This section highlights FDA-related milestones and regulatory updates for drugs developed by Silence Therapeutics (SLN).
Over the past two years, Silence Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
divesiran, SLN124, SLN360, and zerlasiran. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
divesiran - FDA Regulatory Timeline and Events
divesiran is a drug developed by Silence Therapeutics for the following indication: In patients with polycythemia vera.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- divesiran
- Announced Date:
- June 12, 2025
- Indication:
- In patients with polycythemia vera
Announcement
Silence Therapeutics plc today presented additional data showcasing the SANRECO Phase 1 study of divesiran in patients with polycythemia vera (PV) at the European Hematology Association (EHA) 2025 Annual Meeting in Milan, Italy.
AI Summary
Silence Therapeutics recently presented updated Phase 1 data for divesiran at the EHA 2025 Annual Meeting in Milan, Italy. The study focused on patients with polycythemia vera (PV) and showed that divesiran effectively maintained rapid and durable hematocrit control, keeping levels at or below 45%. This helped nearly eliminate the need for therapeutic phlebotomies in phlebotomy-dependent PV patients. The data also suggested that divesiran, a first-in-class siRNA therapeutic, may allow for less frequent dosing and has a favorable safety profile, with no dose-limiting toxicities observed during the trial. Additionally, the treatment improved iron regulation by increasing hepcidin levels without altering white blood cell counts. These encouraging findings support further clinical development of divesiran as part of the SANRECO study program for the treatment of PV.
Read Announcement- Drug:
- divesiran
- Announced Date:
- December 9, 2024
- Indication:
- In patients with polycythemia vera
Announcement
Silence Therapeutics plc announced additional results from the Phase 1 open label portion of the SANRECO study of divesiran, a siRNA targeting TMPRSS6, in patients with polycythemia vera (PV) were presented at the American Society of Hematology (ASH) Annual Meeting being held in San Diego, California.
AI Summary
Silence Therapeutics announced new Phase 1 data for divesiran, a siRNA therapy targeting TMPRSS6, in patients with polycythemia vera (PV). The results, presented at the American Society of Hematology Annual Meeting in San Diego, showed that divesiran notably reduced the frequency of phlebotomies and lowered hematocrit levels. In this open label portion of the SANRECO study, encouraging outcomes indicated a sustained reduction in hematocrit during the treatment period, along with consistent improvements in iron metabolism markers.
Based on these positive findings, Silence Therapeutics is prioritizing divesiran as a first-in-class siRNA treatment for PV. The company also announced that the first subject has been dosed in the Phase 2 study of divesiran, marking a significant step forward in its clinical development program.
Read Announcement
SLN124 - FDA Regulatory Timeline and Events
SLN124 is a drug developed by Silence Therapeutics for the following indication: Polycythemia Vera (PV).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- SLN124
- Announced Date:
- June 27, 2024
- Indication:
- Polycythemia Vera (PV)
Announcement
Silence Therapeutics plc announced that Data support advancing divesiran into Phase 2
AI Summary
Silence Therapeutics announced very promising Phase 1 results for divesiran, a treatment for polycythemia vera (PV). In the study, well-controlled patients did not need any phlebotomies during treatment, and the drug showed a sustained reduction in hematocrit along with favorable changes in iron metabolism. These positive results indicate that divesiran not only achieves its intended effect by increasing hepcidin levels but also supports better disease management without frequent dosing.
Based on these encouraging early findings, the company is moving forward with plans to start a Phase 2 trial by the end of this year. The advancement underscores the potential of divesiran as the first siRNA therapy for PV and highlights its promising safety and efficacy profile in managing blood parameters in patients with this rare condition.
Read Announcement- Drug:
- SLN124
- Announced Date:
- June 27, 2024
- Indication:
- Polycythemia Vera (PV)
Announcement
Silence Therapeutics plc announced positive results from the ongoing SANRECO Phase 1 repeat dose study of divesiran (SLN124), a siRNA (short interfering RNA) targeting TMPRSS6, in patients with polycythemia vera (PV).
