New zerlasiran data show significant time-averaged Lp(a) reductions with effects persisting 60 weeks following the first dose

Represents first study to report time-averaged Lp(a) results to further evaluate potential clinical benefits

Data simultaneously published in the Journal of the American Medical Association

Silence Therapeutics plc, Nasdaq: SLN ("Silence" or the "Company"), a global clinical stage biotechnology company committed to transforming people's lives by silencing diseases through precision engineered medicines, today presented end-of-treatment data from its Phase 2 ALPACAR-360 study of zerlasiran, a short interfering RNA (siRNA), in atherosclerotic cardiovascular disease (ASCVD) patients with high lipoprotein(a) [Lp(a)] levels (≥125 nmol/L). These data were presented during the Late-Breaking Science Session of the American Heart Association (AHA) Scientific Sessions 2024 in Chicago, Illinois, and simultaneously published in the Journal of the American Medical Association (JAMA).

Results presented today showed that zerlasiran (300 mg every 16 weeks, 300 mg every 24 weeks or 450 mg every 24 weeks) produced greater than 80% mean time-averaged placebo-adjusted reductions from baseline in Lp(a) concentrations over 36 weeks. This is the first study to report time-averaged Lp(a) analyses, which more accurately evaluates the effects of treatment over time, including intervals between doses. Maximum Lp(a) reductions exceeded 90%. At the final visit, 60 weeks following initial drug administration, reductions in Lp(a) persisted and no safety concerns emerged with infrequent dosing.