Large damages payment looms for generic manufacturers in relation to Escitalopram
Published on 12 Oct, 2015
The Full Federal Court of Australia has dismissed an appeal by Alphapharm and others against the Federal Court decision to allow a patent term extension on Lundbeck’s patent covering the antidepressant drug Escitalopram (LEXAPRO) (the Escitalopram Patent) – Alphapharm Pty Ltd v H Lundbeck A/S  FCAFC 138.
The patent at issue, Australian Patent No. 623144, concerns the (+)-enantiomer of citalopram marketed under the name LEXAPRO. A racemic mixture of citalopram is marketed under the name CIPRAMIL. In December 2003, Lundbeck sought a patent term extension for the Escitalopram Patent based on the inclusion of LEXAPRO in the Australian Register of Therapeutic Goods (ARTG). However, in a decision of the Full Federal Court, in 2009 (The 2009 Decision; H Lundbeck A/S v Alphapharm Pty Ltd  FCAFC 70), it was held that the patent term extension request should have been based on the inclusion of CIPRAMIL in the ARTG. Consequently, Lundbeck applied and was granted a patent term extension of their Escitalopram Patent based on inclusion of CIPRAMIL in the ARTG. Alphapharm opposed the Patent Office decision to grant the extension and failed, and subsequently appealed to the Federal Court (Alphapharm Pty Ltd v H Lundbeck A/S  FCA 1185).
In the appeal to the Federal Court, Alphapharm and a number of other generic manufacturers opposed the grant of the patent term extension raising several allegations of failure to comply with the relevant requirements under Sections 70(2)(a), 70(3) and 70(4) of the Australian Patents Act. The Federal Court rejected all arguments made by Alphapharm and dismissed the appeal. Commentary in relation to the primary Federal Court decision can be found here.
The issue decided by the Full Federal Court in the instant case was whether the claim to the (+)-enantiomer of citalopram is to a pharmaceutical substance per se for the purposes of Section 70(2)(a).
The Full Federal Court’s decision
It was submitted that the claim was previously construed in the 2009 Decision, and applied by others, to be akin to the “pure or isolated or separated” enantiomer, as such, the claim is to a pharmaceutical substance limited by a requirement of purity. Alphapharm contended that a claim limited by the requirement, that it be separated or isolated or pure, is not a claim to the substance itself but rather to the substance defined in a particular environment as having been subjected to a particular process. On the basis that the claim imports a limitation, in effect an additional integer, it was asserted that the claim is not to the substance itself as required by Section 70(2)(a).
The Full Federal Court rejected Alphapharm’s argument on the basis that the use of the words “pure or isolated or separated” had been taken out of context. In particular, the decision describes at [91 to 93] that in seeking to describe the difference between the racemate containing the two enantiomers and the claim to one of the enantiomers, expressions such as “pure”, “isolated” and “separated”, were simply used, and that the word “itself” could just as easily have been used and would have carried the same meaning in context. On the basis that there is no additional integer read into the claim and the claim is to the (+)-enantiomer and nothing else, at , the Full Court affirmed:
The claim is to (+)-citalopram, irrespective of how it is produced. The isolated (+)-enantiomer plainly qualifies as a pharmaceutical substance per se and the primary Judge was correct in concluding that it satisfies s 70(2)(a) of the Act.
This Full Federal Court decision, in addition to the previous Federal Court and Patent Office decisions, has confirmed the validity of Lundbeck’s patent term extension on its Escitalopram Patent. Notwithstanding Alphapharm and the other generic manufacturers may attempt to seek other creative avenues for appeal, it appears for now, that they may have exhausted their arguments and face payment of considerable damages to Lundbeck for infringement of the Escitalopram Patent.