This study will be a placebo-controlled, double-blind, randomized, phase 3 study in participants with heterozygous familial hypercholesterolemia (HeFH) and/or atherosclerotic cardiovascular disease (ASCVD) or multiple ASCVD risk factors to evaluate the efficacy, safety, and tolerability of obicetrapib as an adjunct to diet and maximally tolerated lipid-lowering therapy. The screening period for this study will take up to 14 days. Afterwards patients will be randomized 1:1:1:1 to Obicetrapib 10 mg and ezetimibe 10 mg fixed dose combination, obicetrapib 10 mg, ezetimibe 10 mg or placebo for a 84 day treatment period. After the treatment period, patients will have an end of study follow-up visit.