Lp(a)-Lowering Drugs Approach a Crucial Test

Why Is Lipoprotein(a) an Important Cardiovascular Risk Factor?

Lipoprotein(a) is an LDL-like particle containing apolipoprotein(a). Genetic and epidemiological evidence links higher concentrations with atherosclerotic cardiovascular disease and calcific aortic valve disease. Unlike LDL cholesterol, Lp(a) usually changes little in response to diet, exercise, or weight loss, so people may have markedly elevated levels despite otherwise healthy habits.

Clinical guidelines commonly treat an Lp(a) concentration of at least 50 mg/dL, or approximately 125 nmol/L, as a cardiovascular risk-enhancing factor. These units describe different laboratory measurements and should not be converted with a single universal formula. Elevated Lp(a) does not guarantee that someone will develop heart disease, but it can strengthen the case for intensive control of LDL cholesterol, blood pressure, diabetes, and smoking exposure.

How Do the New Lp(a)-Lowering Drugs Work?

Pelacarsen is an antisense oligonucleotide, while agents including olpasiran and lepodisiran use small interfering RNA technology. Both approaches are designed to prevent liver cells from producing apolipoprotein(a), thereby reducing circulating Lp(a). Published phase 2 trials of pelacarsen and olpasiran demonstrated substantial, dose-dependent reductions, with the higher olpasiran regimens lowering Lp(a) by more than 90% in many participants.

These biomarker results are scientifically compelling, but they do not prove that treatment prevents cardiovascular events. Phase 3 studies such as Lp(a)HORIZON and OCEAN(a)-Outcomes are testing whether pharmacologically lowering Lp(a) reduces outcomes including myocardial infarction, ischemic stroke, and urgent coronary treatment. Regulators will also assess adverse effects, dosing convenience, durability, and which patients have enough baseline risk to benefit.

What Should Patients With High Lp(a) Do Now?

European and North American expert guidance supports measuring Lp(a) at least once in adulthood, particularly when there is premature cardiovascular disease, familial hypercholesterolemia, or a strong family history. Because concentrations are largely inherited, an elevated result may also justify discussing testing with close biological relatives. Repeat testing is not routinely necessary unless the initial result is uncertain or a treatment specifically targeting Lp(a) is introduced.

No supplement or lifestyle program has been shown to selectively produce the large Lp(a) reductions achieved by the investigational medicines. Patients can nevertheless reduce their total risk by treating LDL cholesterol, controlling blood pressure and diabetes, avoiding tobacco, exercising regularly, and following a heart-healthy diet. Existing therapies should not be stopped or changed without medical advice, and trial participation may be an option for eligible patients with established cardiovascular disease and elevated Lp(a).