Magenta Therapeutics, Inc. announced that it will make three presentations relating to its ongoing clinical trials at the 2022 American Society of Hematology (ASH) Annual Meeting, to be held in New Orleans from December 10-13, 2022 and virtually. In addition, an academic collaborator will present data from a preclinical program from Magenta's research platform. MGTA-117: Antibody Drug Conjugate (ADC) Targeted Conditioning.

MGTA-117 is Magenta's most advanced targeted conditioning product candidate designed to deplete target cells prior to a patient undergoing stem cell transplant or receiving an ex vivo gene therapy product. The program is currently enrolling patients with relapsed/refractory acute myeloid leukemia (AML), and myelodysplastic syndromes (MDS), in a Phase 1/2 dose escalation clinical trial. MGTA-117 is an anti-CD117 antibody conjugated to an amanitin payload.

CD117, also known as c-Kit receptor, is highly expressed on hematopoietic stem cells, progenitor cells, and leukemic cells. Magenta is developing MGTA-145, in combination with plerixafor, to improve the process by which stem cells are stimulated out of the bone marrow and into the bloodstream, known as stem cell mobilization. The mobilized cells are then collected and available for transplant.

This is the first step for patients and is required for the majority of transplants and stem cell gene therapies. This is a Phase 2 open-label clinical trial designed to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of one or two doses of MGTA-145 combined with plerixafor for the mobilization of hematopoietic stem cells in patients with sickle cell disease. The primary endpoint is the total number of collected stem cells.

Key exploratory endpoints include characterization of the phenotype and function of cells collected by apheresis and assessment of the potential for collected cells to undergo gene modification. The results of this clinical trial will provide direction regarding the potential of MGTA-145, in combination with plerixafor, to rapidly and safely mobilize sufficient numbers of high-quality stem cells for hematopoietic stem cell transplant in patients with sickle cell disease.