An Irish pharmaceutical manufacturer has succeeded in a High Court counterclaim against international giant Merck Sharp and Dohme (MSD) in a patent rights row over a cholesterol-reducing drug.

MSD had sued Clonmel Healthcare claiming the defendant was breaching its 2005 supplementary protection certificate (SPC) governing MSD's authorisation for its drug "Inegy".

Clonmel, which produces the Ezetimibe/Simvastin generic, counterclaimed, contending the SPC breached a 2009 EU SPC regulation. Clonmel said the combination of the two active ingredients of Ezetimibe and Simvastin was not protected by the underlying patent.

Clonmel also contended Ezetimibe was the only compound that is protected. The combination drug was previously authorised and therefore MSD’s 2005 SPC was invalid, it said.

MSD disputed Clonmel’s claims. It said once the combination has been the subject of a specific claim in patent, this was a complete answer to Clonmel’s case.

Mr Justice McDonald said his judgment addressed the invalidity claim.

He concluded that the combination of Ezetimibe and Simvastatin is not an invention covered by the patent.

“There is nothing in the evidence or in the materials before the court to explain how the combination can be said to be an invention in itself,” he said.

He held the combination was not protected within Article 3(a) of the 2009 SPC regulation.

Clonmel was therefore entitled to a declaration the SPC was invalid and must be revoked.

In light of his findings, the judge also said there was no basis for him to make a reference on the matter to the Court of Justice of the EU.

MSD is one of the top 10 largest pharmaceutical companies in the world, and says it has spent more than $7.3 billion (€6.6bn) on research and development.