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

Cardiac Myosin Inhibition in Heart Failure With Normal and Supranormal Ejection Fraction: Primary Results of the EMBARK-HFpEF Trial

Importance

Patients with heart failure with preserved ejection fraction (HFpEF) who have left ventricular ejection fraction (LVEF) of 60% or greater have limited treatment options.

Objective

To examine the effects of cardiac myosin inhibition with mavacamten in patients with HFpEF with LVEF of 60% or greater.

Design, Setting, and Participants

The EMBARK-HFpEF trial was a phase 2a, open-label, single-arm, multicenter trial conducted from November 6, 2020, to February 26, 2024, at 20 sites in the US and Canada. Patients with symptomatic HFpEF (defined as a New York Heart Association [NYHA] functional class II or III), LVEF of 60% or greater, elevated N-terminal pro-B-type natriuretic peptide (NTproBNP), and left ventricular hypertrophy were eligible for inclusion.

Intervention

Mavacamten treatment for 26 weeks, starting at 2.5 mg and potentially titrated up to 5 mg at week 14 based on prespecified LVEF and NTproBNP criteria.

Main Outcomes and Measures

Primary efficacy end points (measured as the change from baseline to week 26) included NTproBNP and high-sensitivity troponin T (hsTnT); additional efficacy end points included changes in high-sensitivity troponin I (hsTnI), NYHA functional class, and echocardiographic parameters (resting and peak exercise). Safety end points included treatment-emergent adverse events and reductions in LVEF to less than 30%.

Results

A total of 30 patients were enrolled and treated with mavacamten. Median (IQR) patient age was 76 (70-80) years, and 16 patients (53.3%) were female. From baseline to week 26, mavacamten was associated with reductions in NTproBNP (mean reduction, -26%; 95% CI, -44% to -4%; P = .04), hsTnT (mean reduction, -13%; 95% CI, -23% to -3%; P = .02), and hsTnI (mean reduction, -20%; 95% CI, -32% to -6%; P = .01). Cardiac biomarker values returned toward baseline levels 8 weeks after drug discontinuation. NYHA class improved in 10 of 24 patients (41.7%) who had evaluable NYHA class data at the end of treatment, and improvements in echocardiographic markers of LV diastolic function were observed. Mean LVEF decreased by 3.2 absolute percentage points (95% CI, 1.1-5.4; P = .005) during treatment. Mavacamten was interrupted in 3 patients (10% of the study population; 95% CI, 2.1%-26.5%) due to protocol prespecified criteria of LVEF less than 50% (n = 2) or a more than 20% relative decrease from baseline (n = 1; nadir LVEF, 58%), with LVEF recovery observed in all 3 patients. There were no deaths or instances of LVEF less than 30%; 1 patient had worsening heart failure deemed unrelated to the study drug.

Conclusions and Relevance

In an open-label trial in patients with HFpEF with LVEF of 60% or greater, mavacamten was associated with improvements in biomarkers of cardiac wall stress and injury, with no sustained reductions in LVEF observed.

Trial Registration

ClinicalTrials.gov Identifier: NCT04766892.

The U.S. FDA approved cardiovascular drugs from 2011 to 2023: A medicinal chemistry perspective

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. A total of 28 new molecular entities (NMEs) were approved by the U.S. Food and Drug Administration (FDA) for the treatment of cardiovascular diseases from 2011 to 2023. Approximately 25 % of the medications were sanctioned for the management of diverse vascular disorders. The other major therapeutic areas of focus included antilipemic agents (15 %), blood pressure disease (11 %), heart failure, hyperkalemia, and cardiomyopathy (7-8% each). Among all the approved drugs, there are a total of 22 new chemical entities (NCEs), including inhibitors, agonists, polymers, and inorganic compounds. In addition to NCEs, 6 biological agents (BLAs), including monoclonal antibodies, small interfering RNAs (siRNAs), and antisense oligonucleotides, have also obtained approval for the treatment of cardiovascular diseases. From this perspective, approved NCEs are itemized and discussed based on their disease, targets, chemical classes, major drug metabolites, and biochemical and pharmacological properties. Systematic analysis has been conducted to examine the binding modes of these approved drugs with their targets using cocrystal structure information or docking studies to provide valuable insights for designing next-generation agents. Furthermore, the synthetic approaches employed in the creation of these drug molecules have been emphasized, aiming to inspire the development of novel, efficient, and applicable synthetic methodologies. Generally, the primary objective of this review is to provide a comprehensive examination of the clinical applications, pharmacology, binding modes, and synthetic methodologies employed in small-molecule drugs approved for treating CVD. This will facilitate the development of more potent and innovative therapeutics for effectively managing cardiovascular diseases.

