Background: Frontline and relapsed /refractory (R/R) acute myeloid leukemia (AML) patients carrying fms-related tyrosine kinase 3 [FLT3]-mutations (FLT3 mut+) benefit from FLT3 inhibitors (FLT3i) that have emerged as active therapeutic agents for this subset of AML encompassing up to 30-40% of all AML cases. The FLT3i gilteritinib, as monotherapy for R/R AML pts, has improved outcomes but the duration of remission achieved is transient and often brief. The Phase 3 randomized ADMIRAL trial of gilteritinib demonstrated a 20% CR rate and 2.8 months event-free-survival (EFS) (Perl, et al., NEJM 2019). The development of new targeted agents which synergize with FLT3 inhibitors, and ideally also inhibit the emergence of resistance, is therefore a major medical need in AML.