1. What is the best technique for haploidentical BMT
What is the best technique for haploidentical BMT?: ex- vivo cell depletion Dr Mary Slatter CBMTG 2018 ANNUAL MEETING

2. No financial disclosures

3. HSCT: Which Donor? HLA identical sibling
Other family member - match/1Ag mismatch
Matched unrelated donor
Mismatched
– unrelated
- haploidentical parent 3

4. HLA-haploidentical stem cell transplantation
Haploidentical HSCT Obstacles
Graft versus host disease
Rejection
Delayed recovery of adaptive immunity
Various methods of T cell depletion
Soybean lectin aggluttination & sheep RBC rosetting
In-vitro Campath 1-M
CD34+ stem cell selection
CD3/CD19 depletion
Replete marrow with post infusion cyclophosphamide
CD45RA depletion
CD3 TCRαβ/CD19 depletion

5. Primary Immunodeficiencies
Intrinsic defects →infection, autoimmunity, immune dysregulation
T cells, B cells, Phagocytic cells
Severe Combined Immunodeficiency (SCID)
Severe (<1 year)
Combined T+B cells
Viral gut and lung infection, Pneumocystis, Candida
Failure to thrive
Other PID
T cell deficiencies, Wiskott Aldrich syndrome, CD40 Ligand deficiency
Haemophagocytic
Lymphoproliferative
Phagocytic
Intractable colitis/Immune dysregulation
Innate
Infection
Malignancy
Auto-inflammation
Auto-immunity
Allergy

6. Newcastle HSCT for PID/AID – survival with time
10 year survival
19/41 46%
110/156 71%
220/267 82%
91%
Number
Time in 3 year blocks

7. Non-SCID PID and HLA-matching, 1990-2006
10 years
Survival rate
783 patients
Geno : 72%
MUD : 64%
Pheno : 57%
mmRel : 40%
Gennery A.R., Slatter M. et al. Transplantation of Haematopoietic Stem Cells and Long Term Survival for Primary Immunodeficiencies in Europe: entering a new century, do we do better? J Allergy Clin Immunol (2010)
P=0.0002 5 7

8. Long-term immune reconstitution after anti-CD52-treated or anti-CD34 treated
hematopoietic stem cell transplantation for severe T-lymphocyte immunodeficiency
anti-CD52–treated HSCs
superior donor stem cell engraftment
better complete donor myeloid and B-lymphocyte engraftment
Slatter MA, et al. J Allergy Clin Immunol. 2008;121:361-7

9. Alloreactive NK cells facilitate engraftment
Progenitor cells/ dendritic cells
→ CD3/CD19-Depleted Transplants

10. CD3/CD19-Depleted Transplants
Slatter M. J Allergy Clin Immunol Jun;131(6):1705-8
CD3/CD19 depleted grafts engraft more quickly than CD34+ selected grafts
Comparing 2 virally infected patients who received HSCT for severe T-lymphocyte immunodeficiencies with anti-CD34–stem cell selected marrow, with 3 who received anti-CD3/CD19–depleted PBSC
T cells appeared much
earlier in the CD3/CD19
depleted recipients than in the
patients who received CD34+
selected stem cells, which lead
to much earlier viral clearance
and successful outcomes

11. HLA-haploidentical stem cell transplantation after removal of CD3+ TCR αβ+ and B cells
Permits transfer of high numbers CD34+ cells, but also mature donor NK cells and TCR γδ+ T cells
γδ+ are non-alloreactive lymphocytes with important anti- infectious and anti-tumour properties
- αβ+ major GVHD effectors
Organic iron bead attached to antibody, run through magnetic column.

12. 70 children
MAC + ATG No post HSCT GVHD prophylaxis
2 graft failure Skin only aGVHD I=II 30%
4 died (NRM 5%) relapsed
Median follow up 46 months 71% survival – equivalent MSD/MUD

13. HLA-haploidentical stem cell transplantation after removal of αβ+ T and B cells in children with nonmalignant disorders Alice Bertina, Pietro Merli et al. Blood, 2014, Vol 124, No
23 patients Age yrs (Median 3.3)
SCID 8
Fanconi 4
SAA 4
IPEX 1
CAMT 1
SDS 1
HLH 1
DOCK 8 1
Osteopetrosis 1
Thalassemia 1
Donor – Father 8, Mother 15
NK cell B haplotype
2 had plerixafor + G-CSF mobilisation
Conditioning
ATG Fresenius 4mg/kg D-5 to D-3
RTX 200mg/m2 D-1
Bu/flu/TT 3
Treo/flu/TT 4
Treo/flu 8
Flu/Cy/TBI 8
Median CD x 106/kg
CD3+ αβ+ 4.0 x 104/kg

