By Kevin E. Noonan --
The Federal Circuit last week clarified two frequently-disputed areas of patent prosecution: how to claim progeny of inventions that inherently self-replicate, and how to appropriately fulfill both the written description and enablement requirements of 35 U.S.C. § 112, first paragraph, and at the same time disclose broadly enough to support claims of appropriate breadth.
Monsanto Co. and its wholly-owned subsidiary, DeKalb Genetics Corp., sued Syngenta Seed Co. for infringing patents relating to transgenic corn seed, specifically corn resistant to Monsanto's RoundUp®-brand insecticide (glyphosate) by expressing Agrobacterium 5-enolpyruvoyl-shikimate-3- phosphate synthetase (EPSPS). The patents at issue were U.S. Patent No. 4,940,835, claiming a chimeric plant gene that confers glyphosate resistance; U.S. Patent No. 5,538,880, claiming methods for producing herbicide-resistant and insect-resistant corn (Zea mays) plants; and U.S. Patent No. 6,013,863, claiming methods for producing glyphosate-resistant transgenic corn using a screenable marker gene. The alleged infringing acts were producing transgenic corn using seed harvested from transgenic corn obtained from Monsanto under a license that precluded 
harvesting seed for replanting (said licenses were to Monsanto licensee companies acquired by Syngenta, at least some of whom were named as defendants).
Claim 1 of the '835 patent reads:
1. A chimeric plant gene which comprises:
(a) a promoter sequence which functions in plant cells;
(b) a coding sequence which causes the production of RNA, encoding a chloroplast transit peptide/5-enolpyruvylshikimate-3- phosphate synthase fusion polypeptide, which chloroplast transit peptide permits the fusion polypeptide to be imported into a chloroplast of a plant cell; and
(c) a 3' non-translated region which encodes a polyadenylation signal which functions in plant cells to cause the addition of polyadenylate nucleotides to the 3' end of the RNA;
the promoter being heterologous with respect to the coding sequence and adapted to cause sufficient expression of the fusion polypeptide to enhance the glyphosate resistance of a plant cell transformed with the gene.
Claim 4 of the '880 patent reads:
4. A process comprising obtaining progeny from a fertile transgenic plant obtained by the process of claim 1 which comprise said DNA.
Claim 5 of the '863 patent reads:
5. The process of claim 1 further comprising obtaining transgenic glyphosate resistant progeny plants of subsequent generations from said fertile transgenic plant.
The District Court granted summary judgment to Syngenta on invalidity of the '835 patent and non-infringement of the '880 and '863 patents. The District Court found the '835 invalid for failing to satisfy the enablement requirement, because the asserted claims encompassed all plant cells, and while the patent enabled genetic transformation of dicotyledonous plants it was filed prior to the time that methods were known in the art for genetically-transforming monocots. The patent specification not providing methods for transforming monocots, while the claims encompassed monocots, rendered the specification non-enabling throughout the scope of the asserted claims.
With regard to infringement, the District Court found that the asserted claims of the '880 and '863 patents required not merely the step of obtaining transgenic progeny but also the process of producing the transgenic plant in the first place, based on the dependent-claim structure of the asserted claims of these patents. It was undisputed that DeKalb had produced the transgenic plants initially and had thus performed these steps recited by the claims. In addition, the District Court found that Syngenta had lawfully obtained the disputed seed through acquisition of the named defendant subsidiaries, and that part of that right included the right to further produce progeny transgenic plants comprising the resistance gene.
The Federal Circuit unanimously affirmed in an opinion by Judge Rader. The CAFC rejected both of Monsanto's theories of infringement: first, that claim 4 of the '880 patent was an independent claim and did not require performance of the steps recited in earlier claims; or second, that performance of the transgenic plant production steps by DeKalb did not preclude a finding of Syngenta's infringement by performing the ultimate step of obtaining the progeny transgenic plants. Regarding Monsanto's first theory, the Federal Circuit stated that claim 4 of the '880 patent and claim 5 of the '863 patent were cast in the conventional form of dependent claims. This is not sufficient, according to the Federal Circuit, and the CAFC analyzed these claims with regard to whether they not only referenced at least one earlier claim but further limited the referent claim (pursuant to 35 U.S.C. § 112, fourth paragraph). In this analysis, the Federal Circuit held that claim 4 fulfilled the statutory requirements of a dependent claim, and further stated that while Monsanto could have presented claim 4 as merely requiring the product of process claim 1 as a starting material, it had not. The prosecution history supported this interpretation, as the claim as originally presented was "unquestionably" a dependent claim, and the patentees had asserted that amendments made to cast the claim into the form that issued as claim 4 were "directed to matters of form not affecting the scope of the invention" and did not introduce new matter. The Federal Circuit also rejected Monsanto's contention, made during oral argument, that claim 1 was a product-by-process claim and thus merely provided a starting material for the process of claim 4.
