Shire Pharmaceuticals says that Teva Pharmaceuticals has applied to market a copycat version of its top-selling ADHD medicine, Adderall XR (amphetamine salts extended-release).

Teva joins a growing queue of companies lining up to market their generic versions of the $474 million-dollar-a-year drug, which is one of Shire's key growth drivers [[12/03/04c]], . Impax Laboratories was hit with two lawsuits after it filed its version of the product with the US Food and Drug Administration [[14/01/05c]], [[05/01/04d]], [[19/11/03b]], and Shire also has suits pending against Barr Laboratories – the first company to announce its intent to win the green light for a generic copy of Adderall XR [[10/01/03b]], [[26/02/03d]], [[18/02/03a]] – but has decided not to sue Colony Pharmaceuticals, which filed a notice letter late last year [[03/12/04d]].

The UK company, which notes that the drug is protected by two US patents that are not due to expire until 2018 [[14/01/05c]], says it is currently reviewing the details of Teva’s notification.