This study is a multicentre study evaluating for the first time the safety and efficacy of GNbAC1 in T1D subjects for a first bouble-blind period of 20 weeks followed by an optional open-label period of 24 weeks. The primary objective of the study is to assess the safety and tolerability of six consecutive 4-weekly doses of GNbAC1 in subjects with T1D. Secondary objectives are to determine the pharmacodynamic response to GNbAC1 on biomarkers of T1D.