Acumen Pharmaceuticals presented data at the 17th Annual Clinical Trials on Alzheimer’s Disease (CTAD) conference, highlighting the effectiveness of its plasma pTau217 assay in screening participants for the Phase 2 ALTITUDE-AD clinical trial of sabirnetug. The assay serves as an enrichment tool, identifying individuals with a higher probability of amyloid pathology, thereby reducing the necessity for extensive amyloid PET scans or lumbar punctures in ineligible candidates.
Streamlining Trial Enrollment with pTau217
The ALTITUDE-AD trial, a Phase 2 multi-center, randomized, double-blind, placebo-controlled study, aims to evaluate the efficacy and safety of sabirnetug in approximately 540 adults aged 50 to 90 years. A key inclusion criterion for such trials is the confirmation of cerebral amyloid accumulation, typically assessed via PET scan or CSF analysis. The pTau217 assay offers a less burdensome initial screening step.
Todd Feaster, Psy.D., Senior Clinical Research Scientist at Acumen Pharmaceuticals, emphasized the importance of the pTau217 screening assay, stating, "The pTau217 screening assay enrichment approach is an important part of the clinical trial process for Alzheimer’s treatments because it could spare patients from invasive lumbar punctures and unnecessary radiation exposure with an amyloid PET scan."
Enhanced Participant Selection
The study established a pTau217 threshold of ≥0.15 pg/mL for enrichment purposes. Data showed that over half of potential participants were excluded due to pTau217 levels below this threshold. Impressively, 74% of participants with pTau217 ≥0.15 pg/mL met amyloid burden eligibility requirements after confirmatory assessment, compared to only 40% in the Phase 1 INTERCEPT-AD trial, which used amyloid PET as the initial screening tool.
Sabirnetug: Targeting Soluble Amyloid Beta Oligomers
Sabirnetug (ACU193) is a humanized monoclonal antibody selectively targeting soluble amyloid beta oligomers (AβOs), believed to be a highly toxic form of Aβ. By targeting these oligomers, sabirnetug aims to address a primary cause of neurodegeneration in Alzheimer’s disease. The FDA has granted Fast Track designation to sabirnetug for the treatment of early Alzheimer’s disease.
ALTITUDE-AD Trial Details
The ALTITUDE-AD trial is currently enrolling participants at 75 sites across the U.S., Canada, EU, and U.K., with completion of enrollment expected in the first half of 2025. The trial evaluates sabirnetug infusions administered every four weeks compared to placebo in individuals with early Alzheimer's disease (mild cognitive impairment or mild dementia due to AD).
Daniel O’Connell, President and Chief Executive Officer of Acumen, noted, "The study is not only a testament to our commitment to advancing a next-generation treatment for Alzheimer’s disease but also our commitment to pioneering clinical trial designs that provide an improved patient experience."
