Mavacamten in Patients With Hypertrophic Cardiomyopathy Referred for Septal Reduction: Week 128 Results from VALOR-HCM.

Background: In severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM), VALOR-HCM trial (Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive HCM Who Are Eligible for Septal Reduction Therapy [URL: https://clinicaltrials.gov; Unique identifier: NCT04349072]) reported that mavacamten reduced the short-term need for septal reduction therapy (SRT). The current report examined the longer-term effect of mavacamten through end of treatment at week 128.

Mavacamten-Associated Temporal Changes in Left Atrial Function in Obstructive HCM: Insights From the VALOR-HCM Trial.

Background: In severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM), the VALOR-HCM (A Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy) trial showed that mavacamten reduced the eligibility for septal reduction therapy with sustained improvement in left ventricular outflow tract gradients. Mavacamten also resulted in favorable cardiac remodeling, including improvement in biomarkers (eg, N-terminal pro-B-type natriuretic peptide and troponin T). However, the impact of mavacamten on left atrial (LA) function is unknown.

Serial Changes in Ventricular Strain in Symptomatic Obstructive Hypertrophic Cardiomyopathy Treated With Mavacamten: Insights From the VALOR-HCM Trial.

Background: In severely symptomatic patients with obstructive hypertrophic cardiomyopathy, VALOR-HCM (A Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy) demonstrated that mavacamten reduces the need for septal reduction therapy with sustained improvement in left ventricular (LV) outflow tract gradients and symptoms. Global longitudinal strain (GLS), a measure of regional myocardial function, is a more sensitive marker of systolic function. In VALOR-HCM, we assessed serial changes in LV and right ventricular (RV) strain.

Mavacamten for Obstructive Hypertrophic Cardiomyopathy: Rationale for Clinically Guided Dose Titration to Optimize Individual Response.

Mavacamten is the first and only cardiac myosin inhibitor approved in 5 continents for the treatment of adults with symptomatic New York Heart Association class II and III obstructive hypertrophic cardiomyopathy. An evidence-based rationale was used to develop individualized mavacamten dosing, guided by commonly used clinical parameters. Echocardiography is recommended as part of routine clinical assessment of patients with hypertrophic cardiomyopathy, and left ventricular (LV) outflow tract gradient and LV ejection fraction are parameters that can be readily assessed and monitored by echocardiography.

Characterization of mavacamten pharmacokinetics in patients with hypertrophic cardiomyopathy to inform dose titration.

Mavacamten is a selective, allosteric, reversible cardiac myosin inhibitor that has been developed for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (HCM). A population pharmacokinetic (PopPK) model was developed to characterize mavacamten pharmacokinetics (PK) and the variation in mavacamten exposure associated with intrinsic and extrinsic factors. Data from 12 clinical studies (phases 1, 2, and 3) were used.

Recommendation of mavacamten posology by model-based analyses in adults with obstructive hypertrophic cardiomyopathy.

Mavacamten is the first cardiac myosin inhibitor approved by the US Food and Drug Administration for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (HCM). The phase III EXPLORER-HCM (NCT03470545) study used a dose-titration scheme based on mavacamten exposure and echocardiographic assessment of Valsalva left ventricular outflow tract gradient (VLVOTg) and left ventricular ejection fraction (LVEF). Using population pharmacokinetic/exposure-response modeling and simulations of virtual patients, this in silico study evaluated alternative dose-titration regimens for mavacamten, including regimens that were guided by echocardiographic measures only.

Long-Term Safety and Efficacy of Mavacamten in Symptomatic Obstructive Hypertrophic Cardiomyopathy: Interim Results of the PIONEER-OLE Study.

Background: The phase 2 PIONEER-HCM (Phase 2 Open-label Pilot Study Evaluating Mavacamten in Subjects With Symptomatic Hypertrophic Cardiomyopathy and Left Ventricular Outflow Tract Obstruction) study showed that mavacamten improved left ventricular outflow tract gradients, exercise capacity, and symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM), but the results of longer-term treatment are less well described. We report interim results from the PIONEER-OLE (PIONEER Open-Label Extension) study, the longest-term study of mavacamten in patients with symptomatic obstructive HCM.

