An experimental drug for a rare, inherited form of amyotrophic lateral sclerosis (ALS) has shown promise in a phase 1/phase 2 clinical trial conducted at Washington University School of Medicine in St. Louis, Massachusetts General Hospital in Boston and other sites around the world and sponsored by the pharmaceutical company Biogen Inc. The trial indicated that the experimental drug, known as tofersen, shows evidence of safety that warrants further investigation and lowers levels of a disease-causing protein in people with a type of amyotrophic lateral sclerosis, or ALS, caused by mutations in the gene SOD1.
The results of the study, published July 9 in The New England Journal of Medicine, have led to the launch of a phase 3 clinical trial to further evaluate the safety and efficacy of tofersen.
“ALS is a devastating, incurable illness,” said principal investigator Timothy M. Miller, MD, PhD, the David Clayson Professor of Neurology at Washington University and director of the ALS Center at the School of Medicine. “While this investigational drug is aimed at only a small percentage of people with ALS, the same approach – blocking the production of specific proteins at the root of the illness – may help people with other forms of the illness.
“This trial indicated that tofersen shows evidence of safety that warrants further investigation and that the dose we used lowers clinical markers of disease. There are even some signs that it slowed clinical progression of ALS, although the study was not designed to evaluate effectiveness at treating the disease, so we can’t say anything definitive. Overall, the results are just what we hoped for, and a phase 3 trial is currently underway.”