Recently, biopharmaceutical company Acumen Pharmaceuticals announced the results of its global Phase 2 clinical trial ALTITUDE-AD for its investigational Alzheimer's disease candidate Sabirnetug (ACU193) : the trial failed to meet the primary endpoint, and the company immediately announced the termination of drug development. The stock price of Acumen Pharmaceuticals fell by about 90% that day .
Sabirnetug is a humanized monoclonal antibody whose mechanism of action is not to directly clear amyloid plaques, but rather to selectively target soluble amyloid β-oligomers . These oligomers are considered to have strong neurotoxicity and may be involved in the neurodegenerative process of Alzheimer's disease at an earlier stage.
The drug had previously received Fast Track designation from the U.S. FDA . The ALTITUDE-AD study included 542 patients with early-stage Alzheimer's disease, covering multiple centers in the United States, Canada, the European Union, and the United Kingdom. The primary endpoint was the change in iADRS cognitive and functional scores from baseline after 18 months of treatment.
The results showed that neither the 35 mg/kg nor the 50 mg/kg dose groups were significantly superior to placebo on the primary endpoint , and the key secondary endpoint CDR-SB also failed to reach statistical significance. PET imaging showed that both dose groups significantly reduced amyloid plaques at weeks 36 and 76, but this biological change did not translate into clinical benefit at the cognitive or functional level.
In terms of safety, the drug was generally well tolerated, with approximately 10% of subjects experiencing ARIA-E.
Based on the above results, Acumen decided to halt all clinical development of Sabirnetug , including the originally planned open-label expansion, and to initiate cash-saving measures while evaluating strategic options, including the EBD brain delivery program.
This incident also highlights the high degree of uncertainty still facing the development of Alzheimer's disease drugs. Even if a drug can reduce amyloid plaques and has clear biological activity, it may not necessarily improve patients' cognitive and functional outcomes.
For companies focused on biopharmaceutical innovation and overseas expansion, such failures are not uncommon. However, they also serve as a reminder that the valuation of innovative drugs is highly dependent on key clinical data, and a setback in a single core asset can quickly alter a company's prospects. Investors and industry observers need to be more cautious in distinguishing between "novel mechanisms," "improved biomarkers," and "clinical endpoint benefits."

Source: https://news.yaozh.com/archive/49316.html