The CIT consortium conducted a total of 9 studies across North America (CIT02 through CIT08) and the Nordic region (CIT01). CIT08 was a long-term follow-up study for interested participants at the North American sites. The target population was individuals with type 1 diabetes, normal kidney function, and intractable hypoglycemia. All studies treated participants with up to 3 separate infusions of islets. The focus of CIT04 was to evaluate the effectiveness of an IS regimen that included belatacept. For immunosuppression, CIT04 subjects received belatacept, basiliximab, and mycophenolate mofetil in an open-label fashion.

CIT-04: The primary objective of this protocol is to assess the safety and efficacy of an immunosuppressive medication consisting of a monoclonal antibody IL-2 receptor blocker (basiliximab), belatacept and mycophenolate mofetil in islet transplantation. The primary efficacy measure will be the proportion of insulin-independent subjects at day 75 (+/- 5 days) following the first isletL transplant. The secondary objective is to assess islet graft function in the absence of calcineurin inhibitor drugs, with determination of success being the proportion of patients attaining and maintaining insulin independence after receiving a maximum of 3 islet transplants.

CIT-08: The primary objective is to provide extended follow-up for safety and efficacy and to support continued islet graft function to participants previously enrolled in CIT02, CIT03, CIT04, CIT05, CIT06, or CIT07.

The primary outcome measure was the proportion of participants with insulin independence at 75 days following the first transplant infusion. Secondary outcome measures included reduction in insulin requirements, mean amplitude of glycemic excursions, HbA1c levels, incidence of immune sensitization (defined by detected anti-HLA antibodies not present prior to transplantation), and quality of life.

Individuals who met the following criteria were eligible for enrollment:

• Clinical history compatible with type 1 diabetes with onset at less than 40 years of age, insulin dependence for at least 5 years at study entry, and a sum of age and insulin dependent diabetes duration of at least 28
• Absent stimulated C-peptide (less than 0.3 ng/mL) 60 and 90 minutes post-mixed-meal tolerance test
• Involvement of intensive diabetes management, defined as: (1) Self-monitoring of glucose values no less than a mean of three times each day averaged over each week; (2) Administration of three or more insulin injections each day or insulin pump therapy; (3) Under the direction of an endocrinologist, diabetologist, or diabetes specialist with at least three evaluations during the 12 months prior to study enrollment
• At least one episode of severe hypoglycemia in the 12 months prior to study enrollment
• Reduced awareness of hypoglycemia.

Exclusion criteria are documented in the study protocol.

This study has been concluded, but results have not yet been published.