Emerging Nucleic Acid-Based Therapies for Hypercholesterolemia with Focus on a New Modality, Liver-Directed miR-30c Analog C2.

Despite major advances in lipid-lowering therapies, a significant unmet need remains, particularly for patients with homozygous familial hypercholesterolemia (HoFH), severe heterozygous familial hypercholesterolemia (HeFH), and those who fail to achieve guideline-recommended LDL-C targets. Nucleic acid-based therapeutics have emerged as a transformative approach for treating hypercholesterolemia. Antisense oligonucleotides and small interfering RNAs (siRNAs) have demonstrated durable hepatic gene silencing and have led to approved therapies, while gene replacement and in vivo genome-editing strategies offer the potential for long-lasting, and possibly one-time, interventions. In parallel, microRNAs (miRNAs) have attracted increasing interest because of their ability to coordinately regulate multiple genes involved in lipoprotein metabolism, cholesterol transport, and lipid homeostasis. Human genetic studies further support the importance of miRNA-mediated regulation, exemplified by a rare ~2.5 kb deletion in the distal LDLR 3'UTR ("del2.5") that disrupts miRNA-binding sites and is associated with lifelong low LDL-C levels. This review summarizes recent advances, mechanisms of action, clinical progress, and remaining challenges across antisense oligonucleotides, siRNAs, gene therapy, genome editing, and emerging miRNA-based therapeutics for hypercholesterolemia. As an example of the latter approach, the liver-directed miR-30c analog C2 has demonstrated preclinical activity by coordinately reducing hepatic lipoprotein secretion and lipogenesis while enhancing cholesterol elimination, resulting in reduced LDL-C and atherosclerosis. However, it must be noted that these findings remain preclinical, and further optimization of delivery, pharmacokinetics, safety, and long-term efficacy will be required before clinical evaluation. Continued advances in RNA chemistry, targeted delivery, and genome engineering are expected to further expand the therapeutic landscape for dyslipidemia and cardiovascular disease.