Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)Phase 2AMBER-HFpEFNCT06793371
AMBER-HFpEF: Assessment of CK-4021586 in a Multi-Center, Blinded Evaluation of Safety and Tolerability Results in HFpEF
A Phase 2 study testing CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg) in people with Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF), run by Cytokinetics at 26 sites in United States.
Trial summary
This is a Phase 2 dose-finding study in adult participants with symptomatic HFpEF. Read more about this study
- Who is it for?
- Ages 40 to 85 years
- Conditions the study is for
- Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)
- What is being tested?
- CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 26 sitesUnited States
- Study dates
- 6 Feb 2025to Sep 2026
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
26 sites in 1 country. Contact the study team or a site near you to ask about taking part.
26 sites in 1 country
United States26 sites, 24 recruiting
- Recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02214
- Recruiting
The Lindner Center for Research & Education at The Christ Hospital
Cincinnati, Ohio, 45219
- Recruiting
University of Texas Southwestern Medical Center, Dallas
Dallas, Texas, 75390
- Recruiting
Eastern Shore Research Institute, LLC
Fairhope, Alabama, 36532
- Recruiting
Las Mercedes Medical Research
Hialeah, Florida, 33012
- Recruiting
New Generation of Medical Research
Hialeah, Florida, 33016
- Recruiting
Center for Advanced Heart Failure
Houston, Texas, 77030
- Recruiting
BioSolutions Clinical Research Center
Imperial, California, 92251
- Recruiting
John L. McClellan Memorial Veterans Hospital
Little Rock, Arkansas, 72205
- Recruiting
Froedtert Hospital - Center for Advanced Care
Milwaukee, Wisconsin, 53226
- Recruiting
Morristown Medical Center
Morristown, New Jersey, 07960
- Recruiting
NYU Langone Health
New York, New York, 10016
- Recruiting
Mount Sinai West
New York, New York, 10019
- Recruiting
Profound Research LLC
Pasadena, California, 91105
- Recruiting
Methodist Medical Center of Illinois
Peoria, Illinois, 61636
- Recruiting
Oregon Health and Science University
Portland, Oregon, 97239
- Recruiting
Mayo Clinic
Rochester, Minnesota, 55905
- Recruiting
University of California, San Francisco - Heart and Vascular Center
San Francisco, California, 94143
- Recruiting
FOMAT - Comprehensive Cardiovascular Care
Santa Maria, California, 93454
- Recruiting
Swedish Heart & Vascular Institute, Advanced Cardiac Support Program
Seattle, Washington, 98122
- Withdrawn
Louisiana Heart Center
Slidell, Louisiana, 70458
- Recruiting
Washington University Center for Advanced Medicine
St Louis, Missouri, 63110
- Recruiting
University of Arizona Sarver Heart Center
Tucson, Arizona, 85724
- Withdrawn
DelRicht Research
Vienna, Virginia, 22182
- Recruiting
Blue Coast Research Center, LLC
Vista, California, 92081
- Recruiting
Cleveland Clinic Florida
Weston, Florida, 33331
About this study
Official title: A Multi-Center, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CK-4021586 in Adults With Symptomatic Heart Failure With Preserved Ejection Fraction
This is a Phase 2 dose-finding study in adult participants with symptomatic HFpEF.
- Being tested
- CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg), Placebo to match CK-4021586
- 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
- Medical subject headings
- Heart Failure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)Drug
Also called ulacamten
CK-4021586 administered orally
Placebo to match CK-4021586Drug
Placebo administered orally
| Study group | Role | What they receive |
|---|---|---|
| CK-4021586 - Cohort 1 | Experimental | Participants may receive 150 mg or 300 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. Receives: Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg) |
| Placebo - Cohort 1 | Placebo comparator | Participants will receive placebo daily for up to 12 weeks. Receives: Drug: Placebo to match CK-4021586 |
| CK-4021586 - Cohort 2 | Experimental | Participants may receive 300 mg or 450 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. Receives: Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg) |
| Placebo - Cohort 2 | Placebo comparator | Participants will receive placebo daily for up to 12 weeks. Receives: Drug: Placebo to match CK-4021586 |
| CK-4021586 - Cohort 3 | Experimental | Participants may receive 450 mg or 600 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. Receives: Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg) |
| Placebo - Cohort 3 | Placebo comparator | Participants will receive placebo daily for up to 12 weeks. Receives: Drug: Placebo to match CK-4021586 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of early drug discontinuation
Incidence of early drug discontinuation observed during dosing of CK 4021586 in patients with HFpEF
Measured: 12 weeks
Incidence of LVEF < 40%
Incidence of left-ventricular ejection fraction (LVEF) < 40% observed during dosing of CK-4021586 in patients with HFpEF
Measured: 12 weeks
Incidence of AEs
Incidence of adverse events observed during dosing of CK-4021586 in patients with HFpEF
Measured: 12 weeks
