Skip to content
You are now leaving to visit


Chemistry: Generation 2+

Tofersen (formerly IONIS-SOD1Rx), also known as BIIB067, is an investigational antisense medicine targeting superoxide dismutase 1 (SOD1), which is the second most common and best understood genetic cause of amyotrophic lateral sclerosis (ALS). Patients with a mutation in the SOD1 gene develop a form of ALS referred to as SOD1-ALS. There is substantial evidence that mutations in the SOD1 gene are responsible for a toxic gain of function that can lead to rapid progressive loss of motor neurons in patients with SOD1-ALS. As a result, patients with SOD1-ALS experience muscle weakness, loss of movement, difficulty in breathing and swallowing and eventually succumb to their disease.

About Amyotrophic Lateral Sclerosis

ALS is a rare, fatal neurodegenerative disorder characterized by loss and dysfunction of neurons in motor pathways. It is estimated that there are ~55,000 patients diagnosed with ALS in major markets1. Approximately 90 percent of patients with ALS have no known family history, while approximately 10 percent of patients have a known genetic cause for their disease. People with ALS suffer progressive degeneration of motor neurons, which results in a declining quality of life due to muscle weakness, loss of movement and difficulty in breathing and swallowing. Currently, treatment options for patients with ALS are extremely limited with no drugs that significantly slow disease progression.