* Commercial Court rules Seretide combination patent invalid
* Decision is win for Teva, though other patents still apply
* Glaxo may appeal to protect its top-selling drug
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LONDON, June 26 (Reuters) - An Irish court has ruled that a key patent protecting GlaxoSmithKline’s (GSK.L) biggest-selling medicine is invalid, the British-based drugmaker said on Friday.
The ruling from the Commercial Court in Dublin is a victory for Teva Pharmaceutical Industries (TEVA.TA), whose Ivax unit had challenged the combination patent for Seretide. The patent relates to the combination of the active ingredients salmeterol and fluticasone propionate, and expires in 2013.
Seretide, known as Advair in the United States, raked in global sales last year of 4.1 billion pounds ($6.66 billion) as a treatment for asthma and chronic obstructive pulmonary disease (COPD).
Glaxo said it was studying the judgment and would be exploring the possibility of an appeal to a higher court.
It noted that the decision related solely to the Irish combination patent and was not binding elsewhere. The company has other patents registered in Ireland related to Seretide, including the Diskus dry powder inhaler and HFA aerosol formulation patents, expiring in 2011 and 2012 respectively.
Because Seretide/Advair is an inhaled drug, there also considerable technical hurdles in producing a cheap generic version, even if the patents are overturned.
Recently, however, some generic companies have been making progress in developing formulations of the medicine, raising some uncertainty about how long Glaxo will be able to retain exclusivity.
In addition to Teva, Novartis’s NOVN.VX generics arm Sandoz is also keen to make a copy of the blockbuster drug. [ID:nLM109152]
Reporting by Ben Hirschler; editing by John Stonestreet