09 June, 2009

Sigma Pharmaceuticals (Australia) v Wyeth

Sigma Pharmaceuticals (Australia) v Wyeth

In the recent Australian Federal Court decision of Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth [2009] FCA 595, Wyeth were successful in preventing Sigma’s launch of a generic version of EFEXOR-XR™ (venlafaxine hydrochloride), the leading antidepressant in Australia in terms of units sold and value of sales.

The decision of Justice Sundberg granted Wyeth an interlocutory (pre-trial) injunction restraining Sigma from continuing its launch of its generic version of EFEXOR-XR™ pending final determination of infringement/revocation proceedings in respect of Wyeth’s method of treatment patent claims.

Despite Sigma establishing a prime facie case of invalidity for lack of inventive step (obviousness) and not meeting the threshold requirement of an “invention”1 , as well as Sigma’s preparedness to undertake that it would not apply for PBS listing, maintain full and complete accounts and sales records, retain all sales proceeds apart from disbursements in a separate account and would not discount or provide material benefit to purchasers by “bundling” EFEXOR-XR with other pharmaceuticals, Justice Sundberg found that the balance of convenience favoured the grant of interlocutory relief to Wyeth pending final determination at trial.

Notably, Wyeth argued that if Sigma’s product entered the market and Wyeth later succeeded at trial it may lead to a reduction in the beneficial effect of the medication as changes in the appearance of the medication may cause confusion and, as a result, missed doses or discontinuance.

Justice Sundberg appeared to accept this argument (at [65]):

“It is not in the public interest that vulnerable people, those with mental health issues, including depression, and elderly patients with a variety of medications, be subjected to confusion as a result of the refusal of interlocutory relief.”

With this latest decision, patentees of pharmaceutical inventions have had a 75% success rate2 in obtaining interlocutory injunctions in the Federal Court of Australia since 2006.

1 Specifically, that the claimed methods of treatment amounted to no more than a new use of a known substance for which it’s known properties make it useful. It should also be noted that claims to methods of medical treatment are patentable subject-matter in Australia.

2 Merck & Co Inc v GenRX Pty Ltd (2006) 70 IPR 286 – granted (FOSAMAX™); Roche Therapeutics Inc v GenRX Pty Ltd (2007) 71 IPR 456 – refused with undertakings (DILATREND™ and KREDEX™); Interpharma Pty Ltd v Commissioner of Patents (2008) 79 IPR 261 – granted (EBEGEMCIT™); Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth [2009] FCA 595 (3 June 2009) – granted (EFEXOR-XR™). Not including matters resolved by the giving of undertakings and consent orders.

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