Biogen and Ionis Pharma shares slide as they end development of ALS treatment

By Ciara Linnane

An early-stage trial failed to slow disease process

The stocks of Biogen Inc. and Ionis Pharmaceuticals Inc. were lower Thursday, after the partners said they were terminating development of a treatment for the fatal disease Amyotrophic Lateral Sclerosis, or ALS, after a disappointing trial.

The companies said the Phase 1/2 study of BIIB105 did not result in a clear signal it slowed the disease's process. It did however show statistically significant cerebrospinal fluid (CSF) ATXN2 protein reductions, which is one of the areas researchers are exploring.

"However, over the 6-month placebo-controlled period, treatment with BIIB105 did not result in a reduction in levels of plasma neurofilament light chain (NfL), a marker of neurodegeneration and neuronal damage," the companies said in a joint statement.

It also did not show an impact on clinical outcome measures relating to function, breathing and strength.

"While BIIB105 lowered ATXN2 protein, it did not reduce neurofilament, which gives us confidence that BIIB105 did not slow the disease process," said Stephanie Fradette, head of the neuromuscular development unit at Biogen.

ALS is a progressive neurodegenerative disease that attacks and kills the nerve cells that control voluntary muscles. Also known as Lou Gehrig's disease, after the baseball player who died of it in 1941 at age 38, the disease causes nerves to lose the ability to activate specific muscles, leading to paralysis and death.

There are very few treatments, despite some high-profile campaigning and pleas for more research and development.

The Centers for Disease Control and Prevention estimates that between 16,000 and 32,000 Americans are living with ALS.

The companies said they will continue to analyze the data and will present them at the European Network to Cure ALS (ENCALS) meeting in Stockholm, Sweden in June.

They also committed to continue to develop treatments for patients diagnosed with the illness.

Last year, Biogen won accelerated Food and Drug Administration approval for tofersen, a treatment for a rare form of ALS where there's a mutation in the gene called SOD1.

The accelerated program is used to approve drugs for serious conditions that have an unmet medical need, where a drug is shown to have an effect on an endpoint that is reasonably likely to predict a clinical benefit to patients.

Biogen's stock (BIIB) was down 2.5% Thursday and is down 11.3% in the year to date. Ionis (IONS) was down 5.9% and has lost 27% in the year to date. The S&P 500 SPX has gained 11.3% in the same time frame.

-Ciara Linnane

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05-16-24 1407ET

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