Pharmacokinetics and safety of mavacamten in healthy Chinese participants with different CYP2C19 phenotypes

Obstructive hypertrophic cardiomyopathy (oHCM) is a subtype of HCM characterized by left ventricular outflow tract obstruction resulting from cardiac muscle hypertrophy and anatomic alterations in the mitral valve and apparatus. Mavacamten, a cardiac myosin inhibitor metabolized primarily by CYP2C19 in the liver, is the first and only targeted medication approved for the treatment of symptomatic New York Heart Association (NYHA) class II-III oHCM. Previous pharmacokinetic (PK) results of mavacamten in healthy Caucasian, Japanese, and Asian participants demonstrated that mavacamten exposure was affected by CYP2C19 metabolism status. This open-label, parallel-group, phase I trial aimed to determine the PK and safety of mavacamten in healthy Chinese participants with different CYP2C19 genotypes. The primary outcome was to define the PK of mavacamten in healthy Chinese participants; the secondary outcome was to examine safety and tolerability. After a single oral dose of 15 or 25 mg mavacamten in fasted healthy adult Chinese individuals, Cmax was reached within a median Tmax of 0.6-1.5 h, indicating rapid absorption. Inter-individual variability was moderate, and individuals carrying non-functional CYP2C19 alleles (*2/*2, *3/*3, or *2/*3) exhibited longer half-life and increased total exposure. After stratification of CYP2C19 genotypes, total mavacamten exposures were similar among different ethnic groups when compared with prior PK studies. No significant adverse events were observed in this study. Single oral administration of mavacamten at 15 mg was well tolerated across all CYP2C19 genotypes, and 25 mg dose was well tolerated in healthy participants with CYP2C19 genotypes UM/RM/NM. The PK profile of mavacamten in the healthy Chinese population was consistent with that in other healthy populations.

Promising therapies for adults with symptomatic obstructive hypertrophic cardiomyopathy: 2023 and beyond

INTRODUCTION

Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic heart disease with an estimated prevalence in the general population of 0.2% to 0.6%. Clinically, HCM can range from no symptoms to severe symptoms such as heart failure or sudden cardiac death. Currently, the management of HCM involves lifestyle modifications, familial screening, genetic counseling, pharmacotherapy to manage symptoms, sudden cardiac death risk assessment, septal reduction therapy, and heart transplantation for specific patients. Multicenter randomized controlled trials have only recently explored the potential of cardiac myosin inhibitors (CMIs) such as mavacamten as a directed pharmacological approach for managing HCM.

AREAS COVERED

We will assess the existing medical treatments for HCM: beta-blockers, calcium channel blockers, disopyramide, and different CMIs. We will also discuss future HCM pharmacotherapy guidelines and underline this patient population's unfulfilled needs.

EXPERT OPINION

Mavacamten is the first-in-class CMI approved by the FDA to target HCM pathophysiology specifically. Mavacamten should be incorporated into the standard therapy for oHCM in case of symptom persistence despite using maximally tolerated beta blockers and/or calcium channel blockers. Potential drug-drug interactions should be assessed before initiating this drug. More studies are needed on the use of CMIs in patients with kidney and/or liver failure and pregnant/breastfeeding patients.

Myosin Heavy Chain 7 (MYH7) Variant Associated Cardiovascular Disease: An Unusual Case of Heart Failure in a Young Male

