The study is a two-arm, multicenter, double-blinded clinical trial testing sequential therapy with rituximab-pvvr followed by abatacept versus rituximab-pvvr alone in new onset T1D. The primary objective is to test whether the C-peptide response to a 2-hour mixed meal tolerance test, will be improved in participants with new onset T1D who are treated with Abatacept after Rituximab-pvvr compared to those treated with Rituximab-pvvr and placebo 24 months after enrollment. Secondary outcomes include: the safety and tolerability of these regimens; the impact on additional metabolic measures, including changes of either study arm relative to historical controls, insulin use and hemoglobin A1c levels, and effects of drug therapy on responses to a neoantigen (Keyhole limpet hemocyanin (KLH) immunization). In addition, other metabolic and immunologic measures will be done as exploratory studies.
