Cardiologists Expected This New Drug To Prevent Heart Attacks — So Why Did It Fail?

A drug that heart doctors widely expected to become the next major weapon against heart attacks has failed in a large clinical trial, drugmaker Novartis announced.

The experimental drug, pelacarsen, did lower blood levels of a fatty particle long tied to heart disease. But patients who took it did not have fewer heart attacks, strokes or heart-related deaths than patients who got a placebo, the company said Friday.

Dr. Harlan Krumholz, a cardiologist at Yale University in New Haven, Connecticut, called the news extremely disappointing, but drew a broader lesson from it. 

Even strong evidence that two things occur together is still never proof that one causes the other, he told The New York Times.

The particle in question is lipoprotein(a), often shortened to Lp(a). About 1 in 5 people worldwide have elevated levels, and nearly a third of people who develop heart disease early in life do, according to Novartis. 

Roughly 90% of a person’s Lp(a) level is set by their genes. Unlike cholesterol, it barely moves with diet or exercise.

Those features made it an appealing target. Lp(a) could help explain why some people have a heart attack despite doing everything right — normal cholesterol, controlled blood pressure, no smoking, regular exercise, reports The Times.

The trial followed 8,323 people who had high Lp(a) and existing heart disease for seven years, Novartis said. 

Participants injected themselves once a month with either the drug or a placebo. Then researchers tracked a combined count of cardiac deaths, non-fatal heart attacks, non-fatal strokes and emergency procedures to reopen blocked arteries.

An earlier study had shown the drug cut Lp(a) levels by 80%, which made success look close to a sure thing, The Times reported.

“This is a huge blow,” Dr. David Maron, president of the American Society for Preventive Cardiology, told The Times.

Dr. Shreeram Aradhye, president of development and chief medical officer at Novartis, said the trial still answered an important question.

“These are not the results we hoped for,” he said in a company announcement, adding that the findings advance scientific understanding of Lp(a) and may shape future approaches to heart risk.

Heart medicine has faced setbacks like this before, including a drug meant to raise “good” cholesterol that failed years ago and an anti-inflammatory heart drug that failed just last month. 

Other drugmakers are still running large trials of similar Lp(a) drugs, so the idea is not dead yet.

The full results are expected at a major heart meeting in November, alongside publication in a medical journal, according to The Times. 

More information

Visit the U.S. Centers for Disease Control and Prevention for more information about preventing heart disease.

SOURCES: The New York Times, Sept. 4, 2026; Novartis, company announcement, Sept. 4, 2026