simrepmasiran

**Simrepmasiran** is an investigational small interfering RNA (siRNA) therapeutic designed to silence the TMPRSS6 gene, which negatively regulates hepcidin, the master regulator of iron metabolism. By inhibiting TMPRSS6 expression primarily in the liver, simrepmasiran increases hepcidin levels, thereby restricting iron availability to the bone marrow and reducing excessive red blood cell production. Developed by Silence Therapeutics using their proprietary mRNAi GOLD™ platform, it is being evaluated for hematological disorders such as polycythemia vera (PV), where it aims to maintain hematocrit levels below 45% and eliminate the need for phlebotomies with infrequent subcutaneous dosing every six weeks.