SFH-4090

SFH-4090 (also known as MT-4090 or MT-DUX4-ASO) is a chemically novel, systemically administered unconjugated gapmer antisense oligonucleotide (ASO) designed to target and reduce the expression of double homeobox 4 (DUX4), the primary pathogenic driver of facioscapulohumeral muscular dystrophy (FSHD). Discovered by Mitsubishi Tanabe Pharma Corporation and developed in collaboration with the venture philanthropy organization SOLVE FSHD, SFH-4090 is engineered with a novel chemistry that enhances tissue penetration and retention in skeletal muscle following subcutaneous administration. In nonclinical studies, SFH-4090 demonstrated robust and sustained skeletal muscle distribution, significantly exceeding plasma levels, and effectively reduced DUX4-related gene activity and improved motor function in mouse models of FSHD. The FDA has granted Orphan Drug Designation to SFH-4090 as it advances toward clinical trial readiness.