The anti-tumor activity of D-1553 is evaluated across a panel of cancer cell lines including lung, pancreatic and colorectal cancers and shown to be active only in cancer cells with KRas-G12C mutation....When D-1553 is combined with MEK inhibitor, SHP2 inhibitor or cytotoxic agents, further tumor growth inhibition or regression was observed in tumor xenograft models. These data suggest that D-1553 has anti-tumor activity in a broad spectrum of cancers and is suitable for tissue-agnostic clinical development targeting cancers with KRas-G12C mutation.