The Autism Biomarkers Consortium for Clinical Trials (ABC-CT) is a US-based network designed to develop objective measures to more sensitively and validly quantify ASD symptomatology and its change in clinical trials and to stratify ASD into meaningful subgroups. This symposium will present results from ABC-CT interim analyses, when half of the total sample has been evaluated at the second of three time points. This panel brings together six autism research centers, with panelists spanning early career faculty to senior leaders in the field. The first lecture will provide an overview of study design, with focus on progress to date and unique elements of the approach to biomarker development. The second lecture will present clinical data from the interim sample, and the third and fourth lectures will provide preliminary biomarker results obtained from EEG and eye-tracking studies, respectively. The discussion, provided by leadership from EU-AIMS, a collaborating European biomarker consortium, will focus on unique concerns for biomarkers that can facilitate prediction of outcome and diagnostic stratification and on development of large-scale consortia and clinical networks for study of biomarkers in ASD.