Silence Therapeutics advances blood cancer drug with durable trial data
Silence Therapeutics (NASDAQ:SLN) reported positive follow-up and quality-of-life clinical data for its experimental blood cancer treatment, divesiran, demonstrating a sustained reduction in the medical procedures required to manage the rare disease.
The London-based biotechnology company presented the results at the European Hematology Association (EHA) 2026 Annual Congress in Stockholm, Sweden.
The data tracks the long-term impact of divesiran, a first-in-class small interfering RNA (siRNA) treatment designed to treat polycythemia vera (PV)—a chronic, myeloproliferative neoplasm characterized by the overproduction of red blood cells, which thickens the blood and dramatically spikes the risk of cardiovascular blood clots and strokes.
By silencing the TMPRSS6 gene in liver cells, the therapeutic molecule triggers an increase in hepcidin, a hormone that restricts systemic iron absorption and successfully caps red blood cell manufacturing.
The updated analysis focused on a 34-week, open-label Phase 1 segment of the SANRECO trial evaluating 21 patients with a documented dependency on therapeutic phlebotomies—a standard, crude treatment protocol where blood is regularly drawn from a patient's vein to force a drop in hematocrit levels below the safe threshold of 45%.
According to the EHA clinical charts, the 21 enrolled participants required a combined total of 80 phlebotomies in the six months immediately preceding the study.
During the active subcutaneous dosing period of the trial, that total figure dropped to just five procedures, all of which occurred exclusively in individuals whose baseline hematocrit markers were severely uncontrolled at the outset.
The clinical benefit persisted long after the active therapy concluded, reflecting the extended cellular duration of action typical of GalNAc-conjugated siRNA platforms.
During a 16-week untreated follow-up period following the final dose, investigators recorded only four total phlebotomies across the entire group.
Among a subset of 14 patients tracked into extended longitudinal monitoring, the median time elapsed before a patient required their first therapeutic blood draw stretched to 287 days.
Beyond physical biomarker modifications, the company presented new patient-reported outcomes utilizing the standard MPN-10 total symptom score index.
A clear majority of patients reported significant reductions in severe disease-related symptoms, such as chronic fatigue, bone pain, microvascular itching, and sleep disturbances, by the 34th week of monitoring, indicating a fundamental improvement in overall quality-of-life baselines.
The investigational drug was well tolerated across all tested dose tranches, which ranged from 3 mg/kg to 9 mg/kg.
The clinical staff observed no dose-limiting toxicities, serious adverse events, or side effects leading to permanent treatment discontinuations.
The most frequent complications were classified as mild, self-resolving skin reactions at the localized subcutaneous injection site.
