Phase 1 Study of Tagraxofusp Alone or With Chemotherapy for Children and Young Adults Aged 1 to 21 With Relapsed or Refractory Blood Cancers Expressing CD123

What this Trial Is About

Researchers are evaluating the safety and appropriate dosing of Tagraxofusp, a protein-drug conjugate targeting CD123, in children and young adults with relapsed or refractory blood cancers that express CD123. This study aims to improve survival rates by examining Tagraxofusp alone and in combination with chemotherapy. The trial focuses on pediatric patients with various hematologic malignancies, including leukemia, lymphoma, and blastic plasmacytoid dendritic cell neoplasm BPDCN. The study is a Phase 1 trial sponsored by the Therapeutic Advances in Childhood Leukemia Consortium. The trial includes two parts a monotherapy phase and a combination chemotherapy phase. Tagraxofusp is administered intravenously over 15 minutes with doses assigned at study entry. In combination therapy, Tagraxofusp is given alongside chemotherapy drugs such as fludarabine, cytarabine, dexamethasone, vincristine, or azacitidine on specified schedules over several days. Intrathecal IT therapy with methotrexate, cytarabine, or triple IT is also given at various time points depending on the treatment group and disease status. Additional IT therapy may be provided during end-of-cycle disease evaluations. Participants will receive close monitoring including assessments of dose-limiting toxicities during the first cycle of therapy 21 days for monotherapy, 28 days for combination therapy. The study will assess toxicities, pharmacokinetics, and pharmacodynamics of Tagraxofusp. Participants must undergo various laboratory tests, imaging, and clinical evaluations to determine eligibility and monitor disease status. The trial expects to enroll about 54 children and young adults aged 1 to 21 years, including patients with Down syndrome in the monotherapy phase.

Tagraxofusp in Pediatric Patients With Relapsed or Refractory CD123 Expressing Hematologic Malignancies