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Volume 85 Issue 3 | pp. 31-32
Issue Date: January 15, 2007

Cover Stories: Taming Stem Cells

Claims Under Fire

The future of embryonic stem cell research in the U.S. may hinge on the current review of key patents
Department: Science & Technology | Collection: Stem Cells
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Roadblock
Some researhers and observers fear that three WARF patents will choke human embryonic stem cell research in the U.S.
Credit: Jeff Miller/UW Madison
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Roadblock
Some researhers and observers fear that three WARF patents will choke human embryonic stem cell research in the U.S.
Credit: Jeff Miller/UW Madison

When it comes to doing research with human embryonic stem cells, U.S. scientists face many hurdles. The most prominent of these may be current U.S. policy, which strictly limits the stem cell lines eligible for government funding. But some researchers and other observers believe another hurdle is even greater.

They refer to three patents held by the Wisconsin Alumni Research Foundation (WARF), a nonprofit organization that manages patents for the University of Wisconsin, Madison. Together, the patents cover all U.S.-based research using primate embryonic stem cell lines, including those derived from humans. Thus, they give WARF a virtual monopoly on deciding who can do stem cell research in the U.S.

Undifferentitated embryonic stem cells, genetically modified to express a fluorescent protein marker (green fluorescent protein or GFP), are seen here growing in culture. The left panel is a pseudocolor image of GFP fluorescence within the cells and the right panel is a phase-contrast image of the embryonic stem cell colony.
Credit: Courtesy of UW Madison

The concern is that these patents present a major roadblock to moving research in this area into therapeutic use because they require anyone doing commercial research on embryonic stem cells in the U.S. to pay for the rights to use this technology. Specifically, researchers and others familiar with the field worry that WARF' s aggressive assertion of the patents will stifle promising research and that scientists and companies will move outside the U.S. to avoid seeking and paying for the necessary rights to use the patented work.

Because of these concerns, in July 2006, two nonprofit groups—the public interest group Foundation for Taxpayer & Consumer Rights (FTCR) and the legal services group Public Patent Foundation (PubPat)—asked the U.S. Patent & Trademark Office to take another look at the technical merit of the patents. In October, PTO agreed, and the office is now reexamining the trio of patents to verify their validity. WARF maintains that the patents are valid and that its assertion of them has been fair. Others disagree.

"The claims of these patents are directed to all human embryonic stem cells," says Daniel B. Ravicher, executive director of PubPat. (Claims define the boundaries of a patented invention.) "Just the existence of stem cells—not a particular method of using them or process for creating something from them—infringes the WARF patents, WARF claims," he explains.

Ravicher
Credit: Courtesy of PubPat
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Ravicher
Credit: Courtesy of PubPat

The broad nature of the patents was not the only concern that led PubPat to challenge the patents. "WARF was aggressively asserting these patents against the entire stem cell industry in the U.S.," Ravicher says. He adds that WARF was being especially ferocious with its threats against California' s stem cell initiative, which is a program approved by Californians in 2004 to provide $3 billion in funds for human embryonic research over 10 years.

The California initiative is also what led Santa Monica-based FTCR to get involved. John M. Simpson, director of the Stem Cell Project at FTCR, learned about the WARF patents while preparing a policy report on what intellectual property rules California should put in place to protect the state' s interests in research resulting from initiative grants.

"In preparing that report, I kept coming across the overarching patents WARF holds," Simpson says. "The more I talked to people from academia, small stem cell research companies, and some of the larger companies that are involved, the more I became convinced that these patents were genuine blocks to serious research in the U.S." They are, he says, driving research money, and to some extent the researchers themselves, out of the U.S. and into countries where the patents aren' t recognized.

Simpson
Credit: Jerry Flanagan/FTCR
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Simpson
Credit: Jerry Flanagan/FTCR

In some ways, Simpson says, these patents are more detrimental to the progress of stem cell research than federal policy is right now. He believes many researchers in the field agree with his view, but few are willing to speak out.

