Servier best method & amendment

Servier has lost what may be its last round[1] in the arginine perindopril litigation against Apotex. Servier began the litigation back in 2007. Ultimately, it lost with its patent being found invalid on the ground that Servier had failed to disclose the best method of performing the invention. After that ruling, Servier applied to amend its patent to include the best method. Its application failed on discretionary grounds. Now, we have the Full Court’s decision dismissing Servier’s appeal from that refusal.

Best method

Servier’s first argument was that, following the High Court’s Kimberley-Clark decision, all s 40(2)(a) required was a disclosure sufficient to enable a skilled person to produce something within each claim without new invention or additions or prolonged study of matters presenting initial difficulty. Servier argued that there was no separate and independent requirement to disclose the “best method”.

After an extensive review of the case law, the Full Court rejected that argument, ruling that disclosure of the best method was indeed a separate requirement. In this case, Servier had failed to comply with that requirement.

Claim 1 of the patent was for the arginine salt of perindopril. There had been an earlier patent for perindopril and sodium and maleate salt forms had been identified. According to the Specification, the arginine salt form had particular stability advantages in conditions of heat and humidity which resulted in longer shelf life and permitted the use of less expensive forms of packaging. The achievement of these advantages, however, could be affected by the method of production. The Specification described the claimed arginine perindopril only as being produced by “a classical method of salification”.

The experts agreed this description of how to prepare the salt was “pregnant with ambiguity” and following from this evidence the trial judge had found this description was “wholly inadequate” and did not:

allow the skilled addressee to follow a routine process of deduction from that description because it leaves open too many variables.

Servier itself had used two different methods before the filing date – the 1986 method and the 1991 method – and another method – the 2002 study – after the priority date. The evidence showed that the method of salification used and variables such as the solvent used and whether and when to stir significantly affected the properties of the resulting salt, including its stability.

Accordingly, the Full Court upheld the trial judge’s conclusion that Servier had not disclosed the best method known to it of performing the invention.

Amendment

Servier had applied after the trial to amend the Specification to add the best method.

The Full Court affirmed the Pfizer Full Court’s ruling that the best method requirement required disclosure of the best method of performing the invention known to the applicant at the filing date. However, it was possible to remedy a failure to disclose the best method by amendment of the Specification made after the filing date.

The Full Court agreed with the trial judge that the amendment power under s 105 could be invoked even after trial and judgment finding all claims invalid. While there was a proprietal interest in being allowed to amend, it was still necessary for the patentee to satisfy the Court that discretionary grounds did not warrant exclusion.

In this case, however, discretionary grounds warranted refusal. Back in 2004, the examiner had issued a report as a result of which Servier’s patent attorney had advised Servier to include a description of the method of manufacture of arginine perindopril, even if it was well known. The inhouse instructor replied “we will see later”.

Although there was no suggestion of bad faith on the part of the inhouse instructor, the Full Court upheld the trial judge’s conclusion that the inhouse instructor’s decision to ignore the advice of her Australian patent attorney was not reasonable.

The Full Court considered that there was no error of principle in the trial judge’s rejection of the length of the delay as otherwise warranting rejection of the application. However, they would appear themselves have felt the trial judge had been overly generous.

Finally, the Full Court allowed Apotex’ appeal from the trial judge’s order that Apotex pay 66% of Servier’s costs. Rather, Servier should pay 40% of Aptex’ costs of the revocation proceeding and 75% of Aptex’ costs of the amendment proceedings.

Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27 (Bennett, Besanko and Beach JJ)


  1. Barring (potentially) a special leave application.  ?