A 37-year-old male with type two diabetes presented to the hospital with new-onset heart failure and renal dysfunction. His left ventricular (LV) ejection fraction was less than 10%. Transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging also revealed severe bicuspid aortic valve stenosis, dilated cardiomyopathy with LV hypertrophy, prominent LV trabeculations, and features suggestive of mild myocarditis with active inflammation. While myocarditis was suspected on CMR imaging, his mild degree of myocardial involvement did not explain the entirety of his clinical presentation, degree of LV dysfunction, or other structural abnormalities. An extensive work-up for his LV dysfunction was unremarkable for ischemic, metabolic, infiltrative, infectious, toxic, oncologic, connective tissue, and autoimmune etiologies. Genetic testing was positive for a myosin heavy chain 7 (MYH7) variant, which was deemed likely to be a unifying etiology underlying his presentation. The MYH7 sarcomere gene allows beta-myosin expression in heart ventricles, with variants associated with hypertrophic and dilated cardiomyopathies, congenital heart diseases, myocarditis, and excessive trabeculation (formerly known as left ventricular noncompaction). This case highlights the diverse array of cardiac pathologies that can present with MYH7 gene variants and reviews an extensive work-up for this unusual presentation of heart failure in a young patient.

The Revolution of Cardiac Myosin Inhibitors in Patients With Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy worldwide and causes significant morbidity and mortality. For decades, medical treatment options have been limited and untargeted, with frequent need for invasive interventions not readily accessible to many HCM patients. More recently, our understanding of the genetic basis and pathophysiologic mechanism of HCM has grown significantly, leading to the discovery of a new class of medications, cardiac myosin inhibitors (CMIs), that shift myosin into the super-relaxed state to counteract the hypercontractility in HCM. Subsequent clinical trials have proven the mechanism and efficacy of CMIs in humans with obstructive HCM, and additional trials are under way in patients with nonobstructive HCM. With favourable results in the completed clinical trials and ongoing research on the horizon, CMIs represent a bright new era in the targeted management of HCM. This review is focused on the discovery of CMIs, provides a summary of the results of clinical trials to date, provides clinicians with a roadmap for implementing CMIs into practice, and identifies gaps in our current understanding as well as areas of ongoing investigation.

AAV9:PKP2 improves heart function and survival in a Pkp2-deficient mouse model of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a familial cardiac disease associated with ventricular arrhythmias and an increased risk of sudden cardiac death. Currently, there are no approved treatments that address the underlying genetic cause of this disease, representing a significant unmet need. Mutations in Plakophilin-2 (PKP2), encoding a desmosomal protein, account for approximately 40% of ARVC cases and result in reduced gene expression.

METHODS

Our goal is to examine the feasibility and the efficacy of adeno-associated virus 9 (AAV9)-mediated restoration of PKP2 expression in a cardiac specific knock-out mouse model of Pkp2.

RESULTS

We show that a single dose of AAV9:PKP2 gene delivery prevents disease development before the onset of cardiomyopathy and attenuates disease progression after overt cardiomyopathy. Restoration of PKP2 expression leads to a significant extension of lifespan by restoring cellular structures of desmosomes and gap junctions, preventing or halting decline in left ventricular ejection fraction, preventing or reversing dilation of the right ventricle, ameliorating ventricular arrhythmia event frequency and severity, and preventing adverse fibrotic remodeling. RNA sequencing analyses show that restoration of PKP2 expression leads to highly coordinated and durable correction of PKP2-associated transcriptional networks beyond desmosomes, revealing a broad spectrum of biological perturbances behind ARVC disease etiology.

CONCLUSIONS

We identify fundamental mechanisms of PKP2-associated ARVC beyond disruption of desmosome function. The observed PKP2 dose-function relationship indicates that cardiac-selective AAV9:PKP2 gene therapy may be a promising therapeutic approach to treat ARVC patients with PKP2 mutations.

Discerning the stability behaviour of mavacamten availing liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy: In silico toxicity and mutagenicity prediction of degradation products

