Islet Cell Transplantation in Type 1 Diabetes: An Analysis of Efficacy Outcomes and Considerations for Trial Designs
07/2012
Journal Article
Authors:
Tiwari, J.L.;
Schneider, B.;
Barton, F.;
Anderson, S.A.
Secondary:
Am J Transplant
Volume:
12
Pagination:
1898-1907
URL:
http://www.ncbi.nlm.nih.gov/pubmed/22486926
Keywords:
Clinical efficacy; Clinical trials; islet transplantation; Kaplan–Meier survival analysis; sample size; Type 1 diabetes
Abstract:
To estimate treatment effect size and other parameters required for planning the designs and analyses of future phase 3 islet transplant trials, we analyzed key clinical and laboratory outcomes of 347 allogeneic islet transplant recipients, using data from the Collaborative Islet Transplant Registry (CITR). At 1 year, approximately 59% of all transplant recipients were free of severe hypoglycemic events and maintained hemoglobin A1c (HbA1c) level of ≤6.5%. The Kaplan-Meier (KM) survival analyses showed that 69%, 54% and 44% of these 1-year responders maintained this composite endpoint at 2, 3 and 4 years, respectively. Ninety-one percent of all recipients were free of severe hypoglycemic episodes at 1 year. Furthermore, the KM survival estimates showed that 91%, 85% and 80% of these subjects maintained this clinical benefit at 2, 3 and 4 years, respectively. These results can be very useful in developing framework for study designs, sample size estimates, and statistical analysis plans for future pivotal trials of islet cell transplantation in type 1 diabetes.
