Tofersen is an antisense oligonucleotide being evaluated for the potential treatment of superoxide dismutase 1 amyotrophic lateral sclerosis (SOD1 ALS).
In October 2021, the Phase 3 Valor trial failed to meet its primary endpoint after six months, although trends of reduced disease progression across multiple secondary and exploratory endpoints encouraged an extension of the study.
Now, combined Valor and open-label-extension 12 month data has shown a slowed decline in clinical function, respiratory function, strength, and quality of life with earlier initiation of tofersen.
“The ALS community has been actively pursuing new medicines for decades. To have data like these published in NEJM gives us energy and hope. We are now seeing in the data what we suspected about tofersen for a long time – that it has the potential to make a clinical difference for people living with SOD1-ALS,” said Merit Cudkowicz, M.D., co-principal investigator of the Valor trial and co-founder of the Northeast ALS Consortium, Director of the Healey & AMG Center for ALS and Chair of Neurology at Massachusetts General Hospital and the Julieanne Dorn Professor of Neurology at Harvard Medical School.
SOD1 gene mutations
After the launch of its Alzheimer’s drug Aduhelm (aducanumab), tofersen represents one of Biogen’s most advanced drugs in its pipeline. The US FDA recently accepted tofersen’s New Drug Application (NDA) for priority review, with an action date of January 23, 2023.
Amyotrophic lateral sclerosis (ALS) is a rare, progressive and fatal neurodegenerative disease that results in the loss of motor neurons in the brain and the spinal cord that are responsible for controlling voluntary muscle movement. People with ALS experience muscle weakness and atrophy, causing them to lose independence as they steadily lose the ability to move, speak, eat, and eventually breathe. Average life expectancy for people with ALS is three to five years from time of symptom onset.