Pelacarsen, a promising drug for an inherited heart risk, flops, stunning doctors

Key Points:

• A large study led by Dr. Steven Nissen tested pelacarsen, a drug designed to lower lipoprotein (a) [Lp(a)] and reduce cardiovascular events, but it failed to show any benefit in reducing heart attacks, strokes, or cardiovascular deaths despite significantly lowering Lp(a) levels.
• The trial involved 8,350 patients with previous cardiovascular events and high Lp(a) levels, randomly assigned to pelacarsen or placebo, and followed for nearly five years; outcomes were virtually identical between groups, leading Novartis to discontinue the drug's development.
• The negative results challenge the current understanding of Lp(a) as a causal factor in heart disease and suggest that lowering Lp(a) alone may not reduce cardiovascular risk, prompting calls for further research into different patient populations, drug mechanisms, or alternative markers.
• Despite the drug’s failure, experts emphasize the importance of testing for Lp(a) as recommended by heart associations, to identify high-risk individuals who can manage other modifiable risk factors such as LDL cholesterol, exercise, and weight control.
• Researchers remain hopeful, noting that other more potent Lp(a)-lowering therapies are in development and that earlier intervention might yield better outcomes, underscoring that scientific progress often involves setbacks before breakthroughs.