Generics company, Teva Pharmaceutical Industries, was celebrating yesterday after the US Food and Drug Administration granted tentative approval for the firm’s copycat version of Eli Lilly’s anti-psychotic, Zyprexa (olanzapine).

In a statement, Teva said that final approval remains subject to the resolution of patent litigation and the expiration of exclusivity periods held by any other generics manufacturers – the first company to market a copycat version of a branded drug is typically awarded 180 days of market exclusivity.

Teva, Dr Reddy’s and Ivax have launched legal challenges to the multi-billion dollar drug, claiming that Eli Lilly has “double patented” the product and are seeking to have a patent, which is not set to expire until 2011, invalidated [[28/01/04d]], [[03/03/04b]].

Zyprexa is the world’s fifth best selling drug, with 2004 sales coming in at a not insignificant $4.8 billion [[10/03/05f]]. However, sales have been slowing down somewhat on the back of heightened market competition, primarily in the USA.

- Meanwhile, Teva says that it has also won the tentative nod for a generic version of Pfizer’s $2.4 billion hypertension offering, Norvasc (amlodipine).

Specifically, the company said that the tentative approval was for the 2.5mg, 5mg and 10mg tablet doses of the drug and that final approval is expected when the patent covering the product expires on September 25, 2007.