Cytokinetics Inc v. Bristol Myers Squibb Co

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cytokinetics, Incorporated (Delaware)
  • Defendant: Bristol-Myers Squibb Company (Delaware); MyoKardia, Inc. (Delaware)
  • Plaintiff's Counsel: Shaw Keller LLP
• Case Identification: 1:26-cv-01026, D. Del., 08/12/2026
• Venue Allegations: Venue is alleged to be proper in the District of Delaware as both Defendant corporations are organized under the laws of Delaware and thus reside in the district.
• Core Dispute: Plaintiff seeks a declaratory judgment of non-infringement and invalidity for a patent covering a method of treating hypertrophic cardiomyopathy (HCM) with aficamten, the active ingredient in Plaintiff's FDA-approved drug, MYQORZO®.
• Technical Context: The technology involves small-molecule cardiac myosin inhibitors used to treat hypertrophic cardiomyopathy, a genetic heart disease characterized by excessive muscle contractility.
• Key Procedural History: The complaint alleges a complex history where Plaintiff Cytokinetics initially collaborated with Defendant MyoKardia, leading to the development of a first-generation HCM drug, mavacamten. After Defendant Bristol-Myers Squibb acquired MyoKardia, MyoKardia allegedly amended a pending patent application to specifically claim methods of use for aficamten-the active ingredient in Cytokinetics's competing drug, MYQORZO®-shortly before MYQORZO® received FDA approval. This amendment, which led to the patent-in-suit, forms the basis for Plaintiff's invalidity challenge, which questions whether Defendants actually invented the claimed subject matter related to aficamten.

Case Timeline

Date	Event
1998-01-01	Cytokinetics is founded.
2012-08-01	Cytokinetics agrees to "incubate" Defendant MyoKardia.
2018-01-01	Cytokinetics begins human clinical trials for aficamten.
2020-01-06	Cytokinetics announces the start of a Phase 2 clinical trial for aficamten.
2020-08-28	'697 Patent Priority Date (filing of U.S. Provisional App. 63/072,094).
2020-10-05	Bristol-Myers Squibb announces its acquisition of MyoKardia.
2021-08-26	Non-provisional application leading to the '697 Patent is filed.
2021-12-09	FDA grants aficamten Breakthrough Therapy Designation.
2022-01-01	Defendants' drug CAMZYOS® (mavacamten) receives FDA approval.
2024-12-02	Cytokinetics submits New Drug Application for aficamten.
2025-11-12	Defendants amend the patent application to specifically recite aficamten.
2025-12-19	FDA approves Plaintiff's drug MYQORZO® (aficamten).
2026-05-05	U.S. Patent No. 12,616,697 issues.
2026-08-12	Complaint for Declaratory Judgment is filed.

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 12,616,697 - "Methods of Treatment with Myosin Modulator"

• Patent Identification: U.S. Patent No. 12,616,697, "Methods of Treatment with Myosin Modulator", issued May 5, 2026.

The Invention Explained

• Problem Addressed: The patent's background section describes hypertrophic cardiomyopathy (HCM) as a progressive disease driven by excessive heart muscle contraction for which treatment options are limited '697 Patent, col. 1:26-34 The specification notes that while therapies like mavacamten are being developed, new insights are needed into how myosin inhibitors can be used to treat HCM '697 Patent, col. 1:45-50 '697 Patent, col. 2:1-5
• The Patented Solution: The patent discloses a method of treating HCM that involves administering a myosin inhibitor to a patient who is already on beta-blocker therapy, and then transitioning that patient by discontinuing or reducing the beta-blocker therapy '697 Patent, col. 2:8-18 This specific treatment regimen is claimed to result in improved patient outcomes, such as an improvement in peak oxygen uptake (pVO₂) '697 Patent, col. 3:41-47
• Technical Importance: This method of transitioning patients from a standard-of-care beta-blocker to a new myosin inhibitor purports to offer a defined therapeutic strategy for managing HCM, potentially improving efficacy and patient outcomes beyond what might be achieved with either drug class alone or in a simple combination (Compl. ¶7; Compl. ¶8; Compl. ¶9).

