Methods to mobilize progenitor/stem cells

Patent Number: 6987102

Hematopoietic stem cells stay in the bone marrow due in part to secretion of SDF-1 by bone marrow stromal cells. The chemotactic gradient of SDF-1 is also what causes hematopoietic stem cells to home to the bone marrow of the recipient after a bone marrow transplant. This invention covers some antagonists of the receptor for SDF-1, CXCR-4 which when administered cause the stem cell cells to leave the bone marrow microenvironment since the homing signal that keeps them in the bone marrow is not as strong. This is useful for the procedure called "mobilization". Due to the difficulting of extracting bone marrow from donors, there has been interest in using "peripheral blood" stem cell transplants. The issue with peripheral blood stem cells is that there is usually a very small concentration of hematopoietic stem cells circulating in the peripheral blood. Other investigators administer growth factors such as G-CSF, for example to cause the hematopoietic stem cells to enter peripheral blood from the bone marrow. This patent uses antagonists of CXCR-4. The patent has 2 independent claims. The first covers the use of a specific CXCR-4 antagonist for mobilization. The second covers CXCR-4 antagonist, BY WHATEVER MEANS for mobilization of the bone marrow stem cells. This of course brings a really interesting question. If somebody was to discover a new CXCR-4 antagonist and use it for mobilization of stem cells, would they be infringing on this patent? Conceptually they should be, since the issued claim appears to represent ANY antagonism. The importance of this claim seems to be very significant since it is a claim on a pathway, not just on a specific product or embodiment.

View this patent on the USPTO website.