A Study of Evorpacept (ALX148) With Azacitidine for Higher Risk Myelodysplastic Syndrome (ASPEN-02)

Inclusion Criteria: * Phase 1: Diagnosis of higher risk MDS that is either previously untreated or relapsed/refractory. * Phase 2: Diagnosis of higher risk MDS that is previously untreated. * Adequate renal and liver function. * Age ≥18 years. * Adequate performance status. Exclusion Criteria: * Previous allogeneic hematopoietic stem cell transplant (allo-HSCT) for MDS or AML. * Prior treatment with any anti-CD47 or anti-SIRPα (signal regulatory protein alpha) agent. * Known active viral infections, including hepatitis B and C, human immunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS) related illness, or SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2).