Eileen McDermott, New York and Eklavya Gupte, London
The Wisconsin Alumni Research Foundation (WARF) was celebrating last month after the USPTO issued favourable decisions on three controversial patent applications for stem cells. But two public interest groups who challenged the patents have vowed to fight the latest rulings.
Last month, the PTO approved amended applications for two of the patents (numbers 5,843,780 and 6,200,806), which claim preparations of, respectively, primate and human embryonic stem cells and methods for their isolation. In a separate decision, on February 23, a third patent (number 7,029,913) was upheld by the PTO following an obviousness challenge.
The technology in all three patents was developed by the scientist who established the world's first human embryonic stem cell line, James Thomson. He assigned the patent applications to WARF, which has licensed the technology to Geron.
The patents were challenged by the Public Patent Foundation (PUBPAT) and the California-based Foundation for Taxpayer and Consumer Rights (FTCR) in 2006, and the USPTO launched a reexamination proceeding. The groups argued that "the three WARF patents were impeding scientific progress and driving vital stem cell research overseas" and claimed that the patents were invalid for reasons of obviousness.
Although the USPTO initially upheld the challenges by the two groups on all three patents in April 2007, WARF appealed, and examiner Gary Kunz upheld the '913 patent on February 25. That patent underwent a different review process, which allows for public comment and appeal, and PUBPAT and FTCR have said they plan to fight the decision all the way to the US Court of Appeals for the Federal Circuit if necessary. But WARF managing director Carl Gulbrandsen said in a statement: "It [the '913 decision] affirms what WARF has believed all along, that Dr Thomson's breakthrough discoveries are patentable inventions."
According to statements issued by Geron and WARF on March 11, the USPTO has now issued notices of intent to issue ex parte reexamination certificates for the other two patents. The Geron statement indicated that the certificates were issued after WARF made "minor amendments" to some of the claims "to improve clarity and consistency" and also added three new claims to each patent. The statements also said that the decisions on the two patents are final and cannot be appealed.
But Dan Ravicher, executive director of PUBPAT, characterized those statements as "misleading" and "false" in an interview with Managing IP. "We can still file a whole new challenge against them," said Ravicher, although he did not confirm what course of action the groups planned to take. He added that the revised patents were amended based on some of the concerns PUBPAT and FTCR presented in the reexamination request. A recent FTCR statement also said that the groups' challenges helped to convince WARF in January to ease its licensing requirements on human embryonic stem cells.
Despite these changes, Ravicher said he still does not believe the claims constitute patentable subject matter. "We still disagree with the amended claims and think the patent is obvious," he said. "This is just the second decision in a line of decisions to come. [Geron and WARF] want to make it seem as though this is the final word, but nothing could be further from the truth."
"The examiner based his decision [on the '913 patent] on his own belief that it would not have been obvious to isolate human stem cells using widely known methods to isolate mouse stem cells, which contradicts the sworn testimony that we provided of four renowned stem cell embryologists who were doing such work," Ravicher added.
Corresponding patent applications at the European Patent Office have also attracted controversy, and an appeal decision is pending.
