Patients (pts) with advanced NSCLC harboring an EGFR Exon 20 insertion (Cohort A) or HER2 activating mutation (Cohort B) with progressive disease after platinum-based chemotherapy or with any solid tumors harboring an NRG1, EGFR, HER2 or HER4 fusion (cohort C) were eligible....23 pts (11 cohort A, 11 cohort B, 1 cohort C) were treated with tarloxotinib....In cohort A, the best response was stable disease (SD) in 6/11 (55%) and progressive disease (PD) in 5/11 (45%). In cohort B, 4/9 evaluable pts (44%) exhibited tumor reduction by RECIST and 2/9 pts experienced confirmed PR (22%), 4/9 (44%) pts had SD, and 3/9 (33%) pts had PD.