The limited benefit of “product-by-process” claim

ABSTRACT

A product-by-process claim was initially developed when the invention could not otherwise be adequately defined. In the US, a patent applicant can use a product-by-process claim for a new product, no matter whether the product can also be defined by using structure features. However, the applicant mainly bears the burden to establish the novelty between the claimed product and the prior art product. Moreover, in terms of infringement, the very recent CAFC cases indicate that the product must be made by a process recited in the claim to infringe a product-by-process claim. Thus, an assignee almost can not take advantage from product-by-process claims during the patent enforcement by comparing with process claims. From the points of the burden during patent prosecution and confined scope in determining infringement, the benefit of using a product-by-process claim would be very limited.

KEYWORDS:

• claim
• development
• infringement
• patent
• patentability
• product-by-process
• viral

By statute, a patent claim shall particularly point out and distinctly claim the invention applied. Indeed, claims, reciting the structure or acts of an invention, serve as tools to determine whether the invention is patentable or infringed.¹ The most common type of claims usually include a preamble, indicating the statutory class and defining the thing claimed, a transitional word, such as comprising or consisting of, and a body, listing the elements of the invention and defining how they are related to each other to make the invention work.²

Other types of claims are developed in response to the need of patent applications. For example, a Markush expression is frequently used in chemical related inventions to claim a genus expressed as a group consisting of certain specific materials.² A product-by-process claim is utilized to claim a product defined by the process to make it.³ However, the very recent cases of the US Court of Appeals for the Federal Circuit (CAFC) would increase the burden during patent prosecution and limit scope in determining infringement. It may be the time to think about the benefit of using product-by-process independent claims.

What is a product-by-process claim?

A product-by-process claim, reciting the process for fabricating the article or its element, was initially developed only when the invention could not otherwise be adequately defined.^4-5 Later, a product-by-process claim has become allowable even though the product could be defined by using structure features. However, European Patent Office does not allow the flexibility in claim drafting. The European Boards of Patent Appeal indicated that a product-by-process was admissible only if the product itself fulfilled the requirements for patentability and there was no other information available in the application which could have enabled the applicant to define the product satisfactorily by reference to its composition, structure or some other testable parameter.^6-7

The typical claim would include the words such as “according to the process of,²” “obtainable by,⁸” “produced by,⁹” “purified from,¹⁰” “the product of the process comprising the steps of,¹⁰” “prepared in accordance with the method of¹¹” or “by a process which comprises the steps of.¹²”

The patentability of a product-by-process claim

The US Manual of Patent Examining Procedure (MPEP) clearly indicates that the patentability of a product-by-process claim depends on the product but not on the method of production.¹³ The CAFC further mentioned that “an old product is not patentable even if it is made by a new process.”¹⁰ In other words, when the product in the product-by-process claim is the same as or obvious from a prior product, the claim is unpatentable even through the process of the production is new and non-obvious over the prior arts.

The MPEP further stresses that once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, the burden shifts to applicant to come forward with evidence establishing an unobvious difference between the claimed product and the prior art product.

For example, the human nerve growth factor (b-NGF) produced by genetic engineering techniques is almost the same as that isolated from human placental tissue. Using product-by-process to claim engineering b-NGF thus was rejected by the patent examiner. Following, the US Patent Appeal Board further affirmed the rejection and stated that the applicant should have made comparison to establish unexpected properties since the materials appeared to be identical or only slightly different.¹⁴

On the other hand, a product claim of erythropoietin (EPO) using recombinant DNA technology was also challenged to be anticipated by old EPO isolated from human urine. However, the patent specification indicated that recombinant EPO had a higher molecular weight and different charge than urinary EPO due to differences in carbohydrate composition. Therefore, CAFC affirmed the district court's ruling that recombinant EPO is not anticipated by the urine EPO.¹⁰

Moreover, if the examiner can demonstrate that the process as claimed can be used to make another materially different product or the product claimed can be made by another materially different process, such a process of making and a product made by the process are 2 distinct inventions.¹⁵ Then, the patent examiner will require the applicant to restrict the product from the process in that distinct inventions cannot be claimed in one application.

In sum, a product-by-process claim would only claim a new product. If the product is not new, the new process certainly cannot make a product-by-process claim allowed by patent examiner and held to be valid in the courts. To support a product-by-process claim, a patent application should distinguish the new product with other prior products. Furthermore, a process of making and a product made by the process would be reviewed as 2 distinct inventions and subjected to restriction.

