Biogen intends to proceed with late-stage testing for an experimental Alzheimer's disease drug, despite mixed results from its mid-stage trial. The company announced Thursday that it will move the treatment into Phase 3 testing, citing signals that the drug may decrease tau levels and slow cognitive decline, particularly at its lowest tested dose.
This decision marks another chapter in Biogen's complex history of developing Alzheimer's treatments. The experimental drug, known as Diranersen, is an antisense oligonucleotide designed to limit the production of tau, a protein implicated in the memory-robbing disease. This approach differs from Biogen's previous Alzheimer's drugs, Aduhelm and Leqembi, which focused on removing amyloid protein from the brain.
While the mid-stage trial data showed that Diranersen did not demonstrate superior responses at higher doses, the company highlighted positive indicators. Dr. Priya Singhal, Biogen's head of development, described the results as compelling, emphasizing the drug's ability to reduce tau pathology and provide cognitive benefits. She noted that the company is nearing the isolation of an optimal dose, stating, "Those are the three requirements you need to go to Phase 3."
The path to developing Alzheimer's therapies has been challenging for Biogen. The company has invested years in researching the disease and has brought two drugs to market aimed at slowing cognitive decline. However, Aduhelm faced significant controversy and was eventually withdrawn. Leqembi, another of Biogen's Alzheimer's drugs, also targets amyloid protein.
Biogen's move with Diranersen comes as rival pharmaceutical companies, including Eli Lilly, are also exploring treatments that target tau protein levels. The progression of Diranersen into late-stage trials represents a significant step forward in the ongoing effort to find effective treatments for Alzheimer's disease.
