Pembrolizumab + Olaparib Combination Shows Overall Response in Breast Cancer

Trial results for the Phase 2 study NCT03025035, investigating pembrolizumab in combination with olaparib for advanced BRCA-mutated or HDR-defect breast cancer, were posted on ClinicalTrials.gov on 2025-05-29. The study reported an Overall Response Rate (ORR) of 7 participants in the combination arm out of 14 enrolled.

Background

This trial aimed to evaluate the use of immunotherapy and PARP inhibition in a population with incurable advanced breast cancer. The study specifically focused on patients with a germline BRCA mutation or a Homology-directed repair (HDR)-defect. Pembrolizumab (Keytruda) is an immunotherapy, while olaparib is a PARP inhibitor, and their combination was explored for its potential synergistic effects in this specific patient group.

Trial design

The study, identified as NCT03025035 and titled "Pembrolizumab in Combination With Olaparib in Advanced BRCA-mutated or HDR-defect Breast Cancer," was a Phase 2 trial that has been COMPLETED. It enrolled a total of 14 participants diagnosed with Breast Cancer. The primary objective was to examine the overall response rate of pembrolizumab in combination with olaparib in advanced BRCA-mutated or HDR-defect breast cancer. The interventions included both pembrolizumab and olaparib, administered together to the study participants.

Key results

For the outcome of "Overall Response Rate (ORR) Per RECIST1.1" in the "Pembrolizumab + Olaparib" group, the trial reported that 7 participants achieved an overall response. This measurement represents the count of participants who met the criteria for overall response according to RECIST1.1 guidelines within the study cohort.

What this means

The reported Overall Response Rate of 7 participants out of 14 in this Phase 2 trial suggests that the combination of pembrolizumab and olaparib demonstrates activity in patients with advanced BRCA-mutated or HDR-defect breast cancer. While the enrollment was small, these results indicate a potential therapeutic benefit for this specific and challenging patient population. Further investigation in larger studies may be warranted to confirm these findings and establish the clinical utility of this combination.

Source

The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03025035, titled "Pembrolizumab in Combination With Olaparib in Advanced BRCA-mutated or HDR-defect Breast Cancer," were posted on 2025-05-29 on clinicaltrials.gov.