In recent years, neuroscience has gained a better understanding of the mechanisms and dynamics of Alzheimer’s disease. However, despite these advances, there are still a few treatment options. Research is progressing slowly due to the complexity of the disease. However, a team of researchers could shed some light on hope with ADDvac1, an experimental peptide vaccine that targets the disease protein tau. It has successfully passed phase 2 clinical trials which have proven to be both safe and effective, and produce good immunity. However, given the sample size and trial criteria, additional studies will be necessary to determine the true potential of this immunotherapy.
A unique experimental vaccine designed to protect against Alzheimer’s disease has passed the final stage in human trials, researchers report in a new study. In a phase II clinical trial, the candidate vaccine AADvac1, developed by biotech company Axon Neuroscience, has been shown to be well tolerated by patients and to produce a response against certain signs of disease.
Safe and effective vaccine
In tests of 193 patients with mild Alzheimer’s disease, 117 patients in the group received AADvac1, while the rest served as a control group, receiving a placebo instead. In a randomized, double-blind, 24-month trial, participants who received AADvac1 took the peptide-based vaccine in 11 doses administered during the trial and showed high levels of immunoglobulin G (IgG) antibody responses.
The researchers speculate that this would make AADvac1 effective against harmful clumps of tau proteins in the brain, which are thought to be a hallmark of the disease. In support of this, the recent trial showed that AADvac1 is associated with a slower accumulation of neurofilament light (NfL) protein, indicating slower neurodegeneration compared to patients who received placebo.
« To my knowledge, this is the first time that tau-targeted immunotherapy has shown clear evidence of an effect on the neurodegenerative process and a strong indication of clinical effect in patients with a confirmed profile of Alzheimer’s disease biomarkers. “,” explains Peter Novak, principal investigator for clinical research at Axon Neuroscience.
Clinical trial limits
But while this disease-modifying effect is certainly a promising development to watch out for, an experimental treatment has not yet shown convincing signs that it counteracts cognitive decline significantly across the spectrum of patients with dementia and Alzheimer’s disease. ” No significant effect was found in the cognitive and functional tests on the entire study sample The researchers write in their study.
However, it must be kept in mind that these results come from a relatively small, early phase II clinical trial designed primarily to test the safety profile of an experimental vaccine. At this point, it was well tolerated and considered successful, and no clinically significant adverse effects attributable to AADvac1 were demonstrated.
Regarding whether AADvac1 is able to deliver on its promise of successfully treating cognitive decline, the researchers say that we will need a larger trial that includes more patients; And perhaps more patients whose mental illness is associated with tau pathology in particular. The small overall size of the current trial, called ADAMANT, and the relative lack of biomarker-based patient pathology within the group are limitations we need to be aware of.
« With 193 patients in the full analysis cohort, the study was designed to detect only significant effects on clinical parameters The researchers wrote, noting that many patients in the study did not meet certain criteria related to tau for diagnostic vital signs.
Action directed against tau protein بروتين
In other words, although some of the findings are ambiguous, there are still positive signs here, particularly when the analysis focuses on patients whose Alzheimer’s disease is associated with biomarkers that tau is responsible for their condition, and who are likely to respond to this vaccine.
In a specific subgroup of 109 patients likely to test positive for amyloid and tau biomarkers, assessments of the rate of dementia and activities of daily living indicated that treatment with AADvac1 likely slowed their deterioration. The placebo group.
« These subsequent analyzes have significant limitations, as they were not previously specified in the clinical study protocol and were not corrected for multiplicity tests. These results should therefore be interpreted with caution and will require confirmation in future clinical development. ‘, the authors conclude.