Mesoblast MPCs used to boost blood cell transplants

Researchers from Mesoblast (ASX:MSB) and the University of Texas may have cracked a way to make the use of umbilical cord blood a more effective option in blood stem cell transplants.

The researchers have published the results of a phase I/II study in which they managed to accelerate the production of new blood in patients undergoing double umbilical cord transplants.

Scientists at the University of Texas MD Anderson Cancer Center took blood cells from one of two umbilical cords to be transplanted, and grew them on a bed of Mesoblast's Mesencymal Precursor Cells (MPCs).

The process improved the time it took for white blood cells to engraft on the transplanted blood cells.

Mesoblast executive vice president of research Dr Paul Simmons was co-author of the study.

Double-cord blood transplant is one of the most viable options for the roughly 75% of patients needing blood stem cell transplants who do not have a matched bone marrow or peripheral blood donor, because the cells do not provoke an immune response.

But patients undergoing this process on average have their white blood cells, or neutrophils, graft in 26 days and their platelets in 53 days, compared to just 11 and 13 days respectively for peripheral blood transplants from a matching donor.

During this time, patients are vulnerable to infections and spontaneous bleeding, and are dependent on transfusions.

Growing cord blood cells with MPCs reduced the median time to neutrophil engraftment to 15 days, compared to 24 days for the controls.

Median time of platelet engraftment was also reduced to 42 days compared to 49 for the controls, according to the results of the study, which were recently published in the New England Journal of Medicine.

Senior author Elizabeth Shpall MD, a professor at MD Anderson's Department of Stem Cell Transplantation and Cellular Therapy, said the process of expanding cord cells using MPCs also substantially increased the number of cells transplanted.

“Expansion achieved a median 12-fold increase in total cells transplanted and a 40-fold increase in the number of CD34+ cells, which are crucial for engraftment,” she said.

Shpall is now leading a phase III, randomised trial of the process across 15 centres and 120 patients.

Shpall originally developed the process of using MPCs to enhance donor cord blood using cells taken from the relatives of patients. But they switched to using Mesoblast's MPCs after finding them to be superior at expanding blood-forming precursors.

Mesoblast has used its off-the-shelf MPCs to develop Revascor, a stem cell treatment for heart failure. Marketing partner Teva this week revealed it plans to take Revascor to phase III trials next year.

Mesoblast (ASX:MSB) shares were trading level at $6.02 as of 3pm on Thursday.