By James DeGiulio --
On
February 9th, Athersys, Inc. was issued U.S. Patent No. 7,659,118 covering
multipotent adult stem cells (MASC), their isolation and expansion, and related
pharmaceutical compositions. In a February 10, 2010 press release, the Cleveland-based company also announced the grant of European
patent EP 1 218 489 B1, the counterpart to the '118 patent. Athersys adds these patents to an already
robust patent portfolio covering its stem cell technology, which includes fourteen
patents and more than 120 global patent applications.
Both
the '118 and '489 patents cover the company's MultiStem technology, which is an investigational
stem cell therapy that has demonstrated therapeutic potential to treat a range
of problems, including heart attack, stroke, bone marrow transplant rejection, and inflammatory bowel disease. MultiStem has the ability to produce a range
of factors and form multiple cell types. MultiStem promotes tissue repair and
healing in multiple ways, such as through the production of multiple
therapeutic factors produced in response to signals of inflammation and tissue
damage. Unlike traditional stem cell therapies
that aim to replace damaged tissue, MultiStem produces factors that regulate
the immune system, protect damaged or injured cells, and promote tissue repair
and healing, giving the therapy a more drug-like effect. Thus, the company believes that
MultiStem represents a unique "off-the-shelf" stem cell product.
The '118 patent describes the advantages of using cells from the developed
individual rather than an embryo, specifically overcoming the problem of tissue
incompatibility. The claimed MASC
are negative for many common antigens, including CD44, CD45, and HLA class I
and II. The MASC express
transcription factors Oct3/4, REX-1, and ROX-1, express telomerase, and respond
to the growth factor LIF. The patent
describes the method of MASC isolation from human bone marrow, after which the
MASC can be maintained in undifferentiated state or differentiated into several
cell types, depending on desired use. The MASC are also suited for ex vivo
genetic alteration prior to introduction or engraftment into a human patient. The MASC are described as efficient for a number of uses, including cancer
treatment, tissue damage repair, induction of immune responses to fight
infection, and cardiovascular therapy. The patent contains 11 examples, which
describe the isolation, differentiation, development, characterization, and
engraftment of the cells.
Both
the U.S. and European patents claim the MASCs and pharmaceutical compositions, as well
as methods for their production. The '489 patent contains 21 claims, additionally claiming the use
of the MASC for agent screening applications. The '118 patent contains 12 claims; representative
claims include:
1. A cell culture comprising isolated expanded human multipotent, non-embryonic,
non-germ cells that can differentiate into at least one cell type of each of
the endodermal, ectodermal, and mesodermal embryonic lineages and express
telomerase, said cells having undergone at least 10-40 cell doublings in culture.
9. A pharmaceutical composition comprising a pharmaceutically acceptable carrier
and isolated expanded human multipotent, non-embryonic, non-germ cells that can
differentiate into at least one cell type of each of the endodermal,
ectodermal, and mesodermal embryonic lineages and express telomerase, said
cells having undergone at least 10-40 cell doublings in culture, said cells
obtained from the cell culture of claim 1 or 2.
10. A method for making a pharmaceutical composition comprising admixing a pharmaceutically
acceptable carrier and isolated expanded human multipotent, non-embryonic, non-germ
cells that can differentiate into at least one cell type of each of the
endodermal, ectodermal, and mesodermal embryonic lineages and express
telomerase, said cells having undergone at least 10-40 cell doublings in
culture, said cells obtained from the cell culture of claim 1 or 2.
In a December 2009 press release, Athersys
announced a strategic
partnership with Pfizer under which the companies will jointly develop
MultiStem for inflammatory
bowel disease, and a partnership with Angiotech to develop
MultiStem in acute myocardial infarction and other cardiovascular
indications. Athersys is still seeking
partners to develop MultiStem for stroke victims as well as leukemia patients
who have rejected bone marrow treatments.
On
February 16, 2010, Athersys, Inc. announced that it has completed patient
enrollment for its phase I clinical trial which will test administration of
Multistem to individuals following acute myocardial infarction.
James
DeGiulio has a doctorate in molecular biology and genetics from
Northwestern University and is a third-year law
student at the Northwestern University School of Law. Dr. DeGiulio
was a member of MBHB's 2009 class of summer associates, and he can be
contacted at degiulio@mbhb.com.