At present, no treatments exist to preserve insulin production when T1D is diagnosed. We seek adults aged 18-35 years within 100 days of T1D diagnosis to receive an immunosuppression medication called ‘ustekinumab’ (2 out of 3 chance), currently used for other autoimmune diseases, or placebo (1 out of 3 chance). Study sites are Toronto and Vancouver, but we will work to fund travel if you live elsewhere. We expect that ustekinumab may delay diabetes progression. Principal Investigator: Jan Dutz