Positive Interim Results on Trontinemab Validate Brainshuttle Technology for Alzheimer Disease Treatment

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Roche presented interim trial data for trontinemab, a novel anti-amyloid monoclonal antibody, to clinically validate its proprietary Brainshuttle technology for the treatment of prodromal or mild to moderate Alzheimer disease (AD), at the AD/PD 2025 International Conference on Alzheimer’s and Parkinson’s Diseases. The encouraging results prompted Roche to initiate a phase 3 study of trontinemab, expected to begin later this year.^1-3 

Trontinemab is a reformulation of anti–beta-amyloid antibody gantenerumab, modified with the Brainshuttle platform to bind to transferrin receptors on endothelial cells and cross the blood-brain-barrier. Roche aims to utilize Brainshuttle to deliver higher antibody concentrations to the brain while reducing the risk of amyloid-related imaging abnormalities (ARIA).

“We are pleased with the progress across our [AD] portfolio as we move ahead with a phase 3 trontinemab programme and continue to expand our diagnostic solutions,” said Levi Garraway, MD, PhD, chief medical officer and head of global product development for Roche. “Well over 55 million people worldwide are living with dementia, of which around 70% have [AD]. Moreover, up to three-quarters of people experiencing symptoms of [AD] remain undiagnosed. This growing population needs more accurate, less invasive diagnostic approaches paired with effective disease-modifying treatments to slow neurodegeneration as early as possible.”³

Results from the phase 1B/2A Brainshuttle AD study showed that trontinemab achieved rapid and robust amyloid plaque reduction at low systemic doses. Investigators enrolled 114 participants who were amyloid-positive and had either mild cognitive impairment or prodromal AD, to receive either a 1.8 mg/kg or 3.6 mg/kg intravenous dose of trontinemab every 4 weeks, where rapid and significant amyloid lowering was observed. The data showed adjusted mean reductions from baseline in amyloid positron emission tomography of 78 centiloids (CLs) at 28 weeks at the 1.8 mg/kg dose and 96 CLs at 28 weeks at the 3.6 mg/kg dose. The 3.6 mg/kg dose showed approximately 60% amyloid reduction after 8 weeks following 2 treatment doses. By the end of the 28-week treatment period, 81% of participants in the higher dose 3.6 mg/kg group were below the amyloid positivity threshold of 24 CLs. Participants also saw "early and significant" reductions across several cerebrospinal fluid and plasma AD biomarkers, including total tau, phosphorylated Tau (pTau)181, pTau217, and neurogranin. Additionally, there were no nonresponders to treatment at the 28-week follow-up.

These data build on a readout from March 2024, which showed the 3.6 mg/kg-dose group experienced a mean reduction of 91 CLs by week 12.

"Based on data in the field, both the speed of amyloid lowering, and the ability to lower below the amyloid positivity threshold early on, are important to achieve clinically meaningful benefit in early [AD]," Roche stated.

Trontinemab also demonstrated a positive safety profile. Roche reported that brain swelling linked to ARIA (ARIA-E) occurred in less than 5% of participants, and that each case was radiographically mild. If the results hold up in a large phase 3 study, trontinemab's safety could give it an edge over the 2 anti–beta-amyloid antibodies on the market: for lecanemab, ARIA-E was observed in 13% of patients, and for donanemab, ARIA-E was observed in 24% of patients.

References

1. Eaton ES. Roche planning phase III Alzheimer's study after Brainshuttle antibody achieves plaque elimination — safely. First Word Pharma. April 3, 2025. Accessed April 4, 2025. https://firstwordpharma.com/story/5947420

2. AD/PD 2025: Roche’s Brainshuttle technology promises next generation of amyloid beta mAbs. Clinical Trials Arena. April 4, 2025. https://www.clinicaltrialsarena.com/analyst-comment/roche-brainshuttle-technology-next-generation-amyloid-beta-mabs/?cf-view

3. Roche presents novel therapeutic and diagnostic advancements in Alzheimer’s at AD/PD 2025. News release. April 2, 2025. Accessed April 4, 2025. https://www.roche.com/media/releases/med-cor-2025-04-03