by Dennis Crouch
Almirall, LLC v. Amneal Pharmas LLC (Fed. Cir. 2022)
The court here affirms a PTAB conclusion cancelling claims 1-8 of Almirall’s U.S. Patent 9,517,219 as obvious. The patent claims a method of treating acne/rosacea using a particular formulation:
- Active Ingredient: about 7.5% dapsone;
- Solvent: about 30% to about 40% diethylene glycol monoethyl ether;
- Gelling Agent: about 2% to about 6% of A/SA; and
[note – I edited these for compactness]. The claim also indicates that the composition “does not comprise adapalene.” This concentration of the active ingredient was already known, the idea behind the invention here was to have a product that works well, that customers like, and that has a long shelf life. Thus, the figure submitted to the PTO shows shelf-life:
The prior art includes the commercial product (Aczone) that includes 7.5% dapsone and no adapalene. For the IPR, the PTAB looked at a patent application publication (Garrett) that described the Aczone product in detail. Garret taught a different gelling agent — Carbopol rather than A/SA as required in the patent. A different reference (Nadau-Fourcade) taught the use of A/SA agents in roughly the same concentration range for use in acne/rosacea products. The Board found the combination appropriate and concluded that the claims were invalid.
Presumption of Obviousness: On appeal, the patentee argued that the Board improperly presumed obviousness based upon overlapping ranges. The basic argument is that A/SA was brought from a different reference and there should not be a presumption that its concentration would obviously be the same in the new combination. On appeal, however, the Federal Circuit affirmed the Board’s ruling — finding that the presumption was appropriate here because the evidence proved similarity between carbomers (disclosed in Garret) and A/SA agents (substituted from Nadau-Fourcade)
The Board also credited expert testimony that a person of ordinary skill in the art
would have been able to immediately appreciate that the carbomers and A/SA agents at issue perform the same function and are interchangeable. Moreover, there was no evidence that A/SA agents would have different interactions with the other ingredients of the compositions relative to carbomer. Indeed, the Board credited expert testimony that a skilled artisan “would not have expected any incompatibilities in substituting” the gelling agents.
It was this close similarity in the substitution that allowed the range disclosures to create a presumption of obviousness. In its decision, the court also notes that the stated presumption-of-obviousness is not any kind of burden shifting. Rather, it is simply shorthand for the proposition that overlapping ranges in the prior art justify a factfinder in concluding that the claimed range was known in the art. The patentee is free to provide evidence showing why its particular range is meaningful and thus non-obvious in the face of a similar disclosure range in the prior art.
Negative Limitation: The claims expressly exclude adapalene from the formulation. “[W]herein the … composition does not comprise adapalene.” The key prior art reference (Garrett) does not even mention adapalene, and so, according to the patentee, we are left wondering whether Garrett might include the substance. The Board rejected that argument as did the Federal Circuit. In particular, the court restated its prior precedent that negative limitations need not be expressly stated in the prior art. “[A] reference need not state a feature’s absence in order to disclose a negative limitation.” AC Techs., S.A. v. Amazon.com, Inc., 912 F.3d 1358 (Fed. Cir. 2019).
Reasonable Expectation of Success: Finally, the Court found that the Board had properly identified reasons to combine the references. In particular, the patent challenger provided evidence that gelling compounds were effective and compatible substitutes. As such, the substitution of A/SA was a “predictable design choice.” This falls within the Supreme Court’s guidance from KSR: “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.”
The court also places substantial weight on whether the substitution would have “a reasonable expectation of success.” Here, though, expert testimony was provided regarding their interchangeability. Further, [a] finding of a reasonable expectation of success does not require absolute predictability of success.”