Secondary outcomes (5)
Change in NT-proBNP
Change from baseline values in NT-proBNP to Week 6 and Week 12
Measured: Baseline to Week 6 and Week 12
Plasma concentrations of CK-4021586
Observed 2-hour post dose plasma concentration (C2hr) and minimum plasma concentration (Cmin) for CK-4021586 over the dosing interval
Measured: 12 weeks
Concentration-response relationship of CK-4021586 on NT-proBNP change
Slope of the relationship of plasma concentration of CK-4021586 to the change from baseline in the NT-proBNP
Measured: Baseline to Week 12
Concentration-response relationship of CK-4021586 to LVEF change
Slope of the relationship of plasma concentration of CK-4021586 to the change from baseline in the LVEF
Measured: Baseline to Week 12
Change in LVEF
Change from baseline in LVEF at Week 6 and Week 12
Measured: Baseline to Week 6 and Week 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jan 2025
- Study start6 Feb 2025
- Primary completionSep 2026 (estimated)
- Study completionSep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cytokinetics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Cytokinetics MD, Study director, Cytokinetics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06793371
- Sponsor's protocol ID
- CY 9021
- Other IDs
- 2024-516349-38-00
- Acronym
- AMBER-HFpEF
- Status last verified
- Jan 2026
- First submitted
- 21 Jan 2025
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multi-Center, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CK-4021586 in Adults With Symptomatic Heart Failure With Preserved Ejection Fraction
- ClinicalTrials.gov ID
- NCT06793371
- Acronym / sponsor ID
- AMBER-HFpEF / CY 9021
- Keywords
- Symptomatic heart failure with preserved ejection fraction, HFpEF, Heart failure, CK-4021586, CK-586, AMBER-HFpEF, AMBER, Cardiac myosin inhibitor
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- CytokineticsIndustry (pharma, biotech, devices)
- Study start
- 6 Feb 2025 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 27 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a Phase 2 dose-finding study in adult participants with symptomatic HFpEF.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| CK-4021586 - Cohort 1 | Experimental | Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)Participants may receive 150 mg or 300 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. |
| Placebo - Cohort 1 | Placebo comparator | Drug: Placebo to match CK-4021586Participants will receive placebo daily for up to 12 weeks. |
| CK-4021586 - Cohort 2 | Experimental | Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)Participants may receive 300 mg or 450 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. |
| Placebo - Cohort 2 | Placebo comparator | Drug: Placebo to match CK-4021586Participants will receive placebo daily for up to 12 weeks. |
| CK-4021586 - Cohort 3 | Experimental | Drug: CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)Participants may receive 450 mg or 600 mg of CK-4021586 daily, guided by echocardiography assessments, for 12 weeks total. |
| Placebo - Cohort 3 | Placebo comparator | Drug: Placebo to match CK-4021586Participants will receive placebo daily for up to 12 weeks. |
Who may qualify
- Ages
- 40 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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.
Key exclusion criteria (2 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg)Also: ulacamtenCK-4021586 administered orally | Drug | CK-4021586 - Cohort 1, CK-4021586 - Cohort 2, CK-4021586 - Cohort 3 |
| Placebo to match CK-4021586Placebo administered orally | Drug | Placebo - Cohort 1, Placebo - Cohort 2, Placebo - Cohort 3 |
Primary outcome
Incidence of early drug discontinuation
Time frame: 12 weeks
Incidence of early drug discontinuation observed during dosing of CK 4021586 in patients with HFpEF
Incidence of LVEF < 40%
Time frame: 12 weeks
Incidence of left-ventricular ejection fraction (LVEF) < 40% observed during dosing of CK-4021586 in patients with HFpEF
Incidence of AEs
Time frame: 12 weeks
Incidence of adverse events observed during dosing of CK-4021586 in patients with HFpEF
5 secondary outcomes
Change in NT-proBNP
Time frame: Baseline to Week 6 and Week 12
Plasma concentrations of CK-4021586
Time frame: 12 weeks
Concentration-response relationship of CK-4021586 on NT-proBNP change
Time frame: Baseline to Week 12
Concentration-response relationship of CK-4021586 to LVEF change
Time frame: Baseline to Week 12
Change in LVEF
Time frame: Baseline to Week 6 and Week 12
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Cytokinetics MD study director
Cytokinetics
26 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing CK-4021586 (150 mg, 300 mg, 450 mg, and 600 mg) in people with Symptomatic Heart Failure With Preserved Ejection Fraction (HFpEF), run by Cytokinetics at 26 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 26 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cytokinetics MD (650-624-2929, medicalaffairs@cytokinetics.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of early drug discontinuation (time frame: 12 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Aug 2026.