Novartis Scales Back Pelacarsen After Neutral Heart Outcome; Valve Study Moves On

What the trial showed

Novartis unveiled full data Saturday at the American Heart Association meeting in Chicago, alongside a simultaneous New England Journal of Medicine publication. The study followed 8,322 patients for seven years and, despite monthly injections that sharply cut an inherited cholesterol particle called Lp(a), event rates did not budge for heart attacks or strokes. Investigators also found no hints of benefit in any subgroup they examined.

Cleveland Clinic cardiologist Steven Nissen, the paper's senior author, summed it up bluntly: the trial "is completely neutral." He added, "It is is not harmful. It is not helpful. It is just stone cold neutral."

How scientists are reading it

Pelacarsen was the first large study to cross the finish line for the strategy of lowering Lp(a), a cholesterol-carrying particle linked to plaque buildup and clotting. Expectations were high until September, when Novartis said the trial had failed without offering many details. Speaking with journalists in October, Novartis CEO Vas Narasimhan said, "I was devastated." "I've been working on the candidate since 2015 and had high hopes that it could work."

Why the miss? One theory is timing. Lp(a) levels are set by genetics and remain elevated for life, unlike LDL cholesterol that typically rises in adulthood. As Nissen put it, "It just may be that five years of treatment for a disease that is present for life when you start at age 60 isn't going to get it done." Another possibility is that today's aggressive care for cholesterol and blood pressure may already dampen some Lp(a)-related risk in such patients.

At Boston University, Donald Lloyd-Jones, who holds a professorship in preventive medicine and epidemiology, urged patience on the target, saying, "This does temper some of our enthusiasm, but I don't think it tempers our desire to really understand more about this molecule and whether it's something we can use as a target."

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Industry impact and Novartis plans

Novartis will stop developing pelacarsen for atherosclerotic cardiovascular disease, but it is keeping one trial open in patients with calcific aortic valve stenosis. Safety and tolerability matter here too: about 21% of patients on pelacarsen discontinued due to adverse events, versus 7.5% on placebo.

Competitors are still in the hunt. Companies such as Amgen and Eli Lilly are testing Lp(a)-lowering medicines, including candidates that appear stronger and potentially easier to tolerate than pelacarsen. Some ongoing trials, including Lilly's injectable lepodisiran, include patients who have not yet had a heart attack. Nissen, who led an earlier lepodisiran study, remains committed to that work: "The horse threw us," he said. "We're going to get back on the horse and keep going with the lepodisiran trial."

Novartis also has DII235, an siRNA-based Lp(a) therapy in a midstage study. The company has not decided on next steps and plans to share an update later.

What this means for your portfolio

For investors tracking cardiovascular pipelines, the takeaway is clear: lowering a biomarker is not the same as lowering events. This neutral readout resets expectations for the Lp(a) class, but it does not close the book. Watch two threads from here: Novartis' decision on DII235 and competitor readouts that treat earlier or enroll patients pre-heart attack. Trial design, patient selection and duration now move center stage.

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