Grifols' Alzheimer Vaccine ABvac40 Demonstrates 53% Reduction in Cognitive Decline Risk in Phase 2 Trial
核心洞察
ABvac40, an investigational amyloid-β (搜索) vaccine from Grifols, showed a 53% reduction in risk of meaningful cognitive decline compared to placebo in a 24-month phase 2 study of 97 patients with mild cognitive impairment (搜索) or very mild Alzheimer's disease (搜索).
The strongest treatment effects were observed in amyloid-PET positive patients, with those having higher antibody levels showing an 81% reduction in cognitive decline risk.
The vaccine demonstrated a favorable safety profile with no reports of amyloid-related imaging abnormalities-edema or aseptic meningo-encephalo-myelitis, distinguishing it from traditional anti-amyloid therapies.
Grifols' investigational Alzheimer's vaccine ABvac40 demonstrated significant potential to slow cognitive decline in early-stage disease, according to phase 2 trial results presented at the 2025 Alzheimer's Association International Conference (AAIC) in Toronto. The AB1601 study revealed a 53% reduction in risk of meaningful cognitive decline over 24 months, with the strongest effects observed in patients with the highest antibody levels.
Trial Design and Patient Population
The double-blind, placebo-controlled AB1601 phase 2 study (NCT03461276) enrolled 97 patients with mild cognitive impairment (搜索) or very mild Alzheimer's disease (搜索) in the per-protocol cohort. Of these participants, 69 (71.1%) were amyloid-PET positive. Patients receiving ABvac40 were stratified by cerebrospinal fluid (CSF) antibody levels into two groups: high levels (quartile 4) and low levels (Q1-Q3).
The primary endpoint focused on meaningful within-patient changes (MWPC), defined as a decline of at least 3 points in Mini-Mental State Exam (MMSE) scores at two consecutive visits over the 24-month treatment period. Cox proportional hazards models assessed MWPC risk, adjusting for baseline MMSE score, age, apolipoprotein E4 carrier status, clinical stage, and baseline Alzheimer's medication use.
Significant Cognitive Benefits Across Patient Subgroups
After 24 months of treatment, ABvac40-treated patients demonstrated a reduced risk of MWPC relative to placebo (HR, 0.47; 95% CI, 0.27-0.85; P = .012). The treatment effect was particularly pronounced in the amyloid-PET positive subgroup (HR, 0.38; 95% CI, 0.20-0.75; P = .005) compared to non-amyloid PET positive patients.
Within the amyloid-PET positive subgroup, patients with lower antibody levels showed a 63% lower risk of MWPC (HR, 0.37; 95% CI, 0.16-0.83; P = .016), while those with higher antibody levels demonstrated an even more substantial 81% reduction (HR, 0.19; 95% CI, 0.04-0.84; P = .029).
María Pascual-Lucas, PhD, senior scientist at Araclon Biotech (搜索), presented the findings and concluded that the data support ABvac40's potential to influence disease progression, warranting further studies to explore its impact on brain vessels as a potential driver of the observed cognitive benefits.
Favorable Safety Profile Distinguishes Vaccine Approach
The trial demonstrated a notably favorable safety profile that distinguishes ABvac40 from traditional anti-amyloid therapies. In the active treatment group, researchers reported no instances of amyloid-related imaging abnormalities-edema or aseptic meningo-encephalo-myelitis. Additionally, there were few instances of micro-hemorrhages compared with placebo, and none led to treatment discontinuation.
Other neuropsychological assessments, including the Repeatable Battery for the Assessment of Neuropsychological Status and the Trial Making Test, showed favorable results for ABvac40 versus placebo. While global or functional scales showed no differences between treatment groups, volumetric MRI revealed a lesser increase in whole brain atrophy with ABvac40 treatment.
Mechanism and Future Directions
ABvac40 represents an active immunization approach targeting amyloid-β (搜索) (Aβ), designed to stimulate the patient's immune system to produce antibodies against amyloid plaques (搜索). Jose Terencio, PhD, vice president of Innovation and New Technologies at Grifols, emphasized the vaccine's positive safety profile and its differentiation from traditional anti-amyloid therapies that are associated with amyloid-related imaging abnormalities.
The phase 2 study met its primary endpoints and showed differences between vaccine- and placebo-treated groups in several secondary exploratory endpoints. These results, initially announced at the 2023 Clinical Trials on Alzheimer's Disease (搜索) annual meeting, provide compelling evidence for ABvac40's therapeutic potential in early-stage Alzheimer's disease.