The Last Frontier in Cardiology: Why the Lp(a) Drug Race Could Rewrite Heart Disease Prevention

Cardiovascular medicine has spent decades building an impressive toolkit. Statins, PCSK9 inhibitors, and ezetimibe have given physicians powerful ways to lower LDL cholesterol and reduce the risk of heart attacks and strokes. For most patients with elevated cardiovascular risk, those tools work. But for roughly one in five people worldwide, a separate inherited risk factor has been quietly driving heart disease with no approved pharmacological remedy in sight. That is about to change.

The risk factor is lipoprotein(a), abbreviated Lp(a) and pronounced "L-P-little-A." It is a blob of lipids and proteins that promotes the formation of arterial plaques and makes blood clots more likely. Unlike LDL cholesterol, which can be meaningfully reduced through diet, exercise, and medication, Lp(a) levels are almost entirely determined by genetics. If you have high Lp(a), you were born with it, and until very recently, there was nothing medicine could offer you beyond managing your other risk factors and hoping for the best.

That gap is now the most consequential open question in cardiovascular drug development. Three major pharmaceutical companies are racing to answer it, and the first pivotal data could arrive within weeks.

What Lp(a) Actually Does

Lp(a) was first identified in 1963, but its clinical significance took decades to establish. Mendelian randomization studies, which use genetic variants as natural experiments to test causal relationships, have now demonstrated convincingly that elevated Lp(a) is an independent cause of coronary artery disease, heart attack, stroke, peripheral arterial disease, and calcific aortic valve stenosis. People with high Lp(a) face more than twice the risk of heart attack compared to those with normal levels, even when their LDL cholesterol is well controlled.

The scale of the problem is substantial. Approximately 1.5 billion people globally carry elevated Lp(a) levels, and the condition is significantly undertested. Less than one percent of US adults were screened for Lp(a) in 2024, according to a study of electronic health records. Leading cardiology organizations have only recently begun recommending that every adult be tested at least once in their lifetime. The combination of high prevalence, genetic causation, and a complete absence of approved treatments has made Lp(a) one of the most attractive targets in all of cardiovascular medicine.

Three Companies, Three Approaches

Novartis, in partnership with Ionis Pharmaceuticals, holds the frontrunner position with pelacarsen, an antisense oligonucleotide that targets the liver's production of apolipoprotein(a), the protein component of the Lp(a) particle. In Phase 2 trials, pelacarsen reduced Lp(a) levels by up to 80 percent. The pivotal Phase 3 Lp(a) HORIZON trial enrolled 8,323 patients with established cardiovascular disease and Lp(a) levels of at least 70 mg/dL. It is the first cardiovascular outcomes trial ever designed to test whether pharmacological Lp(a) lowering actually reduces heart attacks and strokes. Novartis has guided investors to expect results in the second half of 2026, making the readout one of the most anticipated events in cardiology this year.

Amgen's olpasiran takes a different molecular approach, using small interfering RNA to degrade the messenger RNA that encodes apolipoprotein(a) in liver cells. Phase 2 data showed reductions exceeding 95 percent at the highest doses, a more potent effect than pelacarsen achieves, with the added convenience of dosing every 12 weeks rather than monthly. Amgen's Phase 3 OCEAN(a)-Outcomes trial enrolled approximately 7,000 patients with established atherosclerotic cardiovascular disease and Lp(a) of at least 200 nmol/L. Results are expected by the end of 2026.

Eli Lilly is pursuing two parallel strategies. Lepodisiran, another siRNA agent, demonstrated a 94 percent reduction in Lp(a) with a single 400 mg dose in Phase 2 data, with effects lasting nearly a year from a single injection. That durability profile supports dosing every six months, a meaningful practical advantage for patients managing chronic conditions. Lilly's Phase 3 ACCLAIM-Lp(a) trial is the largest of the group, targeting 16,700 participants across both secondary prevention and primary prevention populations. Results are not expected until approximately 2029. Separately, Lilly is also developing muvalaplin, an oral small molecule that disrupts Lp(a) particle assembly, with a Phase 3 outcomes trial now enrolling.

Why the HORIZON Readout Is a Field-Defining Moment

The Novartis HORIZON trial is not just a product catalyst for pelacarsen. It is a proof-of-concept test for the entire Lp(a)-lowering hypothesis. The field has established, with considerable confidence, that these drugs can lower Lp(a) dramatically. What remains unproven is whether lowering the biomarker translates into fewer cardiovascular events in patients who are already receiving optimized standard care, including high-intensity statins and PCSK9 inhibitors.

That is a harder question than it might appear. The history of cardiovascular medicine includes several cases where drugs that lowered an attractive biomarker failed to reduce clinical events. Niacin lowered LDL and raised HDL but did not reduce heart attacks in large trials. Torcetrapib raised HDL dramatically but increased mortality. The Lp(a) hypothesis is supported by far stronger genetic evidence than either of those targets, but the outcomes data does not yet exist. HORIZON will provide it.

A positive result would validate the class simultaneously, accelerating the development timelines for olpasiran, lepodisiran, and muvalaplin. It would also trigger a wave of combination therapy research, since patients with both elevated LDL and elevated Lp(a) represent a large and currently undertreated population. Analysts at Evaluate have projected consensus peak sales of approximately $5.6 billion annually by 2032 for the Lp(a) drug class, a figure that could prove conservative if the outcomes data is compelling and testing rates rise toward the levels that cardiology organizations are now recommending.

The Testing Gap and What It Means

One of the more striking aspects of the Lp(a) story is how poorly understood the risk factor remains in clinical practice. Despite decades of epidemiological evidence and the clear recommendation from major cardiology societies to test every adult at least once, the vast majority of patients with elevated Lp(a) have never been told they have it. That is partly a function of awareness, partly a function of the historical absence of any treatment to offer, and partly a function of testing infrastructure that has not kept pace with the science.

The arrival of approved Lp(a)-lowering therapies, if the outcomes trials succeed, will change that calculus. When physicians have something to prescribe, they have a reason to test. The commercial success of PCSK9 inhibitors, which also target a genetically determined cardiovascular risk factor, demonstrated that the market for injectable lipid-lowering therapies can be substantial once the clinical case is established. The Lp(a) opportunity is larger in terms of population prevalence, though the path to broad uptake will depend heavily on how payers respond to the pricing of these agents and how quickly testing rates improve.

What Comes Next

The second half of 2026 is shaping up as a pivotal period for cardiovascular medicine. The HORIZON readout will either validate the Lp(a)-lowering hypothesis and open a new treatment category, or it will force the field to recalibrate its assumptions about patient selection, dosing thresholds, and trial design. A neutral result would not necessarily kill the hypothesis, given that olpasiran and lepodisiran achieve deeper Lp(a) reductions than pelacarsen, but it would introduce uncertainty that the field would need to work through.

For the roughly 1.5 billion people worldwide carrying elevated Lp(a), the stakes are not abstract. They represent a population that has been told for years that their inherited cardiovascular risk cannot be pharmacologically addressed. The science has now advanced to the point where that may no longer be true. Whether it actually changes clinical practice will depend on the data that is now weeks away from being reported.