Key Claims at a Glance

• The complaint asserts non-infringement and invalidity of claims of the '697 patent, focusing on independent claim 1 and its dependent claims Compl. ¶¶57-59
• The essential elements of independent claim 1 are:
  • A method of treating a patient having cardiac hypercontractility, impaired cardiac relaxation and/or left ventricular hypertrophy;
  • wherein the patient is undergoing β blocker therapy;
  • the method comprising: discontinuing the β blocker therapy or reducing the amount of β blocker therapy; and
  • administering to the patient a therapeutically effective amount of a myosin inhibitor;
  • wherein the patient achieves an improvement in pVO₂ of at least about 2.2 mL/kg/min.
• The complaint notes that dependent claim 8 requires the myosin inhibitor to be aficamten Compl. ¶44 Plaintiff reserves the right to seek judgment on other claims of the '697 Patent Compl. ¶58

III. The Accused Instrumentality

Product Identification

• The subject of this declaratory judgment action is the commercialization of MYQORZO®, a drug whose active ingredient is aficamten Compl. ¶1

Functionality and Market Context

• MYQORZO® is a cardiac myosin inhibitor developed by Cytokinetics and approved by the FDA for the treatment of obstructive hypertrophic cardiomyopathy (oHCM) Compl. ¶4 Compl. ¶32
• The complaint alleges that MYQORZO® demonstrates substantial efficacy and a favorable safety profile, offering a straightforward and flexible dosing regimen with no requirement for drug-drug interaction monitoring Compl. ¶4 It is positioned as a direct competitor to Defendants' drug CAMZYOS® (mavacamten) and is described by industry observers as a potential "best-in-class" therapy Compl. ¶4 Compl. ¶42 The infringement controversy centers on whether the FDA-approved use of MYQORZO®, as described in its label and marketing, constitutes practice of the method claimed in the '697 Patent Compl. ¶¶57-59

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

As this is a declaratory judgment action, the analysis below summarizes Plaintiff Cytokinetics' stated bases for non-infringement of the '697 Patent.

'697 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Non-Infringing Functionality	Complaint Citation	Patent Citation
A method of treating a patient having cardiac hypercontractility, impaired cardiac relaxation and/or left ventricular hypertrophy...	Plaintiff Cytokinetics argues it does not directly infringe because it is a pharmaceutical company that sells MYQORZO® but does not itself treat patients or administer the drug.	¶58	col. 2:8-12
wherein the patient is undergoing β blocker therapy, the method comprising: discontinuing the β blocker therapy or reducing the amount of β blocker therapy;	Plaintiff alleges that the FDA-approved label for MYQORZO® does not teach, instruct, or promote administering the drug to patients already on β blocker therapy and then "actively discontinuing" or reducing that therapy as part of a prescribed method.	¶59	col. 2:13-18
and administering to the patient a therapeutically effective amount of a myosin inhibitor;	Plaintiff argues that it does not directly "administer" the drug and that its promotional materials do not induce infringement of the claimed method, which requires administration in the specific context of discontinuing or reducing beta-blocker therapy.	¶58; ¶59	col. 2:19-21
wherein the patient achieves an improvement in pVO₂ of at least about 2.2 mL/kg/min.	This limitation describes a result of the claimed method. Plaintiff's non-infringement argument is based on not performing or inducing the preceding method steps that would lead to this result.	¶57; ¶59	col. 4:41-42

