Results of a Phase 1 Trial of Treg Adoptive Cell Transfer (TRACT) in De Novo Living Donor Kidney Transplant Recipients

Transcription

1 Results of a Phase 1 Trial of Treg Adoptive Cell Transfer (TRACT) in De Novo Living Donor Kidney Transplant Recipients A Skaro, A LeFever, J Mathew, L Gallon, J Hie, C Hansen, D Stare, G Johnson, J Leventhal June 13, 2016 ATC Boston MA

2 As we understand immune regulation, immunosuppression is evolving Corticosteroids Azathioprine CNIs PAST Induction Therapy (Lymphodepletion) Maintenance Rx CsA, FK MMF, mtor Co-stim. blockade PRESENT Drug-free donorspecific tolerance Therapeutic cell transfer FUTURE

3 Cell Therapies being considered for Tolerance Induction HSC to induce chimerism HSC to induce immunomodulation Regulatory T cells Dendritic cells (DC) Mesenchymal Stem Cells (MSC) Apoptotic Cell Delivery (ECDI, ECP) Future possibilities Combination of cell types (HSC + Treg) Single vs multiple infusions

4 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 Wood KJ and Sakaguchi S. Nat Rev Immunol Mar;3(3):

5 Tregs in transplantation: clinical evidence Higher circulating numbers of Tregs in tolerant kidney transplant recipients Increased numbers of Tregs in tolerant liver transplant recipients Improved outcomes in stem cell transplant patients receiving infusion of expanded Tregs Sagoo P, Perucha E, Sawitzki B, et al. Development of a cross-platform biomarker signature to detect renal transplant tolerance in humans. J Clin Invest 2010; 120:1848. Wood KJ, Regulatory T. cells in transplantation. Transplant Proc 2011; 43: Leventhal JR, Mathew JM, Salomon DR, et al. Am J Transplant Jan;16(1): Nonchimeric HLA-Identical Renal Transplant Tolerance: Regulatory Immunophenotypic/Genomic Biomarkers Sawitzki B, Brunstein C, Meisel C, et al. Prevention of graft-versus-host disease by adoptive T regulatory therapy is associated with active repression of peripheral blood Toll-like receptor 5 mrna expression. Biol Blood Marrow Transplant Feb;20(2):

6 Lymphodepletion maximizes efficacy of Treg therapy % Graft Survival No ntreg TGF-β/IL-2 ntreg RA/TGF-β/IL-2 ntreg TSA/RA/TGF-β/IL-2 ntreg Days Post-Transplantation 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

7 A PHASE 1 TRIAL OF 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). Investigating whether TRACT leads to transplant rejection/allosensitization and/or nonspecific immunosuppression Performing limited immune monitoring. Methodology: dose escalation of expanded autologous ntregs in experimental arm (0.5, 1, 5 & x10 9 cells/subject, n=3 in each tier) Primary Outcome Measure: Patient and Graft 1year

8 Inclusion Criteria Patients males or females age years. No prior organ transplant. Patients who are single-organ recipients (kidney only). Women of childbearing potential must have a negative serum pregnancy test and agree to use a medically acceptable method of contraception throughout the treatment period. Recipient is able to understand the consent form and give written informed consent.

9 Exclusion Criteria 1. Known sensitivity or contraindication to Sirolimus, tacrolimus or MMF. 2. Patient with significant or active infection. 3. Patients with a positive flow cytometric crossmatch using donor lymphocytes and recipient serum. 4. Patients with PRA >20%. 5. Patients with current or historic donor specific antibodies. 6. Body Mass Index (BMI) of < 18 or > Patients who are pregnant or nursing mothers. 8. Patients whose life expectancy is severely limited by diseases other than renal disease. 9. Ongoing active substance abuse, drug or alcohol. 10. Major ongoing psychiatric illness or recent history of noncompliance. 11. Significant cardiovascular disease (e.g.): Significant non-correctable coronary artery disease; Ejection fraction below 30%; History of recent myocardial infarction. 12. Malignancy within 3 years, excluding non-melanoma skin cancers. 13. Serologic evidence of infection with HIV or HBVsAg positive. 14. Patients with a screening/baseline total white blood cell count < 4,000/mm3; platelet count < 100,000/mm3; triglyceride > 400 mg/dl; total cholesterol > 300 mg/dl. 15. Investigational drug within 30 days prior to transplant surgery. 14. Anti-T cell therapy within 30 days prior to transplant surgery.

