'Best method' a heavy burden for patentees

Industrials Intellectual Property Patents & Trade Marks

In brief

Despite a global trend away from requiring patentees to disclose the best method of performing their invention, Australia continues to impose an arguably obsolete, yet increasingly onerous, statutory best method requirement. Associate Claire Gregg discusses the recent developments.

Best method back in the spotlight

Failure to disclose the best method known to the patentee of performing the invention described in a patent specification is a particularly damaging ground of invalidity, as it invalidates the entire patent. Since the controversial decision of the Full Federal Court in Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27 (Servier), best method has been a popular ground of attack before both the Australian Patent Office (APO) and the courts.

We discussed some of the relevant decisions in our article of 15 September 2017. In particular, the Full Federal Court in Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2017] FCAFC 138 (Sandvik) found that a lack of disclosure of the best method in relation to non‑essential features of the invention was fatal to the patent. Further, in Kineta, Inc. [2017] APO 45(Kineta), the APO found that the applicant failed to disclose the best method of performing the invention because it had not disclosed that the only method known to it of obtaining the compounds of the invention was to commission their synthesis from a particular supplier.

The Court in Servier confirmed there is a residual requirement to disclose the best method beyond the requirement for sufficiency of disclosure. However, that case was decided pursuant to the pre-Intellectual Property Laws Amendment (Raising the Bar) Act 2012(Raising the Bar) law, under which the specification must only enable one embodiment falling within the scope of each claim. Arguably, the best method requirement now has limited relevance in view of the post-Raising the Bar sufficiency test, which necessitates enablement across the full breadth of the claims. Despite this, best method remains a validity requirement under Australian law. Moreover, for applicants seeking to file divisional applications, the disclosure requirements have become particularly onerous.

A heavy new burden for divisional patents

The assessment of best method involves an inquiry into the subjective knowledge of the patentee at a particular point in time. Given the filing date of a complete specification for a divisional patent will typically differ from the filing date of its parent, the relevant date for the assessment of best method of divisional patents has been a matter of debate.

In Kineta, the prohibition on added subject matter under Raising the Bar meant the applicant could not amend the specification to include the best method in order to gain acceptance. Instead, the applicant filed a divisional application, supplemented to include the best method. This 'topped up' divisional was ultimately granted by the APO which, in doing so, embraced the practice of assessing the best method at the time of filing the complete specification (in this case, the divisional filing date).

The Federal Court in Dometic Australia Pty Ltd v Houghton Leisure Products Pty Ltd [2018] FCA 1573 (Dometic) confirmed the relevant date for assessing best method with respect to a divisional innovation patent was the date of filing of the complete specification for the divisional application. Although evidence was adduced that a better method of performing the invention was developed by one of the inventors between the date of the patent and the divisional filing date, knowledge of this improved method could not be attributed to the patentee in all the circumstances. While this turned out to be a lucky case of 'what the patentee didn't know, couldn't hurt them', applicants for divisionals should proceed with caution and ensure the best method is disclosed.

Ramifications of Dometic

The Dometic decision highlights the need to disclose the best method of performing the invention at the time of filing a divisional application. Applicants who wish to file a divisional application, but who become aware of a better method of performing the invention between the filing date of the parent application and the divisional filing date, need to include the improved method in the divisional specification. However, this creates a risk of adding new information in the divisional specification, which could also affect the priority date of any claims that rely on the added matter. It also means that already granted divisional patents are at risk of an invalidity challenge where evidence can be adduced that the patentee became aware of a better method of performing the invention during the relevant time.

Both the IP Committee of the Law Council of Australia and the Institute of Patent & Trade Mark Attorneys have previously filed submissions to IP Australia to repeal the best method requirement. More recently, they have entered into discussions with IP Australia to try to temper the retrospective effects of the Dometic decision on already granted divisional patents. We will keep you informed of any new developments.