Appeals court reverses district court decision on Altace

A federal appeals court has reversed a decision made by the U.S. District Court for the Eastern District of Virginia, which had found that Lupin Pharmaceuticals had infringed on a compound patent of King Pharmaceuticals’ hypertension drug Altace under the doctrine of equivalents due to obviousness.

The ‘722 patent covers a stereoisomer of ramipril, the key ingredient in Altace. Circuit Judge Richard Linn explained that a stereoisomer, “is an isomer in which the same atoms are bonded to the same other atoms, but where the configuration of those atoms in three dimensions differ.”

Linn decided that Aventis, who King licensed the patent from, failed to “rebut this prima facie case of obviousness by arguing that purified 5(S) ramipril exhibited unexpected results.”