized in other regions of the body—is generally poor. Additionally, patients often experience painful side effects from CRPC that has spread to the bones. Therefore, most treatments are palliative and are intended to manage symptoms and improve quality of life.
In the phase 2 TRAPEZE trial, combinations of strontium-89 (Sr89), zoledronic acid (ZA), or both with the standard treatment of docetaxel were found to be safe for patients with CRPC. In a phase 3 trial, investigators sought to determine whether Sr89 with docetaxel or ZA with docetaxel could improve survival compared with docetaxel alone. The primary outcome measure was clinical progression-free survival (CPFS), and secondary outcomes included time free of skeletal-related events (SREs), pain progression, total number of SREs, and overall survival.
Overall, 757 participants with CRPC were enrolled in the trial (median age, 68 years) and received some combination of the drugs. The results, published in JAMA Oncology, showed that Sr89 with docetaxel significantly improved CPFS compared with docetaxel alone, but the ZA plus docetaxel combination did not. However, ZA plus docetaxel did have a significant effect on the SRE-free interval and reduced total SREs by around one-third compared with docetaxel alone. Neither agent had an effect on overall survival.
The investigators, led by Nicolas D James, PhD, University Hospital Birmingham, England, concluded that Sr89 and ZA can be used to complement docetaxel therapy in patients with CRPC.
