Novel and existing patient-derived cell lines and xenografts harboring EGFR exon 20 insertion mutations, ERBB2 (HER2) mutations and amplification, and NRG1 fusions were tested in vitro and in vivo with tarloxotinib...Tarloxotinib-E inhibited cell signaling and proliferation in patient-derived cancer models in vitro...In vivo, tarloxotinib induced tumor regression or growth inhibition in multiple murine xenograft models.