Mgta-456 Contains Large Numbers of Expanded Cord Blood (CB) CD34+CD90+ Hematopoietic Stem Cells (HSC) Which Confer All Engraftment Activity and Correlate with Accelerated Neutrophil Recovery after Myeloablative Conditioning in Patients with Hematologic Malignancy

Background: Patient access to well-matched CB containing high doses of stem cells remains a challenge for successful transplants. Low numbers of CD34+ cells in CB has resulted in delayed neutrophil recovery and a risk of graft failure relative to other hematopoietic stem cell (HSC) sources. MGTA-456 is a cell therapy that consists of CD34+ cells expanded in a 15-day culture in the presence of an aryl hydrocarbon receptor antagonist (AHRa) and the CD34 depleted fraction obtained from the same CB unit. Thus far, 40 patients with hematological malignancy (n=36) and non-malignant diseases (n=4) have received MGTA-456 with a median follow-up of 2.5 years (range 0.1 to 5 years) and 75 days (20 to 143 days) respectively. All patients engrafted at a significantly faster rate as compared to similarly treated historical controls (p