– Maximal inhibition of ERK phosphorylation at 6 hours after treatment (MIA PaCa-2, H1373 and H2122 xenografts). – Inhibition of tumor growth in MIA PaCa-2 and H358 xenografts.– Inhibition of tumor growth in human KRAS G12C-mutant cell line and patient-derived xenograft models. Tumor regression exceeding 30% volume reduction from baseline in 65% of these models after 3 weeks of treatment. No effect in non KRAS G12C models. – In xenograft models: TP53, STK11, KRAS mutant allele frequency and CDKN2A not identified as predictive biomarkers. The gene discussed is STK11; the disease is neoplasm.