Esperion Therapeutics Inc. shares plummeted 20% in premarket trade Wednesday on late-stage clinical trial results for its cholesterol-lowering medication. The phase 3 trial, which enrolled 2,230 patients, met the primary endpoint of safety and tolerability and the key efficacy endpoint, lowering LDL-C an additional 20% after 12 weeks, the company said. LDL-C was also lowered 20% at 24 weeks, and 16% at 52 weeks. Investors and Wall Street will be watching any potential safety issues with the therapy closely. Safety issues for individuals on the therapy, bempedoic acid, happened at a rate of nearly 80%, and serious safety issues were seen at nearly 11%, with the company noting there were “no clinically relevant differences” for those measures between the therapy and the placebo groups. Fatal adverse events that the company said were “unrelated to study treatment” happened at a nearly 1% rate for patients on bempedoic acid, or 13 patient deaths, relative to a 0.3% rate for patients on the placebo, or two patient deaths, according to an Esperion presentation. Bempedoic acid is intended for high-risk patients with atherosclerotic cardiovascular disease, or artery-clogging fat deposits, who haven’t responded well enough to cholesterol-lowering drugs like statins. Other companies that have or are developing cholesterol-lowering medications include Regeneron Pharmaceuticals Inc. and Sanofi , Amgen Inc. and Medicines Company , and Regeneron recently announced discounts for its cholesterol-lowering drug, in hopes of boosting sales. Esperion shares have lifted 0.7% month-to-date, compared with a 0.3% rise in the S&P 500 and a 0.3% decline in the Dow Jones Industrial Average .