Addressing derivation and obviousness issues, the US Court of Appeals for the Federal Circuit affirmed the district court’s denial of a generic drug manufacturer’s attempt to invalidate a patent based on the theory that the claimed invention was the result of an exchange with the US Food and Drug Administration (FDA) during the drug’s approval process, rather than the named inventor’s idea. Cumberland Pharms. Inc. v. Mylan Institutional LLC, Case No. 16-1155 (Fed. Cir., Jan. 26, 2017) (Taranto, J.).

The case relates to a formulation for the medication acetylcysteine, sold by Cumberland under the brand name Acetadote® as an intravenous antidote for acetaminophen poisoning. The relevant claims cover a stable formulation of acetylcysteine that is “free of chelating agents.” Chelating agents are preservative chemicals that bind to heavy metal ions that would otherwise cause the degradation of the acetylcysteine, interfering with its stability and shelf life.

Mylan filed an application with the FDA to market a generic acetylcysteine product, and argued that patents covering the chelating-agent-free formulation were invalid under § 102(f) and § 103. Mylan’s invalidity theory was based on the fact that Cumberland’s Acetadote® formulation originally included the chelating agent EDTA, but the FDA asked Cumberland to justify the inclusion of EDTA during the regulatory approval process. Cumberland responded that it included the EDTA as a preservative, and also proposed a stability study comparing the original formulation to those with less or no EDTA. The FDA agreed with the proposal and requested that Cumberland perform the stability study, which ultimately showed that, under certain preparation conditions, acetylcysteine would remain stable without the inclusion of EDTA. Mylan argued that because the direction to perform the study came from the FDA, the invention was either derived from the FDA under § 102(f) or obvious.

Both the district court and the Federal Circuit disagreed. The Federal Circuit affirmed the district court’s ruling that the patent was not invalid under either § 102(f) or § 103. With respect to § 102(f), the Court noted that derivation would have required the FDA to have conceived of the invention and all its claim limitations and then have communicated that to Cumberland. As the Court explained, the mere direction to perform a study did not meet this standard, particularly in light of the evidence showing that a Cumberland scientist initially conceived of the study. The Court also found that the FDA’s guidance regarding the EDTA-free study did not render an EDTA-free formulation obvious, even in light of another reference that was silent as to the presence of EDTA. The Court focused on the fact that, even though the prior art suggested EDTA-free formulations, there was no reasonable expectation that the formulations would be “stable,” as required by the claims, because the prevailing view in the art at the time was that chelating agents were required for stability.