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NCT Number: NCT07298044

A Study to Learn More About the Change in the Blood Levels of Transthyretin When Participants With Transthyretin Amyloidosis With Cardiomyopathy Switch From Tafamidis to Acoramidis

Transthyretin (TTR) is a protein made by the liver that helps transport thyroid hormone and vitamin A in the blood. In some people, this protein breaks down and forms harmful clumps called amyloid. TTR amyloid gets deposited in the heart wall and stops it from pumping blood properly, which may lead to heart failure. The breakage in TTR protein can be age-related (wild-type ATTR-CM), or genetic (variant ATTR-CM).

The study drug, acoramidis, works by attaching itself to the TTR protein, making TTR more stable and less likely to break down and form amyloid (clumps). This helps to slow down the progression of the disease, improve heart function, and increase the TTR levels in the blood. Acoramidis is an approved treatment for wild-type or variant ATTR-CM in Europe and the United States.

Tafamidis is another drug that stabilizes TTR and prevents it from breaking down.

In this study, acoramidis will be studied in participants with ATTR--CM who were previously treated with tafamidis. The main purpose of this study is to assess the change in blood TTR levels after participants are switched from tafamidis to acoramidis. This will be studied to understand if acoramidis causes an increase in blood TTR levels beyond the levels achieved with tafamidis.

For this, the researchers will measure the change in the levels of TTR protein in participants' blood after 6 months of the treatment with acoramidis, or earlier if a participant stops the treatment before reaching that six-month mark.

All participants will continue taking tafamidis during the screening period. In the treatment period of the study, participants will take acoramidis as two tablets twice daily by mouth, for up to 6 months.

At the start of this study, the study doctors will review each participant's medical history and check their overall health. The study doctors will perform electrocardiograms (ECG), and measure blood pressure and heart rate. Researchers will also take blood and urine samples from the participants to measure levels of TTr, NT-proBNP, hs-TnT, hs-CRP, RBP4, eGFR, creatinine, cystatin-C, UACR, and TSH at the start of the study, and at various time points thereafter (during the study) to assess heart, kidney and thyroid function.

There will be a total of 9 study check-ins. Participants will visit the study site twice: at screening and at the end of treatment period. A study nurse will visit the participant's home 6 times, at the start of treatment, Weeks 1, 2, 3 and 4, then again at 3 months. The final check-in will be done by phone.

The study doctors will monitor the health of the participants regularly for any medical problems during follow-up visits. Participants will know the treatment they will receive during the study. Each participant could be in the study for about 8 months.

Recruiting

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Key information

Conditions

Transthyretin Amyloid Cardiomyopathy

Age range

18 year–90 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Universitätsklinikum St. Pölten - Lilienfeld - Klinische Abteilung für Innere Medizin 3, Sankt Pölten, Lower Austria, Austria

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Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Participants must be 18 to 90 years of age inclusive, at the time of signing the informed consent.
  • Diagnosis of ATTR-CM; disease defining examination, i.e., Single Photon Emission Computed Tomography (SPECT) or SPECT/Computed Tomography (CT) or biopsy, within 24 months prior to Visit 1 (V1).
  • Participants must currently be treated with tafamidis and have used tafamidis for at least the previous 3 months prior to V1 and have adhered to tafamidis therapy.
  • New York Heart Association (NYHA) class ≤ II at V1.
  • Estimate glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73m^2 at V1.
  • N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) > 300 and ≤ 7000 pg/mL at V1.

Exclusion criteria

  • Prior liver or heart transplantation or planned within the next 12 months.
  • Current or planned use of ventricular assist device.
  • Active cancer or other disease that decreases the life expectancy to less than one year.
  • Heart failure due to ischemic heart disease.
  • Myocardial infarction, cardiovascular (CV) surgery, or unstable angina within the last 90 days prior to V1.
  • Confirmed diagnosis of light-chain amyloidosis.
  • Dialysis or severe renal impairment as reflected by Urinary Albumin Creatinine Ratio (UACR) > 300 mg/g at V1.
  • Major surgery 90 days prior to V1.
  • Recent initiation of Sodium-Glucose-Cotransporter-2 inhibitors (SGLT2i) within 3 months before V1.
  • Initiation of treatment with a diuretic or increase in diuretic dose within 3 months before V1.
  • Treatment with calcium channel blockers (e.g., verapamil, diltiazem) or digitalis.
  • Recent CV hospitalization within 3 months before V1.
  • Known hypersensitivity to acoramidis or to any of the excipients.
  • A condition that, as judged by the investigator, would preclude compliance with the study protocol, such as a history of substance abuse, alcoholism, or a psychiatric condition.
  • Known or suspected liver disorder and bile secretion/flow (cholestasis, also history of it).
  • Abnormal liver function tests at V1, defined as ALT (GPT) or AST (GOT) ≥ 3 x ULN or total bilirubin ≥ 3 x ULN at V1.