14. HLA-haploidentical stem cell transplantation after removal of αβ+ T and B cells in children with nonmalignant disorders Alice Bertina, Pietro Merli et al. Blood, 2014, Vol 124, No
4 rejections
SAA 2, Thalassemia, Osteopetrosis
→ reTx same donor 2
other parent 2
3 GrI-II aGVHD skin
No cGVHD
2 deaths
SAA CMV D+120
CAMT Adeno D+116
Median follow up 18 months
9 viral reactivations
No EBV-PTLD

15. All retransplanted-1 died CMV
BBMT 21 (2015)
37 median age 2.6 yr
MUD 27
MMRD 10
Median FU 15m – 2 deaths
Graft failure 10 (27%)
All retransplanted-1 died CMV
1 death NBS - relapse non-Hodgkin lymphoma
aGVHD 8 (22%)- 7 Grade II
-1 Grade IV (no conditioning)
CMV 16 (46%)

16. Haploidentical paternal TCR alpha beta and CD19 depleted stem cell transplant for Wiskott Aldrich syndrome with disseminated cytomegalovirus Infection Gaurav Kharya et al J Allergy Clin Immunol (5):1199 Patient 1
One year old boy with WAS (c.7781G>A intron 8)
disseminated CMV infection requiring ventilation for CMV pneumonitis aged 4 months
haploidentical paternal HSCT in absence of suitable MSD/MUD
pre-treated with ganciclovir
on admission CMV PCR negative - started on prophylactic foscarnet

17. Treatment Conditioning rabbit ATG (15mg/kg total day-12 till day-9),
Busulfan iv AUC targeted to 80mg/l x h
Fludarabine (40mg/m2 x 4)
Thiotepa (5mg/kg x 3)
GVHD Prophylaxis
CsA + MMF
Stem cell mobilization using G-CSF and peripheral blood stem cells were harvested
Dose Cells/kg
Log reduction
TNC ^8
CD34+ ^6
CD19
3.1 10^4
3.7
TCR αβ
1.3 10^4
4.5
TCR γδ
3.2 10^7

18. Results
Polymorphonuclear cell and platelet engraftment were seen on D+15 and D+17 respectively
Chimerism on day +16 showed 100% donor cells
No aGvHD or cGvHD
CMV reactivation, treated with therapeutic doses of foscarnet.
CMV became undetectable at day +36 post transplant
Patient is alive and well, 5.5 years post transplant, stopped IVIG, with good immune reconstitution and 100% donor chimerism

19. 25 patients
1 rejection (SCN)
11 aGVHD skin
Median FU 20.8m
21/25 Alive and cured (84%)

20. Survival according to CMV/Adenoviral infection status on Day 0

21. Great North Children’s Hospital 38 patients
36 conditioned. 2 unconditioned SCID
Variety PID – CGD 5, MHC II 6, WAS 3, DOCK 8 4, Omenn’s 3, Artemis 2, CγC 5
1 each: STAT 3 GOF (mMUD), Undefined CID , IRF 8 (mMUD), Periodic fever, IKBαGOF, AI enteropathy, CD40L , HLH, DNA Ligase IV, undefined SCID
3 x 2nd transplants for resistant GvHD*
2 x 2nd transplants for secondary graft failure
*Haploidentical TCRαβ and CD19 Depleted second Stem Cell Transplant for steroid resistant acute skin graft versus host disease. Mary Slatter et al. J Allergy Clin Immunol (2):
33/38 alive (87%) 1 severe encephalopathy
No rejections
Chimerism - unconditioned mixed
- conditioned 27/ %
15 skin GvHD I/II (1 late gut)
4 TMA (Artemis 2, DNA Ligase IV, DOCK 8)
26 viral infection/reactivation in blood
13 Bellicum study

22. Phase I/II Study of CaspaCide T Cells from an HLA-partially Matched Family Donor After Negative Selection of TCR αβ+T Cells in Pediatric Patients Affected by Hematological Disorders ClinicalTrials.gov identifier: NCT

23. Rationale
Addition of mature T cells which exhibit a broad repertoire of T cell immunity against viral antigens, as well as against cancer antigens, might provide a clinical benefit.
Expected side effect of the presence of T cells is the potential occurrence of aGVHD.
The use of a suicide gene switch which would trigger the initiation of the apoptosis (killing) of the alloreactive T cells by the infusion of dimerizer drug (Rimiducid) would represent the potential means for restoring early immunity with a built in “safety switch” against GVHD side effects.

