Shire faces Impax lawsuit

Shire Pharmaceuticals has received a counter-suit regarding a patent dispute with Impax.

The company said that its subsidiary, Shire Laboratories, had a complaint made against it by Impax Laboratories. Impax claim that they have not broken patents in proposing to make generic versions of Adderall XR. The firm said that Shire’s patent was invalid.

Shire had previously begun proceedings against Impax and Barr Laboratories for filing an Abbreviated New Drug Application (ANDA) for a generic version of the ADHD treatment, saying that it infringed US patent 6,913,768, which is claimed by the firm.

Adderall XR is prescribed to children, teenagers and adults who suffer from attention-deficit hyperactivity disorder (ADHD), characterised by over-activity and a lack of attention from the child. Other popular treatments include Ritalin.

The drug has generated $607 million in sales for the company, which is Britain’s third largest drugs maker.

The drug has not been without problems since its launch. In August federal pharmaceutical regulators in Canada reinstated Adderall XR after a period when it was removed from use.

Health Canada was worried that it was associated with sudden deaths of people taking it, although the drug was later found to be safe.

© Adfero Ltd