The Milwaukee Journal Sentinel (Wisconsin)

The Madison foundation that holds three key human embryonic stem cell patents provided more information Tuesday to the U.S. Patent and Trademark Office in an effort to solidify its claims.

The Wisconsin Alumni Research Foundation said its filings “more clearly differentiate” the discoveries by University of Wisconsin-Madison scientist James Thomson from work previously conducted by others.

The filings also clarify language used in the foundation’s original patents and make it consistent across the three patents.

The filings are the latest volley in a dispute that began last year when two groups challenged the validity of the three embryonic stem cell patents.

The groups — the Foundation for Taxpayer and Consumer Rights in Santa Monica, Calif., and the Public Patent Foundation in New York City — argue that any good scientist with access to embryos and funding could have done what Thomson did.

The patent office preliminarily rejected the stem cell patents in April in its first action related to the re-examination.

“We continue to remain confident that, when all the facts are known and the process runs its course, our patents will be upheld,” said Carl Gulbrandsen, the Madison foundation’s managing director.

John Simpson, stem cell project director at the Foundation for Taxpayer and Consumer Rights, said he hadn’t seen the Madison foundation’s filings but expected it was narrowing the claims made in the original patents.

“The best thing WARF could do for stem cell research and for itself would be to abandon all claims under these three patents.”

The Wisconsin Alumni Research Foundation started patenting Thomson’s work in 1995, when it filed for rights to embryonic stem cells in all primates. The federal government funds only a limited amount of embryonic stem cell research because of restrictions put into place by President Bush.