25. BPX-501: Donor-derived CaspaCIDe T-cells
From normal donor leukapheresis - GMP facilities US / Europe
Activated and expanded in culture, transduced with the iC9 suicide gene and selected for CD19+ cells
Cryopreserved and stored in liquid nitrogen
Maintain characteristics of normal T cells
Broad T-cell repertoire
Antiviral and antigen specific activity

26. Patient demographics (46)
No. %
Media n
Range
 Male 29 63
 Female 17 37
Patient age, years
1.2
0.1-15
Disease type
Severe Combined Immunodeficiency
Wiskott-Aldrich Syndrome 9
19.6
Hemophagocytic Lymphohistiocytosis 5
10.9
Chronic Granulomatous Disease 3
6.5
Combined Immunodeficiency
MHC-II Deficiency
DOCK8 Deficiency 2
4.3
OTHERS 4
8.7
Median follow-up (months)
18.7
European centers experience on PIDs patients enrolled in the study

27. Donor and transplant characteristics%
Median
Range
Type of donor
Father 21 46
Mother 24 52
Sister 1 2
Donor age, years 31
22-49
No. of cells infused
CD34+ × 106 per kg
23.3
7.3-57
TCR-αβ+CD3+ × 104 per kg 4
0-9.4
TCR-γδ+CD3+ × 106 per kg
21.5   
NK cells × 106 per kg
40.6   
No. %
Conditioning regimen
Busulfan-thiotepa-fludarabine 13 28
Treosulfan-thiotepa-fludarabine 21 46
Treosulfan-fludarabine 12 26
Donor/recipient combinations
Female donor/male recipient
Other combinations 34 74
Median time to BPX501 infusion 15 days (11-55)
European centers experience on PIDs patients enrolled in the study

28. Neutrophil and platelet recovery
European centers experience on PIDs patients enrolled in the study

29. Cumulative incidence of GvHD
Acute GvHD
No patients developed chronic GvHD
Number of patients
European centers experience on PIDs patients enrolled in the study

30. Pre-Rimiducid infusion Post-Rimiducid infusion
Rimiducid use
Patient ID
aGVHD, grade
Response
Skin, II
Complete
Skin+UGI,II
Pre-Rimiducid infusion
Post-Rimiducid infusion
European centers experience on PIDs patients enrolled in the study

31. Transplant-related mortality
A CID patient died due to pulmonary hemorrhage caused by aspergillus infection, which was already existing before HSCT.
A WAS patient died due to leukoencephalopathy of unknown origin.
European centers experience on PIDs patients enrolled in the study

32. Overall and disease-free survival
European centers experience on PIDs patients enrolled in the study

33. Event-free survival
Death, primary and secondary graft failure are considered as events
European centers experience on PIDs patients enrolled in the study

34. T-cell immune reconstitution
Median CD3 a 1 m 153 ( )
Median CD3 a 3 m 453 ( )
European centers experience on PIDs patients enrolled in the study

35. BPX501 expansion and persistence
European centers experience on PIDs patients enrolled in the study

36. Immune reconstitution – impact of CMV reactivation
(defined as >1.000 DNA copies/mL)
Num-
ber
Percentage
YES
17/44
39% NO
27/44
61%
European centers experience on PIDs patients enrolled in the study

37. Conclusions CD3 TCRα/β/CD19 depletion is safe
Outcome is as good as MUD/MSD
Good engraftment for all types of PID
Low incidence GvHD of low grade
No post HSCT GVHD prophylaxis
Viral clearance
A possible treatment for resistant GVHD
New strategies for further improvement
Infusion of a titrated number of BPX-501 cells is safe and well tolerated
BPX-501 cells infused expand in vivo and persist over time, contributing to faster adaptive immune recovery
CMV reactivation is the main driver of BPX-501 cell expansion.

39. The debate CD3 TCRα/β/CD19 depletion Post transplant Cyclophosphamide
Everyone has a donor
Cheaper than MUD
Quick to organise
CD3 TCRα/β/CD19 depletion
Post transplant Cyclophosphamide

40. Acknowledgements
Andy Gennery
Ravi Shah
Andrew Cant
Mario Abinun
Terry Flood
Sophie Hambleton
Stephen Owens
Marieke Emonts
Eleri Williams
Emma Lim
Rod Skinner
Geoff Shenton
Alex Battersby
Ward 3 team BMT liaison team Laboratory staff Pharmacy Dieticians Social workers Psychologists GNCH RU Patients and families