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CK-4021586

Phase 2

Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF) | Small molecule | Cardiovascular |Cytokinetics, Incorporated|Trials Updated: Aug 27, 2026

CK-4021586 development status

Highest phase Phase 2
Registered trials 1 across 1 sponsor since May 2023

CK-4021586 target and mechanism

Molecular targetcardiac myosin
Target classProtein
ModalitySmall molecule

Success Probability

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Market & Valuation

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Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLED
Total Trials1
Total Enrollment60

FDA Designations

No designations recorded

CK-4021586 clinical trials

CK-4021586 · 1 trial · 1 indication

Phase 2 1
NCT06793371AMBER-HFpEF: Assessment of CK-4021586 in a Multi-Center, Blinded Evaluation of Safety and Tolerability Results in HFpEFSymptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)
RECRUITING60 Analytics
PHASE2RECRUITING
AMBER-HFpEF: Assessment of CK-4021586 in a Multi-Center, Blinded Evaluation of Safety and Tolerability Results in HFpEF
Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)Unlock trial analytics

Study Endpoints

Primary Endpoints

Incidence of early drug discontinuation
12 weeks

Incidence of early drug discontinuation observed during dosing of CK 4021586 in patients with HFpEF

Incidence of LVEF < 40%
12 weeks

Incidence of left-ventricular ejection fraction (LVEF) \< 40% observed during dosing of CK-4021586 in patients with HFpEF

Incidence of AEs
12 weeks

Incidence of adverse events observed during dosing of CK-4021586 in patients with HFpEF

Secondary Endpoints

Change in NT-proBNP
Baseline to Week 6 and Week 12
Plasma concentrations of CK-4021586
12 weeks
Concentration-response relationship of CK-4021586 on NT-proBNP change
Baseline to Week 12
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Study Design & Arms

AllocationRANDOMIZED
MaskingTRIPLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
CK-4021586 - Cohort 1EXPERIMENTALParticipants may receive 150 mg or 300 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.
Placebo - Cohort 1PLACEBO_COMPARATORParticipants will receive placebo daily for up to 12 weeks.
CK-4021586 - Cohort 2EXPERIMENTALParticipants may receive 300 mg or 450 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.
Placebo - Cohort 2PLACEBO_COMPARATORParticipants will receive placebo daily for up to 12 weeks.
CK-4021586 - Cohort 3EXPERIMENTALParticipants may receive 450 mg or 600 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.
Placebo - Cohort 3PLACEBO_COMPARATORParticipants will receive placebo daily for up to 12 weeks.

Interventions

NameTypeDescription
CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)DRUGCK-4021586 administered orally
Placebo to match CK-4021586DRUGPlacebo administered orally
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Eligibility Criteria

Age Range40 Years to 85 Years
SexALL
Healthy VolunteersNo
Study Sites26

Inclusion Criteria: * Males and females ≥ 40 years and ≤ 85 years of age at screening. * Diagnosed with HF with NYHA functional class II or III. * Screening echocardiography with LVEF ≥ 60%. * Screening NT-proBNP ≥ 300 pg/mL for participants in sinus rhythm and ≥ 900 pg/mL for participants with com...

Countries:United States
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Recent Changes (Last 90 Days)

LOWAug 27, 2026NCT06793371lastUpdatePostDate: changed
LOWAug 27, 2026NCT06793371lastUpdatePostDate: changed

Frequently asked questions about CK-4021586

What is CK-4021586?

CK-4021586 is an investigational small molecule being developed by Cytokinetics, Incorporated for symptomatic heart failure with preserved ejection fraction, or HFpEF. It is currently in Phase 2 clinical development and has not been approved by the FDA. It is being studied in a placebo-controlled trial called AMBER-HFpEF.

What is CK-4021586 used for in HFpEF?

CK-4021586 is being studied for the treatment of symptomatic heart failure with preserved ejection fraction (HFpEF), a form of heart failure in which the heart's pumping function appears preserved but patients experience symptoms. It is investigational and has not been approved for any indication. The Phase 2 AMBER-HFpEF trial is evaluating its safety and tolerability in this population.

What does CK-4021586 target?

CK-4021586 targets cardiac myosin, a protein that drives heart muscle contraction. By acting directly on cardiac myosin, the drug is designed to modulate the contractile machinery of the heart. This mechanism is being explored in symptomatic heart failure with preserved ejection fraction, where impaired cardiac relaxation and contraction contribute to symptoms.

Who is developing CK-4021586?

CK-4021586 is being developed by Cytokinetics, Incorporated, a biopharmaceutical company traded on the Nasdaq under the ticker CYTK. Cytokinetics is focused on cardiovascular therapeutics and is running the Phase 2 AMBER-HFpEF trial of CK-4021586 in the United States.

What phase is CK-4021586 in?

CK-4021586 is in Phase 2 clinical development. It is investigational and has not been approved by the FDA. The ongoing Phase 2 trial, AMBER-HFpEF, is currently recruiting participants and is designed to assess safety and tolerability in patients with symptomatic heart failure with preserved ejection fraction.

What clinical trials is CK-4021586 in?

CK-4021586 is being evaluated in one active clinical trial, NCT06793371, also known as AMBER-HFpEF. This Phase 2 study is a multi-center, randomized, double-blind, placebo-controlled trial assessing safety and tolerability in symptomatic heart failure with preserved ejection fraction. It is recruiting in the United States and plans to enroll 60 participants aged 40 years and older.