Silence Therapeutics Reports Positive 48-Week Phase 2 Data for Zerlasiran in Elevated Lipoprotein(a)

Silence Therapeutics plc, a prominent biotechnology firm listed on Nasdaq under the ticker SLN, has announced promising 48-week results from its ALPACAR-360 phase 2 study of zerlasiran (SLN360). This study involved 178 participants with initial lipoprotein(a), or Lp(a), levels of 125 nmol/L or higher, who were at high risk for atherosclerotic cardiovascular disease (ASCVD). Zerlasiran is an siRNA (short interfering RNA) developed to reduce the body's production of Lp(a), a genetic risk factor impacting up to 20% of the global population.

In the double-blind, placebo-controlled study, patients received zerlasiran subcutaneously at doses of 300 mg every 16 or 24 weeks, and 450 mg every 24 weeks, starting with a median baseline Lp(a) level of about 215 nmol/L. The findings showed a highly significant decrease in Lp(a) levels compared to placebo at the 48-week mark, which represents the end of the treatment and dosing period. The median maximum reduction in Lp(a) levels was approximately 90% or higher for both dosage groups during this period. Furthermore, zerlasiran was well tolerated without serious safety issues.

The study had previously met its primary endpoint, demonstrating a significant reduction from baseline in Lp(a) levels compared to placebo at 36 weeks. The trial is ongoing, and participants will continue to be monitored up to 60 weeks, marking the end of the study.

Dr. Steven Romano, Head of Research and Development at Silence Therapeutics, expressed optimism about the phase 2 data and the competitive profile of zerlasiran. He emphasized the potential of an infrequent dosing regimen of at least quarterly with the 300 mg dose and indicated plans to advance zerlasiran into phase 3 trials as a potential treatment for significant cardiovascular risk.

Silence Therapeutics plans to present the full results at an upcoming scientific meeting or in a publication after the study concludes.

Silence Therapeutics is pioneering a new generation of medicines using the body's natural RNA interference mechanism, or RNAi, to inhibit specific target genes implicated in various diseases with significant unmet needs. Utilizing its proprietary mRNAi GOLD™ platform, Silence Therapeutics creates siRNAs that can precisely target and silence disease-related genes in the liver. This presents a substantial opportunity in treating conditions with high unmet medical needs. Zerlasiran, one of Silence Therapeutics' wholly-owned product candidates, is focused on reducing cardiovascular risks in individuals with elevated Lp(a). Another candidate, divesiran, is aimed at addressing rare hematological diseases such as polycythemia vera. Silence Therapeutics also collaborates with major pharmaceutical companies like AstraZeneca and Hansoh Pharma to advance its research and development efforts.