Method for enhancing engraftment of cells using mesenchymal progenitor cells

Patent Number: 7,442,390

Stem cell transplantation in the form of cord blood, mobilized peripheral blood, or bone marrow, has saved many lives.  One of the limiting factors of this procedure is graft versus host disease (GVHD).  The other is poor engraftment.  This is particularly important in situations where the conditioning of the patient is myeloablative and there is a period of time in which the patient literally lacks an immune response.  The current patent uses the cells described by the same inventor in US patent #6,936,281 to accelerate engraftment.

Essentially the patent covers a way to transplant hematopoietic stem cells through providing to the recipient a mixture of cells that contain hematopoietic cells together with the mesenchymal stem cell population that the inventor previously patented. 

The examples section of the patent is very detailed, including animal efficacy data demonstrating superior engraftment using the inventor's mesenchymal population compared to standard bone marrow stromal cells.

One question is how commercially feasible this approach will be in comparison to Osiris's Prochymal product that is already in Phase III clinical trials?  Since Prochymal will be used by hematologists treating GVHD, the transition to using it to accelerate engraftment would theoretically be easier than the new MSC populations described in this patent.  In any case it will be interesting to follow this technology, which to our knowledge, is actually available for licensing from the University of South Florida.

View this patent on the USPTO website.