Recruiting
Phase 2

CK-4021586

Sponsor:

Cytokinetics

Code:

NCT06793371

Conditions

Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)

Eligibility Criteria

Sex: All

Age: 40 - 70+

Healthy Volunteers: Not accepted

Interventions

CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)

Placebo to match CK-4021586

Study Details

Brief summary:

This is a Phase 2 dose-finding study in adult participants with symptomatic HFpEF.

Conditions

Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)

Study ID

NCT06793371

Start date

Feb 6, 2025

Status verified date

Jan, 2026

Completion date

Sep, 2026

Anticipated

Primary completion date

Sep, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40 - 70+

Healthy Volunteers: Not accepted

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 comorbid atrial fibrillation or flutter.
  • Body mass index < 40 kg/m2.
  • Participants on beta-blockers, angiotensin-converting enzyme (ACE)/angiotensin II receptor blocker (ARB) or angiotensin receptor/neprilysin inhibitor (ARNI), must be on stable doses for more than 30 days prior to screening.
  • Participants on a glucagon-like peptide-1 (GLP-1) agonist must be on a stable dose for more than 24 weeks prior to screening with no anticipated plans to change dose during this study.

Exclusion Criteria:

  • History or evidence of any other clinically significant disorder, malignancy, active infection, other condition, or disease that, in the opinion of the investigator or the Medical Monitor, would pose a risk to patient safety or interfere with the study evaluation, procedures, or completion.
  • Other protocol-defined Inclusion/Exclusion criteria apply.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: CK-4021586 - Cohort 1

Participants may receive 150 mg or 300 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.

placebo comparator: Placebo - Cohort 1

Participants will receive placebo daily for up to 12 weeks.

experimental: CK-4021586 - Cohort 2

Participants may receive 300 mg or 450 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.

placebo comparator: Placebo - Cohort 2

Participants will receive placebo daily for up to 12 weeks.

experimental: CK-4021586 - Cohort 3

Participants may receive 450 mg or 600 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total.

placebo comparator: Placebo - Cohort 3

Participants will receive placebo daily for up to 12 weeks.

Interventions

CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)

CK-4021586 administered orally

Placebo to match CK-4021586

Placebo administered orally

Primary outcome measure

  • Incidence of early drug discontinuation [ Time Frame: 12 weeks ]
  • Incidence of LVEF < 40% [ Time Frame: 12 weeks ]
  • Incidence of AEs [ Time Frame: 12 weeks ]

Central Contacts and Locations

Central contacts

Cytokinetics MD

650-624-2929medicalaffairs@cytokinetics.com

Locations

Eastern Shore Research Institute, LLC

Recruiting

Fairhope, Alabama, United States, 36532

University of Arizona Sarver Heart Center

Recruiting

Tucson, Arizona, United States, 85724

John L. McClellan Memorial Veterans Hospital

Recruiting

Little Rock, Arkansas, United States, 72205

BioSolutions Clinical Research Center

Recruiting

Imperial, California, United States, 92251

Profound Research LLC

Recruiting

Pasadena, California, United States, 91105

University of California, San Francisco - Heart and Vascular Center

Recruiting

San Francisco, California, United States, 94143

FOMAT - Comprehensive Cardiovascular Care

Recruiting

Santa Maria, California, United States, 93454

Blue Coast Research Center, LLC

Recruiting

Vista, California, United States, 92081

Las Mercedes Medical Research

Recruiting

Hialeah, Florida, United States, 33012

New Generation of Medical Research

Recruiting

Hialeah, Florida, United States, 33016

Cleveland Clinic Florida

Recruiting

Weston, Florida, United States, 33331

Methodist Medical Center of Illinois

Recruiting

Peoria, Illinois, United States, 61636

Massachusetts General Hospital

Recruiting

Boston, Massachusetts, United States, 02214

Mayo Clinic

Recruiting

Rochester, Minnesota, United States, 55905

Washington University Center for Advanced Medicine

Recruiting

St Louis, Missouri, United States, 63110

Morristown Medical Center

Recruiting

Morristown, New Jersey, United States, 07960

NYU Langone Health

Recruiting

New York, New York, United States, 10016

Mount Sinai West

Recruiting

New York, New York, United States, 10019

The Lindner Center for Research & Education at The Christ Hospital

Recruiting

Cincinnati, Ohio, United States, 45219

Oregon Health and Science University

Recruiting

Portland, Oregon, United States, 97239

University of Texas Southwestern Medical Center, Dallas

Recruiting

Dallas, Texas, United States, 75390

Center for Advanced Heart Failure

Recruiting

Houston, Texas, United States, 77030

Swedish Heart & Vascular Institute, Advanced Cardiac Support Program

Recruiting

Seattle, Washington, United States, 98122

Froedtert Hospital - Center for Advanced Care

Recruiting

Milwaukee, Wisconsin, United States, 53226

More Information

Sponsor

Cytokinetics

Last update posted

Aug 27, 2026

Last verified

Jan, 2026

Keywords

  • Symptomatic heart failure with preserved ejection fraction
  • HFpEF
  • Heart failure
  • CK-4021586
  • CK-586
  • AMBER-HFpEF
  • AMBER
  • Cardiac myosin inhibitor
  • CMI
  • CY 9021
  • ulacamten

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Cytokinetics on 2026-08-27.