United States: Recent Patent Appeals Court Ruling Clarifies Requirements for Product-by-Process Claims

A recent decision from the U.S. Court of Appeals for the Federal Circuit (CAFC) provides a reminder that the product that is the subject of a "product-by-process" claim must be novel.

A product-by-process claim seeks to protect the product of the process recited in the claim. In U.S. patent practice, product-by-process claims have traditionally been useful when a novel product is difficult to describe in words, or its structure is insufficiently understood, but a process for consistently producing the novel product is known. For example, an inventor may use a product-by-process format to claim a novel, hard-to-describe macromolecule that is consistently produced by the process recited in the claim. Similarly, product-by-process claims may be useful when the novel product is a complex mixture of components that is consistently produced by the process recited in the claim.

It is well-established that the subject matter of product-by-process claims is the product being claimed. For example, the Manual of Patent Examining Procedure (MPEP) of the U.S. Patent and Trademark Office teaches that "even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself" and if "the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." MPEP §2113, quoting In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). Despite the fact that the claim may recite only process limitations, it is the patentability of the product claimed, and not the recited process steps, that must be established. MPEP §2113, citing In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972).

The U.S. Court of Appeals for the Federal Circuit (CAFC) recently considered whether product-by-process claims for a product made by a novel process were valid in light of a prior published disclosure of what was apparently the same product. Affirming a district court decision, the CAFC held that "once a product is fully disclosed in the art, future claims to that same product are precluded, even if that product is claimed as made by a new process." (SmithKline Beecham Corp. v. Apotex Corp., Fed. Cir., No. 04-1522, decided February 24, 2006).

The dispute concerned the compound paroxetine, also known by the trade name Paxil®, which is widely used as an antidepressant. SmithKline Beecham Corporation and SmithKline Beecham, P.L.C. (collectively "SmithKline") brought suit against Apotex Corporation, Apotex Inc., and Torpharm, Inc., (collectively "Apotex") for infringement of U.S. Patent No. 6,113,944 (the "‘944 patent"). Apotex argued that the ‘944 patent was invalid. The district court (E.D. Pa.) granted summary judgment to Apotex, holding that the claims of the ‘944 patent were invalid by reason of anticipation by the disclosure in an earlier patent. The CAFC affirmed the district court decision.

SmithKline’s U.S. Patent No. 4,721,723 (the "‘723 patent") disclosed, inter alia, a pharmaceutical composition in tablet form containing paroxetine, and various paroxetine dosages. (‘723 patent, Col. 5, lines 53-61). SmithKline’s ‘944 patent disclosed, inter alia, paroxetine formulated into tablets using a novel formulation process. The specification of the ‘944 patent disclosed that paroxetine tablets "often develop a pink hue which is highly undesirable" and that all tablets sold to date were formulated using an aqueous granulation process, whereas paroxetine formulated into a tablet using a process in which water is absent, is much less likely to develop a pink hue. (‘944 patent, Col. 1, lines 35-48). The ‘944 patent had two claims, both written in product-by-process format. Claim 1 recited "[a] pharmaceutical composition in tablet form containing paroxetine produced on a commercial scale by a process which comprises the steps of" a dry admixing and compressing process recited in the claim. Claim 2, depending from Claim 1, recited specific amounts of paroxetine in the tablets, and the use of a single punch or rotary tablet machine.

When Apotex, a generic drug maker, began seeking approval to market a generic version of Paxil® (paroxetine), Apotex submitted an Abbreviated New Drug Application (ANDA) to the FDA, including a "paragraph IV certification" stating that the ‘944 patent was invalid. SmithKline brought suit against Apotex under 35 U.S.C. §271(e)(2), which makes submitting an ANDA an act of infringement, alleging infringement of the ‘944 patent by Apotex. Apotex counterclaimed that the ‘944 patent was invalid. During the suit, Apotex moved for summary judgment of invalidity of the ‘944 patent.

The district court noted an apparent conflict between the CAFC decisions in Scripps Clinic & Research Foundation v. Genentech, Inc., 927 F.2d 1565 (Fed. Cir. 1991), which the district court viewed as holding that process steps were not claim limitations, and Atlantic Thermoplastics Co., Inc. v. Faytex Corp., 970 F.2d 834 (Fed. Cir. 1992), which the district court interpreted as finding that process steps were claim limitations (emphasis added). The district court concluded that it was bound to follow the earlier Scripps decision, and found that Scripps required it to evaluate the validity of the ‘944 patent’s claims by reference to the claimed products, without considering the process limitations of the claims. The district court held that, because the ‘723 patent disclosed tablets containing paroxetine, including in the dosages specified in Claim 2 of the ‘944 patent, the ‘723 patent anticipated the claims of the ‘944 patent.

Although SmithKline argued that the paroxetine tablets claimed by the ‘944 patent were different from the tablets claimed in the ‘723 patent, i.e., the contents had a different hue and structure, the district court held that these different characteristics were not required by the ‘944 patent claims and were therefore insufficient to distinguish the product of the ‘944 patent from the products in the ‘723 patent. The district court granted summary judgment to Apotex, holding that the ‘944 patent was invalid by reason of anticipation. SmithKline appealed to the CAFC.

