Biogen said Wednesday its experimental treatment helped children with a devastating muscle-wasting disease even after they received an approved gene therapy from Novartis.
The company already sells a treatment for spinal muscular atrophy. But that drug, Spinraza, requires a series of four loading doses followed by maintenance treatments every four months. All of these must be given through a spinal tap. Salanersen, Biogen hopes, could become a once-a-year treatment. Biogen licensed the rights to salanersen from Ionis Pharmaceuticals, which initially developed the drug.
In the first-phase test, children ages six months to 12 years old received a single dose of salanersen at least six months after undergoing Novartis' gene therapy, Zolgensma. After a year, all patients had a "substantial slowing of neurodegeneration," Biogen said in a news release.
Notably, patients also developed new functional milestones — such as sitting unsupported, crawling, standing without support or walking.
Biogen Moves Into Phase 3 Testing
The key metric in Biogen's study was neurofilament. Neurofilaments are structural proteins that form part of the cytoskeleton of neurons. Neurofilament levels are generally elevated in children with SMA.
Six months after receiving salanersen, neurofilament in the children's plasma was reduced by 70%. Those reduced levels were maintained over time.
Valeria Sansone, clinical and scientific director at the Clinical Center NeMO in Milan, Italy, underscored the importance of the milestone progress. Sansone, also a professor of neurology at the University of Milan, was the study's principal investigator.
"To see a child dosed with gene therapy at one year of age and still unable to sit without support at age five then gain the ability to sit independently just three months after initiating salanersen, that is unexpected," she said in a statement.
Biogen is planning to bypass midstage testing and move salanersen directly into Phase 3 testing. The company will study salanersen in previously treated and untreated patients. Some of the patients in the first-phase study previously received Spinraza or Roche's Evrysdi in addition to Zolgensma gene therapy.
Lowly Rated Biotech Stock
Biogen stock has been under pressure for two years.
Shares have dropped off roughly 57% since May 2023. As a result, Biogen stock has a poor IBD Digital Relative Strength Rating of 12 out of a best-possible 99. That means Biogen shares rank in the bottom 12% of all stocks when it comes to 12-month performance.
Biogen stock has a slightly better Composite Rating of 36. The 1-99 score pits a stock's fundamental and technical measures against all other stocks.
Follow Allison Gatlin on X/Twitter at @AGatlin_IBD.
