OMECAMTIV MECARBIL

Omecamtiv mecarbil, also known as CK-1827452, is an investigational medication being studied for its potential benefits in treating heart failure. This cardiac myosin activator works in a unique way by enhancing heart muscle contraction without increasing the heart’s oxygen demand. Clinical trials have examined various formulations of this drug—including intravenous infusions and oral capsules—in patients with heart failure, ischemic cardiomyopathy, and angina. These studies have focused on understanding how the drug affects heart function, exercise capacity, and overall cardiac efficiency while monitoring its safety profile and determining optimal dosing regimens.

Table of Contents

What is Omecamtiv Mecarbil?

Omecamtiv mecarbil (also known as CK-1827452) is an investigational medication being studied for the treatment of heart failure. It belongs to a novel class of drugs called cardiac myosin activators[1]. Unlike many existing heart failure medications that affect heart rate or force the heart to contract more strongly, omecamtiv mecarbil works through a unique mechanism that aims to improve the efficiency of the heart’s pumping action.

How Does Omecamtiv Mecarbil Work?

Omecamtiv mecarbil works by activating cardiac myosin, a key protein involved in heart muscle contraction. By enhancing the function of this protein, the medication helps the heart contract more effectively without increasing its oxygen demand[4]. This is particularly important because many traditional heart failure medications increase the heart’s workload and oxygen consumption, which can sometimes worsen symptoms.

Clinical studies have shown that omecamtiv mecarbil increases the systolic ejection time (the period during which the aortic valve is open and blood is flowing out of the heart) and improves fractional shortening (a measure of how well the heart contracts)[3]. These improvements in heart function occur without significantly increasing the heart’s oxygen consumption, potentially leading to better myocardial efficiency (the ratio of work performed to oxygen consumed)[4].

Medical Conditions Treated

Omecamtiv mecarbil is being studied primarily for the treatment of heart failure, particularly in patients with reduced ejection fraction (when the heart muscle doesn’t contract effectively)[2][3][4]. The clinical trials have included patients with various forms of heart failure, including:

  • Stable heart failure – Heart failure that is not currently worsening but still affects daily activities[2][3]
  • Ischemic cardiomyopathy – Heart failure caused by coronary artery disease and reduced blood flow to the heart muscle[1]
  • Left ventricular systolic dysfunction – Weakened pumping ability of the heart’s main chamber[4]

Some studies have also specifically examined the medication’s effects in patients who have both heart failure and angina pectoris (chest pain caused by reduced blood flow to the heart)[1]. This is important because some heart failure medications can worsen angina symptoms.

Formulations and Dosing

Based on the clinical trials, omecamtiv mecarbil has been studied in several different formulations and dosing regimens:

  • Intravenous (IV) formulation: Used in shorter-term studies with various dosing protocols, including:
    • 2-hour infusions[3]
    • 20-hour infusions[1]
    • 24-hour infusions[3]
    • 72-hour infusions[3]
  • Oral formulations: Developed for longer-term use and include:
    • Immediate-release (IR) capsules taken three times daily (TID)[1][2]
    • Modified-release (MR) capsules taken twice daily (BID)[2]

The dosing of omecamtiv mecarbil varies across studies, with oral doses ranging from 12.5 mg to 100 mg depending on the formulation and frequency[2]. Intravenous dosing is typically weight-based, with rates adjusted to achieve specific blood concentrations of the medication[3][4].

Clinical Research Findings

Multiple clinical trials have investigated the effects of omecamtiv mecarbil on various aspects of heart function and patient outcomes. Key findings from these studies include:

Effects on Exercise Capacity

One important study examined how omecamtiv mecarbil affects exercise tolerance in patients with ischemic cardiomyopathy and angina[1]. This was critical to determine whether the medication might worsen angina symptoms during physical activity. The study used a modified Naughton Exercise Treadmill Test to assess patients’ exercise capacity before and during treatment.

Results showed that most patients did not experience worsening of angina symptoms during exercise while taking omecamtiv mecarbil compared to placebo[1]. This suggests that the medication may be suitable for heart failure patients who also have angina, a common comorbidity.

Effects on Heart Function

Several studies have examined how omecamtiv mecarbil affects various measures of heart function:

  • Systolic ejection time: The medication consistently increases the time during which the heart is actively pumping blood, with greater increases seen at higher blood concentrations of the drug[3].
  • Fractional shortening: Studies show improvement in this measure of how well the heart contracts[3].
  • Myocardial efficiency: Research suggests that omecamtiv mecarbil may improve the efficiency of the heart by increasing its performance without proportionally increasing oxygen consumption[4].
  • Pressure-volume relationships: Studies have examined how the medication affects the relationship between pressure and volume in the heart chambers[4].

These findings support the unique mechanism of action of omecamtiv mecarbil, which aims to improve heart function without increasing the heart’s workload or oxygen demand[4].

Safety and Tolerability

The clinical trials have also assessed the safety and tolerability of omecamtiv mecarbil in various patient populations. The studies examined both short-term intravenous administration and longer-term oral dosing[1][2].

One study specifically looked at the tolerability of the oral formulation when administered three times daily for up to 7 days in patients with ischemic cardiomyopathy and angina[1]. Another examined the safety of modified-release and immediate-release formulations when taken for 10 days in patients with stable heart failure[2].

