The findings of the study further suggest that it may be possible to assess and monitor the effects of potential therapeutic agents on amyloid-beta deposits in patients with Alzheimer’s disease using this neuroimaging technique.

Patients in the study were randomized to either bapineuzumab treatment or placebo groups. The estimated mean difference in PiB retention ratio change from baseline to week 78 between the bapineuzumab group and the placebo group was -0.24. Differences between the bapineuzumab group and the placebo group in the individual regions of interest were similar to the overall mean difference.

The study, conducted in patients with mild to moderate Alzheimer’s disease was a Phase II multi-center, double-blind, placebo-controlled multiple ascending dose study. Twenty-eight patients were randomized to receive one of three dose levels of bapineuzumab in a 1-hour IV infusion every 13 weeks for up to 6 infusions (a total of 78 weeks) or placebo. Each patient underwent (11C)PiB PET, (18F) FDG PET, clinical assessments of cognition function, CSF sampling for amyloid-beta and tau, volumetric and safety MRIs, and safety evaluations.

The study was powered to detect a treatment difference in (11C)PiB PET retention between bapineuzumab and placebo treated patients from baseline to study end. The study was not powered to evaluate efficacy on clinical or other biomarker outcomes. Adverse events were typically mild to moderate in severity and transient.

Menghis Bairu, chief medical officer of Elan, said: “We are encouraged by the findings of this study. The potential to use PiB PET imaging to monitor the effectiveness of potential therapeutics on amyloid beta load during treatment could play a major role in Alzheimer’s research and future clinical trial designs.”