Treg Therapy in Subclinical Inflammation in Kidney Transplantation

Inflammation occurs when the body's defense system recognizes a foreign object (such as a
transplanted kidney), and responds by sending white blood cells to attack the foreign object.
These cells and the substances they produce can damage the transplanted kidney. There is
currently no standard treatment for inflammation in the kidney; some transplant centers do
not treat inflammation at all. Rejection is a more severe form of inflammation and injury.
Both inflammation and rejection are diagnosed by looking at a piece of kidney (a kidney
biopsy) under a microscope. Kidneys that have inflammation and/or rejection do not work as
well or last as long as kidneys without injury.

People who have a transplant take immunosuppressive drugs (IS) to prevent inflammation and
rejection. Although kidney transplant recipients usually do well in the first five years
after transplant, transplant researchers are interested in finding ways to prevent
inflammation and rejection without IS, or with lower doses of IS in order to avoid side
effects.

While some white blood cells cause inflammation, other types of white blood cells, called T
regulatory cells (Tregs), can control inflammation. Tregs may have an important role in
controlling or preventing inflammation and rejection. A person's Tregs can be grown in the
laboratory to increase their number (polyTreg). These Tregs can be given back through a
needle placed in a vein (IV). Researchers can expose a transplant recipient's Tregs to the
donor's cells, which results in Tregs that recognize the donor. These are called donor
reactive Tregs (darTreg). Both polyTregs and darTreg, when given to the recipient, might
reduce inflammation in the transplanted kidney. However, this effect has not yet been shown.
The darTregs are thought to be more effective because they might be able to help the body
specifically recognize and accept the donated kidney. This is one of the first clinical
trials using darTregs.

One of the IS drugs used in kidney transplant is Everolimus. Everolimus has been shown to
help Tregs survive better than other types of IS drugs.

This is a randomized open‐label trial to determine the safety and efficacy of a single dose
of autologous polyTregs or darTregs in renal transplant recipients with subclinical
inflammation (SCI) in the 6 month post‐transplant allograft protocol biopsy compared to
control patients treated with CNI‐based immunosuppression. The efficacy of the Treg therapy
will be assessed by the reduction of graft inflammation on biopsies performed at 7 months
after study group allocation compared to the eligibility biopsy.

Inclusion Criteria:

Individuals who meet all of the following criteria are eligible for enrollment as study
participants:

1. Subject must be able to understand and provide informed consent;

2. Age ≥18 years of age at the time of study entry

3. Recipients of non- Human Leukocyte Antigen (HLA) identical living renal transplants;

4. Living donor able and willing to have 100 ml blood draw for Treg manufacture (darTreg
group only);

5. Protocol renal allograft biopsy at 5 months (± 8 weeks) after transplantation with
Banff i1 and/or ti1 with concomitant t scores t0, t1,t2 or t3; Banff i2 and/or ti2
with concomitant t scores t0 or t1; and without v > 0, [ptc + g] ≥2, C4d >1 (by
immunofluorescence, IF), or C4d > 0 (by immunohistochemistry, IHC); confirmed by
central pathologist. Subjects must not be treated for pathologic criteria (e.g.
steroids).

6. Estimated glomerular filtration rate (eGFR) ≥35 ml/min at the time of study entry;

7. Maintenance immunosuppression consisting of tacrolimus, MMF/MPA (≥1000 mg/720 mg
daily) ± prednisone (≤10 mg/day);

8. Positive Epstein-Barr Virus (EBV) serology at the time of study entry;

9. Current immunizations including TdAP, hepatitis B, pneumococcal and seasonal influenza
vaccines at the time of study entry, completed prior to enrollment and no less than 14
days prior to planned manufacturing collection.

10. Documented Hepatitis B (HB) serologies must be:

1. Positive HB surface antibody, negative HB core antibody and negative HB surface
antigen for recipients immune to hepatitis B

2. Negative HB surface antibody, negative HB core antibody and negative HB surface
antigen for non-immune/ HBV naïve recipients provided donor had negative HB core
antibody and negative HB surface antigen at the time of donation.

