Mobocertinib had the lowest HER2 exon 20 insertion IC50 / WT EGFR IC50 ratio of all three HER2 exon 20 insertion mutations compared with osimertinib, poziotinib, afatinib, neratinib, and pyrotinib, indicating that mobocertinib displayed the best selectivity profile in these models and could provide an improved efficacy and safety profile in clinic....HER2 exon 20G776>VC lung tumor had sustained complete response to mobocertinib