The fatal consequences for patentees who fail to satisfy the “best method” requirement.
Under Australian law, patent applicants are required to disclose in their specifications, the best method known to them at the filing date for performing the claimed invention. Although Australia has had a best method requirement since commencement of the Patents Act 1952, the requirement has received little judicial consideration.
However, the Federal and Full Federal Courts have now had the opportunity to clarify the scope of the best method requirement in two separate cases, Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd  FCA 236 (“Sandvik”) and Les Laboratoires Servier v Apotex Pty Ltd  FCAFC 27 (“Servier”).
In light of these recent decisions, this article considers the fatal consequences for patentees who fail to satisfy the best method requirements under Australian patent law.
Case 1 - Les Laboratoires Servier v Apotex Pty Ltd
The patent at issue in Servier, was directed to the arginine salt of perindopril (perindopril arginine), its hydrates and pharmaceutical compositions thereof. Perindopril, an angiotensin-converting enzyme (ACE) inhibitor, is used for the treatment of hypertension and related conditions. Due to the inherent instability of perindopril, the preparation of a suitable pharmaceutical form for administration was problematic. The specification indicated that the arginine salt surprisingly exhibited improved stability whilst maintaining good bioavailability.
Limited description of method for preparing claimed salt
With regard to the preparation of perindopril arginine, the patent specification simply stated that it was “prepared according to a classical method of salification [salt formation] of organic chemistry”; that is, a standard method known in the art. No other details relating to the preparation of the claimed arginine salt were provided and no specific method was referred to by citation or otherwise. However, evidence considered by the Court indicated the patentee had prepared perindopril arginine via two distinct methods prior to the filing date. Neither of the specific methods was disclosed in the specification. Despite this, Apotex was unable to establish that Servier was aware, as at the filing date, that any particular method was better than any other given method.
The primary judge held that the mere reference to the use of a classical method of salification was “wholly inadequate”. In particular, the primary judge indicated Servier had used a particular method and parameters that produced a guaranteed result, whereas the complete specification described a very general method of performing the invention. As such, the patent was found to be invalid solely on the ground that it failed to meet the best method requirement. While other grounds of invalidity were also considered by the Court, the invention was held to be novel, inventive, and fully described (except for best method), and the claims were held to be fairly based on the description.
Servier had argued at first instance and on appeal that all claims were directed to a product and, as such, the best method requirement should be satisfied by the identification of the best product per se (i.e. the claimed compound).
However, on appeal the Court held that the nature and extent of the disclosure required to satisfy the best method requirement depend on the nature of the invention itself. The Court acknowledged that in some cases where the claim is to a product, there is no requirement to provide a method of using or making that product. The Court noted, however, that in the case of the patent at issue, the particular salt formation and the methodology to prepare such a salt had more importance than might be the case where the claimed invention was a product for which these characteristics were irrelevant.
Patent invalid for failing to meet best method requirements
By omitting sufficient description of the successful methods used to prepare perindopril arginine, the Full Federal Court found that Servier had failed to describe in the complete specification the best method known at the filing date of performing the invention. As such, the Full Court upheld the primary judge’s decision, finding the patent invalid for failing to meet the best method requirement.
Court rejected application to amend
Servier applied to the Court to amend the specification after grant to remedy the deficiencies with regard to the best method, but the Court declined to exercise its discretion to allow the amendment. While the Court did not comment on the allowability of the amendment, it held that the nature of the amendment and the ground of invalidity sought to be overcome are important matters for the Court to consider in exercising its discretion. In this instance, Servier had received advice from their attorneys during the course of prosecution recommending that further examples be added to the specification (if possible) to satisfy the "written description requirements". Servier’s failure to act on this advice contributed to the Court’s decision to reject the application for amendment.
Servier subsequently sought leave to appeal to the High Court, but their application was refused.
Case 2 - Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd
The patent at issue in Sandvik was directed to an extension drilling system for use in drilling bores, in particular for coal mining. The Federal Court ultimately found the patent was invalid for failing to meet the best method requirement. Furthermore, certain claims were found to lack novelty and all claims where found to lack an inventive step.
Patent specification failed to describe improved water seal
With regard to the best method requirement, the Court heard evidence that during the course of development of the drilling system one of the “real issues” to be addressed was the design of an effective water seal. However, technical drawings which pre-dated the filing of the complete application and which described an improved sealing arrangement for use with the drilling system were not disclosed in the specification at filing. The Court found that the improved seal did not amount to some minor or incidental dimension, but was in fact “the ultimate evolution of the seal” and “a superior design”.
In accordance with the approach in Firebelt Pty Ltd v Brambles Australia Ltd  FCA 1689, the applicants argued that the detailed characteristics of the improved seal did not specifically relate to “a method of performing the invention” and were therefore irrelevant when considering the disclosure of the best method. To this end, there was no indication in the specification that the inventors regarded the seal as an important feature of the invention for which they were seeking protection and none of clams referred specifically to the seal per se.
Failure to describe the best method known at the filing date
The Court held that the inventors were aware that the improved water-sealing arrangement was critical to the efficacy and quality of the ultimate form of the invention as at the date of the filing of the complete specification and, as such, the best method of performing the invention necessarily included that arrangement. In omitting this information from the specification, the applicant had failed to describe the best method known to it at the filing date.
Sandvik has sought leave to appeal the decision to the Full Federal Court. However, as part of associated undertakings, Sandvik has not sought leave to amend the specification to remedy the best method deficiencies.
“Best method” - a uniquely Australian situation
While the United States has moved to curb the consequences for failing to meet the best method requirement, and most other countries do not have a best method requirement, these recent Australian decisions highlight the importance of including the best method in patent specifications destined for filing in Australia.
Australia is now out of step with the rest of the world on this issue. Key stakeholders and peak industry bodies, including the Australian Law Council and the Institute of Patent and Trade Mark Attorneys (IPTA), have called for reform of this provision to realign Australia with International practice. In the absence of reform, and in view of the more stringent standards for amendment under the Intellectual Property Laws Amendment (Raising the Bar) Act 2012 which came into force in 2013, it is paramount that patent applicants in Australia ensure the best method known to them of performing the invention is included in the specification at the time of filing.