Bone Marrow Transplant Product
There are approximately 55,000 bone marrow transplant procedures currently performed worldwide, with the total number of annual procedures estimated to increase to over 75,000.
Today more than 70% of people who could use an unrelated donor bone marrow transplant do not receive one as a fully matched donor cannot be found. Full matching is required because of the high risk of the potentially life-threatening complication of severe graft-versus-host disease (GVHD).
Mesoblast’s objective is to develop a therapy that results in effective bone marrow reconstitution without the potentially life-threatening complication of GVHD that occurs in as many as 60 per cent of patients who receive bone marrow transplants from unrelated adult donors. Mesoblast’s bone marrow-derived allogeneic Mesenchymal Precursor Cells (MPCs) can be used as a feeder layer in combination with hematopoietic growth factors to expand and differentiate hematopoietic precursors from cord blood.
Mesoblast’s MPCs are currently being trialled under a United States FDA Orphan Drug Designation to expand hematopoietic stem and progenitor cell numbers in patients with hematologic malignancies. In the first 25 patients who received cord blood expanded ex vivo by Mesoblast’s MPCs, the numbers of hematopoietic progenitors and stem cells in the cord blood product had been expanded by 40-44 fold following ex vivo culture. After transplantation with the expanded cord, the median time to neutrophil recovery was 15 days and to platelet recovery was approximately 54 days, compared with approximately 30 days and over 90-120 days, respectively, in published reports of patients transplanted with a single unexpanded cord.
In these patients, 80% successfully achieved the key composite endpoint at 100 days of survival with sustained engraftment of both neutrophils and platelets. This is significantly higher than the rate of 38 per cent for this composite endpoint achieved after transplantation with two non-expanded cords in the United States registry of 300 patients collected by the Center for International Blood and Marrow Transplant Research. Preliminary results showed that only 16% receiving expanded cord blood had developed severe GVHD.
Together, these results indicate that transplantation of allogeneic MPC-expanded cord blood is a promising strategy for effective bone marrow engraftment without the high risk of GVHD seen with adult allogeneic marrow.
This product has been granted orphan drug designation in the United States and has the potential to receive fast-track approval, and generate early and significant revenues for Mesoblast.