An article on the 25-year-old patient’s case, titled “Disease reactivation after switching from natalizumab to daclizumab,” was published in the Journal of Neurology.
The U.S. Food and Drug Administration and European Union approved it as therapy for active RRMS cases in 2016. Biogen and AbbVie market the monoclonal antibody, which targets the CD25 protein that scientists have linked to MS.
Researchers studied the 25-year-old patient’s case for clues about whether Zinbryta could benefit MS patients who discontinue Tysabri.
Tysabri kept the patient’s RRMS stable for three years. But eventually he contracted a virus that led to a brain infection. Doctors linked his condition, progressive multifocal leucencephalopathy, to Tysabri, and took him off the drug.
Eight weeks later they started him on Zinbryta. But two months into the treatment, he had a debilitating relapse that included walking and eye problems.
The patient had shown no signs that his disease was progressing under Tysabri, but after he started Zinbryta, an MRI scan spotted several new lesions in his brain. These are patches where the myelin sheath that protects nerve cells has deteriorated.
At that point, doctors took him off Zinbryta.
The key lesson from the case study was that “in some patients, daclizumab might not be sufficient to control disease activity after discontinuing natalizumab treatment,” the research team wrote.
Biogen and AbbVie are conducting a Phase 3 clinical trial (NCT02881567) of Zinbryta’s ability to treat RRMS patients who discontinue Tysabri for safety reasons. The companies are still recruiting participants for the study.