S243249 Monotherapy in Patients With Relapsed or Refractory Acute Leukemia With a KMT2A or NUP98 Translocation or Relapsed or Refractory AML With NPM1c Mutation

The objective of this study is to establish the efficacy, safety, and tolerability of S243249 and to establish the recommended phase 2 dose (RP2D) of S243249 monotherapy in participants with relapsed/refractory (R/R) acute leukemia with select mutations. Phase 1 dose optimization will determine the RP2D to be used in Phase 2 dose expansion. The study will include a screening period, a treatment period consisting of continuous 28-day cycles of treatment, a safety follow-up period and a long-term follow-up period. Participants may undergo blood tests, electrocardiogram (ECG), bone marrow aspirations, vital sign checks, questionnaires, and physical exams.