237-OR: Gastrin Improves Single Islet Transplant Outcomes

Abstract

Background: Multiple allogenic islet transplants (ITs) are usually required to supply adequate islet mass (~10,000 IEQ/kg) to induce insulin independence. Improving outcomes of a SINGLE islet transplant are needed. Gastrin is a gut hormone that is involved in normal fetal pancreas development. Evidence by our group and others have shown gastrin can support islet cell expansion/function and have anti-inflammatory and pro-angiogenesis effects. We compared outcomes of IT alone across 3 clinical trials using: Edmonton-based (ITA), T-cell depleting (TCD), and TCD immunosuppression with an investigational gastrin analogue (GAS). Methods: Between 2004-2022, a total of 31 evaluable T1D patients without a prior history of transplant received IT-alone under the ITA (n=17), TCD (n=7), and GAS (n=7) clinical trials. Participants in ITA and TCD were eligible to receive up to 3 ITs each. GAS participants received only a single IT and two 30-day courses of gastrin (SQ, BID) at the time of IT and again 6 months later. Immunosuppression included basiliximab or daclizumab + etanercept (ITA) and T-cell depletion (anti-thymoglobulin) + etanercept + anakinra (TCD and GAS). Results: Progressive improvements in engraftment were observed in the ITA, TCD, and GAS trials. Average insulin requirements were reduced by 18, 26, and 33 u/day. GAS subjects showed the most rapid reduction of 30.9 u/day (94%) in the first 2 weeks post-IT, compared to 17.5 u/day (67%) in TCD. Rates of subjects achieving insulin independence with a SINGLE islet transplant were 0, 15, and 57%. Subjects required an average of 3 ITs in ITA, 2 in TCD, and only one IT in GAS to achieve insulin independence. Average numbers of islets required to achieve insulin independence were 13,280, 8,433 and 4,837 IEQ/kg. Conclusion: Gastrin use in the peri-transplant period leads to rapid engraftment, larger magnitude of insulin reduction, and permitted achievement of insulin independence in more than half of subjects after a single islet transplant of less than half the normally targeted islet dose. Disclosure J.Hacker-stratton: None. C.Orr: None. K.Omori: None. M.Qi: None. E.Forouhar: None. M.El-shahawy: None. F.R.Kandeel: None. Funding National Institutes of Health (U24DK098085)