On appeal, SmithKline argued that the district court improperly ignored the process limitations of the product-by-process claims in the ‘944 patent. If the district court had treated the process steps as claim limitations, SmithKline asserted, the court would have found that the ‘723 patent did not anticipate the ‘944 patent (or would have found that there was a genuine issue of fact, thereby precluding summary judgment).

In affirming the decision below, the CAFC took the position that SmithKline "misunderstands the nature of anticipation." The CAFC rejected arguments regarding the scope of claim construction and instead focused on the subject matter of the disputed claims, stating: "Regardless of how broadly or narrowly one construes a product-by-process claim, it is clear that such claims are always to a product, not a process." Thus, "the ultimate issue is simply whether the prior art disclosure of a product precludes a future claim to that same product when it is made by an allegedly novel process" and "[a]nticipation by an earlier product disclosure cannot be avoided by claiming the same product more narrowly, that is, by claiming the product as produced by a particular process."

While acknowledging that some commentators have identified a conflict between the decisions in Scripps and Atlantic Thermoplastics, the CAFC stated that it did not need to address this controversy. The court explained: "The issue here does not turn on how broadly or narrowly we construe the ‘944 patent’s claims, for it is undisputed that the product that is the subject of the patent’s claims is paroxetine" and "the ‘723 patent broadly claimed paroxetine without regard to the process by which it was made."

The court observed that this rule was not new. Citing decisions it previously had made, and those of its predecessor court (C.C.P.A.), and the U.S. Supreme Court stretching back to 1884 (Cochrane v. Badische Anilin & Soda Fabrik, 111 U.S. 203 (1884)), the CAFC concluded that the claims of the ‘944 patent, directed to a product described as "[a] pharmaceutical composition in tablet form containing paroxetine" were invalid for anticipation because the product had been disclosed in the ‘723 patent.

SmithKline also sought to raise a second issue. The CAFC observed, however, that SmithKline's opening appellate brief merely "alluded" to the argument that the paroxetine tablets claimed in the '944 patent were different, and that SmithKline "expressed its disagreement" with the district court’s determination that the product claimed in the ‘944 patent was not new. The CAFC held that the argument had not been preserved or developed on appeal.

In a spirited dissent, Judge Newman argued that district court erroneously based its finding on "a claim construction that erased critical limitations of the claim." According to the dissent, the invention described in the ‘944 patent is the production of a stabilized paroxetine tablet by a process that reduces or eliminates the formation of a pink impurity, and these differences distinguish the invention from the prior art because, "[w]hen product and process limitation appear in the same claim it is generally because these limitations serve to define and distinguish the invention." Judge Newman interpreted ‘anticipation’ as meaning that "the invention was previously known to the public; that is, that is previously existed in the precise form in which it is claimed, including all of the limitations in the claim." (Emphasis in the original) Using this definition, she concluded that the district court and the CAFC majority erred in finding that the claims of the ‘944 patent were anticipated by the ‘723 patent.

In light of the holding and dicta in this case, a claim drafter should consider whether a product-by-process claim is appropriate and if so, how properly to draft the product-by-process claim.

1. If a product made by a claimed process has novel properties as a result of using the process, then recite at least one novel property of the product in the claim. In the case discussed above, the CAFC held that the product that was the subject of the ‘944 patent’s claims was paroxetine, and the ‘723 patent had disclosed and claimed paroxetine without regard to the process by which it was made. Thus, when similar products are known, a claim drafter should recite at least one novel feature of the product in any product-by-process claim. By pointing out at least one novel feature, the product can more easily be distinguished from similar products.
2. Make sure the subject matter of the claim is properly defined. As the CAFC stated, "[r]egardless of how broadly or narrowly one construes a product-by-process claim, it is clear that such claims are always to a product, not a process." By defining the subject matter of the claim properly, the claim drafter can influence the scope of claim construction that may be used. Carefully defining the subject matter of the product-by-process claim may allow the claim drafter to point out at least one novel feature of the product.
3. Consider whether product-by-process claims are available. In some cases, a novel method or process may produce a product that is identical to a known product made by a different method or process. The novel method or process may have advantages such as increased efficiency, higher yield, lower energy consumption, different starting materials, fewer unwanted byproducts, etc. However, if the product is not novel, then the claim drafter should probably avoid product-by-process claims.
4. Remember that there may still be a place for product-by-process claims. If a novel product is difficult to describe in words, then product-by-process claims may still provide an acceptable way to claim the novel product. Product-by-process claims have become less common where advances in technology have enabled more precise description of novel products, e.g., where advances in rapid, affordable sequencing or chromatographic analysis provide unambiguous descriptions of products. However, when a novel product cannot be precisely or completely described, a product-byprocess claim remains a useful way to claim an invention.
5. Consult a qualified patent professional to determine the current practice in each national and regional patent office of interest. Laws, regulations, and practices governing the scope of patent rights available from various national and regional patent organizations differ, and are always changing. The foregoing discussion concerns U.S. patent practice. It is always advisable to consult with a qualified patent professional knowledgeable about current product-by-process claim practices in the relevant countries or regions.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.