PCSK9 Synthesis Inhibitor Shows Promise in Lowering LDL-C

PCSK9 Synthetic Inhibitor Injection LDLC
PCSK9 Synthetic Inhibitor Injection LDLC
A mean 51% reduction in low-density lipoprotein cholesterol was seen in the group assigned to the 300 mg dose of inclisiran.

NEW ORLEANS — Subcutaneous injection inclisiran reduced low-density lipoprotein cholesterol (LDL-C) levels in patients with or at high risk for atherosclerotic cardiovascular disease (ASCVD), according to results of a phase 2 clinical trial presented at the 2016 American Heart Association Scientific Sessions.

Kausik K. Ray, MD, MPhil, of Imperial College of London in the United Kingdom, presented the findings on behalf of the ORION-1 investigators. ORION-1 (ClinicalTrials.gov identifier: NCT02597127) is a phase 2 double-blind, randomized controlled trial comparing 6 different subcutaneous injection dosing regimens of a PCSK9 synthetic double-stranded oligonucleotide (inclisiran; The Medicines Company).

As Dr Ray explained, inclisiran is a PCSK9 synthesis inhibitor which acts via RNA interference and requires only 2 to 3 injections per year vs the anti-PCSK9 monoclonal antibodies which need 12 to 24 injections per year.

ORION-1’s primary end point was the percentage change in LDL-C and circulating PCSK9 levels at 180 days. Secondary end points included LDL-C levels at 90 days and PCSK9 levels over time plus safety and tolerability.

A total of 501 patients were randomly assigned to 1 of 6 treatment arms (average age: 63 years; 48.1% with ASCVD; 14.2% with diabetes). More than 80% were taking statins at the study entry and 28.1% were on ezetimibe with a baseline LDL-C of 128 mg/dL.

A mean 51% reduction in LDL-C was seen in the group assigned to the 300-mg dose; a 57% reduction was seen in the group assigned to 2 doses of 300 mg. Additionally, side effects including elevated liver and muscle enzymes, myalgia, and injection site skin reactions were mild.

Dr Ray concluded that inclisiran’s profile has the potential to ensure adherence and positively affect cardiovascular outcomes. These results should support a phase 3 clinical trial.

Disclosures: Dr Ray has received research grants from Sanofi, Regeneron, Pfizer, MSD as well as honoraria from Takeda, Boehringer Ingelheim, Cipla, and AstraZeneca, among others. Dr Ray also serves as a consultant for The Medicines Company, among others. Other investigators reported financial relationships with Amgen, Janssen, Pfizer, Sanofi, The Medicines Company, MSD, Merck, and Regeneron, among others.


Ray KK, Landmesser U, Leiter LA, et al; on behalf of the ORION-1 Investigators. LBCT.03: Insights from new therapeutic trials for lipids. ORION-1. Inclisiran inhibits PCSK9 synthesis by RNA interference. Planned interim analysis of a multi-center randomized controlled dose-finding trial. Presented at: the 2016 American Heart Association Scientific Sessions. November 12-16, 2016; New Orleans, LA.