Selected Papers

Patenting Transgenic Animals — From The Harvard Mouse to "Hello Dolly"

By

Warren D. Woessner

Schwegman, Lundberg & Woessner, P.A.

Minneapolis, Minnesota

Few areas of intellectual property law have generated more attention than the realization that it is now practical to use utility patents to protect rights in higher animals, such as mice, pigs, sheep and cows, so long as they otherwise meet the criteria for patentability. On April 3, 1987, the Board of Appeals in Ex parte Allen refused to grant a patent on a process to make more edible oysters by putting them under pressure. The Board said the claims in question were obvious, but it also said that the mere fact that a multicellular animal was involved was not a bar to patentability. The issue, it ruled, "is simply whether that subject matter is made by man," rather than a product of nature.

Days after the Allen decision, on April 21, 1987, the PTO announced that it would accept applications for "nonnaturally occurring nonhuman multicellular living organisms, including animals." The PTO stated that, to be patentable, the animals must be "given a new form, quality, properties or combination not present in the original article existing in nature in accordance with existing law."

The Allen decision got some attention in the press, but all hell broke out (literally, as some religious objectors might say), when the Patent Office actually went ahead and issued U.S. Patent No. 4,736,866 to Philip Leder and Timothy A. Stewart of Harvard University on April 12, 1988. This is the now famous, or "infamous" to many, "Harvard mouse patent." Here is claim 1:

Two notable features of claim 1 are; (a) it covers all mammals, not just mice, and (b) it specifically covers the progeny of the animals that first received the oncogene. DuPont, who had substantially funded the research, now holds the license to the "oncomouse" and sells the mice to research institutions.

Despite the U.S. Patent and Trademark Officeís affirmative ruling, a consortium of animal rights groups brought an action challenging the Officeís authority to determine that transgenic animals were indeed patentable subject matter. The district court found that the Patent Office rule was an interpretive one and, as such, was exempt from the public notice and comment requirements of the Administrative Procedure Act. The Court of Appeals for the Federal Circuit affirmed the district court holding stating that the Animal Legal Defense Fund was without standing to challenge the Patent Officeís authority to grant animal patents. As a result, no court has yet ruled on whether or not animals are patentable subject matter under § 101.

The Harvard mouse patent has also been at the center of controversy surrounding "patenting life" in Europe. In February 1993, the European Parliament (EU) issued an ëinstructioní to the European Patent Office (EPO) directing it to revoke the Harvard mouse patent and to refuse to grant any more patents on transgenic animals until the legal uncertainties have been clarified. Such an instruction, however, is merely advisory. Meanwhile, environmental activist groups, like the European Green Party and Greenpeace, lobbied the European Parliament and were able to muster enough political clout to defeat the European Parliamentís final draft directive on the legal protection of biotechnological inventions in March of 1995. Positive change may yet come from the European parliament. On January 10, 1997, the Parliament approved the proposal with many amendments, including a new Article 1(b), which stated that "[i]nventions which concern plants or animals may be patented if the practicability of the invention is not technically confined to a particular plant or animal variety." Although the EPO is not an EU institution, there is some indication that the EPO will apply the provisions of the relevant EU Directives.

The Harvard "oncomice" have not simply been altered by environmental pressures, as were the pressurized oysters in Ex parte Allen. they have been genetically engineered. More specifically, the mice are "transgenic," in that at least one additional gene has been introduced into the germ cells of the animal. Furthermore, these mice can pass the new gene onto their offspring. The added gene can come from another animal of the same species, from an animal of a different species, or it can be completely synthetic. In this case, the new gene is a recombinant activated oncogene sequence that causes a high percentage of the mice to develop tumors. Thus, the mice are useful to test anticancer drugs. A number of these genes are known, and can be derived from chickens, monkeys or even humans.

The gene is introduced as linearized plasmid DNA, preferably in combination with an inducible promoter, by injection into the male pronucleus of a fertilized egg. The egg is then transplanted into a host female, where it matures. Interestingly, and distressingly for many researchers, this process was the subject of broad patent claims that issued to an Ohio University group headed by Thomas E. Wagner in October of 1989, well after the issuance of the oncomouse patent. Like claim 1 of the Harvard mouse patent, claim 1 of Wagner et al. covers a method of transforming any mammal with any "exogenous" gene. The broad product-by-process claims were canceled during the 7 years of prosecution.

Since the injected DNA is incorporated into the genome through a process involving disruption and alteration of the chromosomal DNA of the egg at the insertion site, it may result in either lethal mutation or gross morphological abnormalities. Nonetheless, in the case of mice, transgenic animals have been produced which are indistinguishable from unaltered mice, beyond the effects of the expression of the introduced gene sequence. However, this is far from a routine procedure. Transformation by microinjection is about 25% successful using mice. However, the success rate drops off rapidly for larger animals, to 10% in the case of pigs, down to 1% in cattle.

