U.S. FDA fast-tracks approval of MWTX-003 for the treatment of PV

High iron levels are a known complicator of survival and overall quality of life for patients with PV. On September 20, 2023, the United States Food and Drug Administration granted fast-track designation to MWTX-003, an investigational anti-transmembrane serine protease 6 (TMPRSS6) monoclonal antibody designed to increase hepcidin levels and, thereby, reduce serum iron levels in patients with polycythemia vera (PV).

Preclinical data have highlighted strong pharmacodynamic effects, with a single dose resulting in a 70% reduction in serum iron levels for 21 days. Moreover, a related β-thalassemia clinical model demonstrated a 4-fold increase in hepcidin levels, a 60–65% reduction in serum and liver iron, increased red blood cell production, and a decrease in spleen weight. A phase I proof-of-mechanism trial is to begin in the second half of 2023. Further plans for a phase 1b/2a proof-of-concept study evaluating the safety and pharmacokinetic profile of MWTX-003 in patients with PV are also in place.