The slam dunk that wasnt: Promising cholesterol drug fails to prevent heart attacks or stroke

An experimental drug that held great promise in driving down a dangerous form of cholesterol didn’t show any measurable impact on heart attack or stroke in a clinical trial.The failure of the Novartis drug pelacarsen to help people who have high levels of lipoprotein(a) stunned researchers, who called it a massive blow to preventive cardiology.Results of the clinical trial of pelacarsen, an injection, presented Saturday at a meeting of the American Heart Association, found there were zero decreases in stroke, heart attack, cardiovascular deaths or the number of procedures to open blocked arteries or restore blood flow to the heart.“I really thought that this was going to be a slam dunk,” said Dr.

Amanda Doran, an assistant professor of medicine in the division of cardiovascular medicine at Vanderbilt University Medical Center.Vanderbilt was one of nearly 800 sites involved in the clinical trial, called Horizon.

“We were pretty invested, so it obviously hurts.”Pelacarsen targets a stealthy and particularly lethal form of cholesterol called lipoprotein(a), or Lp(a).Much like low-density lipoprotein — LDL, or the “bad” cholesterol — Lp(a) causes plaque to build up in arteries.

But it also helps form blood clots, and unlike LDL, it is entirely genetic.About 1 in 5 Americans have high Lp(a), according to the American Heart Association.Most don’t realize they’re at risk.Because people are born with those high levels, diet and exercise have no effect.

That’s why heart experts have been so keen to find a drug that would handle the problem.The Horizon trial included 8,322 people with high Lp(a) levels and who’d already had a heart attack, stroke or other heart problem within 10 years of starting the trial.The drug did reduce Lp(a) significantly, by 78%, compared to a placebo drug that cut levels by 13%.But that huge reduction ultimately meant nothing in terms of cardiovascular health.Dr.Steven Nissen, the chief academic officer of the Heart, Va...