Methods And Results: Patients who previously completed PIONEER-HCM (n=20) were eligible to enroll in PIONEER-OLE.

Mavacamten Treatment for Symptomatic Obstructive Hypertrophic Cardiomyopathy: Interim Results From the MAVA-LTE Study, EXPLORER-LTE Cohort.

Background: Data assessing the long-term safety and efficacy of mavacamten treatment for symptomatic obstructive hypertrophic cardiomyopathy are needed.

Objectives: The authors sought to evaluate interim results from the EXPLORER-Long Term Extension (LTE) cohort of MAVA-LTE (A Long-Term Safety Extension Study of Mavacamten in Adults Who Have Completed EXPLORER-HCM; NCT03723655).

Methods: After mavacamten or placebo withdrawal at the end of the parent EXPLORER-HCM (Clinical Study to Evaluate Mavacamten [MYK-461] in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy; NCT03470545), patients could enroll in MAVA-LTE.

Effect of Mavacamten in Women Compared With Men With Obstructive Hypertrophic Cardiomyopathy: Insights From EXPLORER-HCM.

Background: Compared with men, women with hypertrophic cardiomyopathy (HCM) have a higher incidence of heart failure and worse outcomes. We investigated baseline clinical and echocardiographic characteristics and response to mavacamten among women compared with men in the EXPLORER-HCM study (Clinical Study to Evaluate Mavacamten [MYK-461] in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy).

Methods: A prespecified post hoc analysis of sex from the blinded, randomized EXPLORER-HCM trial of mavacamten versus placebo in symptomatic patients with obstructive HCM was performed.

Mavacamten in Patients With Hypertrophic Cardiomyopathy Referred for Septal Reduction: Week 56 Results From the VALOR-HCM Randomized Clinical Trial.

Importance: There is an unmet need for novel medical therapies before recommending invasive therapies for patients with severely symptomatic obstructive hypertrophic cardiomyopathy (HCM). Mavacamten has been shown to improve left ventricular outflow tract (LVOT) gradient and symptoms and may thus reduce the short-term need for septal reduction therapy (SRT).

Objective: To examine the cumulative longer-term effect of mavacamten on the need for SRT through week 56.

Effects of Mavacamten on Measures of Cardiopulmonary Exercise Testing Beyond Peak Oxygen Consumption: A Secondary Analysis of the EXPLORER-HCM Randomized Trial.

Importance: Mavacamten, a cardiac myosin inhibitor, improved peak oxygen uptake (pVO2) in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) in the EXPLORER-HCM study. However, the full extent of mavacamten's effects on exercise performance remains unclear.

Objective: To investigate the effect of mavacamten on exercise physiology using cardiopulmonary exercise testing (CPET).

Effect of beta-blocker therapy on the response to mavacamten in patients with symptomatic obstructive hypertrophic cardiomyopathy.

Aims: In the EXPLORER-HCM trial, mavacamten improved exercise capacity and symptoms in patients with obstructive hypertrophic cardiomyopathy (oHCM). Mavacamten effects on the primary endpoint, a composite of peak oxygen consumption (VO ) and New York Heart Association (NYHA) class, were greater in patients not receiving background beta-blockers than in those receiving beta-blockers. We sought to determine if the effect of background treatment was consistent across other clinically meaningful parameters.

Myosin Inhibition and Left Ventricular Diastolic Function in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy: Insights From the VALOR-HCM Study.

Background: In the randomized phase 3 VALOR-HCM study (A Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy) of patients with obstructive hypertrophic cardiomyopathy, mavacamten reduced the need for septal reduction therapy. Because mavacamten improves ventricular compliance, this sub-study examined the effects of treatment with this cardiac myosin inhibitor on diastolic function.

Methods: Symptomatic obstructive hypertrophic cardiomyopathy patients on maximally tolerated medical therapy referred for septal reduction therapy were randomized 1:1 to mavacamten or placebo.

