Phase 1 Study of Shattuck Labs (SL)-172154 in Subjects With MDS or AML

This Phase 1a/1b study is an open label, multicenter trial in subjects with higher-risk (i.e., intermediate, high or very high risk by IPSS-R) MDS or AML. The study is designed to evaluate the safety, PK, pharmacodynamic effects, and preliminary anti tumor activity of SL-172154 monotherapy and SL-1712154 administered with either Azacitidine or Azacitidine and Venetoclax. Subjects will receive SL-172154 as monotherapy or administered with Azacitidine with or without Venetoclax until documented disease progression, unacceptable toxicity or intolerance, withdrawal of consent, or the subject meets other criteria for discontinuation (whichever occurs first).

Part D: Safety and efficacy will be further explored in Part D. Approximately 60 subjects with previously untreated higher-risk MDS will be randomized equally into 3 groups: 3.0 mg/kg SL-172154+azacitidine, 1.0 mg/kg SL-172154+azacitidine and azacitidine monotherapy. Patients will be stratified based on the TP53 mutation status (TP53m vs TP53wt) and bone marrow blast count at study entry (\<5% vs ≥5%).