Federal Circuit reverses infringement ruling in Shire v Watson

The US Court of Appeals for the Federal Circuit has reversed and remanded a decision by a district court centring on the drug Lialda (mesalamine), a treatment for ulcerative colitis.

Watson’s planned generic version of Lialda was found not to infringe Shire’s patent, US number 6,773,720.

A ruling of the US District Court for the Southern District of Florida was reversed on Friday, February 10 in Shire Development v Watson Pharmaceuticals.

Shire had sued Watson for infringing its patent, which concerns a controlled-release oral pharmaceutical composition of mesalamine, after Watson filed an Abbreviated New Drug Application (ANDA) with the Food and Drug Administration seeking to market a generic version of Lialda.

The Federal Circuit reversed the district court’s ruling on the basis that Watson’s proposed generic product does not satisfy the Markush group requirements.

According to the lawsuit, a Markush claim is a particular kind of patent claim that lists alternative species or elements that can be selected as part of the claimed invention.

The district court found that Watson infringed Shire’s patent because the component outside the relevant Markush group is unrelated to the invention.

But the Federal Circuit disagreed with the district court’s interpretation of what constitutes a component unrelated to the invention.

The Federal Circuit said in its ruling: “We conclude that Watson’s ANDA product does not satisfy the claim 1(b) Markush limitation, and, by extension, does not satisfy dependent claim 3.”

It further quoted Wahpeton Canvas Co v Frontier and stated that: “One who does not infringe an independent claim cannot infringe a claim dependent [on] (a nd thus containing all the limitations of) that claim.”

Shire told LSIPR that it is disappointed with the Federal Circuit’s ruling and that it will continue to evaluate the Federal Circuit’s decision as well as Shire’s legal options.

The company added: “Only after Shire has exhausted its options will the case be remanded to the lower court for entry of judgment in accordance with the Federal Circuit’s decision. This may take several months.”