The Wisconsin
Alumni Research Foundation has suffered a blow in its effort to protect a
key patent for embryonic stem cell technology.

The U.S. Patent
and Trademark Office last week reversed an earlier decision in which it
rejected an appeal on one of three basic human embryonic stem cell
patents held by the foundation, known as WARF.

The patent in
question covers early work done by University of Wisconsin-Madison stem
cell pioneer James Thomson. The patent office said it now agrees with
the argument made by two foundations that Thomson’s work covered by the
single patent could have been performed by other scientists with access
to the same resources.

The rejection
does not affect a decision the patent office made in early 2008 to
uphold two other basic embryonic stem cell patents held by WARF.

"WARF has been
invited by the Board of Patent Appeals to continue prosecution of this
application and plans to do so and vigorously pursue these claims with
the patent office," the foundation said in a statement.

Geron Corp.,
which funded some of Thomson’s early work and licenses the patents from
WARF, said in a statement it is confident WARF will make a strong case
to the patent office. Geron also said it has a broad patent portfolio
that will provide protection for its technologies well beyond 2015, when
WARF’s three key patents expire.

The challenges
were brought by the Foundation for Taxpayer and Consumer Rights in Santa
Monica, Calif., and the Public Patent Foundation in New York City. The
groups argued the work done in the mid-1990s by Thomson could have been
done by any good scientist with access to embryos and funding.

"This is a major
victory for unfettered scientific research that could lead to cures for
some of the most debilitating diseases," John M. Simpson, stem cell
project director at the California Foundation, said in a news release.

Geron said it has
also licensed more stem cell patents from WARF other than the original
three the foundations have been contesting.

Thomson has
continued developing stem cell technologies beyond the original patents.
Cellular Dynamics International, a Madison company he co-founded,
recently raised $40.6 million of private equity funding and is making
what are known as induced pluripotent stem, or iPS, cells that have all
the characteristics of human embryonic stem cells, but are made from
tissue and other cells rather than human embryos.

The privately
held company sells its stem cell-derived heart cells to Swiss
pharmaceutical company Roche and others to help them test the toxicity
of drugs.