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In the long-running patent dispute relating to Lundbeck’s blockbuster antidepressant, Lexapro® (escitalopram), the Full Court of Australia’s Federal Court overturned a decision of Jagot J, who had found Sandoz liable for infringement of the Lexapro patent and awarded Lundbeck more than AU$16 million in damages. Lundbeck has recently been granted special leave to appeal to the High Court of Australia, which for the third time will hear an appeal regarding an aspect of this litigation.
The original 20-year term of the Lexapro patent (AU 623144) was due to expire in June 2009. In April 2004, the Commissioner of Patents granted a 5-year extension of the patent term, calculated by reference to the first regulatory approval date for Lexapro. The active ingredient of Lexapro is escitalopram, the S-enantiomer of citalopram. A racemic form of citalopram (a mixture of the S- and R-enantiomers) was earlier marketed in Australia by Lundbeck under the trade name Cipramil.
In subsequent Federal Court proceedings, that extension of term was held invalid (Alphapharm Pty Ltd v H Lundbeck A/S (2008) 76 IPR 618; upheld on appeal: H Lundbeck A/S v Alphapharm Pty Ltd (2009) 177 FCR 151). The Court found that any extension of term application needed to be made by reference to Cipramil, being the first approved therapeutic goods that “contain” the S-enantiomer of citalopram within the meaning of the Patents Act 1990 (Cth) (the Act). It followed that such application was required to be made within six months of the first regulatory approval date for Cipramil. Lundbeck’s application was therefore submitted out of time.
In consequence, the Lexapro patent expired on 13 June 2009, at the end of its original term. Three days later, Sandoz and other generics launched generic escitalopram products. In doing so, they appeared to be taking a risk. On 12 June 2009, Lundbeck had sought an extension of time to submit a new extension of term application, based on the first regulatory approval date for Cipramil.
Given that the time limit for submitting such an application expired in mid-1998, Lundbeck required a 10-year extension of time. Nevertheless, that extension was granted, on the basis that the applicable time limit had been unclear until determined by the Federal Court in June 2009 (Alphapharm Pty Ltd v H Lundbeck A/S (2011) 92 IPR 628; upheld on appeal: Aspen Pharma Pty Ltd v Commissioner of Patents (2012) 132 ALD 648; Aspen Pharma Pty Ltd v H Lundbeck A/S (2013) 216 FCR 508; Alphapharm Pty Ltd v H Lundbeck A/S (2014) 254 CLR 247).
Armed with this extension of time, Lundbeck submitted a new application to extend the term of its Lexapro patent. In June 2014, some 5 years after the patent had expired, that extension was granted (Alphapharm Pty Ltd v H Lundbeck A/S (2014) 109 IPR 323; upheld on appeal: Alphapharm Pty Ltd v H Lundbeck A/S (2014) 110 IPR 59; Alphapharm Pty Ltd v H Lundbeck A/S (2015) 234 FCR 306; Alphapharm Pty Ltd v H Lundbeck A/S  HCATrans 52).
The newly extended term of the Lexapro patent expired in December 2012. By that time, Sandoz and other generics had been marketing escitalopram products in Australia for over three years. Lundbeck sought damages for infringement of the Lexapro patent during that period.
In defence of such damages claim, Sandoz relied on a settlement agreement it had reached with Lundbeck in February 2007 (Settlement Agreement). In return for Sandoz discontinuing its revocation case against the Lexapro patent, Lundbeck agreed to grant Sandoz an irrevocable licence to the patent, effective from a date two-weeks prior to its expiry (the Early-entry licence).
At the time that agreement was reached, the expiry date of the Lexapro patent remained uncertain – litigation concerning the validity of the original extension of term was ongoing. The agreement recorded several alternative dates on which the Early-entry licence might commence. However, it did not address the possibility that the term of the Lexapro patent might expire and, sometime later, be extended. That is, of course, what transpired.
