1. Results of Phase 1 Trial of Treg Adoptive Cell Transfer in Living Donor Kidney Transplant Recipients
TRACT Therapeutics™

2. Regulatory CD4+CD25+FoxP3+ T cells
Derived from the thymus and/or peripheral tissues
Demonstrated to broadly control T cell reactivity
Control immune responsiveness to alloantigens
Contribute to operational tolerance in transplantation models
TRACT Therapeutics
Wood KJ and Sakaguchi S. Nat Rev Immunol Mar;3(3):

3. Lymphodepletion to reduce numbers of circulating effector T cells may be an important adjunct to the use of Tregs as a cellular therapy in organ transplantation….

4. TReg Adoptive Cell Transfer (TRACT) in Clinical Transplant Patients
Increased Regulatory T cells (Tregs) in the immune system have been associated with the elimination of rejection in transplantation by creating tolerance in the immune system
Human Tregs can be isolated and expanded to large numbers while maintaining purity and potency
Clinical trials of Tregs for GVHD, Inflammatory Bowel Disease, and Diabetes are underway
TRACT Therapeutics

5. PHASE 1 TRIAL TREG ADOPTIVE CELL TRANSFER (TRACT) IN LIVING DONOR KIDNEY TRANSPLANT RECIPIENTS
Design: Single center, open label, nonrandomized Objectives: Determine the safety of using expanded Treg Adoptive Cell Transfer (TRACT) Determine whether TRACT leads to transplant rejection/allosensitization and/or nonspecific immunosuppression Immune Monitoring
TRACT Therapeutics

6. PHASE 1 TRIAL TREG ADOPTIVE CELL TRANSFER (TRACT) IN LIVING DONOR KIDNEY TRANSPLANT RECIPIENTS
Methodology: dose escalation of expanded autologous nTregs in experimental arm (0.5, 1, and 5 x109 cells/subject , n=3 in each tier) Primary Outcome Measure: Patient and Graft 1year
TRACT Therapeutics

7. Clinical Protocol TRACT Therapeutics
Pretransplant collection of recipient lymphocytes via leukopheresis; cryopreservation of cells( 1 week - 1year Pretransplant)
Day 0: Living Donor Kidney Transplant: Alemtuzumab Induction, Tacrolimus and Mycophenolate based IS; conversion from Tac to Sirolimus Day +30
Initiate isolation and expansion of autologous Tregs; infusion of expanded cells Day +60; protocol biopsy at 3 months and 1 year post-Tx
TRACT Therapeutics

8. Isolation and Manufacture of Autologous Polyclonal Regulatory T cells
Leukopheresis of recipient pre-transplant
Immunomagnetic selection of Tregs (CD8,CD19 negative depletion, CD25 positive selection) from cryopreserved “raw product”
Ex vivo culture and expansion of Tregs
In process testing of expanded cells for phenotype, function, and sterility
TRACT Therapeutics

9. Release Criteria for Expanded Tregs
>70% cell viability
CD4+/CD25+ > 70%; CD8+.CD19+ <10%
endotoxin < 5 EU/kg
gram stain negative; aerobic, anaerobic and fungal sterility
mycoplasma negative
residual bead count <3,000 beads per 108 cells
>50% suppression at a 1:2 Treg:Teffector cell ratio in a mixed lymphocyte reaction
TRACT Therapeutics

10. Summary All expanded cell products met release criteria
 There were no infusion related serious adverse events
 No evidence of over immunosuppression (opportunistic infections)
 Post-infusion protocol biopsies at 3 months have been normal
 Serial immunophenotypic analysis of subjects shows a sustained increase in circulating Tregs following Treg infusion
TRACT Therapeutics

11. Conclusions
Expansion of sufficient numbers of functional polyclonal Tregs from a cryopreserved leukopheresis product is feasible
Infusion with polyclonally expanded Tregs up to 5x109 cells is safe
TRACT was associated with an increase in circulating numbers of Tregs in the immune system
Data supports the design and initiation of a Phase 2 trial
TRACT Therapeutics