According to the Center for International Blood and Marrow Transplant Research (CIBMTR), there are now over 60,000 autologous and allogeneic bone marrow transplants performed annually worldwide, a number projected to further increase due to the anticipated growth in incidence of hematologic malignancies associated with an aging population.
Of the total transplants performed annually worldwide, approximately 25,000 are allogeneic. This number represents less than 30 per cent of individuals who would otherwise be eligible to receive an unrelated donor bone marrow transplant because for the rest a fully matched donor cannot be found. Perfect matching is required for adult marrow transplants because of the very high risk of potentially life-threatening GVHD when unmatched transplants are performed. GVHD still occurs in as many as 60 per cent of patients who receive fully matched bone marrow transplants from unrelated adult donors.
In contrast, cord blood causes significantly less GVHD, and can be used as a partially mismatched donor source. However, the number of hematopoietic precursor cells in unexpanded cord blood is too few to enable sufficiently robust and predictable bone marrow engraftment.
Mesoblast's objective is to make available a source of unrelated donor hematopoietic precursor cells from cord blood which can be used without full matching to effect rapid bone marrow reconstitution with a low risk of GVHD. The Company believes that this would expand the use of allogeneic bone marrow transplantation to all those in need of the procedure but who currently cannot find a donor, with the potential to expand the total number of unrelated donor transplants performed by three- to four-fold.Mesoblast's Phase 3 trial will be conducted across 50 centers in the United States, Europe and Australia, and will enroll 240 patients with hematologic malignancies undergoing unrelated donor bone marrow transplantation using matched or partially mismatched umbilical cord blood. Patients will be randomized to receive either non-expanded cord blood or cord blood expanded by Mesoblast's MPCs and containing 40-fold higher numbers of hematopoietic cells. The primary endpoint is a shortened time to neutrophil and platelet recovery in the treatment group. Mesoblast Chief Executive, Professor Silviu Itescu, said the initiation of a Phase 3 trial was a landmark milestone for the company. "This achievement again underscores the strength and robustness of Mesoblast's clinical, regulatory, and manufacturing capabilities. It is a significant step in bringing our broad range of adult stem cell therapeutics closer to global licensure, and to patients suffering from severe, debilitating diseases.