New Blood Based Screening Assay Found Efficient and Cost Reducing in Clinical Trials of Sabirnetug for Early Alzheimer Disease

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CONFERENCE REPORTER

Acumen Pharmaceuticals announced that their new blood based pTau217 screening assay reduced overall clinical trial screening costs by 40% in its phase 2 ALTITUDE-AD trial of sabirnetug for early Alzheimer disease (AD). Additionally, a nonclinical study revealed sabirnetug achieved the highest selectivity for amyloid beta oligomers (AβOs)) over Aβ monomers relative to recombinant lecanemab and aducanumab. These results were reported at this week’s Alzheimer’s Association International Conference (AAIC) in Toronto, Canada (July 27-30).¹

“These advances represent important progress in addressing the critical need for effective treatments targeting toxic AβOs in early symptomatic [AD], while simultaneously demonstrating patient-centric and cost-effective trial execution strategies,” said Eric Seimers, MD, the chief medical officer of Acumen Pharmaceuticals.¹

Sabirnetug, a humanized monoclonal antibody, targets soluble AβOs to treat AD. AβOs have been shown to be an early and persistent marker of AD related pathophysiology.² Targeting this marker may slow down neurodegeneration, reduce tau hyperphosphorylation, and prevent synapse loss in cases of early AD.

Acumen is currently testing sabirnetug in ALTITUDE-AD, a phase 2 multi center, randomized, double blind, placebo controlled clinical trial to evaluate the efficacy and safety of infusions administered once every 4 weeks in slowing cognitive and functional decline as compared with placebo in those with early AD. The clinical trial currently has 542 participants with mild cognitive impairment or mild dementia as a result of AD enrolled at multiple sites in the United States, Canada, European Union, and United Kingdom. Sabirnetug received Fast Track designation from the US Food and Drug Administration for evaluating treatment of early AD in October 2022.³

According to investigators of the ALTITUDE-AD phase 2 clinical trial, the implementation of the innovative 2-step screening process using plasma pTau217 biomarker assay testing yielded significant clinical trial screening and cost efficiencies. Approximately 48% of participants initially screened met the biomarker threshold for further confirmatory testing, and 81% of these participants then met amyloid positivity eligibility requirements, marking this screening process as efficient. Additionally, the approach reduced unnecessary PET scans and lumbar punctures for potential participants, and thereby improved enrollment rates.

Furthermore, through surface plasmon resonance testing, sabirnetug demonstrated the highest binding affinities to AβOs preparations compared with other monoclonal antibodies like lecanemab and aducanumab. In support of the drug’s mechanism of action and selectivity for AβOs, it demonstrated an 8750-fold selectivity for Aβ1-42 stabilized oligomers over Aβ1-40 monomers. Sabirnetug also showed minimal interaction with monomeric Aβ, which is notable due to the significantly higher number (7000-fold increase) of monomeric forms of Aβ compared with oligomeric forms in patients with AD related mild cognitive impairment and mild dementia.

“By combining cutting-edge therapeutic development with smart clinical trial strategies, we are working to create a more efficient path forward in bringing potential new options to patients with [AD],” concluded Seimers.¹

References

1. Acumen pharmaceuticals presents studies showing the utility of a pTau217 assay in screening for a phase 2 Alzheimer’s disease trial and validates sabirnetug oligomer-selectivity, at the Alzheimer’s Association International Conference (AAIC) 2025. News release. July 28, 2025. Accessed July 28, 2025. https://investors.acumenpharm.com/news-releases/news-release-details/acumen-pharmaceuticals-presents-studies-showing-utility-ptau217

2. Chen GF, Xu TH, Yan Y, et al. Amyloid beta: structure, biology and structure-based therapeutic development. Acta Pharmacol Sin. 2017;38:1205-1235.

3. United States Securities and Exchange Commission. Form 10-K for Acumen Pharmaceuticals, Inc. Annual Report. Accessed July 29, 2025. https://www.sec.gov/Archives/edgar/data/1576885/000157688524000047/abos-20231231.htm