Long-term Follow-up of Kidney Transplant Recipients in the Spare-the-Nephron-Trial.

Transplantation 2016; [record in progress].

Aims
To analyse both retrospectively and prospectively collected data from an observational, non-interventional extension study in renal transplant recipients who completed the parent Spare-the-Nephron (STN) Kidney Transplant Study*.

Interventions
Data was analysed from the STN Kidney Transplant Study where participants were randomly assigned to either calcineurin inhibitor (CNI) withdrawal or CNI maintenance at between 30 and 180 days after transplantation.

Participants
128 kidney transplant recipients with a functioning graft at two years who completed the parent STN Kidney Transplant Study.

Outcomes
The primary outcome measured was renal function. Secondary outcomes measured included urinary protein excretion, incidence of biopsy-proven late acute rejection, blood pressure, and rates of subject death, graft loss, new onset diabetes,hyperlipidemia, antihypertensive drug usage, cardiovascular related event, cerebrovascular event and late treatment failure.

Follow-up
36 months

CET Conclusions
This paper reports longer term follow up of the "Spare the nephron" trial that has previously been published. Patients eligible for entry into this observational study continued on their current therapy at the end of the main trial if they still had a functioning graft. This report therefore does not represent a powered analysis for the primary outcome of renal function (estimated GFR). Only about half of the patients entered into this extension completed the desired follow up as the sponsor closed the study. Median follow up was approximately 5 years in each group. Patients in both groups did not show a significant increase or decrease in eGFR compared to their baseline. However, there was a significantly higher mean eGFR in the Sirolimus arm compared to the CNI arm for the few patients with 7 years of follow up (although not for those with 6 years of follow up). There were similar instances of acute rejection, graft loss and patient death in both arms. Caution should be exercised in the interpretation of these results.

Jadad score
2

Data analysis
Modified intention-to-treat analysis

Allocation concealment
Yes

Quality notes
Previously reported as *Weir MR, et al. Mycophenolate mofetil-based immunosuppression with sirolimus in renal transplantation: a randomized, controlled Spare-the-Nephron trial. Kidney Int. 2011;79:897–907.

Trial registration
None

Funding source
No funding received