Lausanne-based AC Immune has a focus on developing treatments for neurodegenerative diseases and has several immunotherapies in development targeting both Alzheimer’s and Parkinson’s disease.
The phase 2 VacSYn clinical trial is testing a vaccine-like immunotherapy (ACI-7104.056) designed to target alpha-synuclein buildup in the neurons in the brain, something that occurs in later stage Parkinson’s disease.
The results released today by the company represent 3 months of treatment in the first stage of the two-part trial. The company plans to release further results from the first stage of the trial in the first half of 2025 and also decide about whether to progress to the second part of the trial.
The first part of the trial recruited 30 patients with early-stage Parkinson’s disease who were randomly assigned to receive ACI-7104.056 or placebo at a 3:1 ratio. If AC Immune decides to move to the second part of the trial, then it will aim to recruit up to 150 participants for the next stage and will look at the impact of the therapy on both motor and non-motor symptoms.
The data from the first 3 months of the trial show all patients receiving the immunotherapy had an immune response. The average response in the treatment group after three immunizations was anti-alpha-synuclein antibody levels 16 times higher than those seen in the placebo group.
No major side effects have been reported so far. The most common adverse events in the trial are injection site reactions in 49% of participants and headaches in 18% of participants.
“The level of immunogenicity after only 3 months of treatment as well as the continued positive safety profile, reinforces the best-in-class characteristics of our clinically validated anti-alpha-syn active immunotherapy for the treatment of Parkinson’s disease,” said Andrea Pfeifer, CEO of AC Immune.
“As a leader in active immunotherapies for neurodegenerative diseases with two FDA Fast Track designated candidates, an important recognition of their promise, we are delighted with these initial VacSYn data. They further support the approach of using active immunotherapies to target the hallmark pathological proteins of neurodegenerative diseases… before irreversible damage occurs.”
A different approach to targeting neurodegenerative disease
Parkinson’s disease is a neurodegenerative disease estimated to affect at least 1% of people over the age of 60 years, with risk going up with age. It is known for affecting movement, as one symptom is involuntary tremor and movement difficulties, but people with the condition can also develop dementia-like symptoms at a later stage.
People with Parkinson’s gradually accumulate the protein alpha-synuclein into abnormal aggregations in the neurons known as Lewy bodies, which also occur in people with dementia with Lewy bodies.
AC Immune has several immunotherapies in development that are aiming to stop the accumulation of abnormal proteins in the brain in both Parkinson’s and Alzheimer’s disease, essentially taking a preventative approach at the first signs of disease.
In addition to ACI-7104.056, the company also has two other immunotherapies in development for the treatment of Alzheimer’s disease, an anti-amyloid beta and an anti-pTau active immunotherapy. These are also at phase 2 and are aiming to stop accumulation of amyloid plaques and tau tangles in the brain of people with Alzheimer’s.