Nov. 12, 2002
| Patent protection for genes and proteins is crucial for biotech companies to justify the R&D and commercialization costs associated with genomic discoveries. Patents also continue to be a fundamental asset in corporate partnering transactions and for obtaining financing. But stricter patentability requirements that disproportionately affect genomic inventions have made maximizing the business value of those inventions more challenging.
Genomic inventions by nature tend to be composition-specific — i.e., based on the nucleic acid sequence of the gene and/or the amino acid sequence of the expressed protein. However, changes now in force for the examination guidelines for patents have made it more difficult to broaden patent protection beyond the sequence itself. Also, stricter requirements for proving utility make it harder to obtain patent protection for a gene sequence if its function is unknown.
In January 2001, the U.S. Patent and Trademark Office (PTO) issued final guidelines for examination of two important requirements that must be satisfied under the U.S. Patent Law in order to obtain a patent on a DNA sequence:
1. a written description of the sequence
2. the utility of the sequence.
Although the guidelines are intended to apply to all technologies, they were revised primarily to address the patentability of nucleic acid sequences, including expressed sequence tags (ESTs), single nucleotide polymorphisms (SNPs), and genes. Here's a brief overview of the new guidelines and their impact on obtaining patents covering genomic inventions.
The requirement for a written description is based on a contract between the inventor and the public, in which each provides consideration for the value that each derives from the contract. The inventor obtains a limited monopoly to exploit the invention (i.e., the patent), in return for which the public receives full and complete disclosure of a useful invention and unrestricted use of the invention at the end of the patent term (20 years from the date of filing).
The new guidelines state that to satisfy the written description requirement, a patent specification must describe the claimed invention in sufficient detail such that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention. A patent applicant proves "possession" by describing the claimed invention in such detail as to enable one skilled in the art to use the invention. Thus, the scope of the patent claim dictates how extensive the written description must be.
|The Raised Bar
|The U.S. Patent and Trademark Office's new guidelines for gene patents mean tougher standards for proving possession and usefulness.
Do prove possession by meeting the written description requirement for a gene or other nucleic acid sequence. You must disclose the sequence itself, or its functional characteristics together with a known correlation between function and structure.
Don't settle for disclosing a method of isolating a gene and its function. This isn't sufficient to support a claim to the gene itself. Disclosing a partial structure without additional characterization is likewise insufficient to show possession.
Do prove specific and substantial utility by disclosing a credible and current real-world use for a DNA sequence; for example, as a diagnostic marker for disease.
Don't assert utility based on speculation, however probable. For example, claiming utility for a cDNA sequence as a "probe for obtaining the full-length gene," which then can be used to make the protein, the function of which can then be determined, is neither specific nor substantial enough. It could apply to any member of the class of partial DNAs, and it's not specific to the sequence being claimed. Likewise, it's insubstantial because it would require further research to identify and confirm any real-world use for the protein.
The guidelines emphasize that for emerging and unpredictable technologies, such as genomics, a higher degree of evidence is required to show possession. Thus, disclosing a method of making the invention and its function — a method of isolating a gene and its function, for example — is not sufficient to support a claim to the gene itself. Furthermore, disclosure of a partial structure (an EST) without additional characterization is not sufficient to show possession of the entire structure (the gene).
For a gene or other nucleic acid sequence to meet the description requirement, the applicant must disclose either the sequence itself or its functional characteristics together with a known correlation between the function and the structure.
Like the requirement for written descriptions, the requirement to prove utility is rooted in the patent contract, in which the inventor receives a limited monopoly on his or her invention in exchange for disclosing a useful invention to the public. Utility is a critical component of a patent, and an inventor cannot obtain a patent without proof that the invention is useful.
Usefulness can be a subjective matter, however, and the courts have struggled with attempts to define objective standards by which "utility" can be determined by the PTO. Partly in response to the rapid development of biotechnology inventions, the PTO established guidelines to decide the utility of an invention.
A core requirement is that the claimed invention must have either a "well-established" utility, or the applicant must provide an assertion of a "specific and substantial" utility that's credible. Speculative or potential utility that doesn't have real-world value and doesn't provide a currently available specific benefit to the public fails to meet the requirements under patent law.
An invention has a well-established utility under the guidelines if a person of ordinary skill in the art would immediately appreciate why the invention is useful based on the characteristics of the invention. Alternatively, the utility requirement may be satisfied if an assertion that the invention is useful for a particular, practical purpose would be considered credible by a person of ordinary skill in the art.
The guidelines provide some specific guidance regarding the utility requirements for nucleic acid sequences. For instance, in a negative example, a claimed cDNA sequence has an asserted utility as a "probe for obtaining the full-length gene," which then can be used to make the protein, the function of which can then be determined. This utility fails the "specific and substantial" standards: It's not specific because it's applicable to any member of the of partial DNAs, and it's not specific to the sequence being claimed. It's not substantial because further research would be needed to identify and confirm any real-world use for the protein.
The best way to satisfy the utility requirement for a DNA sequence is to disclose a credible and current real-world use — for example, as a diagnostic marker for disease.
Protect First, Disclose Second
In light of the stricter requirements for patentability, merely filing numerous patent applications on sequences as they are discovered and/or identified is not a viable patent strategy for a genomics company. Patent strategy should first and foremost be aligned with business strategy. A few patents covering a gene that has been validated as a druggable target are likely to be of greater economic value to a company than hundreds of patents covering sequences of questionable utility.
One patent strategy that has gained popularity over the past few years involves making claims on the basis of gene function rather than gene composition. For example, claims would be made to a method for inhibiting gene function instead of to the gene itself. This strategy might be useful when the sequence has been divulged without the gene function being known. These types of claims must comply with the guidelines discussed above, however, and have yet to be tested in the courts.
A basic tenet of patent strategy that remains crucial to biotechnology companies is to file for patent protection prior to public disclosure of any discovery. This is the only way to assure an exclusionary position for the patent holder worldwide. (The United States is the only country that grants a 12-month grace period of patentability from time of published specifications; no other country provides such a grace period.)
There are several well-tested methods for obtaining patent protection while keeping patent costs reasonable, including the use of templates and provisional applications. The thing to remember is that the greatest cost is often the loss of valuable proprietary rights because you failed to file a patent application prior to publicly disclosing the invention.
Paula Campbell Evans is co-chair of the Patent Practice Group at Palmer & Dodge LLP in Boston. She may be reached at firstname.lastname@example.org.