“Reciting 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.”

In re Couvaras, 22-1489 (Fed. Cir., 2023)

In re Couvaras, 22-1489, 2023 WL 3984753 (Fed. Cir., June 14, 2023)

Precedential Opinion by Circuit Judge Lourie; joined by Circuit Judges Lourie, Dyk, and Stoll

The United States Court of Appeals for the Federal Circuit (CAFC) agreed with the Patent Trial & Appeals Board (PTAB), and the USPTO examiner, that claims in U.S. Patent Application No. 15/131,442 (US2016/228,393), which recites methods of increasing prostacyclin release in the systemic blood vessels of a human with essential hypertension to improve vasodilation, were obvious because the claims relate to combatting hypertension with known antihypertensive agents and merely disclose their previously unappreciated mechanism of action.”

High Level Summary

The prior art taught that GABA-a agonists and ARBs reduce anti-hypertension. Dr. Couvaras discovered that GABA-a agonists and ARBs reduce anti-hypertension, in part, because they increase prostacyclin and promote vasodilation. Dr. Couvaras applied for a patent claiming a method of increasing prostacyclin in an individual with hypertension to improve vasodilation by providing an ARB and a GABA-a agonist.  However, the USPTO rejected the claims because the element of increasing prostacyclin was inherent in the well-known prior art method of independently treating hypertension with an ARB or a GABA-a agonist. 

Visualizing the case with diagrams

Now let’s skeletonize the elements of this case down to arrow diagrams. We don’t need too many facts getting in the way of this good story. 🙂 *

Claim 11 (abridged): A method of increasing prostacyclin in an individual with hypertension to improve vasodilation by providing an ARB and a GABA-a agonist. 

* But seriously, although I am scientist reluctant to loose any nuance, technical terms such as Angiotensin II Receptor Blocker (“ARB”) can be distracting in analyzing the the law in case.  Also, I believe that knowing the claims recite a combination therapy is superfluous and thereby distracting itself. (At least I found them distracting at first. Maybe that’s just me. Please work with me for now.) The CAFC’s rule of law works for both mono and combo therapies. See below for a discussion regarding combination therapies.

The overall goal is to get from A to B. Doctors already know how to get from A to B. It is prior art. No argument there. Then an inventor discovers that X is the mechanism of action that leads to B.

Doctors did not already know that going from A to B involves X. This is not taught in the prior art.  A→X is a genuine new discovery. No argument there either.

Now you have  A→ X→ B.

Although the discovery of A→ X is indeed new, inventors should not be able to patent a claim to the discovery. Even though doctors did not know it, doctors were inherently doing the process of A→ X→ B by simply prescribing A to treat B.  It makes sense that someone should not be able to patent a claim to  A→ X→ B, or even simply A→X, then suddenly prevent doctors from prescribing A→ B, which they have been doing all along.

New methods and mechanisms of action may still be patented

In re Couvaras, however, does not mean that all mechanisms and new uses are not patentable. New uses for old compounds May still be patentable. For example, an inventor may discover that A also renders the benefit of C, and that A affects B by going through mechanism Y.

In this example, the inventor may be able to patent a claim to A→C.

If an inventor simultaneously discovers that A→C goes through the mechanism “Y” then they may be able to patent a claim covering both A→C, A→Y,  and A→Y→C.  

NOTE: The inventor should file both claims simultaneously so the inventor’s disclosure of A→C does not block the claim to A→Y. If not, then the inventor will have the same problem from In re Couvaras.

In summary, patentability of mechanisms (X/Y) rest on the whether the overall benefit (B/C) is unexpected from the known composition (A).

Secondary Considerations

Of course, secondary considerations provide some leniency. But the secondary considerations surely need to be compelling.

“To establish unexpected results, Couvaras would have needed to show that the co-administration of GABA-s agonist and an ARB provided an unexpected benefit,” such as, e.g., better control of hypertension or less toxicity.

Failure of others: “The purported failure to achieve prostacyclin increase through pursuing an unrelated goal did not establish the non-obviousness of the claimed method.”

No long felt need: The anti-hypertensive agents were admitted to be available already.

“The pending claims of the ’422 application literally recite methods of increasing prostacyclin release in the systemic blood vessels of a human with essential hypertension to improve vasodilation. That increased prostacyclin release is achieved by co-administering two well-known types of antihypertensive agents: a GABA-a agonist and an Angiotensin II Receptor Blocker (“ARB”). In reality, the claims relate to combatting hypertension with known antihypertensive agents and claiming their previously unappreciated mechanism of action.”

Novelty vs. Obviousness: Inherency

Q: Why is inherency in a case about obviousness and not about novelty?

A: Here is where the combo-therapy aspect comes in. A combination of two known compounds that render the same benefit is obvious. Dr. Couvaras argued that the discovery of the compounds’ mechanism of action overcame the obviousness rejection. Essentially the argument tried to convince the examiner that each mono therapy was novel. With two novel monotherapies in hand, reasoning follows that combination of two novel monotherapies would have been non-obvious.

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Post Script

On bright side, The USPTO awarded Dr. Couvaras with U.S. Patent No. 9,339,542 in his earlier application. Composition claims to combinations were non-obvious.

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