In vivo assay and molecular markers for testing the phenotypic stability of cell populations and selected cell populations for autologous transplantation

Patent Number: 7,479,367

Autologous stem cell transplantation has given positive results in cardiac, hepatic, and various ischemic conditions. 

The current patent addresses the use of autologous chondrocyte populations for treatment of various cartilage disorders.  Cartilage destruction is often seen in conditions such as osteoarthritis.  Use of autologous stem cells in osteoarthritis has been reported in veterinary species by the company Vet-Stem, and clinically by places such as Cellmedicine.  Another more complex way to induce cartilage regeneration is to extract autologous chondrocytes, expand them ex vivo, and subsequently reimplant them.  The problem with this is that it involves the need for a GMP-clean room during processing, as well, differentiated chondrocytes may not be as potent at generating new cartilage as undifferentiated stem cells.

Specifically, the current patent addresses methods of selecting for chondrocytes that possess a "stability of phenotype".  See people can not patent autologous chondrocyte use, since this is already in the prior art, so they have to figure out ways of getting "peripheral" IP that could be used to claim various proprietary advantages.

The first independent claim of the patent, covers essentially the method of identifying a chondrocyte as having phenotypic stability by selecting for cells that are positive for expression of the fibroblast growth factor receptor-3 and bone morphogenic protein-2, but lacking expression of activin-like kinase-1. 

The other dependent claims cover "a method of transplanting cells", "a therapeutic composition for humans", and "a method to identify chondrocyte cells", all essentially employing the phenotype of BMP-2 and/or FGF-R3 positive, and ALK-1 negative.

Other patents of interest to people reading this include:

Genzyme's 7,169,610 patent covering media for expansion of chondrocytes and chondrocyte precursors that is completely synthetic and lacks fetal calf serum. 

OsteoBiologics's 6,001,352 patent covering use of PDGF for ex vivo expansion of chondrocytes for therapy of cartilage defects.

Artecel's 6,841,150 patent which in its broadest claim covers:

"A method of treating a cartilage defect in a mammal, the method comprising:

a) differentiating an isolated human adipose tissue derived stromal cell into a chondrocytic cell;

and b) administering said chondrocytic cell to a cartilage defect area in a mammal" 

View this patent on the USPTO website.