Adcanemab is a human monoclonal antibody being studied as a treatment for Alzheimer's disease. It was developed by Biogen Idec, which licensed the drug from its discoverer, Neuroimmun. The antibody targets beta-amyloid receptors in the brains of people with Alzheimer's, hoping to reduce their buildup. Biogen halted development of the drug in March 2019 after preliminary data from two Phase 3 clinical trials suggested it would not achieve its primary goal. On October 22, 2019, Biogen announced that it would restart the FDA-approved process after new analyses of larger data sets showed that the drug reduced clinical decline in patients with early-onset Alzheimer's when given at higher doses. A reanalysis of data from the halted trials found that patients receiving the higher doses had a 23% reduction in decline. Interim results from the second phase 1 study were reported in March 2015. Phase 1b results were published in August 2016, based on one year of “monthly intravenous administration” of adecanemab, with brain imaging to monitor amyloid plaques. A phase 3 clinical trial had been underway since September 2016, but was cancelled in March 2019 after an independent group analysis showed the trial was unlikely to meet its primary goal. However, in October 2019 the company announced its intention to seek regulatory approval, following a reanalysis of the data.