On Nov. 13, 2020, Merck announced that the U.S. Food and Drug Administration (FDA) had approved KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with chemotherapy for treatment of patients with locally recurrent unresectable or metastatic triple-negative breast cancer (TNBC) whose tumors express PD-L1 (Combined Positive Score [CPS] =10) as determined by an FDA-approved test.

The approval was based on results from the Phase 3 KEYNOTE-355 trial, where KEYTRUDA in combination with chemotherapy – paclitaxel (pac), paclitaxel protein-bound (commonly known as nab-paclitaxel) or gemcitabine (gem) and carboplatin (carbo) – significantly reduced the risk of disease progression or death by 35% for patients whose tumors express PD-L1 (CPS ≥10) versus the same chemotherapy regimens alone.