OBI-998 showed significant anti-tumor efficacy in multiple cancer cell–derived xenograft models at doses of 1, 3, and 10 mg/kg in a dose-dependent manner. More importantly, OBI-998 at a dose of 10 mg/kg showed complete tumor regression in an EGFR-triple mutation non–small cell lung cancer xenograft model, which is resistant to the current last-line tyrosine kinase inhibitor, osimertinib.