AL002 is an experimental antibody that aimed to improve the function of TREM2, a receptor on the surface of the brain's immune cells called microglia[2]. A phase 2 study called INVOKE-2 tested AL002 in patients with early Alzheimer's disease and found that the antibody achieved target involvement in the brain[2]. However, AL002 did not meet the primary endpoint of change in Clinical Dementia Rating-Sum of Boxes[3]. The study also did not meet any of the secondary or exploratory endpoints[3]. Researchers hypothesized that activating TREM2 could improve the brain's ability to clear harmful proteins associated with Alzheimer's disease[2]. Negative results led to stopping the extended part of the study[3]. Alector plans to share detailed results with the scientific community to better understand the biology of TREM2 and develop more effective drugs[3].