A one-patient ALS drug cuts a nerve-damage marker by up to 50%

Mayo Clinic researchers reported on 2 October 2026 the first results of an antisense drug built for a single patient with a rare inherited form of ALS. The study, an N-of-1 investigation, is published in Med (DOI 10.1016/j.medj.2026.101295), with Margot Cousin, director of Mayo’s N-of-1 Therapeutics Program, as lead author and the neurologist Björn Oskarsson as senior author.

The patient carries a harmful variant of the CHCHD10 gene, which produces a toxic protein linked to abnormal changes in TDP-43, a hallmark of ALS. The nonprofit n-Lorem Foundation designed and tested more than 320 antisense oligonucleotides against CHCHD10 before choosing one. Antisense drugs are short strands of genetic material that block a gene’s message before it is turned into protein; this one is injected into the spinal fluid.

After six doses, blood levels of neurofilament light, a marker of nerve damage, fell by up to 50 percent. The patient’s breathing, cognition and physical function stayed stable or improved modestly, and the drug was well tolerated. In a disease that usually progresses steadily, Oskarsson notes that stabilisation alone can be a meaningful observation. The result covers one person, has no control and remains experimental.