Multinational phase 1-2 study of pivekimab sunirine for relapsed or refractory acute myeloid leukemia

CD123 is overexpressed in several hematological malignancies, including acute myeloid leukemia (AML). Pivekimab sunirine (IMGN632) is a first-in-class antibody drug conjugate comprising a high-affinity CD123 antibody, a cleavable linker, and an indolinobenzodiazepine pseudodimer payload. A phase 1-2 study at nine centers in France, Italy, Spain, and the USA evaluates pivekimab sunirine in patients with CD123-positive hematological malignancies. In the cohort with relapsed or refractory (R/R) AML patients the recommended phase 2 dose was selected as 0.045 mg/kg every three weeks. At this dose, the most common grade 3 or worse treatment-related adverse events were febrile neutropenia (10% of patients), infusion-related reactions (7%), and anemia (7%), with an overall response rate of 21% (95% CI 8-40) and complete response rate of 17% (6-36). The authors conclude that pivekimab sunirine showed single-agent activity in patients with R/R AML.