AC Immune SA has entered into collaboration with Bayer Schering Pharma to use the company’s diagnostic imaging in the brain of patients undergoing Phase I clinical testing of the ACI-24 Alzheimer’s vaccine.

AC Immune will use Bayer’s novel positron emission tomography (PET) tracer florbetaben to image beta-amyloid plaques in the brain of patients in the Phase I clinical trial.

This is the first time this PET tracer will be tested in treated Alzheimer’s patients.

AC Immune CEO Andrea Pfeifer said that there is a key trend in the industry to co-develop therapy guiding diagnostics alongside drugs for patients.

“The adoption of a diagnostic imaging substance visualising the deposition of beta-amyloid that is targeted by our vaccine can be an important parameter for dose selection, and will provide useful complementary data,” Pfeifer said.

There is currently no diagnostic test available to detect beta-amyloid plaques in the brain, which are known to be a pathological hallmark of Alzheimer’s disease.

At present the clinical diagnosis of Alzheimer’s disease is based on cognitive tests as well as magnetic resonance imaging (MRI) and computerised tomography (CT) scans, resulting in a clinical diagnosis that is often too late.

The ACI-24 clinical trial is a Phase I/IIa, randomised, double-blind, placebo-controlled clinical study to evaluate the safety and tolerability of ACI-24, an active vaccine to stimulate the patient’s immune system to produce beta-sheet conformation-specific antibodies that clear and prevent plaque deposition.