# Study of Olaparib Plus Pembrolizumab Versus Chemotherapy Plus Pembrolizumab After Induction With First-Line Chemotherapy Plus Pembrolizumab in Triple Negative Breast Cancer (TNBC) (MK-7339-009/KEYLYNK-009)

Source: https://onco.cc/trials/nct04191135/  
OnCo record `nct04191135` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Replacing chemotherapy with olaparib alongside pembrolizumab did not improve the primary progression-free survival outcome in metastatic TNBC.

## Summary

The registry lists NCT04191135 as terminated, last updated 2026-09-14. Enrolment is 462 actual participants. Interventions: Pembrolizumab, Olaparib, Carboplatin, Gemcitabine. Primary measures include Progression-Free Survival (PFS); Overall Survival (OS). The registry reason for stopping is: Business Reasons Results are posted in the registry. The primary paper reports 460 participants receiving induction and 271 randomised; these analysis populations differ from the registry total of 462. Median PFS was 5.5 versus 5.6 months (HR 0.98, 95% CI 0.72-1.33, p=0.4556), and OS 25.1 versus 23.4 months (HR 0.95, 95% CI 0.64-1.40). Exploratory tumour-BRCA subgroup estimates were imprecise and do not establish a positive subgroup trial.

## Fields

- Kind: Trial
- Status: withdrawn
- Last checked: 2026-10-06
- Registry id: NCT04191135
- Phase: 2
- Setting: An Open-label, Randomized, Phase 2/3 Study of Olaparib Plus Pembrolizumab Versus Chemotherapy Plus Pembrolizumab After Induction of Clinical Benefit With First-line Chemotherapy Plus Pembrolizumab in Participants With Locally Recurrent Inoperable or Metastatic Triple Negative Breast Cancer (TNBC) (KEYLYNK-009)
- Sponsor: Merck Sharp & Dohme LLC
- Enrolled: 462
- Outcomes: Progression-free survival, randomised maintenance population: Pembrolizumab plus olaparib 5.5 months vs Pembrolizumab plus chemotherapy 5.6 months, HR 0.98; Overall survival, randomised maintenance population: Pembrolizumab plus olaparib 25.1 months vs Pembrolizumab plus chemotherapy 23.4 months, HR 0.95

## Sources

- ClinicalTrials.gov NCT04191135: https://clinicaltrials.gov/study/NCT04191135
- Primary KEYLYNK-009 publication: https://doi.org/10.1158/1078-0432.CCR-25-1818

## Connected records

- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [PARP](https://onco.cc/targets/parp/)
- drugs: [Olaparib](https://onco.cc/drugs/olaparib/)

---
JSON: https://onco.cc/api/v1/entities/nct04191135.json