Genetic factors behind differing responses to mavacamten in obstructive hypertrophic cardiomyopathy
Studies how genes affect response to mavacamten in adults with obstructive hypertrophic cardiomyopathy.
Plain-language title generated from the registry record
Registry title: Biological Collection for the Purpose of Exploring Genetic and Clinical-biological Factors Associated With Variability in Response to Mavacamten in the Treatment of Obstructive Hypertrophic Cardiomyopathy
Key facts
- Where
- Boulogne-Billancourt, Le Kremlin-Bicêtre, and Paris, FranceSee the 3 sites
Where in France
- APHP, Ambroise ParéBoulogne-Billancourt, FranceNo longer taking part
- APHP, Bicêtre hospitalLe Kremlin-Bicêtre, FranceNo longer taking part
- APHP, La Pitié Salpetriere hospitalParis, FranceNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Assistance Publique - Hôpitaux de Paris
- Trial code
- NCT07439952
- Record updated
- 27 February 2026
- Original description
The European Medicines Agency has required pre-treatment genotyping of CYP2C19 to determine the initial and maximum dosage, in order to avoid overexposure to mavacamten associated with a decrease in ventricular ejection fraction below 50% in slow metabolisers of CYP2C19 (AUC multiplied by 3.4). The study is a requalification for the search for DNA samples obtained during treatment in order to genotype the genes of interest.The primary objective of the study is to estimate, for each of the CYP2C19 phenotypes of interest determined by genotyping (ultra-rapid, rapid, normal/extensive and intermediate metabolisers), the proportion of patients who are non-responders to mavacamten at each time point (D0, Week 4, Week 8, Week 12 and Week 24 in the treatment of HCM). This is a multicentre (3 centres which are hospitals of APHP) study aiming to include 300 patients with obstructive hypertrophic cardiomyopathy treated with Mavacamten who underwent or are undergoing CYP2C19 genotyping at the start of treatment. The inclusion period is 36 months and the follow-up period is 6 months. The total duration of the study is 42 months.Read full original descriptionShow less
Biological Collection for the Purpose of Exploring Genetic and Clinical-biological Factors Associated With Variability in Response to Mavacamten in the Treatment of Obstructive Hypertrophic Cardiomyopathy
The European Medicines Agency has required pre-treatment genotyping of CYP2C19 to determine the initial and maximum dosage, in order to avoid overexposure to mavacamten associated with a decrease in ventricular ejection fraction below 50% in slow metabolisers of CYP2C19 (AUC multiplied by 3.4). The study is a requalification for the search for DNA samples obtained during treatment in order to genotype the genes of interest.The primary objective of the study is to estimate, for each of the CYP2C19 phenotypes of interest determined by genotyping (ultra-rapid, rapid, normal/extensive and intermediate metabolisers), the proportion of patients who are non-responders to mavacamten at each time point (D0, Week 4, Week 8, Week 12 and Week 24 in the treatment of HCM). This is a multicentre (3 centres which are hospitals of APHP) study aiming to include 300 patients with obstructive hypertrophic cardiomyopathy treated with Mavacamten who underwent or are undergoing CYP2C19 genotyping at the start of treatment. The inclusion period is 36 months and the follow-up period is 6 months. The total duration of the study is 42 months.
Inclusion: - Patients aged ≥18 years; Diagnosis of obstructive hypertrophic cardiomyopathy (OHCM), based on the guidelines of the European Society of Cardiology (Arbelo et al. 2023), with unexplained left ventricular hypertrophy and a maximum LVOT gradient ≥ 50 mmHg at rest, or after Valsalva manoeuvre or exercise at the time of diagnosis, and an LVOT gradient with Valsalva manoeuvre ≥ 30 mmHg at selection; With cardiac symptoms defined as NYHA class II/III, persistent despite background treatment (beta-blockers or calcium channel blockers); LVEF ≥55% at the start of treatment with mavacamten; Initiation of treatment with mavacamten or patient already receiving treatment; Prescription of pre-treatment CYP2C19 genotyping performed; Consent to participate signed by the patient; Beneficiary of health insurance.
Exclusion: Minors; Adults under guardianship (legal guardianship and curatorship) or judicial protection; Pregnant or breastfeeding women.