In Falker-Gunter Falkner et al. v. Inglis et al. (Fed. Cir. 2006, 05-1324), on appeal from the USPTO Board of Patent Appeals and Interferences, the U.S. Court of Appeals for the Federal Circuit set out some guidelines on the adequacy of written description and enablement in biotech cases. The Federal Circuit held that:
(1) examples are not necessary to support the adequacy of a written description;
(2) the written description standard may be met (as it is here) even where actual reduction to practice of an invention is absent; and
(3) there is no per se rule that an adequate written description of an invention that involves a biological macromolecule must contain a recitation of known structure.
There was an interference between U.S. Patent No. 5,770,212 (“the Falkner ‘212 patent) and Inglis et al., U.S. Application Serial No. 08/459,040 (“the Inglis ‘040 application”) and the Board held that Falkner could not antedate Inglis’ priority date.
Claim 29 of the Inglis ‘040 application reads:
A vaccine comprising a pharmaceutically acceptable excipient and an effective immunizing amount of a mutant virus, wherein said mutant virus is a mutant poxvirus and has a genome which has an inactivating mutation in a viral gene, said viral gene being essential for the production of infectious new virus particles, wherein said mutant virus is able to cause production of infectious new virus particles in a complementing host cell gene expressing a gene which complements said essential viral gene, but is unable to cause production of infectious new virus particles when said mutant virus infects a host cell other than a complementing host cell; for prophylactic or therapeutic use in generating an immune response in a subject.
Claim 1 of the Falkner ‘212 patent reads:
A vaccine comprising (a) a defective poxvirus that lacks a function imparted by an essential region of its parental poxvirus, wherein (i) said defective poxvirus comprises a DNA polynucleotide encoding an antigen and said DNA polynucleotide is under transcriptional control of a promoter, and (ii) the function can be complemented by a complementing source; and (b) a pharmaceutically acceptable carrier.
The inventors discovered a way of making vaccines safer by deleting or inactivating an essential, rather than an inessential, gene from the viral vector’s genome, while at the same time solving the production problem by growing the vaccines in cells that were complementarily modified to produce the absent essential viral gene product “on behalf of” the vector virus. Thus, the modified vector virus could be readily grown in these complementarily-modified cells, but not in other cells, such as those of an inoculee.
Falkner argued that the claims in Inglis’s ‘040 application were unpatentable because they failed to meet the written description requirement of 35 U.S.C. § 112 because (1) the specification did not identify any essential genes in poxvirus or describe the inactivation of such genes, (2) vaccines based on vaccinia (a type of poxvirus) had not yet been produced, and (3) the bulk of the Inglis specification was directed not to poxviruses but to herpesviruses. Falkner also argued that Inglis did not sufficiently describe and enable the claims in question and that without the benefit of these applications, Inglis would be unable to establish constructive reduction to practice earlier than Falkner.
The Federal Circuit laid out the requirements for enablement and written description as follows:
1. Examples Are Not Required
A claim will not be invalidated on section 112 grounds simply because the embodiments of the specification do not contain examples explicitly covering the full scope of the claim language. That is because the patent specification is written for a person of skill in the art, and such a person comes to the patent with the knowledge of what has come before. Placed in that context, it is unnecessary to spell out every detail of the invention in the specification; only enough must be included to convince a person of skill in the art that the inventor possessed the invention and to enable such a person to make and use the invention without undue experimentation.
2. Actual Reduction to Practice Is Not Required
As we explained in Capon v. Eshhar, “[t]he ‘written description’ requirement implements the principle that a patent must describe the technology that is sought to be patented; the requirement serves both to satisfy the inventor’s obligation to disclose the technologic knowledge upon which the patent is based, and to demonstrate that the patentee was in possession of the invention that is claimed.” 418 F.3d 1349, 1357 (Fed. Cir. 2005). The Board was correct, however, not to view as dispositive that Inglis had not actually produced a poxvirus vaccine, because an actual reduction to practice is not required for written description. See Univ. of Rochester v. G.D. Searle & Co., 358 F.3d 916, 926 (Fed. Cir. 2004) (“We of course do not mean to suggest that the written description requirement can be satisfied only by providing a description of an actual reduction to practice. Constructive reduction to practice is an established method of disclosure . . . .”). Rochester, moreover, is consistent with Supreme Court precedent. In the context of interpreting 35 U.S.C. § 102(b), the Court held that “[t]he word ‘invention’ must refer to a concept that is complete, rather than merely one that is ‘substantially complete.’” Pfaff v. Wells Elecs., 525 U.S. 55, 66 (1998). It then proceeded to make clear that although “reduction to practice ordinarily provides the best evidence that an invention is complete. . . . it does not follow that proof of reduction to practice is necessary in every case.” Id. (emphasis added). Thus, to the extent that written description requires a showing of “possession of the invention,” Capon, 418 F.3d at 1357 (emphasis added), Pfaff makes clear that an invention can be “complete” even where an actual reduction to practice is absent. The logical predicate of “possession” is, of course, “completeness.”
3. Recitation of Known Structure Is Not Required
The descriptive text needed to meet these requirements varies with the nature and scope of the invention at issue, and with the scientific and technologic knowledge already in existence. The law must be applied to each invention that enters the patent process, for each patented advance is novel in relation to the state of the science. Since the law is applied to each invention in view of the state of relevant knowledge, its application will vary with differences in the state of knowledge in the field and differences in the predictability of the science.
Indeed, a requirement that patentees recite known DNA structures, if one existed, would serve no goal of the written description requirement. It would neither enforce the quid pro quo between the patentee and the public by forcing the disclosure of new information, nor would it be necessary to demonstrate to a person of ordinary skill in the art that the patentee was in possession of the claimed invention. As we stated in Capon, “[t]he ‘written description’ requirement states that the patentee must describe the invention; it does not state that every invention must be described in the same way. As each field evolves, the balance also evolves between what is known and what is added by each inventive contribution.” Id. at 1358. Indeed, the forced recitation of known sequences in patent disclosures would only add unnecessary bulk to the specification. Accordingly we hold that where, as in this case, accessible literature sources clearly provided, as of the relevant date, genes and their nucleotide sequences (here “essential genes”), satisfaction of the written description requirement does not require either the recitation or incorporation by reference14 (where permitted) of such genes and sequences.