• Identified Points of Contention:
  • Indirect Infringement Scope: A central dispute is whether the FDA-approved label and promotional materials for MYQORZO® induce infringement of Claim 1. The question for the court will be whether the MYQORZO® label instructs or encourages physicians to perform the specific sequence of acts in the claim, particularly the active discontinuation or reduction of beta-blocker therapy in conjunction with administering the myosin inhibitor Compl. ¶59
  • Written Description and Enablement: A significant point of contention revolves around patent validity under 35 U.S.C. § 112. The complaint alleges that the patent application originally disclosed data only for mavacamten and was amended to specifically claim aficamten only after Cytokinetics publicized positive clinical results for its drug (Compl. ¶7; Compl. ¶8; Compl. ¶9). This raises the question of whether the inventors were in possession of the claimed invention as it pertains to aficamten at the time of filing and whether the specification provides adequate written description and enablement for the full scope of "myosin inhibitors," including aficamten Compl. ¶68

V. Key Claim Terms for Construction

• The Term: "myosin inhibitor"

• Context and Importance: The construction of this term is critical for the invalidity analysis. The complaint alleges the patent specification lacks sufficient written description and enablement for the full scope of this term because it only provides data for mavacamten, yet the claims were amended to cover aficamten Compl. ¶38 Compl. ¶39 Practitioners may focus on this term to determine if the patent properly covers a class of compounds or is limited to the specific examples disclosed.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claims use the broad functional term "myosin inhibitor" '697 Patent, cl. 1 The specification identifies aficamten by name as a compound that could be used in the disclosed methods, which could be argued as evidence of possession Compl. ¶39
  • Evidence for a Narrower Interpretation: The complaint alleges that the patent application's data and examples are limited to mavacamten and a related analog, providing no substantive information or clinical data regarding aficamten (Compl. ¶¶7; Compl. ¶39). This could support an argument that the inventors only possessed the invention as it related to mavacamten.

• The Term: "discontinuing the β blocker therapy or reducing the amount of β blocker therapy"

• Context and Importance: This term is central to the non-infringement dispute. Cytokinetics contends that the MYQORZO® label does not instruct or encourage this specific action Compl. ¶59 The court's interpretation of what actions satisfy this limitation will be pivotal.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A broad reading might encompass any situation where a physician, exercising clinical judgment, decides to taper a beta-blocker after seeing a patient's response to a myosin inhibitor. The patent summary describes the method as "comprising... discontinuing... or reducing" '697 Patent, col. 2:13-18
  • Evidence for a Narrower Interpretation: A narrower reading might require a specific, explicit instruction in the accused product's label to discontinue or reduce beta-blocker therapy as an integral part of the treatment method. Cytokinetics alleges its label does not contain such an instruction to "actively" discontinue the therapy Compl. ¶59

VI. Other Allegations

• Indirect Infringement: As the plaintiff in a declaratory judgment action, Cytokinetics argues that it does not induce or contribute to infringement of the '697 Patent. The complaint alleges that the FDA-approved use and promotional materials for MYQORZO® do not "teach, instruct, encourage, or promote" the methods claimed in the patent Compl. ¶59 It further alleges the existence of substantial non-infringing uses for MYQORZO®, a defense to contributory infringement Compl. ¶60
• Willful Infringement: This is not alleged in the complaint.

VII. Analyst's Conclusion: Key Questions for the Case

• A central issue will be one of validity and possession: does the '697 patent's specification provide sufficient written description to demonstrate that the inventors were in possession of a method using aficamten at the time of filing, as required by 35 U.S.C. § 112, or was the late amendment to include aficamten an improper attempt to cover a competitor's independently developed product?
• A key evidentiary question will be one of inducement: does the FDA-approved label for MYQORZO®, taken as a whole, instruct or encourage physicians to perform the specific, multi-step treatment regimen recited in Claim 1-particularly the step of discontinuing or reducing beta-blocker therapy-or does it merely describe a clinical use that falls outside the patent's claims?
• A third question concerns claim scope and direct infringement: can Defendants establish that any single actor, such as a prescribing physician, performs all steps of the claimed method, including the final step requiring the patient to achieve a specific clinical outcome (an improvement in pVO₂ of at least 2.2 mL/kg/min)?