Monday, March 20, 2006

Stem Cell Patent Issued [United States]

StemCells, Inc. has announced that the Company has been issued U.S. patent 6,777,233 for work done at the Company covering composition of matter claims for the human neural stem cell. According to their press release:
"This patent further strengthens StemCells' leading position in the human neural stem cell field," said Martin McGlynn, President & CEO of StemCells Inc. "The patent covers human neural stem cell cultures derived from any source, including embryonic as well as fetal, neonatal and adult tissue. Next year, we intend to begin the process of testing the potential of our neural stem cells in the clinic to treat a wide range of diseases of, or injuries to, the central nervous system. As we have previously announced, we intend to file our first IND by the first quarter of 2005 for a clinical trial in Batten Disease, a rare, fatal neurodegenerative lysosomal storage disorder affecting the central nervous system," McGlynn added.
Independent claim 1 is fairly broad and recites:
1. A cell culture comprising: (a) a culture medium containing one or more predetermined growth factors effective for inducing multipotent central nervous system (CNS) neural stem cell proliferation; and (b) suspended in the culture medium, human multipotent CNS neural stem cells wherein (i) the cells are grown in culture medium containing one or more predetermined growth factors effective for inducing multipotent CNS neural stem cell proliferation; (ii) the population comprises cells which stain positive for nestin; (iii) in the presence of differentiation-inducing conditions, the cells produce progeny cells that differentiate into neurons, astrocytes, or oligodendrocytes; and (iv) the cells have a doubling rate faster than 30 days.
Stem Cells Inc. touts in its offering prospectus that they are outside the stem cell controversy because their line of stem cells is not directly derived from embryos. Stem Cells Inc.'s process reproducibly grows large numbers of stem cells so that they can be "banked" and used for therapeutic treatments at a later date.
An important distinction to keep in mind, the stem cells claimed by Stem Cells Inc. are downstream stem cells -- i.e. the cells are destined or committed to become a certain type of cell -- i.e. they are "multipotent".
Multipotent or bipotent stem cells are cells that have continued down the path of specialization and are committed to becoming cells of a certain type. For example, hematopoietic (blood) stem cells are committed to becoming cells that circulate in the blood but may become one of many different types of blood cells. Multipotent or bipotent stem cells can be found in children and adults.

Thus, the patent appears to only cover a cell culture capable of enhancing the growth or reproduction of multipotent stem cells and not stem cells in general.
Rodney D. Ryder

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