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Tofersen slows a rare form of ALS — Level A2 — two white tablets

Tofersen slows a rare form of ALSCEFR A2

26 Dec 2025

Adapted from Washington U. in St. Louis, Futurity CC BY 4.0

Photo by Thought Catalog, Unsplash

Level A2 – High beginner / Elementary
2 min
111 words

Researchers studied tofersen for a rare genetic form of ALS caused by changes in the SOD1 gene. This form of ALS often gives a short life expectancy of about two to three years from first symptoms.

The drug lowers production of the mutated SOD1 protein. A phase 3 trial lasted six months and then continued as an open study. Long-term use slowed symptom progression and death. About one-quarter of people had stable function or improvement over roughly three years, including better grip strength and breathing. Common side effects were headache, pain and falls. A new trial is testing tofersen in people with the gene change but no symptoms yet.

Difficult words

  • geneticrelated to genes and inherited traits
  • mutateto change in a gene or DNA
    mutated
  • triala planned medical test of a treatment
  • progressionthe process of a disease getting worse
  • symptoma sign or feeling showing a disease
    symptoms
  • side effectan unwanted health problem from treatment
    side effects
  • grip strengthhow strong a person's hand squeeze is

Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.

Discussion questions

  • Would you consider joining a medical trial before you have symptoms? Why or why not?
  • Which side effect in the article worries you most, and why?
  • Why is it useful to test a drug in people who have the gene change but no symptoms yet?

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Tofersen slows a rare form of ALS — English Level A2 | LingVo.club