Biogen Inc said on Wednesday patients in a long-term trial of its Alzheimer's drug Aduhelm experienced reductions in two key disease indicators after nearly two and a half years of treatment.
Biogen said that Aduhelm "significantly reduced" amyloid beta plaque levels out to week 132 of treatment and also decreased plasma levels of a protein called p-tau181 at week 128, Biogen said.
The company said that patients who at week 78 of the trial had shown reduced levels of plasma p-tau181 had less clinical decline in the extended trial than those whose plasma p-tau181 levels were not reduced earlier on.
Biogen did not provide the details of its findings.
Amyloid-beta and tau make up the plaques and tangles in the brain that are the hallmark of Alzheimer's disease.
Aduhelm, approved last year, became the first treatment to be cleared for Alzheimer's in 20 years, despite one of its two large-scale clinical trials failing to show a benefit to patients.
Regulators approved the drug on the basis of the reduction in the markers for the disease. Leading experts questioned that move and the U.S. government Medicare program has proposed that the drug's use only be allowed by patients enrolled in a new trial.
Biogen presented the data at the International Conference on Alzheimer's and Parkinson's Diseases currently underway in Barcelona.
These findings point to the potential of continued benefit of treatment, Biogen said.
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