Novartis’ pelacarsen failed to reduce cardiovascular death or emergencies such as heart attacks and stroke in the Phase 3 HORIZON trial, according to statements reported by STAT+. The investigational therapy is designed to lower Lp(a), a lipoprotein linked to elevated cardiovascular risk. The setback adds to a recent run of disappointing attempts to drug the Lp(a) pathway with outcomes-focused endpoints. Novartis said the company’s pelacarsen program did not meet the trial’s primary objective against placebo, ending a closely watched efficacy bet in a high-urgency cardiovascular category. In parallel with the clinical impact, the result raises near-term uncertainty for sponsors that have aligned portfolios around Lp(a) as a modifiable driver of major adverse cardiovascular events. It also underscores how hard it is to translate biomarker reductions into event-level benefit in prevention populations.