While detailed safety results aren’t provided in the available study descriptions, the continued development of the medication suggests that it has demonstrated an acceptable safety profile in these initial studies. As with any investigational medication, ongoing and larger studies will provide more comprehensive information about potential side effects and safety considerations.

Trial Identifier Primary Focus Formulations Used Key Measurements Patient Population
NCT00682565 Exercise tolerance in patients with ischemic cardiomyopathy and angina IV infusion (24mg/hr, 48mg/hr) followed by oral capsules (12.5mg, 25mg) Exercise treadmill test performance, angina symptoms Patients with ischemic cardiomyopathy and angina
NCT00941681 Pharmacokinetics of different oral formulations Modified-release (50mg, 100mg BID) and immediate-release (37.5mg TID) capsules C Max, T Max, AUC, safety and tolerability Patients with stable heart failure
NCT00624442 Safety, tolerability, and pharmacodynamics of infusion IV infusion at various doses (2-hour, 24-hour, and 72-hour infusions) Systolic ejection time, fractional shortening, plasma concentration Patients with stable heart failure
NCT00748579 Effects on myocardial efficiency IV infusion (54mg/hr followed by 21mg/hr or 72mg/hr followed by 36mg/hr) Ventricular performance, myocardial oxygen consumption, myocardial efficiency Patients with heart failure and left ventricular systolic dysfunction

Ongoing Clinical Trials on OMECAMTIV MECARBIL

  • Study of Omecamtiv Mecarbil for Treating Patients with Chronic Heart Failure and Severely Reduced Heart Pumping Ability

    Recruiting

    1 1
    Investigated drugs:
    France Germany Greece Italy Poland Spain

Glossary

  • Cardiac Myosin Activator: A type of medication that works by enhancing the function of cardiac myosin, a protein in heart muscle cells that is essential for heart contraction. Omecamtiv mecarbil is a cardiac myosin activator that aims to improve heart function without increasing oxygen demand.
  • Ischemic Cardiomyopathy: A condition where the heart muscle is weakened due to coronary artery disease and inadequate blood supply to the heart tissue, resulting in damage to the heart muscle and reduced pumping function.
  • Angina Pectoris: Chest pain or discomfort that occurs when the heart muscle doesn't receive enough oxygen-rich blood, typically caused by narrowed coronary arteries. It's often described as pressure, squeezing, or pain in the chest.
  • Myocardial Ischemia: A condition where blood flow to the heart is reduced, preventing the heart muscle from receiving enough oxygen. This can lead to heart damage and is often associated with coronary artery disease.
  • Systolic Ejection Time: The period during which the aortic valve is open and blood is flowing from the heart's left ventricle into the aorta. This is an important measure of heart function that was examined in the clinical trials.
  • Fractional Shortening: An echocardiographic measurement that indicates the percentage change in the left ventricular dimension during heart contraction. It's used as a measure of heart function and contractility.
  • Pharmacokinetics (PK): The study of how a drug moves through the body, including its absorption, distribution, metabolism, and excretion. PK studies help determine appropriate dosing and formulation of medications.
  • Pharmacodynamics (PD): The study of how a drug affects the body, including the relationship between drug concentration and its effects. PD studies examine the biological and physiological effects of medications.
  • Immediate-Release (IR) Formulation: A medication formulation designed to release the active drug quickly after administration. In the trials, IR capsules of omecamtiv mecarbil were typically taken three times daily (TID).
  • Modified-Release (MR) Formulation: A medication formulation designed to release the active drug at a controlled rate over time. In the trials, MR capsules of omecamtiv mecarbil were typically taken twice daily (BID).
  • Myocardial Oxygen Consumption: The amount of oxygen used by the heart muscle during functioning. This is an important measure because heart failure treatments ideally improve heart function without increasing oxygen demand.
  • Myocardial Efficiency: The ratio of heart performance (work output) to myocardial oxygen consumption. Higher efficiency means the heart can do more work with less oxygen, which is beneficial in heart failure.
  • Left Ventricular Systolic Dysfunction: A condition where the left ventricle (the heart's main pumping chamber) doesn't contract effectively, reducing the amount of blood pumped to the body with each heartbeat.
  • C Max: The maximum concentration of a drug in the blood after administration. This pharmacokinetic parameter helps understand how high drug levels get in the body.
  • T Max: The time required to reach the maximum concentration of a drug in the blood after administration. This helps understand how quickly a drug enters the bloodstream.
  • AUC (Area Under the Curve): A measurement of the total exposure to a drug over time. This pharmacokinetic parameter represents the total amount of drug in the bloodstream after administration.
  • Exercise Treadmill Test (ETT): A standardized test to evaluate heart function during physical exertion, where patients walk on a treadmill while monitoring heart rate, blood pressure, and ECG changes. Used in the trials to assess how the drug affects exercise capacity.

References

  1. https://clinicaltrials.gov/study/NCT00682565
  2. https://clinicaltrials.gov/study/NCT00941681
  3. https://clinicaltrials.gov/study/NCT00624442
  4. https://clinicaltrials.gov/study/NCT00748579