In defence of Lundbeck’s damages claim, Sandoz submitted that, on a correct construction of the Settlement Agreement, the Early-entry licence commenced in May 2009, two-weeks before expiry of the Lexapro patent, and remained in force thereafter. By contrast, Lundbeck submitted that, because the term of the patent was extended to December 2012, the early-entry licence did not commence until November 2012, leaving Sandoz liable for infringement in the intervening period.
First instance decision
Lundbeck was successful before the primary judge (H Lundbeck A/S v Sandoz  FCA 1797). However, Jagot J did not accept either party’s construction of the Settlement Agreement.
Her Honour found that, under the terms of the Settlement Agreement, the Early-entry licence commenced in May 2009, two weeks before the Lexapro patent expired. In reaching that conclusion, Jagot J held that the operation of the agreement ought not be tested by reference to the fact that, 5 years later, a new extension of term was granted, because this could not have been predicted by the parties in February 2007, when they entered into the Settlement Agreement.
However, in Jagot J’s view, this was not the end of the matter. Noting that Sandoz would not require a licence after the Lexapro patent had expired, her Honour found that the effect of the Settlement Agreement was to confer on Sandoz a licence which commenced in May 2009 and ceased to operate two weeks later, upon the expiry of the patent’s original term.
It followed, in Jagot J’s view, that Sandoz did not have the benefit of a licence when the term of the Lexapro patent was subsequently extended. Based on these findings, Jagot J held Sandoz liable for infringing the patent between June 2009 and December 2012, awarding Lundbeck in excess of AU$16 million in damages.
An appeal by Sandoz to the Full Court was successful. The critical issue on appeal concerned the construction of the Settlement Agreement, in particular, whether the Early-entry licence ceased to operate on expiry of the original term of the Lexapro patent in June 2009, or continued thereafter.
In approaching that question, the Full Federal Court reiterated well-established principles of contract construction. The terms of a contract are to be construed objectively. The question is what the language used would convey to a reasonable business person, in light of the surrounding circumstances known to both parties at the date of their agreement, including the objects of the contract, and assuming that the parties intended to achieve a commercial result. A court will be slow to adopt a construction that would give a contract an effect that is commercially nonsensical.
On the other hand, the Full Court emphasised that commercial common sense and surrounding circumstances may not be invoked to discount the language in which a contract is expressed. The fact that a contractual provision may operate to disadvantage one party to an agreement is not a reason to depart from the ordinary meaning of the language in which that provision is expressed.
In the view of the Full Court, the language of the Settlement Agreement was sufficiently clear. It granted Sandoz an irrevocable licence that commenced in May 2009, two weeks before expiry of the Lexapro patent, and remained in force thereafter. The Full Court held that, objectively ascertained, it was the parties’ intention to stipulate a start date for the licence, but not an end-date.
Notably, the Full Court agreed with Jagot J that it appeared neither party had, at the time of concluding the Settlement Agreement in February 2007, turned their mind to the possibility that the Lexapro patent might expire and only subsequently have its term extended. That is unsurprising, given unprecedented course of the Lexapro proceedings. As the Full Court observed, had the parties been able to foresee the course those proceedings would take, it is likely that express provision would have been made for such eventualities in the Settlement Agreement.
The Full Federal Court’s decision highlights the complexity of the extension of time and extension of term provisions under Australia’s patent legislation which, together or separately, can significantly affect the course of the litigation and the negotiation of commercial settlement terms.
The decision of the Full Federal Court does not yet bring to a close one of the most complex patent disputes in Australian legal history, as Lundbeck was recently granted special leave to appeal to the High Court of Australia (H. Lundbeck A-S & Anor v Sandoz Pty Ltd; CNS Pharma Pty Ltd v Sandoz Pty Ltd  HCATrans 13 (11 February 2021). That will be the third time this litigation has reached the High Court for a substantive appeal, with Lundbeck previously succeeding in obtaining both its application for an extension of time to apply for an extension of term and then the extension of term application itself. Over its long course, the Lexapro litigation has made a number of significant contributions to Australian patent law, including in relation to the validity of enantiomer claims and the operation of the provisions of the Act which govern extensions of term and extensions of time, and now it appears set to contribute to Australia’s contract law as well.
Authored by Andrew Rankine and Duncan Longstaff