Having affirmed the District Court's determination that claims 4 (of the '880 patent) and 5 (of the '863 patent) were dependent claims, the Federal Circuit held that Syngenta's performance merely of the ultimate step of the properly-construed process claim was not infringement as a matter of law. The principle is simple: although an independent claim may be infringed while its dependent claim is not, the converse is not true. Wahpeton Canvas Co., Inc. v. Frontier, Inc., 870 F.2d 1546, 1552 (Fed. Cir. 1989). Here, it was undisputed that the steps comprising the independent claims of both asserted patents were performed not by the accused infringer Syngenta, but by Monsanto or DeKalb. Thus, since Syngenta did not infringe these independent claims, it could not infringe the asserted dependent claims. Moreover, the steps of the corresponding independent claims were practiced by Monsanto or DeKalb prior to grant of either of the asserted patents. Accordingly, this activity did not support Monsanto's infringement claims (made under both § 271(a) and § 271(g)).
Turning to the District Court's invalidity decision, the Federal Circuit focused, as had the District Court, on the term "plant cells" in claim 1 of the '835 patent. The CAFC adopted the lower court's construction of this term to include both monocots and dicots as "plant cells." Analogizing to the factual circumstances of In re Vaeck, the Federal Circuit agreed with the District Court that there was no basis in the patent specification to limit the term "plant cells" and thus both monocots and dicots properly fell within the scope of the claims. Unfortunately for Monsanto, however, it was undisputed that genetic transformation of monocotyledonous plants was not known in the art, nor disclosed in the patent specification, at the '835 patent's filing date. Thus, the practice of the invention claimed in the '835 patent throughout its entire scope, as required by the statute, would require undue experimentation. The Federal Circuit affirmed this conclusion despite the fact that the claims in dispute were not directed to plant cells per se, but to chimeric genes and constructs comprising them. The CAFC stated that this distinction was not dispositive, since the capacity to be expressed in "plant cells" was a required feature of the claimed chimeric genes.
What lessons can the biotechnology patent practitioner take from this decision? First, it is evident that extreme caution should accompany claim drafting dependent on process steps, even should those process steps be necessary to overcome prior art or to fulfill the requirements of § 112. As noted by the Federal Circuit, the outcome might have been different had claim 4 of the '880 patent recited a claim such as: "A process comprising obtaining progeny from a fertile transgenic plant comprising a chimeric gene encoding a chloroplast transit peptide/5-enolpyruvylshikimate-3-phosphate synthase fusion polypeptide expressed at a level sufficient to increase the plant's resistance to glyphosate," or even better, "Progeny of a fertile transgenic plant comprising a chimeric gene encoding a chloroplast transit peptide/5-enolpyruvylshikimate-3- phosphate synthase fusion polypeptide expressed at a level sufficient to increase the plant's resistance to glyphosate." Either of these claims would be free of any process steps that could raise issues with regard to performance of any steps other than the steps Syngenta certainly performed in this case, i.e., producing progeny of Monsanto's transgenic plants.
Second, attempts made during claim drafting to accommodate the Federal Circuit's focus on the written description requirement over the past decade, coupled with the desire to provide a sufficiently broad disclosure to encompass the broadest scope of the invention, must be balanced by a consideration of whether such scope is enabled either explicitly in the specification or by the skill of one having ordinary skill in the art. In the Monsanto case the issue was one of technique: monocots could not be genetically transformed, so claims not limited to dicots could not be enabled. It is foreseeable that in other instances unknown reagents or genes could be implicated, particularly for unrecognized members of known multigene families. In any event, it behooves patent claim drafters to consider carefully the relationship between what is described and what is enabled to avoid the outcome suffered by Monsanto.
Monsanto Co. v. Syngenta Seeds, Inc. (Fed. Cir. 2007)
Panel: Circuit Judges Rader and Gajarsa and District Judge O'Malley
Opinion by Circuit Judge RaderAdditional information regarding this case can be found at Patently-O.
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