FDA Grants Breakthrough Therapy Status to Merck’s Calderasib for KRAS G12C-Mutated NSCLC
Saturday, May 30, 2026
Merck, known as MSD outside the United States and Canada, has received Breakthrough Therapy designation from the U.S. Food and Drug Administration (FDA) for calderasib (MK-1084), an investigational oral KRAS G12C inhibitor.
The designation covers the use of calderasib in combination with KEYTRUDA® (pembrolizumab) as a first-line treatment for patients with advanced or metastatic non-small cell lung cancer (NSCLC) carrying a KRAS G12C mutation and expressing PD-L1 with a tumour proportion score of at least 1%.
The FDA decision was supported by positive results from the Phase I KANDLELIT-001 clinical trial. This marks the first Breakthrough Therapy designation granted to calderasib.
KRAS G12C is the most common KRAS mutation in NSCLC adenocarcinoma and is found in around 14% of patients with the disease. The FDA’s Breakthrough Therapy designation is intended to speed up the development and review of medicines for serious or life-threatening conditions that show the potential to provide significant improvements over existing treatments.
Merck is advancing calderasib through its KANDLELIT clinical development programme, which includes five Phase III studies across different tumour types and treatment settings. These trials are evaluating the candidate in combination with therapies such as KEYTRUDA, KEYTRUDA QLEX, cetuximab, mFOLFOX6 and durvalumab for patients with KRAS G12C-mutated cancers, including NSCLC and colorectal cancer.
Calderasib is being developed under a collaboration established in 2020 between Merck, Taiho Pharmaceutical and Astex Pharmaceuticals, a wholly owned subsidiary of Otsuka Pharmaceutical.
Source: businesswire.com