The present study aimed to separate, identify, and characterise the degradation products formed when mavacamten is exposed to stress degradation as well as the stability of the drug in various environments and also to understand its degradation chemistry. Prediction of in silico toxicity and mutagenicity was aimed at the observed degradation products. Stress degradation along with stability studies and degradation kinetics were performed on mavacamten, and separation of degradation products was carried out by high-performance liquid chromatography. Tandem mass spectrometry studies were executed to characterise the structures of degradation products using product ion fragments. Orthogonally, nuclear magnetic resonance experiments were conducted to elucidate the structures having ambiguity in characterising them. Deductive Estimation of Risk from Existing Knowledge and Structure Activity Relationship Analysis using Hypotheses software were used to establish in silico toxicity and mutagenic profiles of mavacamten and its degradation products. Two degradation products of mavacamten found in acidic hydrolytic stress conditions were separated, identified, characterised, and proposed as 1-isopropylpyrimidine-2,4,6(1H,3H,5H)-trione and 1-phenylethanamine. Mavacamten was found to be stable under different pH and gastrointestinal conditions. The degradation kinetics of mavacamten under 1 N acidic condition followed zero-order kinetics, and it was degraded completely within 6 h. In silico toxicity and mutagenicity studies revealed that 1-phenylethanamine can be a skin sensitiser. A high-performance liquid chromatography method was developed for the separation of degradation products of mavacamten and characterised by liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance. During the manufacturing and storage of drug product, precautions need to be taken when dealing with acidic solutions as the drug is prone to hydrolysis in acidic conditions. The formation of 1-phenylethanamine under these conditions is to be monitored as it is a skin sensitiser.

Medical Therapies to Improve Left Ventricular Outflow Obstruction and Diastolic Function in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy-both obstructive hypertrophic cardiomyopathy (oHCM) and nonobstructive hypertrophic cardiomyopathy (nHCM) subtypes-is the most common monogenic cardiomyopathy. Its structural hallmarks are abnormal thickening of the myocardium and hyperdynamic contractility, while its hemodynamic consequences are left ventricular outflow tract or intracavitary obstruction (in oHCM) and diastolic dysfunction (in both oHCM and nHCM). Several medical therapies are routinely used to improve these abnormalities with the goal to decrease symptom burden in patients with HCM. Current guidelines recommend nonvasodilating beta blockers as first-line and nondihydropyridine calcium channel blockers followed by disopyramide as second- and third-line medical therapies for symptomatic oHCM and give weaker recommendations for beta blockers and calcium channel blockers in nHCM. These recommendations are based on small studies-mostly nonrandomized-and expert opinion. Our review will summarize the available data on the effectiveness of commonly prescribed medications used in oHCM and nHCM to uncover knowledge gaps, but also new data on cardiac myosin inhibitors.

Efficacy and Safety of Mavacamten in the Treatment of Hypertrophic Cardiomyopathy: A Systematic Review

BACKGROUND

Current pharmacological options for hypertrophic cardiomyopathy (HCM) are not disease-specific; while it treats symptoms, mavacamten targets the underlying pathology. We aim to assess the efficacy and safety of mavacamten, a first-in-class cardiac myosin inhibitor, in symptomatic obstructive HCM.

METHODS

This systematic review of the literature followed the PRISMA guidelines. Title/abstract and topics were searched using the following term: "mavacamten". The electronic research literature databases included the Cochrane Library, MedLine, and clinicaltrials.gov from July to August 2022. Primary efficacy endpoint was to assess clinical response at the end of treatment compared with baseline, defined as, at least one New York Heart Association (NYHA) class reduction. Two secondary endpoints from baseline were determined. The first was defined as improvement in mixed venous oxygen pressure (pVO2). The second was defined as reduction of the post-exercise left ventricular outflow tract (LVOT) gradient.

RESULTS

We included in our analyses data from four studies that met our review eligibility criteria. There were three randomised placebo-controlled clinical trials and one non-randomised open-label clinical trial. All four studies showed a reduction in NYHA class from mavacamten use. Three out of four studies demonstrated >1 NYHA functional class improvement ranging from 34% to 80%, while only one study showed a smaller percentage of patients remaining at class 3. Three out of four studies measured pVO2 as an outcome, and all three studies noticed an increase in peak oxygen consumption after mavacamten treatment. Additionally, three out of four studies measured post-exercise LVOT gradient reduction as an outcome and all three found significant reduction in the post-exercise LVOT gradient after treatment. The most commonly observed adverse side effects were atrial fibrillation and decreased left ventricular ejection fraction, but all participants recovered without long-term sequelae and only one patient dropped out of the trial.

CONCLUSIONS

Mavacamten has a greater efficacy than placebo in the treatment of HCM. It also showed promising tolerability and efficacy profiles in the treatment of HCM in adults. The three endpoints used in the evaluation of studies were reduction in NYHA class, increase in pVO2, and post-exercise LVOT gradient reduction. Mavacamten showed greater reduction in NYHA, larger effects on increase of pVO2, and significant reduction of the LVOT gradient. Mavacamten was also found to be well tolerated, like the placebo. The side effect profile was limited for the majority of individuals taking mavacamten. In the future, authors recommended dose-optimisation studies, and studies that evaluate mavacamten both in comparison to, and in conjunction with other current treatments.