11. Negative TB test (PPD, interferon-gamma release assay, ELISPOT testing) within 1 year
prior to enrollment. Subjects with a history of TB (positive TB test without active
infection) must have completed one of the latent TB infection treatment regimens
endorsed by the CDC (Division of TB Elimination, 2016). Alternative regimens for
latent TB infection eradication will be adjudicated by the site's infectious disease
specialist.

12. Women subjects of childbearing potential must have reviewed the Mycophenolate
Mycophenolate Risk Evaluation and Mitigation Strategy (REMS) and have a negative
pregnancy test upon study entry
(Reference:https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPati
entsandProviders/ucm318880.htm);

13. Female subjects with child-bearing potential, must agree to use FDA approved methods
of birth control for the duration of the study; subjects must consult with their
physician and determine the most suitable method(s) that are greater than 80%
effective (http://www.fda.gov/birthcontrol).

Treg Infusion Inclusion Criteria:

1. Individuals randomized to the polyTreg and darTreg groups who continue to meet all of
the enrollment criteria.

mTOR Conversion Inclusion Criteria:

Individuals who meet all of these criteria are eligible for mTOR conversion:

1. Received either polyTreg or darTregs infusion;

2. Inflammatory load on 2 week post-infusion biopsy has decreased by ≥50% relative to the
baseline biopsy, confirmed by central pathologist.

Exclusion Criteria:

Individuals who meet any of these criteria are not eligible for enrollment as study
participants:

1. Inability or unwillingness of a participant to give written informed consent or comply
with study protocol;

2. History of malignancy; except adequately treated basal cell carcinoma;

3. History of graft loss from acute rejection within 1 year after any previous
transplant;

4. History of transplant renal artery stenosis;

5. History of cellular rejection prior to enrollment that did not respond to steroids
and/or subsequent creatinine after treatment for rejection greater than 15% above
baseline;

6. Known hypersensitivity to mTOR inhibitors or contraindication to everolimus (including
history of wound healing complications);

7. Any chronic illness requiring uninterrupted anti-coagulation after kidney
transplantation;

8. HLA-DR matched to donor at both loci;

9. Post-transplant DSA >5000 MFI or post-transplant treatment with IVIg for DSA. Enrolled
subjects with post-transplant DSA >2000 MFI will not be eligible for mTOR conversion.

10. Positive HIV 1 or HIV 2 serology prior to transplantation;

11. Positive Hepatitis C virus (HCV) Ab serology or positive HBSAg prior to
transplantation;

12. Proteinuria with urine pr/cr > 0.5 g/g;

13. Any condition requiring chronic use of corticosteroids >10mg/day at the time of study
entry;

14. Subjects requiring treatment for pathologic findings on study eligibility biopsy (see
inclusion 5).

15. Active infection at the time of study entry;

16. History of active TB or latent TB without adequate treatment (see inclusion 11).

17. Serum BK virus >1,000 copies/ml by Polymerase Chain Reaction (PCR) at the time of
study entry;

18. Hematocrit <27%; White Blood Cell (WBC) count < 3,000/μL; Absolute Neutrophil Count
(ANC) < 1,500/μL; lymphocyte count <800/μL; platelet count <100,000/μL at the time of
study entry;

19. Participation in any other studies with investigational drugs or regimens in the
preceding year;

20. Any condition or prior treatment which, in the opinion of the investigator, precludes
study participation.

21. Unable to provide adequate biopsy specimen (paraffin embedded formalin fixed) from
eligibility biopsy (3-7 months post -transplant) for quantitative analysis.

Treg Infusion Exclusion Criteria:

Individuals randomized to polyTreg and darTreg groups who meet any of these criteria are
not eligible for Treg infusion:

1. Received any vaccination within 14 days prior to blood collection for Treg
manufacture;

2. Unacceptable Treg product;

3. Positive pregnancy test for women of child bearing potential.

mTOR Conversion Exclusion Criteria:

1. Post-transplant Donor-Specific Antibodies (DSA) >2000 mean florescence intensity (MFI).