Novartis said its experimental cardiovascular drug pelacarsen failed to reduce cardiovascular death or emergency events in a pivotal Phase 3 trial, the company announced. The study, HORIZON, tested the Ionis-partnered agent designed to lower Lp(a), a lipid-related biomarker strongly associated with cardiovascular risk. Earlier trials had shown that pelacarsen can sharply reduce Lp(a) levels, but the Phase 3 results did not translate into a statistically significant reduction in major cardiovascular endpoints versus placebo. The negative outcome represents a key read-through on whether lowering Lp(a) via this mechanism can deliver hard clinical benefit. The failure is a major negative for the Lp(a) targeting pipeline and increases scrutiny on how biomarker-lowering strategies are selected for late-stage testing.