Novartis shares fell after the Swiss drugmaker said an experimental medicine failed to reduce cardiovascular risk in a late-stage clinical trial.

Shares in Novartis were down 3.2% in European morning trading Monday, reducing year-to-date gains to 14%.

The company said the late-stage study for its pelacarsen drug missed its primary objective of reducing the risk of cardiovascular events like death, heart attack and stroke compared with placebo.

The drug did bring down levels in the blood of a cholesterol-carrying particle known as lipoprotein (a), or Lp(a), but this didn't lead to lower cardiovascular risk as expected, Novartis said. Elevated Lp(a) is an inherited risk factor for cardiovascular diseases for which no treatment is currently available.

"These are not the results we hoped for, but they provide important evidence that advances scientific understanding of the relationship between Lp(a) lowering and cardiovascular outcomes and may help inform future approaches to cardiovascular risk management," Novartis Chief Medical Officer Shreeram Aradhye said.

Novartis licensed pelacarsen, a so-called antisense oligonucleotide designed to inhibit production of Lp(a) at its source, from Ionis Pharmaceuticals. Rivals Eli Lilly and Amgen are working on other medicines that target Lp(a) through a different pathway.

The success of earlier cardiovascular therapies and broader use of other drugs, like obesity treatments known as GLP-1s, are raising the bar for future cardiovascular outcome-based trials, analysts at Jefferies wrote in a note to clients.

For Novartis, recent positive results from a separate multiple sclerosis study should make the failure of the pelacarsen trial more palatable for investors, Jefferies said. But the company now needs to deliver positive results for a drug it acquired as part of its $12 billion Avidity Biosciences deal to justify the price, the analysts added.

The pelacarsen study results also come less than a week after Novartis said it had paused eight trials of an experimental cell therapy for autoimmune and neurological disorders after three patients died.