Small Molecules acting on Myofilaments as Treatments for Heart and Skeletal Muscle Diseases.
Khulud A AlsulamiSteven B MarstonPublished in: International journal of molecular sciences (2020)
Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are the most prevalent forms of the chronic and progressive pathological condition known as cardiomyopathy. These diseases have different aetiologies; however, they share the feature of haemodynamic abnormalities, which is mainly due to dysfunction in the contractile proteins that make up the contractile unit known as the sarcomere. To date, pharmacological treatment options are not disease-specific and rather focus on managing the symptoms, without addressing the disease mechanism. Earliest attempts at improving cardiac contractility by modulating the sarcomere indirectly (inotropes) resulted in unwanted effects. In contrast, targeting the sarcomere directly, aided by high-throughput screening systems, could identify small molecules with a superior therapeutic value in cardiac muscle disorders. Herein, an extensive literature review of 21 small molecules directed to five different targets was conducted. A simple scoring system was created to assess the suitability of small molecules for therapy by evaluating them in eight different criteria. Most of the compounds failed due to lack of target specificity or poor physicochemical properties. Six compounds stood out, showing a potential therapeutic value in HCM, DCM or heart failure (HF). Omecamtiv Mecarbil and Danicamtiv (myosin activators), Mavacamten, CK-274 and MYK-581 (myosin inhibitors) and AMG 594 (Ca2+-sensitiser) are all small molecules that allosterically modulate troponin or myosin. Omecamtiv Mecarbil showed limited efficacy in phase III GALACTIC-HF trial, while, results from phase III EXPLORER-HCM trial were recently published, indicating that Mavacamten reduced left ventricular outflow tract (LVOT) obstruction and diastolic dysfunction and improved the health status of patients with HCM. A novel category of small molecules known as "recouplers" was reported to target a phenomenon termed uncoupling commonly found in familial cardiomyopathies but has not progressed beyond preclinical work. In conclusion, the contractile apparatus is a promising target for new drug development.
Keyphrases
- hypertrophic cardiomyopathy
- phase iii
- left ventricular
- skeletal muscle
- heart failure
- open label
- clinical trial
- cardiac resynchronization therapy
- acute heart failure
- phase ii
- binding protein
- acute myocardial infarction
- double blind
- mitral valve
- placebo controlled
- left atrial
- smooth muscle
- aortic stenosis
- insulin resistance
- multiple sclerosis
- atrial fibrillation
- machine learning
- oxidative stress
- magnetic resonance imaging
- study protocol
- early onset
- signaling pathway
- systematic review
- nitric oxide
- computed tomography
- blood pressure
- protein kinase
- transcatheter aortic valve replacement
- acute coronary syndrome
- bone marrow
- aortic valve
- metabolic syndrome
- stem cells
- nitric oxide synthase