Silence Therapeutics has unveiled additional data from a mid-stage trial of its siRNA therapy candidate in certain people at risk of heart episodes, setting the stage for potential registrational investigation.
The candidate, dubbed zerlasiran, is designed to lower the body’s production of the bad cholesterol called lipoprotein(a) or Lp(a). High Lp(a) levels are a genetic risk factor for cardiovascular disease and affect up to a fifth of the population, the company said.
In the trial, zerlasiran achieved a “highly significant” reduction in baseline Lp(a) levels versus placebo at 48 weeks, according to a Thursday release. The results add to positive 36-week topline data that the company unveiled back in March, which showed the treatment reached a median 90% or more reduction in baseline Lp(a) in the trial’s primary endpoint.
Competition in the Lp(a) targeting space is growing, with Amgen’s siRNA candidate olpasiran already in Phase 3 after a positive mid-stage readout in August last year. That same month, Novartis spent $60 million upfront to buy an Ionis asset with the same mechanism.
Silence’s placebo-controlled Phase 2 study is testing 300 mg zerlasiran given every 16 or 24 weeks and 450 mg zerlasiran given every 24 weeks. It enrolled 178 people with baseline Lp(a) levels of at least 125 nmol/L at high risk of atherosclerotic cardiovascular disease (ASCVD) events.
Steven RomanoSilence’s share price $SLN was up 6% to $20 at market open Thursday.
“We are encouraged by the strength of the Phase 2 data and emerging competitive profile of zerlasiran, which support an infrequent dosing regimen of at least quarterly with the 300 mg dose,” Silence’s head of R&D Steven Romano said in a statement.
The company said it plans to present the full results at a future scientific meeting or in a publication following the trial’s completion.
Back in November, the treatment showed promise in a Phase 1 test in patients with stable ASCVD and baseline Lp(a) levels of at least 150 nmol/L.