Acumen will implement cash-saving strategies and assess its options after sabirnetug failed to beat placebo, leaving the biotech without a clinical program.
Acumen Pharmaceuticals’ investigational amyloid therapy failed to improve cognitive and function in Alzheimer’s disease during a mid-stage study, prompting the company to discontinue development of the asset and seek strategic options.
The Alzheimer’s candidate was Acumen’s only pipeline program. Friday’s news sent the company’s stock plummeting 80% to 44 cents per share in pre-market trading.
The Massachusetts biotech was testing sabirnetug—also known as ACU193—in patients with early Alzheimer’s. The monoclonal antibody is designed to selectively target toxic soluble amyloid beta oligomers to address the hypothesis that they are an early underlying cause of the neurodegenerative process.
Topline data from Acumen’s Phase 2 ALTITUDE-AD study did not support that hypothesis, with no meaningful difference recorded between sabirnetug and placebo in cognitive and functional improvement at 18 months. Sabirnetug also failed to meet any key secondary endpoints.
The drug was generally well-tolerated, according to Acumen, though amyloid-related imaging abnormalities-edema (ARIA-E)—a treatment-related swelling of the brain— were observed in about 10% of sabirnetug-treated participants.
As such, Acumen has terminated clinical development of the asset, including an open-label extension of the ALTITUDE-AD trial. The biotech’s pipeline consists of sabirnetug in both intravenous and subcutaneous versions. The asset holds fast-track designation from the FDA for early Alzheimer’s.
“While we are disappointed the trial did not meet its primary endpoint, we express our compassion and hope for future therapeutic options for patients with Alzheimer’s disease and their families,” Acumen CEO Daniel O’Connell said in a Friday release. “We have tremendous gratitude toward the patients, caregivers, investigators and clinical trial sites, as well as all Acumen employees, who worked so diligently over many years on this program.”
The biotech now intends on implementing “cash conservation measures” and exploring strategic options. BioSpace has reached out to the biotech for more details on these measures.
One strategy the company is reviewing pertains to its enhanced brain delivery technology. In July 2025, Acumen teamed up with JCR Pharmaceuticals to combine its antibody science with the latter’s blood-brain barrier (BBB)-penetrating technology, J-Brain Cargo, in hopes of creating next-gen central nervous system therapeutics.
Better delivery to the brain has become a focus of the next wave of Alzheimer’s treatments, with companies like Roche and Eli Lilly exploring blood-brain barrier technology.
