ASCO 2021: PEACE-1 Trial of Abiraterone-Based Combination Therapy in Metastatic Prostate Cancer
Posted: Wednesday, June 9, 2021
Karim Fizazi, MD, PhD, of Institut Gustave Roussy, Villejuif, France, and colleagues presented their first results of the phase III PEACE-1 trial of abiraterone acetate plus prednisone and/or local radiotherapy on top of androgen-deprivation therapy (ADT) plus docetaxel in patients with metastatic prostate cancer at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 5000). Their research suggested that the addition of abiraterone significantly improved radiographic progression-free survival, adding about 2.5 years of absolute benefit without “meaningful additional short-term toxicity.”
This study enrolled 1,173 men with de novo metastatic castration-sensitive prostate cancer. All patients received ADT alone (n = 463) or plus docetaxel (n = 710), with or without abiraterone, radiotherapy, or a combination of the two.
The median patient age was 67 years, and 57% and 43% of participants had high-volume and low-volume disease, respectively. The median follow-up was 3.5 years, and there was no apparent interaction observed between the effects of radiotherapy and abiraterone (P = .64).
Abiraterone significantly improved radiographic progression-free survival in both the ADT-plus-docetaxel (hazard ratio [HR] = 0.50, P < .0001) and overall (HR = 0.54, P < .0001) populations, with increases from 2.0 to 4.5 and 2.2 to 4.5 years, respectively. Biochemical progression-free survival was also significantly improved with the addition of abiraterone, from 1.5 to 3.8 years in the overall population (HR = 0.40, P < .0001) and from 1.5 to 3.2 years in the ADT-plus-docetaxel group (HR = 0.38, P < .0001).
In the ADT-plus-docetaxel population, grade 3 to 4 adverse events such as neutropenic fever, liver toxicity, and hypertension affected 4.5%, 19.7%, and 12.2% of patients in the abiraterone arm and 5.4%, 13%, and 8.6% of those in the control arm, respectively.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.