Plain language summary of results from ORION-10 and ORION-11: two studies to learn how well inclisiran works in people with high cholesterol

What is this plain language summary about? This is a summary of the article describing the results of the ORION-10 and ORION-11 studies, which was published in the New England Journal of Medicine in April 2020. The studies included adult participants with atherosclerotic cardiovascular disease (ASCVD). ASCVD happens when the blood vessels that carry blood from the heart to other areas of the body are blocked by fatty build-up (plaque) causing a heart attack, stroke, or other problems. High levels of low-density lipoprotein cholesterol (LDL cholesterol) in the blood can cause this fatty build-up. ORION-11 also included participants who were at high risk for ASCVD due to other conditions or high cholesterol that runs in the family. What was the purpose of the ORION-10 and ORION-11 studies? To help researchers understand whether a medicine called inclisiran could help to lower LDL (bad) cholesterol in participants with ASCVD, or at risk of having ASCVD, who had high cholesterol and were taking the highest dose of statins recommended for them. What happened during the ORION-10 and ORION-11 studies? In the ORION-10 and ORION-11 studies, around half of the participants received inclisiran and around half received a placebo (a placebo looks like the study treatment but has no medicine in it) in addition to their usual cholesterol-lowering treatment. Participants in each study received 4 injections of their assigned treatment: at the start, at 3 months, and then every 6 months. What were the main results of the ORION-10 and ORION-11 studies? LDL cholesterol was lowered by about 50% more in the inclisiran group compared with the placebo group. This lowering of LDL cholesterol was consistent throughout both studies. Adverse events (medical problems) were similar between treatment groups. Participants in the inclisiran group had more reactions where the injections were given than the placebo group, but these were mostly mild and only lasted a few days. Based on the results of these studies, inclisiran was approved by the United States Food and Drug Administration (FDA) as a treatment option for use with statins to reduce LDL cholesterol in people with ASCVD. Clinical Trial Registration: NCT03399370 (ORION-10), NCT03400800 (ORION-11) (ClinicalTrials.gov) </sec.