10 Summary of Enrolled Subjects Subject Subject Gender Age at Race Cause of ESRD # Initials Transplant 1 ECW Male 52y 1m Black HTN/FSGS 2 L-N Female 28y 9m White FSGS 3 A-O Male 47y 8m Hispanic/Latino PCKD 4 J-R Male 30y 3m Hispanic/Latino Membranous Nephropathy 5 JTM Male 53y 0m White HTN 6 V-P Female 24y 6m Native Lupus Hawaiian / Pacific Islander 7 KMG Male 37y 2m White IgA Nephropathy 8 K-G Male 62y 3m White PCKD 9 B-G Female 57y 7m White PCKD PCKD polycystic kidney disease HTN hypertension FSGS focal segmental glomerulosclerosis

11 Clinical Protocol 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

12 Isolation and Manufacture of Autologous Polyclonal Tregs 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

13 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 10 8 cells >50% suppression at a 1:2 Treg:Teffector cell ratio in a mixed lymphocyte reaction

14 Inhibition of Recipient s MLR by Expanded Tregs Inhibition by Tregs 100% 80% Day 0 Day 14 Day 21 60% 40% 20% P < % 1:2 1:4 1:8 1:16 1:32 1:64 Treg : Responder Ratio In Process Testing = Day 14

15 CD3 + CD4 + per μl blood Kinetics of CD3 + CD4 + cells post Treg infusion 0.5x10 9 Tregs 6.8x10 6 /KG 1x10 9 Tregs 15x10 6 /KG 5x10 9 Tregs 50x10 6 /KG Pt. # 1 Pt. # 2 Pt. # 3 Pt. # 4 Pt. # 5 Pt. # 6 Pt. # 7 Pt. # 8 Pt. # 9 0 Pre 1m 3m 6m 9m 12m Months after Transplant

16 Fold Change from Pre-Tx in % of CD4 + CD127 - CD25 high FoxP3 + Cells Increased circulating Tregs post Treg infusion TRACT 0.5x10 9 Tregs 6.8x10 6 /KG 1x10 9 Tregs 15x10 6 /KG Pt. #1 Pt. #2 Pt. #3 Pt. #4 Pt. #5 Pt. #6 10 5x10 9 Tregs 50x10 6 /KG Pt. #7 Pt. #8 Pt. #9 5 0 Pre 3m 6m 9m 12m

17 Current Status of Enrolled Recipients Subject # Initials Transplant Date Treg infusion Date Cell # Administered (10 9 ) 3m biopsy 3m DSA 1yr biopsy 1yr DSA 1 ECW 7/10/14 9/8/ NR - NR + NO 2 L-N 8/7/14 10/6/ NR - NR - NO 3 A-O 8/29/14 10/28/ NR - NR - NO 4 J-R 9/22/14 11/21/ NR - NR - NO 5 JTM 12/4/14 2/2/ NR - NR - NO 6 V-P 1/8/15 3/9/ NR - NR - NO 7 KMG 2/2/2015 4/3/ NR - NR - NO Graft loss 8 K-G 3/27/2015 5/26/ NR - SCR C4d + + NO 9 B-G 4/23/2015 6/22/ NR - NR - NO *NR= no rejection on biopsy *SCR=subclinical rejection

18 Summary & Conclusions Efficient expansion of Tregs from cryopreserved leukopheresis product from all recipients met release criteria No infusion related serious adverse events (5 x 10 9 poly Tregs are safe) 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 Data support the design and initiation of a Phase 2 trial FDA approval for Phase 2 trial secured

19 Acknowledgements Woman s Board of Northwestern Memorial Hospital John & Lillian Mathews Regenerative Medicine Endowment Miltenyi BioTec National Kidney Foundation of Illinois TRACT Therapeutics Inc. Jessica Heinrichs

20 Thank you

21 Questions? Results of Phase 1 Trial of Treg Adoptive Cell Transfer in Living Donor Kidney Transplant Recipients

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23 FOXP3 Expression in Expanded Tregs SS CD25-PC7 CD127-PE FS CD4-ECD FOXP3 + Cells in ungated sample 71.1 ± 12.3% (n=7) FOXP3-PC5