Cumberland Pharms. Inc. v. Mylan Institutional LLC

A suggestion by the FDA to consider whether to include a stabilizer does not establish the necessary proof to make a derivation argument and, due to no reasonable expectation of success, the district court’s validity findings were affirmed.

April 26, 2017

GENERICally Speaking

Case Name:  Cumberland Pharms. Inc. v. Mylan Institutional LLC, Nos. 2016-1155, -1259, 846 F.3d 1213 (Fed. Cir. Jan. 26, 2017) (Circuit Judges Moore, Taranto, and Reyna presiding; Opinion by Taranto, J.) (appeal from N.D. Ill., Pallmeyer, J.)

Drug Product and Patent(s)-in-Suit: Acetadote® (acetylcysteine); U.S. Patent No. 8,399,445 (“the ’445 patent”)

Nature of the Case and Issue(s) Presented:  As of August 24, 2005, the priority date in this case, acetylcysteine was a known antidote for acetaminophen overdoses; it also was known to have a stability problem. A prior-art response to the stability problem was to include edetate disodium (EDTA or edetate) in an acetylcysteine dose. EDTA, a chelating agent, was considered safe, despite potential negative side effects. The ’445 patent claimed stability without the addition of a chelating agent. It covered Cumberland’s chelating-agent-free formulation of Acetadote, an intravenous antidote for overdoses of acetaminophen. Mylan filed an ANDA to market its generic product. Cumberland sued. Mylan stipulated to infringement but asserted invalidity on two grounds: derivation of the claimed invention from someone at the FDA and obviousness. The district court ruled in favor of Cumberland. The district court found that Mylan did not prove: (i) that anyone at the FDA conceived of the claimed invention before the patent-named inventor; and (ii) that there was a reasonable expectation that the claimed formulations, without any chelating agents, would succeed. Mylan appealed and the Federal Circuit affirmed.

Why Cumberland Prevailed:  The district court found that while the evidence did not establish a precise date of conception by the inventor, Mylan failed to persuade the court that anyone other than the inventor ever conceived of it. Given the claim language requiring that the product be “free of chelating agents,” not just EDTA, and the district court’s several references to that particular claim requirement, the Federal Circuit reasoned that the district court’s finding referred to a formulation of Acetadote that simply removed EDTA, without adding another chelating agent in its place. Therefore, Mylan did not prove that an FDA person conceived of that formulation, or communicated it to Cumberland, before the inventor thought of it.

Mylan argued that the FDA’s request for data to support the inclusion of EDTA required Cumberland to undertake research that would have inevitably led it to the invention. But the Federal Circuit ruled that was not enough for derivation because it only evidenced conception and communication of an idea different from the claimed invention that would make the claimed idea obvious. Also, a general goal or research plan does not constitute conception. In any event, documents from the FDA “requesting” that studies be undertaken could be read as focusing on the FDA’s request for a study implementing the idea already suggested by the inventor.

Next, the Federal Circuit affirmed the district court’s rejection of Mylan’s obviousness arguments. Mylan’s principal prior art consisted of EDTA-containing Acetadote and its package insert, which taught all of the claimed limitations except for the removal of EDTA, in combination with references that taught the chelating-agent-free version of acetylcysteine. The Federal Circuit determined that considerable evidence supported the finding that relevant skilled artisans believed that chelating agents were necessary to sequester metal contaminants and prevent oxidative degradation of acetylcysteine and that such artisans had no reasonable expectation of stability without such an agent. Moreover, as late as 2011, Mylan’s own scientists expressed concern that the removal of EDTA would make the product more vulnerable to oxidation. Thus, the district court had sufficient evidence to find no reasonable expectation of success on the part of a skilled artisan.

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