Mavacamten, a precision medicine for hypertrophic cardiomyopathy: From a motor protein to patients

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder characterized by left ventricular hypertrophy, hyperdynamic contraction, and impaired relaxation of the heart. These functional derangements arise directly from altered sarcomeric function due to either mutations in genes encoding sarcomere proteins, or other defects such as abnormal energetics. Current treatment options do not directly address this causal biology but focus on surgical and extra-sarcomeric (sarcolemmal) pharmacological symptomatic relief. Mavacamten (formerly known as MYK-461), is a small molecule designed to regulate cardiac function at the sarcomere level by selectively but reversibly inhibiting the enzymatic activity of myosin, the fundamental motor of the sarcomere. This review summarizes the mechanism and translational progress of mavacamten from proteins to patients, describing how the mechanism of action and pharmacological characteristics, involving both systolic and diastolic effects, can directly target pathophysiological derangements within the cardiac sarcomere to improve cardiac structure and function in HCM. Mavacamten was approved by the Food and Drug Administration in April 2022 for the treatment of obstructive HCM and now goes by the commercial name of Camzyos. Full information about the risks, limitations, and side effects can be found at www.accessdata.fda.gov/drugsatfda_docs/label/2022/214998s000lbl.pdf.

Mavacamten, a First-in-Class Cardiac Myosin Inhibitor for Obstructive Hypertrophic Cardiomyopathy

OBJECTIVE

To assess mavacamten's role in hypertrophic cardiomyopathy treatment.

DATA SOURCES

In addition to clinical guidelines, package inserts, and general reviews, we searched PubMed using the term mavacamten from inception to June 11, 2022.

STUDY SELECTION AND DATA EXTRACTION

English language studies describing mavacamten's mechanism of action, pharmacokinetics, drug interactions, clinical and economic outcomes, and adverse events.

DATA SYNTHESIS

Mavacamten reduces left ventricular outflow obstruction and New York Heart Association functional class while improving Kansas City Cardiomyopathy Questionnaire-Clinical Summary Scores in patients with obstructive hypertrophic cardiomyopathy. With an acquisition cost of $245.20 per capsule, it would cost $1.2 million for every additional quality-adjusted life year. In those with unobstructive hypertrophic cardiomyopathy, there were improvements in N-terminal probrain natriuretic peptide and high-sensitivity cardiac troponin biochemical markers. Mavacamten is a substrate for CYP2C19 and CYP3A4, and a CYP enzyme inducer.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Patients with obstructive hypertrophic cardiomyopathy and an ejection fraction ≥55% have a new option if they remain symptomatic despite maximally tolerated β-blocker or non-dihydropyridine calcium channel blocker therapy. It is an alternative to disopyramide therapy, which has poor patient tolerance, or septal reduction therapies, which are invasive. However, mavacamten is not cost-effective and its role in nonobstructive hypertrophic cardiomyopathy is not well established.

CONCLUSIONS

Mavacamten is a new option for patients with refractory obstructive hypertrophic cardiomyopathy and an ejection fraction ≥55% but its pricing makes therapy not cost-effective. Final health outcomes are not fully elucidated and additional studies are needed to determine long-term effects.

Targeting lipid metabolism as a new therapeutic strategy for inherited cardiomyopathies

Inherited cardiomyopathies caused by pathological genetic variants include multiple subtypes of heart disease. Advances in next-generation sequencing (NGS) techniques have allowed for the identification of numerous genetic variants as pathological variants. However, the disease penetrance varies among mutated genes. Some can be associated with more than one disease subtype, leading to a complex genotype-phenotype relationship in inherited cardiomyopathies. Previous studies have demonstrated disrupted metabolism in inherited cardiomyopathies and the importance of metabolic adaptations in disease onset and progression. In addition, genotype- and phenotype-specific metabolic alterations, especially in lipid metabolism, have been revealed. In this mini-review, we describe the metabolic changes that are associated with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), which account for the largest proportion of inherited cardiomyopathies. We also summarize the affected expression of genes involved in fatty acid oxidation (FAO) in DCM and HCM, highlighting the potential of PPARA-targeting drugs as FAO modulators in treating patients with inherited cardiomyopathies.

