A Thermostable Glucoamylase Patent Invalidation Case

September 13, 2017

The Supreme People's Court (2016) No. 85 Administrative Verdict on the Retrial of the administrative dispute over invention patent invalidation among the Patent Reexamination Board of the State Intellectual Property Office, Novozymes and Jiangsu Boli Bio-Products Co., Ltd..  


Case Summary

This case concerns the invention patent entitled "Thermostable Glucoamylase" ( “the Patent”) granted on June 28, 2006 and owned by Novozymes. On March 11, 2013, at the request of Shandong Longda Bioengineering Co., Ltd. (“Longda”) and Jiangsu Boli Bio-Products Co., Ltd. ( “Boli”), the Patent Reexamination Board of the State Intellectual Property Office (“the Board”) made No. 17956 decision (“the Decision”) based on the modified claims filed by Novozymes, declairng part of the claims are invalid. The claims relating to the focus of this dispute is as follows:

6. an isolated enzyme with glucoamylase activity, which is connected with SEQ ID NO :7, and the degree of homology between the full-length sequences shown in 7 is at least 99%., and has an isoelectric point of less than 3.5 measured by isoelectric focusing.

10. the isolated enzyme according to any one of claims 6-9, wherein the enzyme is derived from filamentous fungus talaromyces, wherein filamentous fungus are T.emersonii strains

11. the enzyme of claim 10, wherein the filamentous fungus is T. emersoniiCBS.793.97

12. a cloned DNA sequence, wherein the DNA sequence shows an enzyme with glucoamylase activity; the DNA sequence comprises the following components:  a) coding part of the glucosaccharase of a DNA sequence shown in SEQ ID NO: 33; b) the DNA sequence shown in the 649th - 2724th positions in SEQ ID NO: 33 or its complementary strands;

13. the DNA sequence of claim 12, wherein the DNA sequence is derived from filamentous fungus talaromyces, wherein the filamentous fungus are bacterial strains of T. emersonii.

14. the DNA sequence of claim 13, wherein the filamentous fungus are T.emersoniiCBS793.97.

The Decision maintained the validity of the disputed claims by concluding that, as the specifications has proven the enzyme from the T.emersonii CBS793.97 has glucoamylase activity, the technical personnel in the field can predict that the polypeptides derived from T.emersonii strain and having a degree of at least 99% of homology with the full length sequence shown in SEQ ID NO: 7 shall also have the activity of glucoamylase; therefore claims 10 and 11 can be supported by the specifications, so are the technical scheme of claim 12 (a) and (b), which are qoted in claim 13 and 14.

The court’s first instance verdict, however, revoked the Decision, stating that although the disputed claims have defined specific strains, the defined amino acid sequence and DNA sequence can include other sequences due to the way of writing concerning homology and openness, and that, given the lack of support by sufficient experimental data in this patent specification, the summary of the disputed claims has clearly exceeded the contents of the specification. The court of second instance maintained the first instance verdict.

Patent Reexamination Board and Novozymes both applied for retrial. After hearing, the Supreme People 's Court revokes the first and second instance judement and maintains the decision at issue.


Typical Significance

In this case, the Supreme People's Court holds that, according to Article 26 (4) of the Patent Law, the technical scheme required for protection under the claims should be obtainable or summarizable by the technical personnel in the technical field concerned from the contents fully disclosed in the specifications and shall not exceed the scope of the specifications.

For SEQ ID NO: 7 having a total length of 591 amino acids, although there is still a difference of about 5 or 6 amino acid positions from the sequence with 99% or more homology, in addition to the homology characteristics, Claim 10,11 have further defined that the enzyme is derived from the T.emersonii strain and the specific strain T.emersonii CBS793.97.

The technical personnel in this field generally believe that specie is the basic unit of taxonomy, and in some basic characteristics, individuals in the same specie exhibit a high degree of similarity to each other. The gene sequence of the same fungus or of an enzyme encoded in the body of the same fungus is generally determined, and occasionally there are very few variant sequences with very high homology, so are the the enzymes encoded by the gene.

In this case, the dual limitations of more than 99% homology and the strain or source of the strain have reduced the scope of protection of claims 10 and 11 to extremely limited enzymes. Moreover, claims 10 and 11 also include the limitation in claim 6 for enzymes isoelectric point and the function of glucoamylase activity.

Thus, as the examples 1-4 of the specifications have proven the above-mentioned SEQ ID NO: 7 has a glucoamylase activity, the protection scopes of claims 10 and 11 are able to be supported by the specification, so are the technical schemes of claim 12 (a) (b) quoted in claim 13 and claim 14.

In this case, the Supreme Court has clarified the rules in judging whether biological sequence claims with use of homology and the limitations of source and function can be supported by the specifications, and the examination standards for biological sequence invention patents. It has provided guiding significance to the writing and examination of proteins or gene-related patents applications, which is also conducive to the promotion of biotechnology industry innovation and development.