A clear mistake in a claim term cannot be corrected through claim construction
Published on 17 May, 2018
In GlaxoSmithKline Consumer Healthcare Investments (Ireland) (No 2) Limited v Generic Partners Pty Limited  FCAFC 71, the Full Federal Court has found that terms used in claims cannot be interpreted beyond their plain meaning. Such a decision emphasises that great care is required when drafting claims that contain words or phrases that have a well-established meaning in the art.
The primary decision
GlaxoSmithKline Consumer Healthcare Investments (Ireland) (No. 2) Limited (GSK) commenced a proceeding against Apotex Pty Ltd (Apotex) and a separate proceeding against Generic Partners Pty Ltd for anticipated infringement of the claims of Australian Patent No. 2001260212 (the 212 Patent). Apotex and Generic Partners brought cross-claims against GSK seeking to revoke claims 1 to 6, 8 to 11, 13 and 14 of the 212 Patent.
The 212 Patent relates to pharmaceutical preparations of paracetamol, with claim 1 directed to a bilayer tablet with a defined dissolution profile, which is determined through the use of a particular recited apparatus: “the USP type III apparatus, reciprocating basket”.
The problem for GSK is that claim 1 defined an apparatus that was not a standard apparatus included in the United States Pharmacopeia (“USP”). The USP type III apparatus includes a reciprocating cylinder, not a basket. Both the consistory clauses and an example in the Patent, however, referred to the dissolution testing apparatus as “the USP type III apparatus (reciprocating basket)”.
The primary judge (Beach J) found that, while the reference to “basket” would have been understood by the skilled addressee as an error, the claim could not be re-written using construction to interpret “basket” to mean “cylinder” as:
- no integer of the claim was ambiguous or uncertain;
- there was no inconsistency between the body of the specification and a claim integer;
- the invention still worked if “basket” meant “basket”;
- there was no case of an erroneous stipulation of an underlying scientific theory upon which the invention proceeded;
- a patent cannot be construed with all the latitude and commercial massaging that is permissible for a commercial contract; and
- rules of benevolent construction which would strive to construe the 212 Patent in a way not claimed could not be applied. Construction that re-writes the claim is in effect construing what ought to have been rather than what is, and it is not permissible to adopt a method of construction that gives a patentee what it might have wished or intended to claim rather than what it did claim.
In GlaxoSmithKline Consumer Healthcare Investments (Ireland) (No. 2) Limited v Apotex Pty Ltd  FCA 608 (31 May 2016), the Federal Court found the claims of the 212 Patent to be valid but not infringed.
The appeal to the Full Federal Court
On Appeal, GSK’s asserted that the primary judge should have found that claim 1 of the 212 Patent refers to a compendial USP type III apparatus with a reciprocating cylinder. GSK submitted that, having found that the reference to “basket” would be understood by the skilled addressee to be an error, his Honour should have given effect to this finding and interpreted the claim accordingly. GSK contended that the primary judge erred in holding that to construe claim 1 in the manner which the skilled addressee would interpret it, would require his Honour to “re-write the claim”.
In a cross appeal, Apotex and Generic Partners asserted that the claims of the 212 Patent were not fairly based and that a best method of performing the invention was not disclosed in the specification.
With regard to claim construction, the Full Federal Court framed the issue as “whether, if the court were to also interpret the claim so as to correct the mistake, it would be re-writing the claim or merely interpreting it through the eyes of the skilled addressee” in accordance with precedent established by, e.g., Catnic Components Limited & Anor v Hill & Smith Limited  RPC 183 (HL) and Kirin-Amgen Inc v Hoechst Marion Roussel Ltd (2004) 64 IPR 444.
The Full Federal Court found that for claim 1 to be interpreted as GSK forwarded, namely as relating merely to an USP type III apparatus, then it would not have been necessary to recite anything other than “USP type III apparatus” in the claim. Further, the Full Federal Court explained that there could have been no problem with language since the language was not describing anything new. Thus, for GSK to succeed in its appeal, the Full Federal Court stated that the words “reciprocating basket” are either interpreted to mean “reciprocating cylinder” or simply ignored, either of which “involved impermissible re-writing of the relevant claims”. The Federal Court found “[t]his is a case in which … the language of the claim must be understood to mean what it actually says”.
With regard to fair basis and best method, the Full Federal Court confirmed the findings of the primary judge, namely that the claims of the 212 Patent were fairly based and that the best method requirement was met. The Full Federal Court found that “A complete speciation may still ‘describe the invention fully’ without explaining why the invention works. After all, the inventor, who presumably believes that the invention described works, may not understand why it works. But this does not prevent him or her from obtaining patent protection for the invention”. The Full Federal Court also found that “the best method was disclosed, albeit at a level of generality that did not include the more detailed but inessential manufacturing and production information described in the MAA [marketing authorisation application] applicable to the commercial embodiment”.
The good news for patentees is that this case would appear to be a rather unique case and that, as shown by the Full Federal Court’s analysis, there may be leeway in the case law for “correcting” an error in claim terms when describing something new. However, in describing something established in the art, the choice of words must be carefully considered. The Full Federal Court decision also highlights that a specification may describe the invention fully without explaining why the invention works, and that a low degree of generality may be sufficient to satisfy the best method requirement.