LDLR and familial hypercholesterolemia: However, a substantial number of patients who lack sufficient functional LDL receptor (LDLR) and are unable to reach sufficiently low levels of LDL-C (≤ 70 mg/dl in non-familial hypercholesterolemia), are drug intolerant, or do not meet the U.S. Food and Drug Administration (FDA) and the 2017 clinical American College of Cardiology Expert consensus guidelines [1] for combination therapies.