The U.S. Patent and Trademark Office (USPTO) [1] came down on the side of Wisconsin Alumni Research Foundation (WARF) [2] in upholding one of its patents on human embryonic stem cells.
WARF’s licensee, Geron Corp., holds an exclusive license to these patents to develop and commercialize therapies based on three types of cells derived from human embryonic stem cells: neural cells, cardiomyocytes and pancreatic islet cells.
Earlier [3], the USPTO announced [4] it would re-examine patents covering embryonic stem cell discoveries made by University of Wisconsin researchers. The patents, US Pat. Nos. 5,843,780 [5], 6,200,806 [6], and 7,029,913 [7], cover all embryonic stem cell research in the U.S. The USPTO granted each of the requests in September 2006 and rejected all claims of each of the patents on March 30, 2007.
In the Office Actions rejecting the claims, the examiners said the Wisconsin cells appeared to be either the same or obvious variations of cells described in previous patents issued to others or in scientific papers.
In the latest action on the reexamination of ‘913 Patent (95/000,154), the Patent Office has confirmed that the amended claims 1-3 are allowable and has closed prosecution on the merits. The original patent covered all embryonic stem cells no matter how they are derived. However, in the course of the re-exam, the applicants have now narrowed the claim only to stems cells derived from pre-implantation embryos.
The amended claim 1 is to:
1. (amended) A replicating in vitro cell culture of pluripotent human embryonic stem cells derived from a pre-implantation embryo, wherein the stem cells [comprising cells which] (i) [are capable of proliferation] will proliferate in an in vitro culture for over one year in an undifferentiated state without the application of exogenous leukemia inhibitory factor, (ii) maintain a karyotype in which the chromosomes are euploid through prolonged culture, (iii) maintain the potential to differentiate to derivatives of endoderm, mesoderm, and ectoderm tissues throughout the culture, and (iv) are inhibited from differentiation when cultured on a fibroblast feeder layer
The reexamination requesters, the Foundation Taxpayer and Consumer Rights (FTCR) [8] and the Public Patent Foundation (PUBPAT) [9], , tried to get the claims rejected as unpatentable under 35 U.S.C. §103(a) as being obvious in view of the Declaration by Dr. Jeanne F. Loring. They indicated that the Loring Declaration was submitted in order to explain “what the prior art disclosed to, and what motivations or suggestions it provided to those of ordinary skill in the art.”
However, the USPTO came back and indicated that only patents or printed publications can be used in the reexamination proceeding to raise a substantial new question of patentability. The USPTO said that the Loring declaration cannot by itself provide the necessary motivation to combine references even though the declaration had been given full consideration as evidence supporting obviousness in each rejection under 35 USC §103(a) in the non-Office action. Accordingly, the proposed rejections were not adopted.
The question now is whether or not a newer stem cell technology, Induced Pluripotent Stem Cells (IPS cells) [10] , which are derived without destroying embryos, would be covered by the more narrowly-defined patent scope.
Still, a lot of money is at stake. WARF has made free licenses and cells available to more than 300 academic research groups but charges companies $75,000 to $400,000, depending on their size and the terms of the license. WARF also claims royalties from products produced using the patents. WARF has said the patents apply to all human embryonic stem cells, no matter how derived, but had not slowed research.
If the action is made final, look for the nonprofit groups to appeal the patent claims to the patent office’s Board of Patent Appeals and Interferences [11]. They also could appeal any board decision to federal district court. The parallel reexamination proceedings involving U.S. Patent Numbers 5,843,780 and 6,200,806 which claim preparations of, respectively, primate and human embryonic stem cells and methods for their isolation, are still pending.
Copies of the challenges filed by FTCR and PUBPAT [12].
If you are interested in more details of the ongoing dispute between California and Wisconsin, check out the coverage on the California Stem Cell Report [13].
Also see: