Federal Circuit affirms Latuda decision in Sumitomo clash
The US Court of Appeals for the Federal Circuit affirmed a lower court’s claim construction of a patent which covers Sunovion’s schizophrenia and bipolar depression drug Latuda on Monday, April 16.
Sumitomo Dainippon Pharma, the parent company of Sunovion, owns US patent number 5,532,372, which relates to “novel imide compounds and their acid addition salts” that are useful as antipsychotic agents.
The patent discloses and claims more than one billion compounds, some of which have stereoisomers.
Stereoisomers are molecules with the same chemical formula and structure but different 3D configurations. If two stereoisomers are “non-superimposable mirror images” of one another, they are called enantiomers.
Lurasidone, the enantiomer of an imide compound covered by the ‘372 patent, is the active ingredient in Sunovion’s Latuda.
Emcure, Teva and other generic companies filed Abbreviated New Drug Applications seeking approval to market generic versions of Latuda.
Sumitomo and Sunovion sued, accusing the defendants of infringing claim 14 of the patent (which covers lurasidone).
The US District Court for the District of New Jersey had to decide what combination of enantiomers claim 14 encompassed—and it construed the claim to cover the two 3D orientations in isolation (the one shown in the claim and the mirror image) as well as mixtures of the two in any ratio.
The generic companies had sought to limit the claim to “a racemic mixture of two enantiomers of which the structural formula is representative” but this was rejected by the court. They then appealed to the Federal Circuit.
“Although the compound can exist in two different 3D orientations that are mirror images of each other, only one is portrayed in the claim,” said Circuit Judge Kara Stoll, on behalf of the court.
Stoll added that the plain claim language and specification demonstrate that claim 14 covers what it depicts: the enantiomer.
“This suffices to resolve the parties’ dispute because appellants concede that the district court’s judgment can be affirmed if we conclude that claim 14 at least covers the enantiomer.”
The Federal Circuit affirmed the lower court’s judgment, concluding that determining whether claim 14 covers additional scope is unnecessary.
Preston Ratliff, partner at Paul Hastings and Sunovion's representative, said: “We are pleased that the Federal Circuit unanimously affirmed the district court’s claim construction.”
Did you enjoy reading this story? Sign up to our free daily newsletters and get stories sent like this straight to your inbox.
Join us at LSPN North America on April 26, find out more here.
