Conversion to Envarsus Post Kidney Transplant Protects Against BK Infection

The purpose of this study is to assess if the use of Envarsus in place of Tacrolimus-immediate release (IR) in rapid metabolizers post kidney transplant will reduce incidence of BK infection. Efficacy evaluations will include measurement of urine and serum BK values at specified time points and review of any biopsy for BK virus nephropathy. Incidence of rejection, graft failure, and graft dysfunction will also be measured at specified time points.

This will be a single center prospective case control study. The investigators expect 40% of patients will develop BK viruria, 20% BK viremia, 5% BK viral nephropathy (BKVN). Patients will be managed using standard of care for the investigator's center (thymoglobulin induction, tacrolimus/mycophenolate/prednisone). Target tacrolimus level is 8-12 ng/mL for the first 6 months post transplant and 6-9 ng/mL thereafter. BK urine/serum is monitored at 1, 3, 6, 9, 2 months post transplant. A population of 100 patients is calculated to show significant difference for p value \< 0.05.

Population:

Study Group: Post transplant patients (kidney transplant alone) with standard of care immunosuppression, no prior rejection, prior BK or opportunistic infection, and negative BK screening at post-transplant month 1, who have a tacrolimus concentration/dose of \< 1 and a steady state therapeutic level will be eligible. Patients who consent will be converted to Envarsus at 20% reduction in tacrolimus dose.

Control Group: Post transplant patients (kidney transplant alone performed between 10-2016 and time of enrollment) with standard of care immunosuppression, no prior rejection, prior BK or opportunistic infection, whom had a negative BK screening at post-transplant month 1 and tacrolimus concentration/dose of \< 1 at post-transplant month 1, and BK data available for months 2, 3, 6, 9,12 post transplant.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥18 years of age at the time of study entry
* Recipient of a deceased or living donor kidney transplantation
* Maintenance immunosuppression consisting of tacrolimus/ mycophenolate mofetil (MMF)/mycophenolic acid (MPA) (≥1000 mg/720 mg daily) ± prednisone (≤10 mg/day)
* Patient is less than or at 8 weeks post transplant with a negative serum BK Virus screen at 3-4 weeks post transplant
* Patient has a tacrolimus drug dose/concentration of \> 1 with therapeutic tacrolimus levels.
* Women of childbearing potential defined as all women physiologically capable of becoming pregnant, must have reviewed Mycophenolate Risk Evaluation and Mitigation Strategy (REMS) and have a negative pregnancy test upon study entry.
* Female (and male) subjects with reproductive potential must agree to use a highly effective method of birth control for the duration of the study. Please note that according to the US product information for MMF/MPA, two reliable forms of contraception must be used simultaneously unless female sterilization, male sterilization, post-menopausal status or total abstinence is the chosen method.

Exclusion Criteria:

* Inability or unwillingness of a patient to give written informed consent or comply with study protocol
* History of graft loss from acute rejection within 1 year after any previous kidney transplant
* History of previous liver, heart, pancreas, or lung transplant
* History of cellular rejection of current allograft prior to enrollment.
* Serum BK virus ≥500 copies/ml by polymerase chain reaction (PCR) at the time of study entry
* Female subjects who are pregnant or breast feeding
* Participation in any other studies with investigational drugs or regimens in the preceding year from the time of study entry
* Any condition or prior treatment which, in the opinion of the investigator, precludes study participation
* Patients requiring the use of azathioprine or a class of drugs that inhibit the mammalian target of rapamycin (mTOR inhibitors)
* Patients with active peptic ulcer disease