Magenta Therapeutics, Inc. announced that its Investigational New Drug (IND) application for MGTA-117 is active with the U.S. Food and Drug Administration (FDA). The company expects to open the Phase 1/2 clinical trial in Fourth Quarter 2021 to evaluate its MGTA-117 antibody-drug conjugate (ADC) targeted conditioning program. The multi-center, open label Phase 1/2 clinical trial with single-dose escalating cohorts will evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of MGTA-117 as a single agent in relapsed/refractory AML and MDS patients. Magenta will continue to engage with the FDA to transition the trial to the intended primary target population of hematopoietic stem cell transplant-eligible AML and MDS patients. In addition, Magenta has planned gene therapy clinical trial collaborations with AVROBIO and Beam Therapeutics to evaluate the potential utility of MGTA-117 for conditioning gene therapy patients without the use of non-selective busulfan or other toxic chemotherapies. Magenta’s MGTA-117 program is the company’s lead targeted conditioning product candidate, an antibody-drug conjugate (ADC) designed to selectively deplete hematopoietic stem cells (HSCs) from patients prior to transplant or HSC-based gene therapy to reduce the need for high-dose or high-intensity chemotherapeutic agents or, in the case of gene therapy applications, to potentially eliminate the need for chemotherapeutic agents altogether. MGTA-117 targets the CD117 receptor, which is highly expressed on the cell surface of HSCs and leukemia cells, making it a promising target for conditioning across broad sets of diseases, including certain blood cancers, hemoglobinopathies (sickle cell disease and beta thalassemia) and inherited metabolic disorders.