ESMO 2019: CHEIRON Update on Enzalutamide Plus Docetaxel in Castration-Resistant Prostate Cancer
Posted: Monday, October 28, 2019
The addition of enzalutamide to docetaxel as first-line chemotherapy appears to prolong 6-month disease control in men with metastatic castration-resistant prostate cancer compared with docetaxel alone, according to an updated survival analysis of the phase II CHEIRON trial. The chemotherapy combination also significantly prolonged progression-free survival versus the standard chemotherapy. Orazio Caffo, MD, of the Santa Chiara Hospital, Italy, and colleagues presented these study findings at the European Society for Medical Oncology (ESMO) Congress 2019 in Barcelona (Abstract 854P) and published them in the Annals of Oncology.
The study included 246 patients with no prior treatment of metastatic castration-resistant prostate cancer and an Eastern Cooperative Oncology Group performance status of up to 2. Participants were randomly assigned to receive either eight cycles of docetaxel at 75 mg/m2 intravenously on day 1 of every 3-week cycle plus prednisone at 5 mg by mouth twice daily alone (n = 126) or with the addition of enzalutamide at 160 mg by mouth daily (n = 120).
At 6-month follow-up, the rate of patients without disease progression was significantly higher with docetaxel plus enzalutamide than with docetaxel alone (89.1% vs. 72.8%; P = .002). Patients who achieved a reduction in prostate-specific antigen of 50% or more was also significantly higher in the docetaxel-plus-enzalutamide arm (92% vs. 69%; P < .0001). The median progression-free survival was 10.1 months and 9.1 months with docetaxel plus enzalutamide and with docetaxel alone, respectively (P = .01). As for safety, grade 3 or 4 neutropenia was observed in 19 patients in the combination arm and 15 in the docetaxel-alone arm.
Disclosure: Full disclosures of the study authors can be found at academic.oup.com.