No other "composition of matter" patents issued in United States classification 800 until December 29, 1992, when the Patent Office issued three more. The patents claim (a) a mouse that develops an enlarged prostate gland (U.S. Patent No. 5,175,383), (b) transgenic mice depleted in mature T-cells (U.S. Patent No. 5,175,384) and (c) a virus-resistant mouse that produces beta-interferon (U.S. Patent No. 5,175,385). The '384 and '385 patents had been pending 4 and 5‡ years, respectively. The first claims of the '384 and '385 patents are shown below:

However, unlike claim 1 of the oncomouse patent which was not even limited to mice, or to any particular oncogene, these claims are both limited to mice and to "single genes" which accomplish a specific function. As in the case of transgenic plants, the early bird gets a transgenic stick of great breadth, while later comers tend to get the narrow end of the stick.

The first patent on a non-murine animal also issued to the U.S. Government DHHS in February of 1993 (U.S. Patent No. 5,183,949). Claim 1 of this patent is directed to "a rabbit infected with HIV-1 virus, said rabbit produced by the infection of human T-cells infected in vitro with HIV-1." This rabbit is a potential animal model on which to test anti-HIV drugs. However, this is not truly a transgenic animal, since its genome was not augmented with a preselected construct comprising recombinant DNA.

While the beta-interferon mouse could fairly be described as a lucky mouse, in that it was meant to resist infection, this line of research led mostly to mice afflicted with increasingly exotic pathologies. Such transgenic mice can be used both to test new drugs and to test compounds which might protect them against the effects of natural and synthetic pathogens such as carcinogens or mutagens. Much has been made of the production of giant pigs, fish or chickens by the introduction of growth hormone genes, and, in fact, mice grew to the size of rats when they were transformed in this way. However, attempts to alter whole animal morphology of farm animals, at least by microinjection of zygotes, are both time-consuming and difficult to evaluate from a cost/benefit standpoint in terms of the myriad of other side effects which might occur. Rather, as reflected by the increasing number of issued patents, commercial interest followed two main threads: transgenic animals, mainly mice, as models for human diseases, and transgenic farm animals that can produce valuable compounds, such as human pharmaceuticals, more efficiently than bacteria and yeasts.

The Patent Office did not issue another patent on a transgenic mouse useful as a model for human pathology until February 7, 1995, when it issued Cordell (U.S. Patent No. 5,387,742), assigned to Scios Nova Inc., which claimed transgenic mice displaying the amyloid deposits typical of Alzheimerís disease. Claim 1 reads as follows:

The heterologous DNA sequences are limited to those encoding two ß-amyloid precursor proteins. The DNA sequences must also be operatively linked to a nerve tissue specific promoter. These mice are disclosed to be useful to test drugs as potential candidates to treat various neurodegenerative diseases. However, behavioral degeneration of the mice is not disclosed in the specification. If the mice in fact remain behaviorally unaffected by the ß-amyloid deposits in their brains, should the Examiner have rejected the claims on the basis of an insufficient disclosure of utility/"how-to-use" the invention? Since issuing Cordell, the Patent Office has issued at least 16 patents on transgenic mice as models of specific pathologies. A representative group is summarized on Table 1, below.

Table 1

Despite the problems of low transformation frequency associated with the microinjection of naked DNA into the pronuclei of higher animals, such as cows and sheep, much effort has gone into patenting animals that can produce valuable heterologous proteins and excrete them into their milk in high levels. One of the first patents to issue in this area contained claims to a transgenic female sheep that expressed the transgene in the mammary gland so as to produce the target protein in its milk. Claim 1 of Clark et al. (U.S. Patent No. 5,476,995), reads as follows:

The dependent claims recite that the proteinaceous compound is a blood coagulation factor, i.e., factor IX, or alpha-1-antitrypsin, which is useful to treat emphysema or cystic fibrosis patients. The owner of this patent, PPL Therapeutics, has this compound in phase II clinical trials.

This research has led to an Old McDonaldís Bioreactor on the hoof, as illustrated by the patents listed in Table 2, below.

Table 2

All of these transgenic animals were produced by variations of the now old technique wherein recombinant DNA segments are introduced into fertilized eggs of mammalian species and the embryos are implanted into surrogate mothers to obtain transgenic offspring. Apart from the low transformation frequency, this process is slow; in cows, their long gestation period can mean that up to three years is required before a protein can be harvested from the milk. The other phenotypic properties of a transgenic animal are also up for grabs, because the genome is being altered at the very early developmental stage, while producer animals are selected at the end of the process.

