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ALSJuly 2020Summary reviewed July 2026

A Spinal Injection Reduced Harmful Protein Levels by 33% in ALS Patients

Scientists tested tofersen, a treatment given by spinal injection, in 50 adults with ALS caused by a specific gene mutation (SOD1). The highest dose reduced a harmful protein in spinal fluid by 33% after 12 weeks, suggesting the drug reached its target.

What the trial was testing

The trial enrolled 176 patients with als. The study was sponsored by Biogen and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was an early-stage trial — researchers are still confirming safety and getting an early look at how well the treatment works. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.

What the results showed

The highest dose of tofersen reduced SOD1 protein levels in spinal fluid by 33%.

The New England journal of medicine · 2020 · NCT02623699

These findings — that the highest dose lowered harmful SOD1 protein in spinal fluid — were published in the The New England journal of medicine and represent the headline result of the study.

Researchers tracked outcomes across 176 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.

What this means for patients

For patients with als, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.

What you can do now

This was a safety testing study (Phase 1-2) and tofersen was not yet FDA-approved at the time. The drug has since been approved by the FDA in 2023 for adults with ALS caused by SOD1 mutations. If you have SOD1-related ALS, ask your doctor whether tofersen might be right for you.

Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.