Amgen has reported positive results from its Phase III GLAGOV trial of Repatha (evolocumab) added to optimised statin therapy in treating statistically significant regression of atherosclerosis in patients with coronary artery disease (CAD).
Repatha is a human monoclonal antibody designed to inhibit proprotein convertase subtilisin / kexin type 9 (PCSK9).
It binds to PCSK9 and prevents circulating PCSK9 from binding to the low-density lipoprotein (LDL) receptor (LDLR) thereby inhibiting PCSK9-mediated LDLR degradation and permitting LDLR to recycle back to the liver cell surface.
The inhibition of the binding of PCSK9 to LDLR increases the number of LDLRs available to clear LDL from the blood, thereby lowering LDL-C levels.
The Phase III multicentre, double-blind, randomised, placebo-controlled, global assessment of plaque regression with a PCSK9 antibody as measured by intravascular ultrasound (GLAGOV) trial was conducted to evaluate the efficacy of Repatha in modifying atherosclerotic plaque build-up in the coronary arteries of patients who were already receiving optimised statin therapy, as measured by intravascular ultrasound (IVUS).
Results suggested that the study achieved its primary endpoints as Repatha induced regression in percent atheroma volume (PAV), which is the proportion of arterial lumen occupied by plaque.
Additionally, Repatha resulted to plaque regression in PAV.
South Australian Health and Medical Research Institute professor of cardiology and deputy director Stephen Nicholls said: “Based on previous studies, we did not know if GLAGOV would show additional plaque regression at LDL-C levels below 60 milligrams per decilitre (mg/dL).
“One of the most compelling results from GLAGOV is the continued reduction of plaque at LDL-C levels well below commonly accepted thresholds.”
An exploratory analysis of the study also revealed that lesser, positively adjudicated, major cardiovascular events were happening in patients receiving Repatha compared with those receiving placebo.
Amgen is also conducting the FOURIER trial, intended to determine the efficacy of Repatha added to optimised statin therapy in reducing the risk of cardiovascular events in patients with clinically evident atherosclerotic disease.
Image: Repatha inhibits binding of PCSK9 to LDLR. Photo: courtesy of Amgen.