Regulatory approval

Published by the Food and Drug Administration.

The U.S. Food and Drug Administration granted approval to pembrolizumab in combination with chemotherapy for the treatment of patients with locally recurrent unresectable or metastatic triple negative breast cancer (TNBC) whose tumors express PD-L1 (CPS >= 10), as determined by an FDA approved test. This indication is based on KEYNOTE-355 (NCT02819518), a multicenter, double-blind, randomized, placebo-controlled trial where patients received either paclitaxel and paclitaxel protein-bound, or gemcitabine and carboplatin.

This is written in the approval document as:

KEYTRUDA is a programmed death receptor-1 (PD-1)-blocking antibody indicated in combination with chemotherapy, for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS >=10) as determined by an FDA approved test.

Citation

Merck Sharp & Dohme Corp. Keytruda (pembrolizumab) [package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/125514s174lbl.pdf. Revised April 2025. Accessed April 30, 2025.

Therapeutic response

Precision oncology relationships for therapeutic response derived from this regulatory approval.

Type	Biomarker(s)	Cancer type	Therapy(ies)
Sensitivity (+)	ER negative, HER2-negative, PD-L1 (CPS) >= 10, PR negative	Invasive Breast Carcinoma	Paclitaxel, Pembrolizumab
Sensitivity (+)	ER negative, HER2-negative, PD-L1 (CPS) >= 10, PR negative	Invasive Breast Carcinoma	Carboplatin, Gemcitabine, Pembrolizumab