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Thermostable Glucoamylase – Feasible Way to Define a New Protein Patent and Subsequently Obtained Scope of Protection


Thermostable Glucoamylase – Feasible Way to Define a New Protein Patent and Subsequently Obtained Scope of Protection

Novo Nordisk vs. Longda Co. and Boli Co. – Feasible Way to Define a New Protein Patent and Subsequently Obtained Scope of Protection (Civil Judgments (2012) Jin Gao Min San Zhong Zi No.41 and 42 by the Tianjin High People’s Court on October 31, 2013)

With reference to new protein inventions, applicants always define biological sequences by the combination of homology and function, so as to obtain a broader scope of protection. However, considering that the association between the primary structure and the function of a protein is highly unpredictable, thus defined protein claim is always considered as not supported by the description and not conforming to Article 26.4 of the Chinese Patent Law. Therefore, discussions in this filed focuses on a proper manner to define a new protein patent and subsequently obtained protection scope. This is the first case for successful enforcement of biological patent in China, which clarifies a feasible definition of new protein patent, i.e. defining homology, origin (species), and function simultaneously. Furthermore, this case provides directions to judgment of future invalidation and infringement cases of new protein patents.

The patentee Novo Nordisk from Denmark possesses an invention patent titled “Thermostable Glucoamylase” with the patent number No. ZL98813338.5 (hereafter referred to as “the involved patent”). In 2001, Novo Nordisk sued Shandong Longda Bioproducts Co., Ltd. (hereafter referred to as “Longda Co.”) and Jiangsu Boli Bioproducts Co., Ltd. (hereafter as “Boli Co.”) for infringing its patent to the Tianjin Second Intermediate People’s Court.

In June of 2011, the above two alleged infringer companies filed a Request for Invalidation to the Patent Reexamination Board (PRB) to invalidate the involved patent, respectively. The patentee amended claims of the involved patent during the invalidation procedure.

Amended claim 6 reads as “an isolated enzyme with glucoamylase activity, which is at least 99% homologous with the full length sequence shown in SEQ ID NO: 7 and has a PI below 3.5 determined by isoelectrical focusing.” This is a typical technical solution defined by the combination of homology and function of a polypeptide. However, only two polypeptide, the one as shown in SEQ ID NO:7 and the one encoded by SEQ ID NO:34, are verified in the embodiments to have glucoamylase activity. Apart from this, there is no experimental data in the description related to the defined homologous polypeptides. Therefore, the PRB held that those skilled in the art cannot determine that all polypeptides defined by homology to specified sequence, e.g. polypeptides from different origins, will all have the alleged function and can achieve the objective of the present invention. In addition, there is no corresponding experimental data in the description. Therefore, the PRB concluded that technical solutions related to homology are not supported by the description.

The amended claim 10 further defines the enzyme as derived from a filamentous fungus of the genusTalaromyces, wherein the filamentous fungus is a strain of Talaromyces emersonii. The amended claim 11 further defines that the filamentous fungus is Talaromyces emersonii CBS 793.97. T. emersonii and Talaromyces emersonii CBS 793.97 obviously belong to the same species. The PRB held that an active gene with a specific function normally will only has one sequence in organisms of the same species, and its mutant sequences with very high homology will have the same function. Therefore, given that the glucoamylase activity of the enzyme derived fromTalaromyces emersonii CBS 793.97 is verified in the description, those skilled in the art can foresee that polypeptides derived from T. emersonii and having at least 99% sequence homology will have glucoamylase activity.

Therefore, the PRB concluded that claims 10 and 11 can be supported by the description.

In summary, the PRB issued the No.17956 Examination Decision of Request for Invalidation, announcing claim 6 (homology + function) as invalid, and maintaining claim 10 (homology + species of original strain + function) as valid.

The First Instant Court tried the corresponding infringement case based on the above valid claim 10. The patentee submitted an appraisal conclusion made by a judicial appraisal institute agreed by both parties, indicating that the accused infringing product has the same technical feature with claim 10 in aspects of protein sequence and isoelectric point. The patentee further submitted a search report made by the Patent Searching and Consulting Center of the SIPO, indicating that the accused infringing protein cannot originate from other organisms than T. emersonii. The accused infringer failed to prove that accused infringing enzyme with the above protein sequence originated from other strains.

Therefore, the First Instant Court held that Longda Co. and Boli Co. did infringe upon Novo Nordisk’s patent, and should pay the plaintiff economic lost and other fees, which are more than RMB 2.2 million in total (around USD 350,000).

Longda Co. and Boli Co. unsatisfied with the decision of the first instance and appealed. The Tianjin High People’s Court concluded that the facts identified in the first instance are clear and the laws applied are proper, and rejected the request for the appeal and affirmed the judgment of the first instance.


During the invalidation proceeding of this case, the PRB clarified that a claim merely defined by “function + homology” cannot be supported by the description when experimental data proving function of homologous proteins are not sufficiently provided. More importantly, the PRB clarified that a definition by “function + homology + original species” can be supported by the description, which was affirmed by the court. This fact provides clear and positive teaching to applicants in the biology field who have doubts on how to properly obtain a good scope of protection. Furthermore, as the very first case of successful patent enforcement in the biology field, the detailed procedure of evidence preservation and judicial appraisal and provision of a number of evidences are essential to the positive result of this case, and of course enlightened other patent owners.

In the prosecution of bio-related invention applications, the U.S. is always considered to have the easiest criteria. However, in the decision of AbbVie v. Janssen Biotech and Centocor Biologics made by the United States Court of Appeals for the Federal Circuit on July 1, 2014, the antibody of claim 29 defined by “function + indexes” was invalidated for not disclosing any structural features common to the members of the genus, and lacking sufficient representative embodiments.[1] It is also recited in the decision that functional claim limitations are patentable only if they are linkable to structure. As can be seen, stricter criteria on support issue becomes a new trend worldwide. Under this trend, more attention should be paid to representativeness, numbers and types of embodiments when drafting claims so as to ensure better protection.

Written by Lingyun FU and Juan LEI

Author Profile: Ms. Fu is a patent attorney in our biological & chemical division.


Ms. Lei is a patent attorney in our biological & chemical division.


[1] United States Court of Appeals for the Federal Circuit: ABBVIE DEUTSCHLAND GMBH & CO. v. JANSSEN BIOTECH, INC., 2013-1338,-1346, decided: July 2, 2014