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

Cytokinetics

Status and phase: Invitation-only; Phase 3; Phase 2

Conditions: Symptomatic Hypertrophic Cardiomyopathy (HCM)

Treatments: Drug: Aficamten (5 - 20 mg)

Study type: Interventional

Funder types: Industry

Identifiers

NCT04848506

CY 6022

2023-508963-58-00 (Other Identifier)

2023

2020-003571-17 (EudraCT Number)

Details and patient eligibility

About

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

Enrollment: 900 estimated patients

Sex: All

Ages: 18 to 85 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

---

900 participants in 1 patient group

Aficamten

Experimental group

Description:

Participants in this arm take aficamten starting at the lowest prespecified dose and titrating up to their individual maximum tolerated dose. 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. After Week 48, the visits can be yearly if participants meet criteria.

Treatment:

Drug: Aficamten (5 - 20 mg)