Acumen Pharmaceuticals Completes Enrollment of Phase 2 Clinical Trial of Sabirnetug in Early Alzheimer’s Disease

Acumen Pharmaceuticals, Inc. recently announced the completion of enrollment in its ALTITUDE-AD Phase 2 trial of sabirnetug (ACU193) in patients with early Alzheimer’s disease. Acumen completed enrollment ahead of schedule and plans to report topline results, including efficacy and safety data, in late 2026.

“We are pleased to complete enrollment for our Phase 2 ALTITUDE-AD trial of sabirnetug,” said Daniel O’Connell, President and Chief Executive Officer of Acumen. “Achieving this milestone is a testament to the significant interest in our approach from both patients and the scientific community, and we are grateful to all the participants, investigators and trial sites, and our clinical team for enabling us to complete enrollment efficiently. We look forward to sharing topline results in late 2026 and advancing sabirnetug as a next-generation treatment for Alzheimer’s disease.”

Sabirnetug is the first humanized monoclonal antibody to demonstrate in AD patients selective target engagement of AβOs, a soluble and highly toxic form of Aβ that accumulates early in AD and is a persistent trigger of synaptic dysfunction and neurodegeneration. The Phase 1 INTERCEPT-AD clinical trial demonstrated sabirnetug was generally well-tolerated with low overall rates of ARIA-E. The trial also showed dose- and exposure-dependent target engagement and statistically significant amyloid plaque reduction compared to placebo at higher dose multiple-ascending dose cohorts evaluated in the study.

ALTITUDE-AD (NCT06335173) is a Phase 2, multi-center, randomized, double-blind, placebo-controlled clinical trial that enrolled 542 patients with early AD at sites in the United States, Canada, the European Union and the United Kingdom. The study participants were randomized to receive one of two dose levels of sabirnetug (35mg/kg or 50mg/kg once every four weeks) or placebo. The primary endpoint is change from baseline in the Integrated Alzheimer’s Disease Rating Scale (iADRS) at 18 months. Secondary endpoints include the Clinical Dementia Rating – Sum of Boxes scale (CDR-SB), ADAS-Cog13, ADCS-ADL and various AD biomarkers. Standard safety measures and MRIs will also be assessed. Participants who completed the double-blind portion of the study will have the opportunity to continue into an open-label extension.

Sabirnetug (ACU193) is a humanized monoclonal antibody (mAb) discovered and developed based on its selectivity for soluble amyloid beta oligomers (AβOs), which are a highly toxic and pathogenic form of Aβ, relative to Aβ monomers and amyloid plaques. Soluble AβOs have been observed to be potent neurotoxins that bind to neurons, inhibit synaptic function and induce neurodegeneration. By selectively targeting toxic soluble AβOs, sabirnetug aims to address the hypothesis that soluble AβOs are an early and persistent underlying cause of the neurodegenerative process in Alzheimer’s disease (AD). Sabirnetug has been granted Fast Track designation for the treatment of early AD by the U.S. Food and Drug Administration and is currently being evaluated in a Phase 2 study in patients with early AD.

Initiated in 2024, ALTITUDE-AD is a Phase 2, multi-center, randomized, double-blind, placebo-controlled clinical trial designed to evaluate the efficacy and safety of sabirnetug (ACU193) infusions administered once every four weeks in slowing cognitive and functional decline as compared to placebo in participants with early Alzheimer’s disease. The study has enrolled approximately 540 individuals with early Alzheimer’s disease (mild cognitive impairment or mild dementia due to AD) at multiple investigative sites located in the United States, Canada, the European Union and the United Kingdom. More information can be found on www.clinicaltrials.gov, NCT identifier NCT06335173.

Acumen Pharmaceuticals is a clinical-stage biopharmaceutical company developing a novel therapeutic that targets toxic soluble amyloid beta oligomers (AβOs) for the treatment of Alzheimer’s disease (AD). Acumen’s scientific founders pioneered research on AβOs, which a growing body of evidence indicates are early and persistent triggers of Alzheimer’s disease pathology. Acumen is currently focused on advancing its investigational product candidate, sabirnetug (ACU193), a humanized monoclonal antibody that selectively targets toxic soluble AβOs, in its ongoing Phase 2 clinical trial ALTITUDE-AD (NCT06335173) in early symptomatic Alzheimer’s disease patients, following positive results in its Phase 1 trial INTERCEPT-AD. For more information, visit www.acumenpharm.com.