When the Prior Art Just Gels: Motivation to Combine and a Reasonable Expectation of Success at the Federal Circuit
The Federal Circuit affirmed a USPTO inter partes review decision finding claims 1-8 of Almirall LLC’s US Patent No. 9,517,219 invalid for obviousness.
The 219 Patent relates to methods of treating acne or rosacea with dapsone formulations that include, among other things, an acrylamide/sodium acryloyldimethyl taurate copolymer (“A/SA”) thickening agent. During the IPR, the challenger Anmeal Pharmaceuticals, LLC successfully argued the patent was obvious in light of three prior art documents: Garrett, Nadau-Fourcade, and Bonacucina.
Almirall argued on appeal that (1) the USPTO erred in presuming obviousness based on overlapping ranges for components; and (2) the USPTO’s obviousness determinations were unsupported by the substantial evidence.
The Federal Circuit found “[a] prima facie case of obviousness typically exists when the ranges of a claimed composition overlap the ranges disclosed in the prior art.” In this case, Garrett disclosed overlapping ranges for all components of the claimed compositions except for the A/SA thickening agent, which Garrett substituted for a carbomer gelling agent. Nadau-Fourcade and Bonacucina both disclosed an A/SA thickener within the claimed ranges. As carbomer and A/SA agents were interchangeable (discussed below), the USPTO did not err in concluding the claimed ranges had been disclosed.
Even if the USPTO had not presumed obviousness, the Federal Circuit found the matter was “simply a case of substituting one known gelling agent for another.”
As a preliminary argument, the patentee asserted that Garrett failed to disclose the limitation in claims 1 and 6: “wherein the topical pharmaceutical composition does not comprise adalpene.” The Federal Circuit disagreed, finding “[a] reference need not state a feature’s absence in order to disclose a negative limitation.” Garrett disclosed a complete formulation—excluding an additional active ingredient.
Next, the Court found the record supported a motivation to replace the carbomer gelling agent in Garrett with a A/SA thickening agent from either Nadau-Fourcade or Bonacucina. In particular, the Court held that A/SA copolymers would have been “predictable design choices” for POSITA in developing topical dapsone formulations, citing KSR International Co. v Teleflex Inc, 550 US 398 (2007).
Although “a reasonable expectation of success does not require absolute predictability of success,” the Court held that POSITA would have understood the use of A/SA agents in Garrett to be routine. The prior art taught that an A/SA agent was interchangeable with a carbomer agent, both of which were known for use in topical compositions with water insoluble drugs, and POSITA would not have expected any incompatibilities. The use of an A/SA agent was also known to overcome problems with grittiness and requirements for neutralization associated with a carbomer agent.
A copy of the decision can be found here.