BIIB080 shows Alzheimer’s-related tau protein reduction in study

Participants are being recruited for Phase 2 CELIA trial

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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Treatment with the experimental therapy BIIB080 led to long-term reductions in the levels of disease-associated tau protein in the brains of people with early Alzheimer’s disease.

That’s according to new data from a Phase 1b trial (NCT03186989) presented by Biogen at the International Conference on Alzheimer’s and Parkinson’s Diseases in Gothenburg, Sweden, March 28-April 1.

“We are encouraged by the promising new Phase 1b BIIB080 data and what the implications could mean for the Alzheimer’s disease (AD) community,” Dominic Walsh, PhD, vice president of the Alzheimer’s disease and dementia research unit at Biogen, said in an email to Alzheimer’s News Today.

“Given the complexity and urgent unmet need in Alzheimer’s disease, Biogen continues to evaluate multiple modalities and targets including tau, which is believed to play a critical role in cognitive decline,” Priya Singhal, MD, executive vice president and head of development at Biogen, said in a company press release.

Biogen, which obtained license rights to the therapy from Ionis in 2019, is conducting a Phase 2 trial, called CELIA (NCT05399888), to further evaluate BIIB080 in Alzheimer’s patients. The main goal is to test whether it can slow dementia progression, as assessed by scores on a clinician-rated dementia staging system, called the Clinical Dementia Rating (CDR) scale.

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Recruitment begins to test BIIB080 in CELIA study

CELIA seeks to recruit about 735 adults, ages 50-80, with mild cognitive impairment or mild dementia due to Alzheimer’s who haven’t received any other treatment for the disease. Recruitment is ongoing at several centers across the U.S. and Canada.

Participants will be randomly assigned to one of four groups — a high dose of BIIB080 given every 12 weeks; a high dose every 24 weeks; a low dose every 24 weeks; or placebo every 12 weeks. The therapy is administered via intrathecal (into-the-spine) injection.

BIIB080 (formerly IONIS-MAPTRx) is designed to interfere with tau protein production, thereby lowering its levels. In Alzheimer’s, tau forms clumps, or tangles, in the brain, which are thought to play a role in driving the disease.

A Phase 1b clinical trial tested the safety of various doses of BIIB080 in 46 people with early Alzheimer’s. Top-line data suggested it was well tolerated and capable of reducing tau levels as intended.

After the initial six-month trial, the participants could enroll in an open-label extension, where they all were treated with BIIB080 for a year.

New PET imaging data from the extension study showed tau aggregation was reduced across all tested brain regions. This positive effect was seen as early as week 25 and sustained until its end at week 100. These benefits were also observed in those given a placebo in the main trial who started BIIB080 at week 25 in the extension study.

“These new data are particularly exciting as they represent the first time a reduction of this magnitude across brain regions in tau PET has been observed in a clinical study,” Walsh said. “These data also suggest that tau PET may evolve to become as important a biomarker as amyloid PET has proven to be.”

Similarly, tau levels in the cerebrospinal fluid — the fluid that surrounds the brain and spinal cord — were reduced across all dose groups by about 60% in all patients by the end of the extension study.

Safety data showed the most common side effects associated with treatment were headache, back pain, and complications related to the spinal injection. Most side effects were mild or moderate, according to Biogen.

“Although these findings are early stage, we believe in the potential of BIIB080, and look forward to what lies ahead as the Phase 2 CELIA study advances,” Walsh said.