A procedure that is potentially more predictable and more efficient, "adult cell cloning" was first reported by a group at Roslin Institute (Edinburgh) and PPL Therapeutics in February of 1997. "Dolly" or lamb number GLL3, was produced by enucleating an unfertilized oocyte from a Scottish Blackface ewe. Cells from the mammary gland of a 6-year-old Finn Dorset ewe in the last trimester of pregnancy were used as nuclear donor cells. The cells were induced into quiescence by reducing the serum in the culture medium. A cell was then electrofused to an enucleated oocyte. The reconstructed oocytes were also activated by electrical pulse and cultured in ligated oviducts of sheep. The morula or blastocysts that developed were transferred to recipients and Dolly was eventually born, exhibiting the same genotype as the Finn Dorset ewe that was the nucleus donor.

As the authors rather dryly conclude:

Here is a representative claim constructed from the independent and dependant claims of Roslin Institute (PCT WO 97/07669):

An animal prepared by a method comprising:

With respect to patentability, consider whether or not Dolly is novel over the lamb version of the donor that certainly existed prior to the invention of Dolly. However, Dolly is not identical to the donor sheep. As stated by the inventors:

Dolly was not transgenic. However, on July 24, 1997 the Roslin/PPL group announced the birth of five more lambs cloned using fibroblasts as nuclei donor cells. The fibroblasts included a selectable marker gene and an undisclosed human gene. One lamb, "Polly," was confirmed to have the human gene. Although the reproducibility of these experiments was questioned, cloned mice have been reported that were produced using a similar procedure in which enucleated oocytes were injected with nuclei from cumulus cells.

On August 7, 1997, ABS Global Inc. of DeForest, Wisconsin, announced the successful cloning of a bull calf named "Gene." The calf was produced by establishing an embryonic stem cell line, then introducing a cloned stem cell into an enucleated calf egg and fusing the two cells to yield a "nuclear transfer embryo." The embryo was induced to replicate and allowed to develop into an immature embryo. The embryo was implanted into a surrogate mother cow, and developed to term. A similar experiment recently yielded cloned transgenic goats expressing a gene encoding recombinant human antithrombin in their mammary glands.

If differentiated human donor cells can be successfully induced into quiescence, and there is no reason to think that they cannot, "adult cloning" of human beings would be possible. Some of the less far-fetched reasons to do this that have been proposed include replacing a terminally ill child or providing the donor with a source of matched tissue for transplantation. Such proposals have further fueled the moral outrage that has led certain religious coalitions, environmental groups and bioethicists to oppose almost every aspect of biotechnology, from patenting genes and transgenic plants to cloning humans. Their concerns will probably not be alleviated by the recent report from the Oregon Regional Primate Center that two rhesus monkeys have been cloned. The stated goal of the research is to produce genetically identical rhesus monkeys for experimental use. The production of genetically identical animals should lead to fewer being needed for research purposes, to average out individual variations, and also to more accurate results.

Following a report by the National Bioethics Advisory Committee that called cloning humans "morally unacceptable," President Clinton banned the use of federal funds for human cloning research, and called for a law that would ban human cloning but allow cloning of genes and animals that advance medicine and agriculture. In July 1997 the House Science Committee approved a bill to prohibit funding to produce cloned human embryos. While the Biotechnology Industry Organization (BIO) has opposed cloning humans, BIO opposed this bill. BIO realizes that bills intended to bar "somatic cell nuclear transfer" to produce a child could inadvertently ban cloning genes in microorganisms or research on processes involved in early human development.

In December 1997, Dr. Stuart Newman, the founder of the Council for Responsible Genetics, filed a patent application claiming, inter alia, human-animal chimeras. Dr. Newman, a cellular biologist at the Medical College of New York, stated that he would use any patent granted to block research of this type. The Patent Office recently rejected the claims as encompassing human beings. Dr. Newman has said he will appeal the ruling, in order to obtain a higher court decision that humans are not patentable.

While this bill did not become law, these legislative and administrative activities represent a fundamental shift in thinking concerning "patenting life." As late as the mid-70's, the primary concerns voiced by opponents of biotechnology were that no one should be allowed to patent "Godís handiwork" ñ that no one should be allowed to go into the jungle of nature and own the new organisms that were discovered there. Today, the opponents of biotechnology seem to be more worried about "manís handiwork" ñ the plants and animals and even the people which our inventors propose to create and to release into the wild.

© 1999 by Warren D. Woessner, Schwegman, Lundberg & Woessner, P.A. This article represents personal opinions of the author, not his employer. It is intended to be a survey of the area, and should not be construed as legal advice for any particular application or circumstance.