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OpenTrials
Enrolling by Invitation

NCT Number: NCT04848506

Open-label Extension Study to Evaluate the Long-term Safety and Tolerability of Aficamten in Adults With HCM

The purpose of this study is to collect long-term safety and tolerability data for aficamten.

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Key information

Conditions

Symptomatic Hypertrophic Cardiomyopathy (HCM) Aortic Stenosis, Subvalvular Aortic Valve Disease Aortic Valve Stenosis Cardiomyopathies Cardiomyopathy, Hypertrophic Cardiovascular Diseases Heart Diseases Heart Valve Diseases

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Instituto Cardiovascular de Buenos Aires(ICBA), Buenos Aires, Argentina

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Completion of a Cytokinetics trial investigating aficamten
  • LVEF ≥ 55% at the Screening Visit

Exclusion criteria

  • Has received treatment with mavacamten: (a) within 56 days prior to dosing and (b) has not received approval for participation from the Medical Monitor.
  • Has participated in another investigational device or drug study or received an investigational device or drug < 1 month (or 5 half-lives for drugs, whichever is longer) prior to screening. Other investigational procedures while participating in this study are not permitted.
  • Since completion of a previous trial of aficamten has:
  • Developed new-onset paroxysmal or permanent atrial fibrillation requiring rhythm restoring treatment (eg, direct-current cardioversion, ablation procedure, or antiarrhythmic therapy) < 30 days prior to screening. Patient may re-screen for CY 6022 after 30 days if heart rate (HR) < 100 bpm and/or rhythm is stable > 30 days
  • Undergone septal reduction therapy (surgical myectomy or transcatheter alcohol ablation)
  • Had a confirmed LVEF < 40% with an associated dose interruption during participation in a prior study with aficamten
  • History of implantable ICD placement within 30 days prior to screening.

Treatment and study plan

Aficamten (5 - 20 mg)

Drug

Aficamten tablets administered orally. During titration phase, clinic visits will occur approximately every 2-6 weeks. In the maintenance phase clinic visits will occur every 24 weeks, with safety check-in occurring every 12 weeks between visits by phone or, if desirable, in the clinic.

Primary outcomes

  1. Incidence of adverse events observed during dosing of aficamten in patients with HCM

    Time frame: Baseline to End of study, up to 5 years

    Patient incidence of reported Adverse Events (AEs)

Secondary outcomes

  1. Incidence of serious adverse events observed during dosing of aficamten in patients with HCM

    Time frame: Baseline to End of study, up to 5 years

    Patient incidence of reported Serious Adverse Events (SAEs)

  2. Incidence of left ventricular ejection fraction (LVEF) < 50% observed during dosing of aficamten in patients with HCM

    Time frame: Baseline to End of study, up to 5 years

    Patient incidence of reported LVEF <50%

  3. Long-term effects of aficamten on left ventricular outflow tract gradient (LVOT G) in patients with oHCM

    Time frame: Baseline through the end of participation at 12-24 week intervals

    Peak LVOT-G at rest; applicable only to patients with oHCM

  4. Long-term effects of aficamten on resting LVOT-G

    Time frame: Baseline through the end of participation at 12-24 week intervals

    Proportion of patients with resting LVOT-G < 30 mmHg; applicable only to patients with oHCM

  5. Long-term effects of aficamten on post Valsalva LVOT-G

    Time frame: Baseline through the end of participation at 12-24 week intervals

    Proportion of patients with post-Valsalva LVOT-G < 50 mmHg; applicable only to patients with oHCM

  6. Long-term effects of aficamten on post Valsalva LVOT-G

    Time frame: Baseline through the end of participation at 12-24 week intervals

    Proportion of patients with post-Valsalva LVOT-G < 30 mmHg; applicable only to patients with oHCM

  7. Long-term effects of aficamten on left ventricular ejection fraction (LVEF) and post-Valsalva LVOT-G

    Time frame: Baseline through the end of participation at 12-24 week intervals

    Proportion of patients with LVEF ≥ 50%, resting LVOT-G < 30 mmHg, and post-Valsalva LVOT-G < 50 mmHg; applicable only to patients with oHCM

  8. Long-term effects of aficamten on time to first resting LVOT-G < 30 mmHg through last follow-up

    Time frame: Time to the following event through last follow-up, up to 5 years

    Applicable only to patients with oHCM

  9. Long-term effects of aficamten on time to first post-Valsalva LVOT-G < 50 mmHg through last follow-up

    Time frame: Time to the following event through last follow-up, up to 5 years

    Applicable only to patients with oHCM

  10. Long-term effects of aficamten on time to first post-Valsalva LVOT-G < 30 mmHg through last follow-up

    Time frame: Time to the following event through last follow-up, up to 5 years

    Applicable only to patients with oHCM

  11. Long-term effects of aficamten on time to first LVEF ≥ 50%, resting LVOT-G < 30 mmHg, and post-Valsalva LVOT-G < 50 mmHg through last follow-up

    Time frame: Time to the following event through last follow-up, up to 5 years

    Applicable only to patients with oHCM

Sponsors and collaborators

Lead sponsor

Cytokinetics

Industry

Registry information

Official study title

A Follow-Up, Open-Label, Research Evaluation of Sustained Treatment With Aficamten (CK-3773274) in Hypertrophic Cardiomyopathy (HCM)

Acronym: FOREST-HCM

Important dates

Study start
2021
Primary completion
2028
Study completion
2028
First posted
Apr 19, 2021
Registry last updated
Jan 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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