Listen to this post

This case addresses obviousness under 35 U.S.C. § 103 in relation to a method of increasing prostacyclin release to reduce hypertension in a patient. In particular, this case discusses issues relating to motivation to combine, unexpected results, and objective indicia of nonobviousness.


John L. Couvaras filed U.S. Patent Application 15/131,442 (the “’442 Patent”) with claims directed to a method of increasing prostacyclin release in systemic blood vessels of a human to improve vasodilation and reduce hypertension. Such method claims were directed to the application of a combination of GABA-a agonist and ARB. During prosecution, Couvaras conceded that GABA-a agonists and ARBs have been known for “many, many decades,” but asserted that the prostacyclin increase was unexpected, and therefore should be patentable. Couvaras appealed the final rejection on the matter to the Patent Trial and Appeal Board (“Board”), which affirmed the rejection and held that the “claimed result of an increased prostacyclin release was inherent in the obvious administration of the two known antihypertension agents.” Further, the Board found that Couvaras’s objective indicia arguments did not overcome the prima facie case of obviousness because no evidence existed or was presented to support such a finding. Couvaras then appealed the Board’s decision to the Federal Circuit.


Whether there is motivation to combine prior art disclosing two different antihypertension agents.

Whether the Board sufficiently weighed objective indicia of nonobviousness, including unexpected results, teaching away, the failure of others, and the length of time that elapsed between the initial discovery of the hypertension agents and the claimed method.


The Federal Circuit held that the Board did not err in finding that a skilled artisan would have a motivation to combine the prior art references cited by the examiner during prosecution.

The Federal Circuit held that the Board did not err in finding that the recitation of various mechanistic steps in the pending claims were insufficient to overcome the prima facie obviousness of the claimed methods.


In affirming the Board’s conclusion that a motivation to combine existed to render the invention obvious, the Federal Circuit focused on the fact that both GABA-a agonists and ARBs were known to be useful in the treatment of hypertension. Additionally, Couvaras conceded that the prior art teaches both the combination of ARBs with other antihypertensive agents to improve treatment and the use of ARBs “in combination with other classes of antihypertensive agents to lower blood pressure.” Couvaras attempted to argue that even if the prior art provided a motivation to co-administer two hypertension treatments, the Board failed to identify a “finite number of identified, predictable solutions” as required under KSR. The Federal Circuit rejected this argument on both procedural and substantive grounds. Procedurally, the argument was raised by Couvaras in a footnote, and the Federal Circuit cited Otsuka Pharm. Co. to note that “[a]rguments raised only in footnotes [] are waived.” Otsuka Pharm. Co. v. Sandoz, Inc., 678 F.3d 1280, 1294 (Fed. Cir. 2012). Substantively, the Federal Circuit noted that Couvaras did not present any evidence to the Board supporting the argument that there are a “’substantial number of hypertension treatment agent classes’ that could be considered for such a combination,” while the Board’s decision was based on substantial evidence in light of the prior art suggesting a motivation to combine.

Couvaras argued that the Board incorrectly determined that the antihypertensive agents’ mechanism of action was inherent. Even if the recited mechanism is inherent, argued Couvaras, the increased release of prostacyclin was unexpected, and thus the limitations cannot be dismissed as having no patentable weight due to inherency. The Federal Circuit rejected this argument, relying on In re Montgomery, 677 F.3d 1375, 1381 (Fed. Cir. 2012) to point out that “[n]ewly discovered results of known processes directed to the same purpose are not patentable because such results are inherent.” The prostacyclin mechanism may have been an unexpected result, but it “exert[s] the same ultimate result as the two separate compounds were known to effect: a decrease in blood pressure.” In sum, the Federal Circuit explained that “[r]eciting the mechanism for known compounds to yield a known result cannot overcome a prima facie case of obviousness, even if the nature of that mechanism is unexpected.”

Similarly, the Federal Circuit rejected Couvaras’s argument that the Board erred by finding that the result of the claimed invention was unexpected, but nonetheless failed to give any weight to the unexpected results indicium of nonobviousness. As explained by the Federal Circuit, the focus of the unexpected results inquiry is an “unexpected benefit.” That is, for Couvaras to establish unexpected results, he would have needed to show “better control of hypertension, less toxicity to patients, or the ability to use surprisingly low dosages,” none of which he did. 

With respect to teaching away, Couvaras argued that the prior art taught away from the combined administration that was recited in the claims. Rejecting this argument, the Federal Circuit pointed out that the alleged “teaching away” involved a reference combining different agents than claimed by Couvaras, agents that “operate through different biological mechanisms” rendering the equivalency useless for the purposes of arguing that a prior art reference “teaches away.” 

With respect to the “failure of others to increase prostacyclin release,” the Federal Circuit quickly dispensed with Couvaras’s argument, noting that evidence showing an “investigation into the impact of angiotensin II levels is not a failure to find a solution for an inability to increase prostacyclin release or a failure of the claimed method.”

With respect to the length of time between the publication dates of the prior art and the claimed invention, the Federal Circuit relied on Leo Pharm. Prod., Ltd. V. Rea, 762 F.3d 1346 (Fed. Cir. 2013) to reason that Couvaras’s reliance on the length of time was not sufficient without additional indicia of nonobviousness such as long-felt but unresolved need and failure of others, which were not present in this case.