Federal Circuit Clarifies The “Written Description” Requirement In Genetic Engineering Case
March 4, 2003
The U.S. Court of Appeals for the Federal Circuit recently issued a decision that modifies and clarifies previous case law regarding the Patent Act’s written description and enablement requirements, making it significantly easier to obtain patents on genetically engineered materials. Amgen, Inc. v. Hoechst Marion Roussel, Inc. and Transkaryotic Therapies, Inc., 314 F.3d 1313 (Fed. Cir. 2003).
The Enablement and Written Description Requirements
The enablement and written description requirements are found in 35 U.S.C. § 112, first paragraph, which states that the patent specification must contain “a written description of the invention, and of the manner and process of making and using it…[such] as to enable any person of ordinary skill in the art to which it pertains … to make and use the same … ” The enablement requirement is part of the fundamental trade-off struck by the Patent Act. In exchange for the grant of a patent, an inventor must teach those with ordinary skill in the art how to make and use the invention without “undue experimentation.” The specification does not need to teach what is already known in the art; the enablement is sufficient if it allows one of ordinary skill in the art to make the invention with only routine experimentation.
Similarly, the written description requirement is intended to define the invention with some specificity, to prevent a patentee from later expanding the scope of his patent. It requires the patentee must “recount his invention in such detail that his future claims can be determined to be encompassed within his original creation.” Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1561, 19 U.S.P.Q.2d 1111, 1115 (Fed. Cir. 1991).
In the context of biotechnology and pharmaceuticals, the leading case explaining the written description requirement is Regents of University of California v. Eli Lilly & Co., 119 F.3d 1559 (Fed. Cir. 1997). In that case, the Federal Circuit considered whether patent claims to recombinant production of human insulin met the written description requirement. The patent at issue in that case, U.S. Patent No. 4,652,525 (the ‘525 patent), contained claims to recombinant plasmids with cDNA coding for (1) rat insulin, (2) human insulin, (3) and vertebrate and mammalian insulin. The specification disclosed the cDNA sequences only for proinsulin (PI) and preproinsulin (PPI) rat insulin; it did not disclose the human, mammalian, and vertebrate cDNA sequences, but indicated that the disclosed method used to obtain the rat sequence could also be used to obtain the human sequence.
The Federal Circuit held that the claims for human, mammalian, and vertebrate cDNA sequence claims were invalid because the patent did not provide a written description to support those claims. The court explained that claims directed to genetic material required language that distinguished the claimed material from others: “[a] written description of an invention involving a chemical genus, like a description of a chemical species, ‘requires a precise definition, such as by structure, formula, [or] chemical name,’ of the claimed subject matter sufficient to distinguish it from other materials.” In other words, a patent claiming DNA required the precise definition of the DNA sequence itself. A mere recitation of its function or a reference to a potential method for isolating will does not suffice.
Recently, however, the Federal Circuit began to move away from this holding. After initially holding that a reference to specified biological material in a public depository was not a sufficient written description, the court on rehearing held that the written description requirement can be met by a functional description of claimed materials, if it is coupled with a known or disclosed correlation between function and structure. Enzo Biochem, Inc., v. Gen-Probe, Inc., 296 F.3d 1316, 63 U.S.P.Q.2d 1609 (Fed. Cir.2002). [See the June 2002 issue of Intellectual Property and Technology for a discussion of the Enzo Biochem decision (/id24660/publicationid2072/returnid31/).]
The Decision in Amgen
Against this backdrop, the Federal Circuit considered the issues of written description and enablement again in Amgen, Inc. v. Hoechst Marion Roussel, Inc. and Transkaryotic Therapies, Inc., 314 F.3d 1313 (Fed. Cir. 2003). In that case, Amgen alleged that Hoechst Marion Roussel, Inc. and Transkaryotic Therapies, Inc. (TKT) infringed various Amgen patents covering erythropoietin (EPO, a naturally occurring hormone that controls the formation of red blood cells in bone marrow), the process for producing EPO, and cells for producing EPO. TKT denied that it infringed the patents. It claimed that its process of producing EPO by inserting an ordinarily unexpressed endogenous (or “native”) EPO DNA in human cells to produce the EPO differed from the method described in Amgen’s patents, which, according to TKT, required a heterologous, or non-native, EPO-encoding sequence. TKT also argued that the patent claims at issue were invalid for failure to satisfy the written description and enablement requirements. The district court held that some of Amgen’s patents were valid and infringed, but that other patent claims had not been infringed, or, alternatively, that the claims were invalid for lack of a written description and enablement. Amgen, Inc. v. Hoechst Marion Roussel, Inc., 126 F. Supp. 2d 69, 57 U.S.P.Q.2d 1449 (D. Mass. 2001). Both Amgen and TKT then appealed.
First, the Federal Circuit held that Amgen’s patent claims – which covered EPO “purified from mammalian cells grown in culture” and “vertebrate cells . . . comprising non-human DNA sequences that control transcription of DNA encoding human erythropoietin – met the written description requirement. Relying on Eli Lilly, TKT argued that the references to “mammalian cells” and “vertebrate cells” were not a sufficient description. The Federal Circuit rejected this argument. It noted first that the patent specification described how the EPO was produced in two species of vertebrate or mammalian cells. Relying heavily on expert testimony from the trial court, the Federal Circuit found that the references in the claims to “mammalian” and “vertebrate” cells was sufficient to identify the cells for one of ordinary skill in the relevant art. The court distinguished Eli Lilly, because in that case those terms were used, and were not sufficient, to describe previously unknown DNA sequences.
The Federal Circuit also found that Amgen’s patent claims were enabled by the specification. TKT argued that the claims lacked enablement because the specification failed to describe how to produce EPO using human cells or endogenous human EPO DNA. Relying on established case law, the court held that the specification need teach only one mode of making and using a claimed composition. In this case, because the patent described a method of obtaining EPO from certain mammalian cells and also described purification techniques, and because the trial court had credited evidence that all mammalian cells produce and secrete hormones like EPO by means of the same fundamental processes, the Federal Circuit affirmed the trial court’s finding that an ordinarily skilled artisan could make the claimed cells without undue experimentation. Accordingly, it held that Amgen’s patent claims were enabled.
In summary, the U.S. Court of Appeals for the Federal Circuit, largely in response to the expert testimony and careful findings of fact by the District Court in this case, upheld broad claims challenged as failing to comply with the written description and lacking enablement. This case modifies and reinterprets the Court’s previous decision in Eli Lilly, and, following the trend initiated in Enzo II, greatly increases the ability to obtain and enforce patents in this challenging area of the law.
For more information, contact Rivka Monheit or Patrea Pabst, toll free, at 1-888-688-8500.