Treatment and study plan

acoramidis

Drug

356 mg film-coated tablets.

The recommended dose of acoramidis is 712 mg (two tablets, 356 mg) orally, twice daily, corresponding to a total daily dose of 1424 mg.

Other names: BAY3684938, BEYONTTRA

Primary outcomes

  1. Change in serum TTR level from baseline to month 6 or premature discontinuation of treatment

    Time frame: From baseline to month 6 or premature discontinuation of treatment

    TTR = Transthyretin

Secondary outcomes

  1. Serum TTR level at baseline, week 1, 2, 3, 4 and at month 3.

    Time frame: At baseline, week 1, 2, 3, 4 and at month 3

    TTR = Transthyretin

  2. Number of participants with TEAEs and serious TEAEs

    Time frame: From the first administration of study drug until 30 days after the last dose of study drug or end of study, whatever occurs first

  3. Change from baseline to month 6 of NT-proBNP

    Time frame: From baseline to month 6

    NT-proBNP = N-terminal pro-B-type Natriuretic Peptide

  4. Change from baseline to month 6 of hs-TnT

    Time frame: From baseline to month 6

    hs-TNT = high-sensitivity Troponin T

  5. Change from baseline to month 6 of hs-CRP

    Time frame: From baseline to month 6

    hs-CRP = high-sensitivity C-reactive protein

  6. Change from baseline to month 6 of RBP4

    Time frame: From baseline to month 6

    RBP4 = Retinol Binding Protein 4

  7. Signs of cardiac remodeling from baseline to month 6

    Time frame: From baseline to month 6

    These signs will be measured by echocardiogram

  8. Change from baseline to month 6 in 6MWD

    Time frame: From baseline to month 6

    The 6-Minute Walk distance (6MWD) measures the total distance that a participant could walk in 6 minutes.

  9. Change from baseline to month 6 in the eGFR

    Time frame: From baseline to month 6

    eGFR = estimated glomerular filtration rate

  10. Change from baseline to month 6 in Creatinine

    Time frame: From baseline to month 6

  11. Change from baseline to month 6 in Cystatin C

    Time frame: From baseline to month 6

  12. Change from baseline to month 6 in UACR

    Time frame: From baseline to month 6

    UACR = Urinary Albumin Creatinine Ratio

  13. Change from baseline to month 6 in TSH

    Time frame: From baseline to month 6

    TSH = Thyroid Stimulating Hormone

  14. Change from baseline to month 6 in KCCQ-OS score

    Time frame: From baseline to month 6

    The Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) is 23-item questionnaire developed to measure health status and health-related quality of life (QoL) in individuals with heart failure. Items include heart failure symptoms, impact on physical and social functions, and how heart failure impacts QoL.

  15. Change from baseline to month 6 of EQ-5D-5L index score

    Time frame: From baseline to month 6

    The EuroQol-5-Dimension-5-Level (EQ-5D-5L) includes two parts. In the first part, participants are asked to rate their current health state on 5 dimensions (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) with each dimension having five levels of function (1-no problem, 2-slight problem, 3-moderate problem, 4-severe problem, and 5-extreme problem). The second part is a self-rating of current health status on a Visual Analogue Scale (EQ VAS) with endpoints labeled "best imaginable health state" (score of 100) and "worst imaginable health state" (score of 0). The scores from the 5 dimensions are used to calculate the index score.

Study contacts

Contact information is provided by the study sponsor or research team.

Bayer Clinical Trials Contact

CONTACT

[email protected]

(+)1-888-84 22937

Sponsors and collaborators

Lead sponsor

Bayer

Industry

Registry information

Official study title

A Prospective, Single-arm, Phase 4 Study to Evaluate the Course of Serum Transthyretin (TTR) Level With Acoramidis in Adult Patients With Variant or Wild-type Transthyretin Amyloidosis With Cardiomyopathy (ATTR-CM) Previously Treated With Tafamidis

Acronym: ACO-SWITCH

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Dec 22, 2025
Registry last updated
Jun 29, 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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