Adding abiraterone plus prednisone (AAP) to androgen deprivation therapy (ADT) and docetaxel was associated with no increase, or a modest increase, in bone loss over the first 2 years of treatment in patients with de novo metastatic castration-sensitive prostate cancer (mCSPC) enrolled in the PEACE-1 trial.1
These results were presented at the ASCO Genitourinary Symposium 2022 by Guilhem Roubaud, MD, of Institute Bergonié in Bordeaux, France.
Prior results from the phase 3 PEACE-1 trial (ClinicalTrials.gov Identifier: NCT01957436) showed an improvement in survival outcomes when AAP was added to ADT plus docetaxel.2 In a follow-up analysis, researchers assessed bone mineral density (BMD) to investigate whether the addition of AAP was associated with bone loss.1
The analysis included 98 patients treated with ADT plus docetaxel and 97 patients who received the same treatment plus AAP. Baseline characteristics were similar between the arms, and baseline BMD density was identical between the arms.
Using dual x-ray absorptiometry, the researchers assessed BMD at 3 sites (lumbar spine, femoral neck, and total hip). BMD was assessed at baseline, 6 months, 12 months, and 24 months in both treatment arms. The evolution of BMD (g/cm2) was evaluated using mean T score and mean percent change in BMD from baseline.
Results showed comparable mean T scores between the treatment arms. There was a decrease in the mean T score in the lumbar spine between 12 months and 24 months. However, there was no meaningful difference between the arms, Dr Roubaud noted, as confidence intervals overlapped.
For the total hip, the mean T score was relatively constant from baseline to 12 months. At 24 months, the mean T score was slightly lower in the AAP arm than in the non-AAP arm, but confidence intervals overlapped here as well.
In terms of mean percent changes in BMD, there was a decrease in both the lumbar spine and total hip from 6 months through 24 months in the non-AAP arm. In the AAP arm, the mean percent change in BMD decreased from baseline through 12 months but increased slightly thereafter for both the lumbar spine and total hip.
At 24 months, the mean percent change in BMD in the lumbar spine was at least 5% in both arms, Dr Roubaud reported. The mean percent change in BMD in the total hip was roughly 5% in both arms.
Dr Roubaud noted that this is the first prospective assessment of BMD in a population treated with AAP with a control arm. He added that the main limitations of this study were the limited number of patients, a short follow-up, and the challenge to reliably assess BMD in patients with bone metastases.
“Bone mineral density should be carefully assessed in patients with mCSPC, and bone resorptive agents are indicated for treatment-induced bone loss only before castration resistance,” Dr Roubaud concluded.
Disclosures: This research was supported by Unicancer, PHRC, Janssen, Ipsen, and Sanofi. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
- Roubaud G, Kostine M, McDermott RS, et al.Bone mineral density in men with de novo metastatic castration-sensitive prostate cancer treated with or without abiraterone plus prednisone in the PEACE-1 phase 3 trial. Presented at ASCO GU 2022; February 17-19, 2022. Abstract 19.
- Fizazi K, Galceran JC, Foulon S, et al. A phase III trial with a 2×2 factorial design in men with de novo metastatic castration-sensitive prostate cancer: Overall survival with abiraterone acetate plus prednisone in PEACE-1. ESMO 2021. Abstract LBA5-PR.
This article originally appeared on Cancer Therapy Advisor