Ionis Begins Clinical Trial of ALS Antisense Therapy Designed to Treat Broad ALS Population

Rare Daily Staff

Ionis Pharmaceuticals reported that it dosed the first patients with ION541 (also known as BIIB105), an experimental antisense medicine being developed as a potential therapy to treat most forms of amyotrophic lateral sclerosis regardless of family history.

Amyotrophic lateral sclerosis (ALS) is a rare, progressive and fatal neurodegenerative disorder that affects approximately 55,000 people globally. About 90 percent of ALS cases occur in people who have no apparent family history of the disease. People with ALS experience muscle weakness, loss of movement, and difficulty breathing and swallowing, resulting in a severely declining quality of life and potentially death.

ION541 targets ataxin-2 RNA (ATXN2), which has been shown to prevent or reverse TDP-43 toxicity in preclinical models of ALS. Almost all cases of ALS share the pathological hallmark of TDP-43 protein aggregation in motor neurons.

It is Ionis’ third experimental antisense therapy targeting ALS, with tofersen and IONIS-C9Rx currently in clinical trials targeting genetic forms of the disease. All three are partnered with Biogen as part of a broad strategic collaboration to advance novel antisense therapies for the treatment of neurological disorders. Ionis received a payment of $10 million from Biogen for initiation of this phase 1/2 clinical trial of ION541.

“Initiation of this clinical trial for ION541 marks an important milestone in Ionis’ ALS program and reaffirms our commitment to the ALS community,” said Frank Bennett, Ionis’ chief scientific officer and franchise leader for neurological programs.

Photo: Frank Bennett, Ionis’ chief scientific officer