Teva: Copying GlaxoSmithKline's Advair too tough for success before 2018

GlaxoSmithKline has always said its asthma treatment Advair would be difficult to copy. Teva, apparently, agrees. The Israeli generics giant ($TEVA) said Tuesday that it doesn't expect to see true substitutes for the GSK best-seller before 2018, despite recent concern from GSK ($GSK) investors that they may arrive earlier.

The key is Advair's Diskus inhaler device. While patents on Advair's active ingredients have expired, the one on Diskus will protect the drug until 2016--and beyond, if generics makers face challenges in bringing quality copies to market. Teva itself acknowledged those challenges in 2010, saying it wouldn't even attempt the job because of the obstacles in replicating the Diskus technology. And if its most recent predictions hold any stock, GSK stands to benefit, with Advair hauling in $8 billion a year for the British drugmaker.

Regulatory guidance published last month threw all of that into question, however. The FDA released guidance for the development of generic copies of combination inhaled drugs like Advair, requiring only preclinical tests deemed "relatively basic" by analysts. The guidance also only required trials for asthma--neglecting them for COPD, Advair's other approved use.    

The news frightened GSK investors and sent shares downward. But now, they can breathe a bit easier knowing that competitors for the drug--which brings in 20% of the company's annual sales--are likely not so close at hand.

And the more time GSK can ward off competitors, the more time it can spend beefing up its respiratory franchise. Glaxo and partner Theravance ($THRX) nabbed approval for respiratory treatment Breo Ellipta in May, and just a couple of weeks ago, the drug followed up in Japan with an approval for asthma. It also recently scored a recommendation from EU regulators for both asthma and COPD.

GSK also has another product awaiting approval in Anoro, a COPD combo therapy.  An FDA advisory panel voted last month in favor of bringing that drug to market, which could add up to $1.4 billion per year to Glaxo's sales, according to Bloomberg estimates.

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