A single dose reduces lipoprotein(a) by over 90% in large international trial
In a landmark development for cardiovascular medicine, the experimental gene-silencing drug Lepodisiran has delivered dramatic reductions in a genetically-driven heart risk factor known as lipoprotein(a) or “Lp(a)”—a target long considered untreatable.
What is Lp(a) and why it matters
Lipoprotein(a) is a cholesterol-like particle produced by the liver, found in approximately one in five people worldwide in elevated levels. Unlike standard LDL cholesterol, Lp(a) is far less affected by diet or exercise, and is strongly genetically determined. High Lp(a) levels contribute to arterial plaque buildup and raise risks of heart attack, stroke and aortic stenosis.Until now, no approved therapies existed specifically to lower Lp(a).
Trial data and scope
In a Phase 2 trial led by the Cleveland Clinic, over 300 patients were enrolled across multiple countries (including the United States, Argentina, China, Germany, Japan and Spain) with a mean age of 62. Participants received a single 400 mg dose of Lepodisiran and were followed up to 540 days. The results? Lp(a) levels dropped by 93.9% from day 60 to day 180 after one dose. Even at 540 days post-dose, levels remained 53% below baseline. Another trial using a different siRNA therapy (Zerlasiran) found reductions of more than 80%.
Safety data to date have been favourable: no major safety signals have emerged. Some injection-site reactions occurred (up to 10% of participants), but no serious adverse events linked to the drug were reported in the primary analyses.
Why this matters globally
Cardiovascular disease remains the leading cause of death worldwide, claiming nearly 18 million lives each year. Yet many patients continue to suffer events even after LDL, blood pressure and lifestyle risk factors are well managed. Elevated Lp(a) is increasingly recognized as explaining part of this “residual risk.” The successful reduction of Lp(a) opens the door to targeting a previously unaddressed risk factor.
Moreover, because the drug requires only infrequent dosing (in the trial, single or two-dose regimens were used) this may offer convenient, long-acting treatment compared to daily medications.
What’s next
The research team emphasises that while Lp(a) reduction is dramatic, the proof point remains whether this translates into fewer heart attacks and strokes. Phase 3 trials are being planned or are underway to assess hard-outcomes (cardiovascular events) over multiple years.
Experts like Dr. Steven Nissen note: “Effective therapies to reduce Lp(a) are being developed and if they show a reduction in risk of heart attack or stroke, we need to know who to treat.”
Challenges & considerations
- Testing and awareness: Many people with elevated Lp(a) are unaware of it because standard lipid panels do not routinely measure it. Physicians must raise awareness and screening may need wider adoption.
- Cost and access: Once approved, pricing and equitable access will be critical, especially in low- and middle-income countries.
- Long-term safety: While short-term safety is promising, long-term effects—especially with gene-silencing therapies—must be monitored.
- Integration into care: Specialists and primary-care physicians must decide appropriate patient populations (e.g., those with familial high Lp(a), premature heart disease) and integrate this new therapy into existing cardiovascular care frameworks.
Final word
Lepodisiran represents a major advance in the fight against cardiovascular disease—offering hope to individuals with a genetic risk factor for which no effective treatment has existed. If the upcoming trials confirm that Lp(a) reduction leads to fewer clinical events, this could reshape preventive cardiology globally.