Cytokinetics challenges BMS patent in bid to clear MYQORZO launch obstacle

Cytokinetics has launched a Delaware patent action against Bristol Myers Squibb and its MyoKardia subsidiary, seeking to clear a recently issued patent that it says does not cover its cardiac myosin inhibitor MYQORZO (aficamten).

Cytokinetics filed the complaint on August 13, seeking declaratory judgments from the US District Court for the District of Delaware that MYQORZO does not infringe US Patent No. 12,616,697 and that the patent’s claims are invalid. The company is also seeking preliminary and permanent relief preventing Bristol Myers Squibb, MyoKardia, and those acting with them from threatening or initiating infringement proceedings against Cytokinetics or users, customers, dealers, suppliers, sellers, and distributors of MYQORZO. 

The action comes just over three months after the patent was issued on May 5, 2026. US Patent No. 12,616,697, titled Methods of treatment with myosin modulator, is assigned to MyoKardia, Inc. and contains 52 claims. The underlying application, however, traces back to an international application filed in 2021 and claims priority to a provisional application filed on August 28, 2020. 

The dispute places two competing cardiac myosin treatments at the center of a patent battle as Cytokinetics continues the US commercial rollout of MYQORZO.

A recently issued method-of-treatment patent

Independent claim 1 covers a method of treating a patient with cardiac hypercontractility, impaired cardiac relaxation and/or left ventricular hypertrophy who is undergoing beta-blocker therapy.

The claim requires discontinuing or reducing beta-blocker therapy and administering a therapeutically effective amount of a myosin inhibitor, with the patient achieving an improvement in peak oxygen consumption (pVO₂) of at least approximately 2.2 mL/kg/min. 

That language is potentially significant because claim 1 does not expressly identify a particular drug such as aficamten. Instead, it refers to a “myosin inhibitor” as part of a specified treatment regimen, along with several other claim limitations.

That does not mean that MYQORZO infringes. Whether a particular product or treatment method falls within the claims will depend on claim construction and the facts established in the litigation. Cytokinetics’ filing makes clear that it disputes both infringement and validity.

Cytokinetics seeks more than a non-infringement declaration

Cytokinetics’ August 13 complaint goes beyond simply asking the court to determine that its product does not infringe.

According to the company’s SEC filing, Cytokinetics is seeking declarations that it has not infringed any valid claim of the ’697 patent and that the patent’s claims are invalid. It is also seeking preliminary and permanent relief preventing the defendants from threatening or initiating infringement litigation against Cytokinetics and parties involved in the commercial distribution and sale of MYQORZO.

The company has demanded a jury trial and is seeking costs and attorneys’ fees, including under 35 U.S.C. § 285 if the case is found to be exceptional. Cytokinetics has also acknowledged that the outcome of the litigation remains uncertain. 

Dow Jones reported that Bristol Myers Squibb had not immediately responded to a request for comment.

A potential question of claim scope

For patent practitioners, the dispute raises an important question about the scope of method-of-treatment claims directed to cardiac myosin inhibition.

The ’697 patent’s first claim does not expressly identify aficamten. Instead, it requires the administration of a therapeutically effective amount of a “myosin inhibitor” alongside specified treatment circumstances and a defined clinical outcome. 

The breadth of that language will not, by itself, determine whether MYQORZO falls within the patent’s scope. Cytokinetics would still need to establish its position on each relevant claim limitation, while its invalidity challenge raises separate questions concerning the patent’s validity.

The case nevertheless illustrates how a recently issued patent can become a potential patent obstacle during the commercial rollout of a competing pharmaceutical product, even where the asserted claims are framed around a treatment method rather than a particular competitor’s molecule.

A flashpoint between rival cardiac-myosin therapies

The commercial backdrop makes the case particularly notable.

MYQORZO (aficamten) is a cardiac myosin inhibitor developed by Cytokinetics. The US action comes as the company continues the commercial rollout of the drug.

The timing is significant: Cytokinetics had previously identified the MyoKardia patent application as a potential third-party intellectual property risk. In an earlier SEC filing, the company disclosed that it was aware of the patent application and the possibility that, following issuance, MyoKardia could assert the resulting patent against certain uses of MYQORZO. Cytokinetics warned that such an assertion could lead to patent litigation and potentially affect commercialization.

The August 13 action represents a proactive response following issuance, with Cytokinetics now asking a federal court to resolve the infringement and validity questions.

The case is also unusual in that it is not a conventional originator-versus-generic dispute. Instead, it pits two innovator companies against one another in a market involving competing cardiac-myosin treatments.

For life-sciences patent strategists, the case could therefore offer a useful illustration of how method-of-treatment patents may function as potential blocking rights around competing products — and how an emerging innovator may respond before an infringement action is brought.

What comes next?

Among the issues likely to become important as the case develops are how the parties characterize the scope and validity of the ’697 claims, what evidence Cytokinetics relies upon in challenging them, and whether Bristol Myers Squibb or MyoKardia responds with infringement counterclaims or other proceedings.

The patent’s reference to a “myosin inhibitor” could make claim construction and the application of the claims to aficamten important areas of the dispute. But it would be premature to conclude from the claim language alone that MYQORZO falls within the patent’s scope.

The litigation may also provide a useful test of how a recently issued method-of-treatment patent can be used in competition between innovative pharmaceutical companies developing drugs that act on the same biological target.

For now, Cytokinetics is seeking to establish in court that it can continue commercializing MYQORZO without infringing the ’697 patent — while also attempting to prevent the patent from being used as a basis for infringement litigation against the company and parties in its commercial chain.

The case provides an early look at a potentially significant patent contest between rival cardiac-myosin drug developers, with the outcome potentially affecting the freedom to commercialize a next-generation treatment for hypertrophic cardiomyopathy.

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