Phase 1b pivekimab sunirine CD123-targeted antibody–drug conjugate in pediatric R/R AML

AbbVie is running this open-label, single-arm Phase 1b study to characterize safety, tolerability, and pharmacokinetics of pivekimab sunirine in children with relapsed or refractory acute myeloid leukemia whose blasts are CD123-positive (CD123 is commonly expressed on AML blasts, enriching for a targetable subset). Pivekimab sunirine (also known historically as IMGN632/PVEK) is a CD123-directed antibody–drug conjugate that delivers a cytotoxic DNA-damaging payload to CD123-expressing cells, aiming to widen the therapeutic window versus non-targeted chemotherapy. Patients enroll into age-based cohorts (including infants/toddlers through adolescents) and receive IV pivekimab sunirine with weight-based dosing, with intensive labs, marrow assessments, and adverse-event monitoring over a long follow-up (~28 months). The key commercial/scientific angle is translating a CD123 ADC—now validated in another CD123-driven hematologic malignancy—into a very high-need pediatric AML salvage setting where options after second-plus relapse are limited and often revolve around re-induction chemotherapy, targeted agents when actionable mutations exist, and transplant or clinical trials when remission can be re-achieved.