An evaluation of mavacamten for the treatment of symptomatic obstructive hypertrophic cardiomyopathy in adults

INTRODUCTION

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disorder leading to hypertrophy of the left ventricle excluding other etiologies. Patients can experience exertional chest pain, dyspnea, syncope or even sudden cardiac death (SCD). Traditional medical management consists of beta blockers (BB), nondihydropyridine calcium channel blockers and disopyramide. Mavacamten, a novel cardiac myosin inhibitor, has recently been shown to improve both quantitative and qualitative measures of obstructive HCM allowing some patients to defer septal reduction therapy.

AREAS COVERED

This review delves into the pharmacotherapy of mavacamten, the evidence behind this first-in-class drug for HCM, guidance for clinical usage, and possible future uses for cardiac myosin inhibitors.

EXPERT OPINION

Mavacamten should be incorporated into the standard armamentarium of medications used to treat obstructive HCM. PIONEER-HCM, EXPLORER-HCM and VALOR-HCM demonstrated improvements in peak LVOT gradient both at rest and post-exercise, cardiac biomarkers, New York Heart Association (NYHA) functional class and Kansas City Cardiomyopathy Questionnaire (KCCQ) scores. Unlike other medications utilized for treatment, mavacamten can delay or even obviate the need for septal reduction therapy.

Review of Mavacamten for Obstructive Hypertrophic Cardiomyopathy and Future Directions

Hypertrophic cardiomyopathy (HCM) is a condition with abnormal hypertrophy of the left ventricle in the absence of common causes. The most common form involves the basal septum and can lead to obstruction of the left ventricular outflow tract. Patients can experience exertional symptoms such as chest pain, dyspnea and syncope. Traditional treatment has included beta blockers and nondihydropyridine calcium channel blockers with second-line therapy being disopyramide. Recently, mavacamten, a cardiac myosin inhibitor, has demonstrated improvement in quantitative measures of obstruction and symptom relief to such a degree that patients were able to defer invasive management of the disease. This review focuses on the pharmacology of mavacamten, its clinical trial data and guidance on how to incorporate this drug into clinical practice. Furthermore, it discusses emerging therapies currently being investigated for HCM.

Mavacamten: A First-in-class Oral Modulator of Cardiac Myosin for the Treatment of Symptomatic Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy is the most common monogenic cardiovascular disease that is caused by sarcomeric protein gene mutations. A hallmark of the most common form of the disease is outflow obstruction secondary to systolic narrowing of the left ventricular outflow tract from septal hypertrophy, mitral valve abnormalities and, most importantly, hyperdynamic contractility. Recent mechanistic studies have identified excessive myosin adenosine triphosphatase activation and actin-myosin cross-bridging as major underlying causes. These studies have led to the development of mavacamten, a first-in-class myosin adenosine triphosphatase inhibitor and the first specific therapy for hypertrophic obstructive cardiomyopathy. Preclinical and subsequent pivotal clinical studies have demonstrated the efficacy and safety of mavacamten. A remarkable improvement among treated patients in peak oxygen consumption, functional capacity, symptom relief and post-exercise left ventricular outflow tract gradient, along with dramatic reductions in heart failure biomarkers, suggests that this new medication will be transformative for the symptom management of hypertrophic obstructive cardiomyopathy. There is also hope and early evidence that mavacamten may delay or obviate the need for invasive septal reduction therapies. In this article, we review the current evidence for the efficacy and safety of mavacamten and highlight important considerations for its clinical use.

Mavacamten: First Approval

Mavacamten (Camzyos™) is an oral small-molecule cardiac myosin inhibitor developed by MyoKardia, Inc., a wholly owned subsidiary of Bristol Myers Squibb, for the treatment of hypertrophic cardiomyopathy (HCM) and diseases of diastolic dysfunction. In April 2022, mavacamten was approved for use in the USA in the treatment of adults with symptomatic New York Heart Association (NYHA) class II-III obstructive HCM to improve functional capacity and symptoms. This article summarizes the milestones in the development of mavacamten leading to this first approval for the treatment of adults with symptomatic NYHA class II-III obstructive HCM.