Behind the Design of the PEACE-1 Trial in mCSPC

Cedric Pobel, MD, medical oncologist, PhD student, Institut de Cancérologie, Gustave Roussy, Paris, France, discusses the design and objectives of the phase 3 PEACE-1 trial (NCT01957436), an open-label, randomized, controlled study that enrolled 1,173 male patients with de novo metastatic castration-sensitive prostate cancer (mCSPC), who were randomly assigned to 1 of 4 treatment arms: standard of care (SOC) alone, SOC plus abiraterone, SOC plus radiotherapy, or SOC plus both radiotherapy and abiraterone.

The trial took place across 77 hospitals in Europe and utilized a 2 × 2 factorial design.

Findings from the PEACE-1 trial revealed that adding radiotherapy to SOC and abiraterone significantly improved radiographic progression-free survival (rPFS) among patients with low-volume mCSPC. In the SOC plus abiraterone and radiotherapy arm, patients had a median rPFS of 7.5 years vs 4.4 years in the SOC and abiraterone alone arm (adjusted hazard ratio [HR] 0.65; P =.019). However, radiotherapy did not show a significant benefit for rPFS in patients not receiving abiraterone.

For safety, outcomes were consistent with that observed in previous studies.

Transcription:

0:10 | The PEACE-1 trial was a paradigm shift in first-line treatment. The design consisted of 4 arms of treatment, standard-of-care with or without abiraterone and without radiotherapy. The results showed benefits in overall survival with the addition of abiraterone to castration and docetaxel.

0:52 | To [explore our hypothesis], we retrieved paraffin-embedded biopsy samples from almost 600 patients. Up to now, we have performed 2 main analyses. The first analysis involved immunohistochemistry using 10 markers, which allowed us to define 5 phenotypes. Secondly, we performed next-generation sequencing using a restricted panel rather than whole-exome sequencing.

REFERENCE:

Bossi A, Foulon S, Maldonado X, et al. Efficacy and safety of prostate radiotherapy in de novo metastatic castration-sensitive prostate cancer (PEACE-1): a multicentre, open-label, randomised, phase 3 study with a 2 × 2 factorial design. Lancet. 2024;404(10467):2065-2076. doi:10.1016/S0140-6736(24)01865-8