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)

Summary

The purpose of this study is to compare the efficacy of olaparib (MK-7339) plus pembrolizumab (MK-3475) with chemotherapy plus pembrolizumab after induction with first-line chemotherapy plus pembrolizumab in triple negative breast cancer (TNBC). The primary hypotheses are: 1. Olaparib plus pembrolizumab is superior to chemotherapy plus pembrolizumab with respect to progression-free survival (PFS). 2. Olaparib plus pembrolizumab is superior to chemotherapy plus pembrolizumab with respect to overall survival (OS). As of Amendment 3, study enrollment was discontinued. Participants who were receiving benefit from the study intervention could continue treatment until criteria for discontinuation are met. Participants who are on study treatment or in follow-up phase will no longer have tumor response assessments by BICR.

Timeline

Start

2019-12-19

Primary completion

2022-12-15

Completion

2025-11-26

Outcome

Missed primary endpoint

registry analysis (superiority test); Pembrolizumab + Olaparib vs Pembrolizumab + Carboplatin + Gemcitabine; p = 0.4556; Hazard Ratio (HR) 0.98 (95% CI 0.72 to 1.33) NCT04191135 ↗

registry analysis (superiority test); Pembrolizumab + Olaparib vs Pembrolizumab + Carboplatin + Gemcitabine; p = 0.3903; Hazard Ratio (HR) 0.95 (95% CI 0.64 to 1.40) NCT04191135 ↗

paper Although the primary endpoint was not met, postinduction pembrolizumab plus olaparib therapy resulted in similar PFS and OS compared with pembrolizumab plus chemotherapy in this setting. PMID 41405563 ↗

Publications

• Results Rugo HS, Cescon DW, Robson ME, Im SA, Dalenc F, Yanez Ruiz E, Reyes-Cosmelli F, Walshe JM, Im YH, Kulyk S, Dudnichenko O, Llinas-Quintero N, Saji S, Miyoshi Y, Bardia A, Harbeck N, Haiderali A, Fan L, Mejia JA, Karantza V, Llombart-Cussac A. KEYLYNK-009: Pembrolizumab plus Olaparib in Locally Recurrent Inoperable or Metastatic Triple-Negative Breast Cancer after Clinical Benefit from First-Line Pembrolizumab plus Chemotherapy. Clin Cancer Res. 2026 Mar 2;32(5):883-893. doi: 10.1158/1078-0432.CCR-25-1818.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Carboplatin	Small molecule	2 unknown	Intravenous
Subject	Gemcitabine	Small molecule	1000 mg/m2	Intravenous
Subject	Olaparib	Small molecule	300 mg	Oral
Background	Pembrolizumab	Monoclonal antibody	200 mg	Intravenous

Indications