The infringement of a product-by-process claim

A product-by-process claim recites the process for fabricating the article or its element. As discussed above, the process does not play any role in the determination of patentability. However, a product-by-process claim is construed as a process claim for infringement and thus it is not infringed by products made by other processes.

In 2009, a majority of the CAFC full court's judges cited US Supreme Court rulings^16-18 and stressed that “each element contained in a patent claim is deemed material to defining the scope of the patented invention.” Thus, the decision of CAFC full court's judges indicated that when an inventor chose to claim the product in terms of its process, the process also governs the enforcement of the bounds of the patent right. In other words, a product-by-process claim is not infringed by a product made by a process other than the one recited in the claim. Another CAFC case ¹⁰ with 3-judge panel also adopted the process limitation to determine infringement for a product-by-process claim.

These CAFC cases, including a full court judges’ decision, clearly indicate that to infringe a product-by-process claim, the product must be made by a process recited in the claim. However, in most countries, a process claim certainly will cover the product made by the process.¹⁹ It would be clumsy to use a product-by-process claim.

A case study

The main role of immune system is to protect its host against pathogens, including viruses. On the other hand, viruses also develop various methods to evade their exposure to the immune system. A genomic analysis demonstrated that the immune evasion of human herpesviruses is phase-dependent.²⁰ Thus, identifying the infection phase of human herpesvirideae virus, may have a chance to early diagnose, treat or even prevent the infection.

An invention purified a nucleic acid sequence encoding a homolog of human interleukin 10 (IL-10) during the latent phase of infection by a herpesvirideae virus. Based on the sequence, the invention can provide polypepide, vector, recombinant host cell capable of expressing the polypepide and isolated ligand to bind the polypepide. Following, the invention can be used to identify a compound that modulates the activity of the polypeptide, to diagnose a disease state, to screen a subject for infection by a herpesvirideae virus and to develop a vaccine comprising the nucleic acid moleculeor, polypeptide or ligand together with a pharmaceutically acceptable carrier, adjuvant and diluent.

The patent assignee drafted 57 claims for the invention, including a product-by-process claim with words of “prepared in accordance with the method of.” The patent examiner classified these claims into 10groups, including a purified nucleic acid sequence, an isolated homolog of human IL-10 polypeptide, a ligand selectively binding to the polypeptide, a method of identifying a compound that interacts with the isolated homolog of the polypeptide, a method of screening a compound that modulates with the polypeptide, a method of diagnosing a disease state by assaying the expression of the polypeptide, a method of inducing an immune response, a method of treatment of a disease by the vaccine, a method of cleansing a biological sample of an infection by herpesvirideae virus and a diagnosis method of using a ligand to detect the peptide. Then, the examiner required that the assignee should restrict the claims in that these 10 groups are different inventions indeed.

To response the request, the assignee select the sequence group, including a purified nucleic acid sequence, a vector containing the sequence, a recombinant host cell comprising the sequence, a kit involving the nucleic acid and a method of screening infection based on the use of the nucleic acid. The product-by-process claim was cancelled during the election request.

Furthermore, it should be mentioned that “a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated.”²¹ Since the purified nucleic acid sequence would not have “markedly different characteristics from any found in nature,” the purified nucleic acid sequence claim would be determined as a product of nature and thus patent ineligible based on the flow chart for determining patent eligibility.²²

Conclusion

In 1990s, a product-by-process claim was considered as a type of biotechnological patent claims to obtain the broadest protection.⁵ However, today, the US patent examiner only allows a new product to be drafted in a product-by-process claim. Even for a new product, if the process can be used to make another different product, the process of making and the product made by the process would be reviewed as 2 distinct inventions and subject to restriction.

The very recent CAFC cases further indicate that to infringe a product-by-process claim, the product must be made by a process recited in the claim. Thus, in determination of patent infringement, the coverage of a product-by-process claim is indeed the same as that of a process claim.

In other words, when comparing with process claims, an assignee cannot benefit from product-by-process claims during the patent enforcement. Furthermore, the patent owner bears additional burden to demonstrate that the product claimed is new during patent prosecution. Therefore, the benefit of using a product-by-process claim would be very limited.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Funding

This work is supported in part by Taipei Veterans General Hospital (V103 C-208, V104 C-197) and Taiwan Ministry of Science and Technology (MOST 104-2221-R-075-001 and 104-2410-H-075-001)