Biogen Shares Positive Data on Phase I/II Trial of Tofersen for SOD1-ALS


Biogen announced on Wednesday that it has seen positive results from its Phase I/II study of tofersen, also known as BIIB067, for the treatment of superoxide dismutase 1 (SOD1) amyotrophic lateral sclerosis (ALS).

“By evaluating genetically validated targets such as SOD1 in defined populations, we believe we can more quickly identify how to treat this devastating disease,” said Toby Ferguson, M.D., Ph.D., Vice President and Head of the Neuromuscular Development Unit at Biogen. “Biogen is committed to furthering ALS research in an effort to potentially bring a therapy to people living with this rapidly progressing neurological condition.”

The Phase I/II study was a randomized, placebo-controlled, single- and multiple-ascending dose study that evaluated the safety, pharmacokinetics, pharmacodynamics and exploratory efficacy endpoints in subjects with SOD1-ALS. In the multiple ascending dose (MAD) part of the trial, participants were randomized to receive tofersen (20 mg, 40 mg, 60 mg or 100 mg) or placebo for 12 weeks.

The most commonly reported adverse effects in subjects who received one or more doses of tofersen were headache, procedural pain, post-lumbar puncture syndrome and falls.

“SOD1-ALS is a neurological disease with no treatment options that reliably slow or halt its rapid progression,” said Merit Cudkowicz, M.D., co-principal investigator and the director of the Sean M. Healey & AMG Center for ALS at Massachusetts General Hospital. “We are dedicated to this research with the goal of bringing a new treatment option to this community with great unmet need.”

A Phase III study is currently underway as well to evaluate the efficacy and safety of tofersen versus placebo in adults with SOD1-ALS. Tofersen, an antisense oligonucleotide, binds to SOD1 mRNA. This allows for its degradation by RNase-H in an effort to reduce synthesis of SOD1 protein production.

Progress has been made in the ALS realm, but many experts still believe there is room for improvement. As a result, the National Institutes of Health (NIH) announced a plan back in June to invest $25 million over five years to spur innovative research on ALS. The program, titled Accelerating Leading-edge Science in ALS (ALS2), is dedicated to answering some of the most pressing questions pertaining to the disease, which paralyzes voluntary muscles and ultimately results in death.

“Over the past few decades, there has been significant progress in our understanding of ALS, but we still do not have any breakthrough treatments for this terrible disease,” said NIH Director Francis S. Collins, M.D., Ph.D. “We hope this program will inject new ideas to the field to push us rapidly toward effective therapies.”

ALS2 will take a three-pronged approach to better understanding ALS. To start, emerging tools and technology will be adopted to identify what causes ALS at a molecular level. Then, new talent from a range of scientific disciplines will be invited to participate in the program. Finally, the biological similarities between ALS and other neurodegenerative diseases will be closely examined.

At the moment, there is no cure for ALS. The U.S. Food and Drug Administration has approved drugs, including riluzole and edaravone, which can prolong the life of ALS patients. However, they do not improve symptoms. Ongoing clinical studies are looking into therapeutic strategies, new drug candidates and devices to improve quality of life for those with the disease. Although genetic research has helped experts better understand ALS, further focused investment in this area may help them capitalize on existing insights.

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