AI Summary
Silence Therapeutics plc announced encouraging results from their ongoing SANRECO Phase 1 study evaluating divesiran (SLN124), a siRNA that targets TMPRSS6 in polycythemia vera (PV) patients. The trial involved repeat dosing every six weeks, and the results showed that divesiran was well tolerated, with no major safety concerns reported. In a key finding, none of the well-controlled patients—those with hematocrit levels at or below 45%—required a phlebotomy during the treatment period. Additionally, the treatment led to a sustained reduction in hematocrit levels and increased hepcidin levels, indicating strong target engagement and a favorable impact on iron metabolism.
Based on these positive results, Silence Therapeutics plans to advance divesiran into Phase 2 later this year, positioning it as a promising siRNA treatment for patients managing PV.
Read Announcement
SLN360 - FDA Regulatory Timeline and Events
SLN360 is a drug developed by Silence Therapeutics for the following indication: Reducing cardiovascular risk in people born with high levels of lipoprotein(a).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- SLN360
- Announced Date:
- June 20, 2024
- Indication:
- Reducing cardiovascular risk in people born with high levels of lipoprotein(a)
Announcement
Silence Therapeutics plc, announced positive topline 48-week data from the ALPACAR-360 phase 2 study of zerlasiran (SLN360) in 178 subjects with baseline lipoprotein(a), or Lp(a), levels at or over 125 nmol/L at high risk of atherosclerotic cardiovascular disease (ASCVD) events. Zerlasiran is a siRNA (short interfering RNA) designed to lower the body's production of Lp(a), a key genetic risk factor for cardiovascular disease affecting up to 20% of the world's population.
AI Summary
Silence Therapeutics plc reported positive 48‐week topline results from the ALPACAR-360 phase 2 study evaluating zerlasiran in 178 patients with elevated lipoprotein(a) (Lp(a)) levels (≥125 nmol/L) who are at high risk for atherosclerotic cardiovascular disease (ASCVD). Zerlasiran is a short interfering RNA (siRNA) designed to lower the body’s production of Lp(a), a key genetic risk factor affecting up to 20% of the world’s population. The study showed that patients receiving zerlasiran experienced a median maximum Lp(a) reduction of around 90% or greater compared to placebo, with the medication well tolerated and no serious safety concerns noted. Based on these promising results, the company plans to advance zerlasiran into phase 3 trials using a 300 mg dosing regimen, potentially offering a significant treatment for individuals with high cardiovascular risk.
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zerlasiran - FDA Regulatory Timeline and Events
zerlasiran is a drug developed by Silence Therapeutics for the following indication: In atherosclerotic cardiovascular disease (ASCVD) patients with high lipoprotein(a) [Lp(a)] levels (≥125 nmol/L).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- zerlasiran
- Announced Date:
- November 18, 2024
- Indication:
- In atherosclerotic cardiovascular disease (ASCVD) patients with high lipoprotein(a) [Lp(a)] levels (≥125 nmol/L).
Announcement
Silence Therapeutics 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).
AI Summary
Silence Therapeutics presented end-of-treatment data today from its Phase 2 ALPACAR-360 study of zerlasiran, a short interfering RNA (siRNA) aimed at patients with atherosclerotic cardiovascular disease (ASCVD) who have high lipoprotein(a) levels (≥125 nmol/L). The study is the first to report time-averaged Lp(a) reductions that measure the treatment’s impact over longer periods, including the time between doses.
The results showed that different dosing regimens of zerlasiran (300 mg every 16 weeks, 300 mg every 24 weeks, or 450 mg every 24 weeks) led to more than 80% mean placebo-adjusted reduction in Lp(a) levels over 36 weeks, with maximum reductions exceeding 90%. Notably, these reductions persisted until the final visit 60 weeks after the first dose, and the treatment was well tolerated. These promising results will help guide the dosing strategy for upcoming Phase 3 trials.
Read Announcement
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