Apotex Inc. v. UCB, Inc., No. 13-1674 (Fed. Cir. 2014)Annotate this Case
Apotex’s 556 patent, titled “Pharmaceutical Compositions Comprising Moexipril Magnesium,” issued in 2004, from an application that claims priority to a Canadian application filed in 2000. The patent is directed to manufacture of moexipril tablets, an angiotensin-converting enzyme (ACE) inhibitor used to treat hypertension. Like other ACE inhibitors, Moexipril and its acid addition salts are susceptible to degradation and instability. To improve stability, the 556 patent discloses tablets consisting mostly of moexipril magnesium obtained by reacting moexipril or its acid addition salts with an alkaline magnesium compound. Several methods for stabilizing ACE inhibitors were known in the prior art. UCB’s accused products, Univasc and Uniretic, moexipril tablets, sold in the U.S. since 1995 and 1997, respectively, are prior art. In allowing the claims of the 556 patent over findings of obviousness, the examiner stated: prior art teaches that only a portion of drug (if any) may be converted to the alkaline salt and that the stable product results entirely or primarily not from conversion to alkaline salts, but from stabilization of the moexipril hydrochloride by the presence of the alkaline stabilizing compound in the final product. In 2012 Apotex accused UCB of infringement. The district court ruled that the 556 patent was unenforceable due to the inventor’s inequitable conduct before the PTO in concealing his knowledge and misrepresenting the nature of Univasc and the prior art and submitting results of experiments that he never conducted. The Federal Circuit affirmed, upholding the finding of inequitable conduct.