title: Amyloid-Related Imaging Abnormalities (ARIA) in Immunotherapy Trials for Alzheimer's Disease: Need for Prognostic Biomarkers?
abstract: At the 8th International Conference on Clinical Trials in Alzheimer's Disease held November 5-7, 2015 in Barcelona, Spain, promising data were presented on two candidate Alzheimer's disease immunotherapeutic agents, gantenerumab and aducanumab. Trial results demonstrated that the implementation of cerebrospinal fluid and Aβ-PET biomarkers improves trial enrichment and outcome, which has led to a change in targeting strategy as clinical trials would be conducted with earlier, even presymptomatic, stages of the disease. Promising findings of outcomes, as measured by Aβ-PET and cerebrospinal fluid tau and P-tau, were, nevertheless, associated with antibody dose-dependent increased risk of severe adverse effects, specifically amyloid-related imaging abnormalities (ARIA). Aducanumab was associated with concomitant time-, dose-, and APOE-related incidence of ARIA in more than one-half of the patients within the high-dose arm. The future challenge will thus be to find biomarkers more favorably balanced between effective dosing of antibody to remove Aβ versus dosing to limit deleterious side effects. Interest was shown by Roche and Biogen, which promoted high-dose phase 3 trials. However, this generated some concerns related to a reasonable expected further increase in the incidence of severe side effects. What has been learned is challenging primary industry strategies for following-up and monitoring safety and effectiveness of anti-Aβ antibodies in clinical trials. Here, we debate the issue of what is an acceptable balance of treatment side effects, i.e., therapeutic-induced ARIA, versus the positive prospects. Indeed, implementation of biomarkers for ARIA might increase value and reduce waste in the design of immunotherapy trials of Alzheimer's disease.
authors.affiliation: The inflammatory cerebral amyloid angiopathy and Alzheimer's disease βiomarkers (iCAβ) International Network, Monza, Italy.|The iCAβ-ITALY Study Group of the Italian Society for the study of Dementia (SINdem), Italy.|School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMi), University of Milano-Bicocca, Monza, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Piazza
authors.affiliation: Karolinska Institutet, Department of NVS, Center for Alzheimer Research, Division of Neurogeriatrics, Huddinge, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Winblad
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000276:immunology; D058227:Amyloidogenic Proteins / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D015415:Biomarkers; D001921:Brain / Q000000981:diagnostic imaging*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D049268:Positron-Emission Tomography; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic / Q000379:methods*
chemical_list: D058227:Amyloidogenic Proteins; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers; C000600266:aducanumab; C571128:gantenerumab
keywords: Aducanumab; Alzheimer’s disease; adverse effects; amyloid-related imaging abnormalities; anti-Aβ autoantibodies; cerebral amyloid angiopathy-related inflammation; clinical trial; drug safety biomarkers; gantenerumab; immunotherapy