Merck, known as MSD outside of the United States and Canada, today announced it has initiated a Phase 3 clinical trial evaluating MK-1084, an investigational oral selective KRAS G12C inhibitor, in combination with KEYTRUDA for the first-line treatment of certain patients with metastatic non-small cell lung cancer (NSCLC) whose tumors harbor KRAS G12C mutations and express PD-L1 (tumor proportion score [TPS] ≥50%).

“KRAS is among the most prevalent mutations in cancer and KRAS G12C is the most common KRAS mutation in patients with non-small cell lung cancer,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “Based on early evidence showing MK-1084 in combination with KEYTRUDA had a manageable safety profile and promising anti-tumor activity, we are now proceeding to a larger Phase 3 trial to evaluate this combination in certain patients with metastatic non-small cell lung cancer.”

Merck has initiated a Phase 3, randomized, double-blind, multicenter clinical trial (NCT06345729) evaluating once daily MK-1084 in combination with KEYTRUDA administered once every three weeks compared with KEYTRUDA plus placebo in previously untreated patients with KRAS G12C-mutated metastatic NSCLC with a PD-L1 TPS ≥50%.

The trial will enroll approximately 600 patients globally. The primary endpoints of the study are progression-free survival and overall survival, and key secondary endpoints include objective response rate and duration of response.

MK-1084 is currently being evaluated in a Phase 1, open-label multicenter clinical trialto assess safety, tolerability, pharmacokinetics and efficacy of MK-1084 as monotherapy and as part of various combination therapies in patients with KRAS G12C mutant advanced solid tumors.