My Alzheimer's Journey

Part 84 - Biogen BIIB080

In late January, I wrote a brief overview on four emerging technologies and therapies. Since then, I have researched and reported on three of the four. Today, let’s look at the forth emerging therapy - Biogen BIIB080.

BIIB080 is an investigational antisense oligonucleotide (ASO) therapy designed to target microtubule-associated protein tau (MAPT) mRNA to reduce the production of tau protein. Antisense oligonucleotides are small molecules that can be used to prevent or alter the production of proteins. In healthy brains, tau protein is found in neurons within the central nervous system, and it stabilizes axonal microtubules. The axon is the single long fiber that extends from the neuron and transmits electrical signals away from the cell body. Microtubules are small hollow tubes involved in the transport of material within cells. In simple terms, the tau protein travels in small hollow tubes.

In Alzheimer’s disease (and a few other neurodegenerative diseases), tau proteins misbehave and become toxic tangles. Misbehave is a very simplified way for me to describe a complex and somewhat uncertain process. Researchers believe that molecular changes, or processes result in tau buildup. One likely molecular process is phosphorylation. During this process, enzymes help phosphate molecules bind to tau.

When I put all of the above information together, I deduce that BIIB080 is going to keep tau in check and prevent it from building up and forming tangles.

BIIB080 was developed by Ionis Pharmaceuticals. They called it IONIS-MAPT. In December 2019, Biogen exercised a license option with Ionis and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize BIIB080. In other words, if BIIB080 is successful, Ionis will earn lots of money.

In April 2025, the FDA granted Fast Track designation to the BIIB080 clinical trial. Fast Track designation is fairly common for investigational drugs that treat serious conditions.

The official title of the trial is A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Assess the Efficacy, Safety, and Tolerability of BIIB080 in Subjects With Mild Cognitive Impairment Due to Alzheimer's Disease or Mild Alzheimer's Disease Dementia.

The purpose of the study is to determine if BIIB080 can slow the worsening of Alzheimer’s disease more than a placebo - and if so, what is the optimal dose. Of course, adverse effects will be determined during this trial. The trial will last about four years. It amazes me that a Fast Track study, or trial will take four years.

BIIB080 is administered as an injection into the fluid around the spinal cord. During the trial, some participants will receive the drug every 12 weeks and others will receive the drug every 24 weeks.

While BIIB080 is certainly an encouraging new therapy, it is NOT a cure for Alzheimer’s disease. The drug would slow the progression or worsening of Alzheimer’s.

Reference Sources:

ClinicalTrials.gov ID#NCT05399888

Biogen Press Release, April 2, 2025

https://ionis.com/science-and-innovation/pipeline