Merck's (MRK) Keytruda, in combination with Gilead's (GILD) Trodelvy, reduced the risk of disease progression or death by 35% compared with Keytruda and chemotherapy for the first-line treatment of patients with locally advanced or metastatic triple-negative breast cancer in a Phase 3 study, the companies announced on Saturday.

The Keytruda-Trodelvy combination resulted in a median progression-free survival of 11.2 months, up from 7.8 months when Keytruda was given in combination with chemotherapy in the 443-patient randomized trial, the companies said.