Long-Term Efficacy and Safety of Tofersen in SOD1-ALS Patients

This paper details the final long-term results of the VALOR study and its open-label extension, which investigated the efficacy of tofersen in adults with SOD1-ALS. Researchers compared patients who began the drug immediately to those who switched from a placebo after six months, finding that earlier treatment led to better outcomes in muscle strength, breathing, and physical function. A critical finding was the sustained reduction of neurofilament light chain levels, a biomarker indicating that the therapy successfully slowed nerve cell degeneration. While the disease is typically characterized by a rapid and fatal decline, some participants experienced a rare stabilization or improvement in their clinical symptoms over several years. The study concludes that tofersen significantly extends survival and offers a clear clinical justification for its use as a targeted therapy for this genetic form of ALS. Most side effects were related to the injection procedure or the illness itself, confirming a manageable safety profile for long-term use.