"Most people in academia felt that they didn' t want to stick their necks out and challenge the patents because they might have to go and get a license for research from WARF," he explains. As for industry support to challenge these patents, he says companies likely refrained from getting involved because they are carrying out only limited research and development with embryonic stem cells.

The three patents that are creating the tension claim different aspects of the same body of work and were all issued to James A. Thomson, professor in the School of Medicine & Public Health at UW Madison. They cover material based on Thomson' s research that led to the first isolation of embryonic stem cell lines from primates in 1995 and from humans in 1998.

In the first patent, issued in 1998, the claims cover a "purified preparation of primate embryonic stem cells." The claims identify the characteristics of these cells as having, among other things, the ability to proliferate in an in vitro culture for more than a year, which is the part of the definition of embryonic stem cells. The other two patents, issued in 2001 and 2006, include claims similar to the original patent' s, but they specify coverage to a "purified preparation of pluripotent human embryonic stem cells."

Although policy issues, such as the broadness of the claims and the chilling effect of these patents on domestic R&D, are motivating factors in requesting PTO to reexamine the patents, PubPat and FTCR acknowledge that the request needed to be based on technological grounds. As a result, they focused their request on evidence they say shows Thomson' s invention could have been anticipated from prior research, thereby making the disclosed discovery unpatentable because it would be obvious to a skilled person working in the field. PTO agreed to reexamine the patents on the basis of this question.

PTO requires that a patent reexamination be conducted in a manner similar to the examination of a new patent application. During the process, the patent as originally issued remains in place. The result of this inspection can confirm the patentability of the claims, amend the patent claims, cancel some or all of the patent claims, or add new claims to the patent.

According to PTO, the process takes on average about 21 months to complete, meaning that this case may not be resolved until sometime in 2008. PTO statistics also show that 74% of patent reexaminations result in at least one of the claims modified or canceled or a new claim added.

Cohn
Credit: Courtesy of WARF
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Cohn
Credit: Courtesy of WARF

For its part, WARF remains confident that PTO will confirm the validity of the patents. "We think the patents are strong," says Andrew Cohn, government and public relations manager for WARF. He adds that the fact that PTO accepted the case for review doesn' t necessarily mean anything because the office accepts nearly all reexamination requests.

"The patent office will make its determination based on the facts," Cohn says. He tells C&EN that WARF will not be discussing any details of its strategy for this case outside of the PTO forum. "We will prosecute our case before the proper authorities" and not in the press, he explains.

As for the allegations that WARF is being too aggressive in its enforcement of these patents, Cohn denies that the foundation is asserting its stem cell patent portfolio any differently than it would other parts of its intellectual property portfolio. In fact, he says, "we are being more generous by providing a license free of charge to researchers."

WARF grants the free license to scientists doing basic research with embryonic stem cells through an agreement with the National Institutes of Health. Under the agreement, researchers who are not doing any commercial work are automatically licensed and do not need to contact WARF. Researchers would need to contact WARF at this stage only if they want to use any of the federally approved embryonic stem cell lines derived and distributed by UW Madison. In this case, Cohn points out, there is a $500 fee for the cells to be sent to them.

Once the research crosses the line from basic to potentially commercial, however, researchers must contact WARF to negotiate necessary rights regardless of which cell lines they use. Contrary to criticism that getting such rights is a significant barrier, Cohn says, WARF works with groups to set up appropriate licensing terms that are not onerous. He adds that the foundation has never had anyone walk away from negotiations without an agreement. After all, he says, the foundation' s number one goal is "to move science forward."

To that end, Cohn explains, WARF has licensing fee tiers for start-ups, small companies, medium companies, and large companies. "If someone wants to do stem cell research, we will make it happen," he says.

As confident as WARF is that its patents will be upheld, so too are the challenging parties that the patents will be limited or invalidated. "We are optimistic that PTO will substantially narrow or completely revoke the patents," Simpson says.

An initial ruling from PTO is expected as early as this month. This action will be the first indication of how this case will play out. In the meantime, researchers will continue to push the science forward, and the public will continue to wait eagerly for the promise of human embryonic stem cell research to be realized.

 
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