Silence Therapeutics is a clinical-stage biotech developing RNA interference (RNAi) therapeutics using siRNA molecules that silence disease-causing genes in the liver. Rather than blocking a protein directly, siRNA degrades the messenger RNA that encodes it, preventing the protein from being produced. Silence delivers siRNA using a molecule called GalNAc, which targets liver cells and enables potent, long-lasting gene silencing from infrequent dosing. The company has no approved products and no commercial sales force, and relies on contract manufacturers for all production. Its roughly 88 employees are focused on R&D. Silence's lead wholly-owned program is divesiran, an siRNA targeting the TMPRSS6 gene for polycythemia vera, a rare blood cancer where the bone marrow overproduces red blood cells. By silencing TMPRSS6, divesiran raises hepcidin levels to restrict iron availability to bone marrow, reducing red blood cell overproduction. A Phase 2 trial is fully enrolled with topline data expected in Q3 2026. The second key program is zerlasiran, an siRNA targeting Lp(a), a genetically-determined cardiovascular risk factor affecting at least 20% of the global population with no approved therapies. Zerlasiran has completed Phase 2 with strong results, but Silence is seeking a partner before initiating Phase 3 to preserve cash. Silence generates revenue through upfront payments, milestones, and royalties from collaboration agreements, the most significant of which is with AstraZeneca.