Opnurasib selectively forms a covalent bond with and inhibits GDP-bound KRASG12C, demonstrating a low reversible binding affinity to the RAS switch II pocket. Additionally, it effectively hinders the proliferation of cell lines carrying KRASG12C mutations, as well as those with double mutations G12C/H95, G12C/R68S, and G12C/Y96.[2]
Opnurasib induces dose-dependent decreases in phosphorylated ERK (pERK) levels and inhibits the proliferation of KRASG12C-mutated cell lines NCI-H358 and NCI-H2122, exhibiting IC50 values of 0.018 and 0.063 μM, respectively.[2]

Opnurasib elicits distinct antitumor responses in patient-derived xenograft (PDX) models of non-small cell lung cancer (NSCLC) and colorectal tumors, and these responses are further enhanced when Opnurasib is used in combination with other therapeutic agents.[2]