Mavacamten to Aficamten Transition in Patients With Obstructive Hypertrophic Cardiomyopathy (CMI-SWITCH)

May 14, 2026 updated by: Ahmad Masri, Oregon Health and Science University
This is an investigator-initiated two-center study. The goal of this study is to investigate the feasibility, safety and efficacy outcomes of a seamless transition from mavacamten to aficamten in patients with obstructive hypertrophic cardiomyopathy (oHCM).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Missouri
      • Kansas City, Missouri, United States, 64111
        • Not yet recruiting
        • St. Luke's Hospital - Mid America Heart Institute
        • Principal Investigator:
          • Michael Nassif, MD
        • Contact:
    • Oregon
      • Portland, Oregon, United States, 97239
        • Recruiting
        • Oregon Health & Science University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Documented history of oHCM with documented resting and/or Valsalva LVOT obstruction ≥ 50 mmHg who are currently receiving mavacamten commercially.
  • Echo-derived LVEF ≥55% on mavacamten at the time of enrollment.
  • Patient willing to consent for the study and undergo the study procedures.

Exclusion Criteria:

  • Severe aortic stenosis or sub-aortic obstruction
  • Known infiltrative or storage disorder causing cardiac hypertrophy that mimics HCM (eg, Noonan syndrome, Fabry disease, amyloidosis).
  • History of LVEF <30%.
  • Paroxysmal atrial fibrillation (AF) with documented episode within 3 months.
  • Atrial fibrillation (paroxysmal or permanent) not on systemic anticoagulation.
  • Documented history of current obstructive coronary artery disease (> 70% stenosis in one or more epicardial coronary arteries) or documented history of myocardial infarction.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CMI
Switching from mavacamten on day 1 to aficamten starting at week 2.
Drug: Aficamten
Patients will be switched from mavacamten to aficamten. Mavacamten will be stopped at enrollment, and aficamten started 2 weeks later.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety Endpoints
Time Frame: Up to 16 weeks

To describe the safety of this proposed protocol. These include:

  1. Participant incidence of reported AEs
  2. Participant incidence of reported SAEs
  3. Participant incidence of LVEF < 40%
Up to 16 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
Proportional change from baseline in resting and Valsalva LVOT gradients during each assessment
Time Frame: Up to 16 weeks
Up to 16 weeks
Proportion of participants with resting LVOT gradient < 30 mmHg and Valsalva LVOT gradient < 50 mmHg
Time Frame: Up to 16 weeks
Up to 16 weeks
Proportional change from baseline in NT-proBNP and high-sensitivity troponin I
Time Frame: Up to 16 weeks
Up to 16 weeks
Proportional improvement in NYHA functional classification by 1 functional class
Time Frame: Up to 16 weeks
Up to 16 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Oregon Health and Science University

Collaborators

Cytokinetics
Saint Lukes Hospital Mid America Heart Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 5, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

March 15, 2027

Study Registration Dates

First Submitted

May 7, 2026

First Submitted That Met QC Criteria

May 14, 2026

First Posted (Actual)

May 20, 2026

Study Record Updates

Last Update Posted (Actual)

May 20, 2026

Last Update Submitted That Met QC Criteria

May 14, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00029878
  • 007119 (Other Identifier: UMKC)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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