Biogen announced Thursday its plan to advance an experimental drug targeting tau protein for Alzheimer's disease into late-stage (Phase 3) clinical trials, despite mixed results from earlier mid-stage testing.
Drug Focus and Trial Data
Biogen's experimental therapy focuses on tau, a protein implicated in the progression of Alzheimer's disease. Initial data from mid-stage trials indicated that the drug did not show superior responses at higher dosage levels.
However, the company intends to proceed to Phase 3 based on encouraging signals observed at lower doses. These signals suggest that the treatment can achieve two key outcomes:
- Reduction of Tau Levels: The drug helps decrease the pathological levels of tau protein.
- Slowing Cognitive Decline: There is evidence that the treatment slows the rate of cognitive decline.
Company Justification for Advancement
Dr. Priya Singhal, Biogen's Head of Development, stated that the combination of findings is highly compelling. She emphasized that the ability to demonstrate both tau reduction and cognitive benefit was crucial for moving forward.
"We're really excited that we've been able to demonstrate an unprecedented combination of tau reduction in pathology and the cognitive benefit and have been really getting close to isolating a dose," Dr. Singhal stated. "Those are the three requirements you need to go to Phase 3."
Context in Alzheimer's Drug Development
This development represents another significant step in Biogen's ongoing, complex research efforts for Alzheimer's. The company has a history of developing treatments for the condition, including:
- Aduhelm: Biogen previously brought this drug to market, though it later faced controversy surrounding its approval and was withdrawn.
- Leqembi: This is another Alzheimer's drug developed by Biogen.
Mechanism of Action Comparison:
- Aduhelm and Leqembi: Both drugs function by targeting and removing amyloid protein from the brain.
- Experimental Drug (Diranersen): This latest drug is an antisense oligonucleotide designed to limit the production of the tau protein.
Biogen's move occurs while competitors, such as Eli Lilly, are also actively researching drugs aimed at decreasing tau levels.
