07 July 2005

Delegate Finds Fair Basis in Thermostable Enzyme

On 4 July 2005, the Delegate of the Commissioner of Patents handed down F.Hoffman-La-Roche AG v Bresagen Ltd and New England Biolabs, Inc [2005] APO 31 .

This matter originated in opposition proceedings launched by Bresagen and New England Biolabs against F.Hoffman-La-Roche. In that matter the Delegate found, inter alia, that the invention as defined in the claims lacked novelty. The Delegate also found that the claims did not comply with section 40 of the Patents Act in that they were not fairly based on the specification. In particular, the Delegate held that the term "thermostable" in the claims was defined too broadly in the specification. F. Hoffman-La-Roche appealed the decision to the Federal Court and amended the specification to narrow the definition in an attempt to comply with section 40. The Federal Court referred the matter back to the Delegate to determine whether or not the claims were fairly based on the specification, as amended.

The relevant amendment appears as follows: "As used herein, the term "thermostable enzyme" refers to an enzyme which is stable to hear and is heat resistant and catalyses (facilitates) combination of the nucleotides in the proper manner to form the primer extension products that are complementary to each nucleic acid strand, and is stable to heat and is heat resistant to the extent that it would be effective for the amplification reaction described herein, ie, the enzyme does not become irreversibly denatured (inactivated) when subjected to the elevated temperatures for the time necessary to effect denaturation of double stranded nucleic acids ." Bresagen and New England Biolabs submitted that the amendment did not overcome the lack of fair basis. They contended that the amendment affected the definition of a specific term, namely "thermostable enzyme". The term was used in the body of the specification but not in the relevant claims. The relevant claims instead used the terms "thermostable DNA polymerase" and "thermostable polymerase", which are not the subject of any definition in the specification. New England Biolabs argued that the amended definition of "thermostable enzyme" could not be read into the claims to qualify the clear meaning of the wording of the claims. They thus held that the term "thermostable" had no clear meaning in the specification and the claims were not fairly based.

The Delegate disagreed. He pointed out that the definition of "thermostable enzyme" as set out in the specification described a specific enzymatic reaction. DNA polymerase is the only enzyme disclosed in the specification which is able to catalyse this reaction. In his view, the claimed DNA polymerase was thus clearly encompassed in the dictionary definition of "thermostable enzyme" provided in the specification. Furthermore, the Delegate held that there was nothing in the specification or in the evidence to suggest that the word "thermostable" would have had a different meaning when used as an adjective for "enzyme" and for "polymerase".

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