On November 7, Swiss drugmaker Novartis said it would stop developing its experimental cardiovascular drug pelacarsen for atherosclerotic cardiovascular disease after a trial found no reduction in heart attacks, strokes, or cardiovascular deaths. According to Sina Finance, the seven-year Phase III Lp(a) HORIZON trial enrolled 8,322 patients and found that pelacarsen lowered lipoprotein(a), or Lp(a), by an average of 78%, but showed no clear cardiovascular benefit in any patient subgroup. The study was the first completed Phase III cardiovascular outcomes trial targeting Lp(a), a lipoprotein largely influenced by genetics and associated with higher risks of atherosclerosis and blood clots; about 20% of the global population has genetically elevated Lp(a). Senior study author Steven Nissen, a cardiovascular specialist at the Cleveland Clinic, called the results “completely neutral,” saying the drug had neither benefit nor harm. Novartis will retain one mid-stage study to assess whether pelacarsen can slow the progression of calcific aortic stenosis. The drug had previously been viewed as a potential blockbuster, with annual sales once expected to reach billions of dollars; the trial result presents a new challenge for strategies to prevent cardiovascular events by lowering Lp(a).