We recently reported the Australian High Court decision of ALPHAPHARM PTY LTD v H LUNDBECK A/S. The High Court concluded that Lundbeck's application for patent term extension was not time-barred. However, the High Court did not consider the substantive merits of the application. That question was already in front of the Federal Court, which has confirmed the patent term ran until 9 December 2012, not 13 June 2009.

Lundbeck owned the patent for the antidepressant drug escitalopram (sold as LEXAPRO). They were granted an extension of the patent term for escitalopram based on the inclusion of LEXAPRO in the Australian Register of Therapeutic Goods (ARTG). However, escitalopram is the (+)-enantiomer of citalopram (sold as CIPRAMIL).   Alphapharm (and others) challenged this extension of term on the basis that CIPRAMIL was already included on the ARTG, and therefore LEXAPRO was not the first entry for escitalopram on the ARTG. The challenge was successful and the patent term extension was revoked. 

Lundbeck submitted a second application for an extension of term on the basis of the ARTG entry for CIPRAMIL. This second application was granted, and subsequently opposed by Alphapharm (and others). 

The key questions before the Federal Court were:

  • whether the entry for a racemic mixture (citalopram) could be used to support an extension for the isolated enantiomer (escitalopram)
  • whether the first (revoked) extension disqualified Lundbeck from being granted an extension, on the basis that section 70(4) of the Patents Act stated that 'The term of the patent must not have been previously extended under this Part'.  

The Federal Court dismissed the opponents appeal. The patent term for escitalopram therefore expired on 9 December 2012.

Although this series of cases may seem like a lot of work for a patent that expired nearly two years ago, this battle is not concerned with mere theoretical questions of law.  Generic escitalopram was released in Australia shortly after the original patent term expired in 2009. However, as a result of the patent term extension being confirmed, those sales could now be considered to be an infringement of Lundbeck's patent. We probably haven't heard the end of this matter yet.