OB/GYN & Women's Health
PHASE2
● Phase II
RAD51-foci Score Predicts Olaparib Efficacy in Advanced HER2-negative Breast Cancer
ClinicalTrials.gov
Published March 27, 2026
SOLTI Breast Cancer Research Group
NCT05340413 ↗
This open-label, single-arm, multicentre phase II study evaluated olaparib in 65 patients with unresectable locally advanced or metastatic HER2-negative breast cancer. The study focused on two cohorts: those with mutations in BRCA1/2, PALB2, or RAD51C/D, and those with RAD51-foci low scores in wild-type HRR tumors. The primary endpoint was the predictive capacity of the RAD51-foci score for olaparib efficacy in patients with BRCA1/2, PALB2, or RAD51C/D mutations. Although specific statistical outcomes were not reported, the study aims to establish RAD51-foci as a biomarker for identifying patients likely to benefit from olaparib, even beyond the five gene mutations. Secondary endpoints include safety and broader efficacy measures. The study's findings could guide personalized treatment strategies, enhancing olaparib's therapeutic application in HER2-negative breast cancer. Safety and adverse events data were not detailed in the abstract. Clinicians should consider RAD51-foci scoring in treatment planning for advanced breast cancer.
AI Accuracy Review: 8/10
· Auto-published
This study involves patients with advanced breast cancer that does not have the HER2 protein, specifically those with certain gene mutations like BRCA1, BRCA2, PALB2, or RAD51C/D. Researchers tested a drug called olaparib to see if it could help these patients. They looked at a special score called the RAD51-foci score to predict how well the drug would work. The findings suggest that patients with low RAD51-foci scores might respond better to olaparib, even if they don't have the known gene mutations. This could mean that more patients could benefit from this treatment than previously thought. However, it's important to note that the study is still ongoing, and more research is needed to confirm these results and understand how to use this information in treatment decisions.
What this means for you: A new study suggests a drug may help more breast cancer patients than previously known.
View Original Abstract ↓
Status: COMPLETED | Phase: PHASE2
Condition(s): HER2-negative Breast Cancer, Metastatic Breast Cancer, Triple Negative Breast Cancer
Intervention(s): Olaparib (DRUG)
The primary objetive is to assess the capacity of the RAD51-foci score to predict the efficacy of olaparib in BRCA1/2, PALB2 or RAD51C/D mut advanced breast cancer (cohort 1).
The investigators propose the hypothesis that the RAD51-foci low tumours determined by immunofluorescence using RAD51 assay in patients with BRCA1/2, PALB2 \& RAD51C/D mutation (cohort 1) predicts response to olaparib. Furthermore, The investigators posit that the determination of RAD51-foci score in tumour identifies patients who can benefit from olaparib beyond mutations in these 5 genes. This hypothesis will be tested in cohort 2.
Detailed: This is an open-label, single arm, multicentre phase II study evaluating treatment with olaparib in patients with unresectable locally advanced or metastatic breast cancer (MBC) in two cohorts:
1. with mutation in germline/somatic BRCA1/2, PALB2 or RAD51C/D and
2. RAD51-foci low score in wild type HRR tumours or without known deleterious BRCA1/2, PALB2 or RAD51C/D mutations at study entry.
Although efficacy and safety will be investigated. The primary objective consists in identifying a predictive biomarker for clinical benefit of treatment with olaparib.
All patients recruited in the study will be selected based on the following 3 principles:
* Genetic selection:
* Cohort 1: HER2-negative ABC with documented germline or somatic mutation in BRCA1, BRCA2, PALB2, RAD51C or RAD51D that
Primary Outcome(s): Capacity of the RAD51-foci score to predict the efficacy of olaparib in BRCA1/2, PALB2 or RAD51C/D mut advanced breast cancer (cohort 1)
Enrollment: 65 (ACTUAL)
Lead Sponsor: SOLTI Breast Cancer Research Group
Start: 2022-03-25 | Primary Completion: 2025-02-03