Dose-Blinded Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy: Outcomes Through 32 Weeks.

Background: Septal reduction therapy (SRT) in patients with intractable symptoms from obstructive hypertrophic cardiomyopathy (oHCM) is associated with variable morbidity and mortality. The VALOR-HCM trial (A Study to Evaluate Mavacamten in Adults with Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy) examined the effect of mavacamten on the need for SRT through week 32 in oHCM.

Methods: A double-blind randomized placebo-controlled multicenter trial at 19 US sites included patients with oHCM on maximal tolerated medical therapy referred for SRT with left ventricular outflow tract gradient ≥50 mm Hg at rest or provocation (enrollment, July 2020-October 2021).

Validation of the Kansas City Cardiomyopathy Questionnaire in Symptomatic Obstructive Hypertrophic Cardiomyopathy.

Background: The primary goal for treating patients with obstructive hypertrophic cardiomyopathy (oHCM) is to improve their symptoms, function, and quality of life. Although the Kansas City Cardiomyopathy Questionnaire (KCCQ) is a valid, reliable, and sensitive measure for other etiologies of heart failure, its appropriateness for patients with oHCM is unknown.

Objectives: The purpose of this study was to establish the interpretability, validity, reliability, and responsiveness of the KCCQ in patients with oHCM.

Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy.

Background: Septal reduction therapy (SRT), surgical myectomy or alcohol ablation, is recommended for obstructive hypertrophic cardiomyopathy (oHCM) patients with intractable symptoms despite maximal medical therapy, but is associated with morbidity and mortality.

Objectives: This study sought to determine whether the oral myosin inhibitor mavacamten enables patients to improve sufficiently to no longer meet guideline criteria or choose to not undergo SRT.

Methods: Patients with left ventricular (LV) outflow tract (LVOT) gradient ≥50 mm Hg at rest/provocation who met guideline criteria for SRT were randomized, double blind, to mavacamten, 5 mg daily, or placebo, titrated up to 15 mg based on LVOT gradient and LV ejection fraction.

Longitudinal Psychometric Analysis of the Hypertrophic Cardiomyopathy Symptom Questionnaire (HCMSQ) Using Outcomes from the Phase III EXPLORER-HCM Trial.

Background: Hypertrophic cardiomyopathy (HCM) symptoms include shortness of breath (SOB), fatigue, chest pain, palpitations, dizziness, and fainting. The HCM Symptom Questionnaire (HCMSQ), the only patient-reported outcome instrument designed to specifically measure HCM symptoms, yields four domain scores (SOB, tiredness, cardiovascular symptoms, syncope) and a total score. We evaluated the longitudinal psychometric properties of the HCMSQ using baseline to week 30 data from the phase III EXPLORER-HCM trial (NCT03470545).

Development of the Hypertrophic Cardiomyopathy Symptom Questionnaire (HCMSQ): A New Patient-Reported Outcome (PRO) Instrument.

Background: Currently, there is no patient-reported outcome (PRO) instrument specifically designed to evaluate hypertrophic cardiomyopathy (HCM).

Objective: We present the development and psychometric validation of a novel PRO measure, the HCM Symptom Questionnaire version 1.0 (HCMSQv1.

The Impact of Mavacamten on the Pathophysiology of Hypertrophic Cardiomyopathy: A Narrative Review.

Hypertrophic cardiomyopathy (HCM) is a chronic, progressive disease of the cardiomyocyte with a diverse and heterogeneous clinical presentation and course. This diversity and heterogeneity have added to the complexity of modeling the pathophysiological pathways that contribute to the disease burden. The development of novel therapeutic approaches targeting precise mechanisms within the underlying biology of HCM provides a tool to model and test these pathways.

Assessment of Disease Status and Treatment Response With Artificial Intelligence-Enhanced Electrocardiography in Obstructive Hypertrophic Cardiomyopathy.

AI analysis of HCM ECGs correlates with longitudinal hemodynamic, cardiac structural and laboratory markers in obstructive HCM patients.