GALACTIC-HF: Omecamtiv Mecarbil Provides Modest Benefit in Heart Failure Patients

John Teerlink, MD

New results from the highly anticipated GALACTIC-HF trial provide data suggesting omecamtiv mecarbil could play a role in reducing worsening heart failure.

Presented at the American Heart Association (AHA) Scientific Sessions 2020, data from the 8000-patient phase 3 trial indicate use of the selective, small molecule activator of cardiac myosin resulted in an 8% lower risk of experiencing a heart failure event or cardiovascular death compared to placebo therapy.

“This study provides substantial evidence characterizing the efficacy and safety of this novel therapy,” said John Teerlink, MD, director of heart failure and of the Echocardiography Laboratory at the San Francisco Veterans Affairs Medical Center and professor of medicine at the University of California San Francisco, in a statement from the AHA. “The trial included a wide range of patients from both the inpatient and outpatient settings, and these findings will inform potential future implementation of omecamtiv mecarbil to treat chronic heart failure.”

A multicenter, international, randomized, double-blind, placebo-controlled, event-driven phase 3 trial, the Global Approach To Lowering Adverse Cardiac Outcomes Through Improving Contractility In Heart Failure (GALACTIC-HF) trial screened more than 10,000 patients across 35 countries with the aim of determining the effects of omecamtiv mecarbil in patients with heart failure. Of the 11,121 patients screened, 8256 underwent randomization in a 1:1 ratio to receive either omecamtiv mecarbil plus standard medical therapies or a placebo group.

Of the 8256 patients randomized, 8232 patients with a median study exposure of 21.8 months were included in the final analysis. Of these, 79% were men and 78% were white. Investigators noted 2084 (25%) of patients included in the final analysis were considered inpatients. had a mean age of 65 years, a mean systolic blood pressure of 116 mmHg, and a median eGFR of 60 mL/min/1.73 m2.

For inclusion in the trial, patients were required to be managed with standard heart failure therapies, have heart failure classified as NYHA class II-IV, a left ventricular ejection fraction of 35% or less, and BNP levels of 125 pg/mL or NT-proBNP levels of 400 pg/mL or more. Patients were also required to be currently hospitalized with for heart failure (inpatients) or have an urgent emergency department visit or hospitalization for heart failure within 1 year prior to screening. Patients were excluded from the study if they were had hemodynamic or clinical instability requiring mechanical support or intravenous medication, systolic blood pressure less than 85 mmHg, or an estimated GFR of less than 20 mL/min/1.73m2.

The primary outcome of the trial was a composite end point consisting of time to first heart failure or cardiovascular death. Of note, urgent clinic visits, emergency department visits, or hospitalizations for subjectively and objectively worsening heart failure leading to treatment intensification were all included in the definition of a heart failure event. Secondary outcomes of interest included time to cardiovascular death, change in KCCQ total symptom score from baseline to 24 weeks, time to first heart failure hospitalization, and time to all-cause death.

Upon analysis, results indicated patients randomized to omecamtiv mecarbil experienced a statistically significant reduction in risk of the study’s primary composite outcome of time to first heart failure event or cardiovascular death (HR, 0.92; 95% CI, 0.86-0.99; P=.025). Additionally, results indicated omecamtiv mecarbil was associated with reductions in first heart failure event (HR, 0.93; 95% CI, 0.86-1.00; P=.06), but not cardiovascular death (HR, 1.01; 95% CI, 0.92-1.11; P=.86) compared to placebo.

Further analysis of results indicated omecamtiv mecarbil appeared to have more pronounced effects in patients with a lower ejection fraction. Analysis of safety data from the trial indicates there were no significant differences in adverse events between the study arms.

This study, “Omecamtiv Mecarbil In Chronic Heart Failure With Reduced Ejection Fraction: The Global Approach To Lowering Adverse Cardiac Outcomes Through Improving Contractility In Heart Failure (GALACTIC-HF) Trial,” was presented at AHA 2020.