New Modalities in Stem Cell Transplantation

Richard Champlin, M.D.

Major Innovations SCT-CT

• Nonmyeloablative Conditioning• Alternative Donors

– Cord Blood– Haploidentical Transplants

• Cell Therapy– T-cells– Chimeric Antigen Receptors– NK Cells

HSCT

DRL

RRL

RR D

DD

D

D

D

DD

Hematopoietic Stem Cell TransplantationPreparativeRegimen

Allogeneic hematopoietic is an effective, but toxic treatment for hematologic malignancies, associated with a high risk of morbidity and mortality (10->50%), restricting its use to young patients withoutcomorbidities

Goal of Conditioning Regimen

• Provide immune suppression to prevent rejection and create “space” for engraftment

• Eradicate the malignancy– Most effective drugs/radiation treatments

for hematologic malignancies also kill normal myeloid and lymphoid cells

– Kill malignant stem cells

BMT

Remission

Limit of Detection

High DoseChemoradiotherapy

Unmodified

T-cell depletionIdentical twin

Donor Lymphocyte Infusion

Time

Allogeneic BMT for CMLImportance of GVL

Graft-vs-Malignancy Allogeneic SCT

• High dose therapy and allogeneic SCT is an effective treatment for hematologic malignancies

• Much of the benefit of alloSCT is due to immune GVL effect; therefore maximally ablative therapy may not be needed.

• Lower dose nonmyeloablative preparative regimens are sufficient to prevent rejection.

• We hypothesized that a reduced intensity, nonmyeloablative allogeneic transplant could reduce toxicity and allow successful treatment of older patients and those with major comorbidities.

Nonablative and Reduced Intensity Regimens

Myelosuppression

FCRMF

BuCy

TBI/CyT

BuFF-TBI2Gy

Nonablative Reduced Intensity Ablative

Champlin et al 2000

HSCT +DLI

DTDNK

DRLRL

RRL R

R DBDsc

DT

DNK

DT

DTDT

Dsc

D

DT

DT

DscD

Complete ChimeraRecipient Donor Mixed Chimera

Nonmyeloablative TransplantPreparativeRegimen

R

AUC

Prob

abilit

y

800 1000 1200 1400 1600 1800

0.0

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0.4

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0.8

AUC

Prob

abilit

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800 1000 1200 1400 1600 1800

0.0

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800 1000 1200 1400 1600 1800

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AUC

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abilit

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800 1000 1200 1400 1600 1800

0.0

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1.0

Probability of Mucositis ≥ 3 Probability of GI Toxicity ≥ 3

Probability of Hepatic Toxicity ≥ 2 Probability of GVHD ≥ 2

Busulfan AUC Relative to Toxicity and aGVHD

Andersson et al 2002

Pathophysiology of Acute GVHD

APC=antigen-presenting cell; CTL=cytotoxic T lymphocyte; IFN=interferon; IL=interleukin; LPS=lipopolysaccharide; Mac=macrophage; NK=natural killer cell; TH=T-helper cell; TNF-α=tumor necrosis factor-alpha.

Days0 50 100

0.00

0.25

0.50

0.75

1.00

NMA

BUCY/FM

ACUTE

GVHD

HR 3.1 (CI= 1.3-7.2)

Grade 2-4 Acute GVHD

Nonablative BMT• Reduced toxicity• Reduced GVHD• Similar infections occur, but generally

respond to therapy

• Lower treatment related mortality• Can extend the use of HSCT to patients

up to 75 years of age

Comparisons Albative vs. RIC SCT• Lack of randomized controlled trials• Non-randomized comparisons always

confounded by different patient populations– Ablative- young, fit patients– RIC- Older patients with comorbidities

• Conclusions– RIC higher relapse, lower NRM, survival not

significantly different. • Can one develop effective anti-tumor

preparative regimens, with acceptable (less) toxicity?

Time(weeks)

Surv

ival P

robabili

ty

0 20 40 60 80 100 120

0.0

0.2

0.4

0.6

0.8

1.0

In remission, PB.blast=0Active Disease, PB.blast=0Active Disease, PB.blast>0

p<0.0001

Time(weeks)

Eve

nt-

free p

robabili

ty

0 20 40 60 80 100 120

0.0

0.2

0.4

0.6

0.8

1.0

In remission, PB.blast=0Active Disease, PB.blast=0Active Disease, PB.blast>0

p<0.0001

IV Bu-Flu Overall Survivaland Event Free Survival

Nonablative AlloSCT vs Chemo for Elderly AML

Opportunities for Cure in CML

Preparative Regimen

Imatinib Donor Lymphocyte Infusion

CM

L C

ell M

ass

Time

Survival

Ablative Allo-BMT in Indolent Lymphoma

van Besien et al. Blood. 1998;92:1832-1836. Years

Prob

abili

ty, %

5432100

20

40

60

80

100

6

SurvivalDFSTreatment-related mortalityRelapse

Rituximab Fludarabine 30 mg/m2 Rituximab375 mg/m2 Cyclophosphamide 750 mg/m2 1000

mg/m2

-13 -6 -5 -4 -3 0 +1 +8

ASCT

Days

NON-MYELOABLATIVE ALLOGENEIC SCT

Conditioning Regimen

•ATG 15 mg/kg daily, was given days –5 to –3 for mismatched or unrelated SCT•Tacrolimus and methotrexate were used for GVHD prophylaxis

FCR allo SCT for Low Grade Lymphoma

Khouri et al Blood 2008

Rituximab: Mechanism of Action

Anderson DR, et al. Biochem Soc Trans. 1997;25:705-708, Clynes RA, et al. Nat Med. 2000;6:443-446.

CD20

CELLLYSIS

FcγRI, FcγRII, or FcγRIII

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

Macrophage,Monocyte,

or Natural Killer Cell

Dendritic Cell

T Cells

Tumor Antigen

RituximabAntigen Presentation and Cross-Priming

Tumor Cell

FcR

Efficacy of Nonablative HSCT

Highly Effective(better than ablative)

Dose Intensity Important

LGL, CLL CML

Mantle cell lymphoma AML /MDS

Myeloma (tandem)? LCL, Hodgkin’s disease

Renal Cell, OvarianBreast CA-Promising

ALL

ATG with RIC SCTCIBMTR-Soiffer Blood 2011

• Compare T-replete transplants with no ATG, ATG, Alemtuzumab

• ATG- assoc with decreased cGVHD, increased relapse, worse PFS and survival

• Alemtuzumab- assoc with decreased acute and cGVHD, increased relapse, no change in survival

Best Available Donor

MD Anderson Cord Blood BankElizabeth J. Shpall MD

Cord Blood Transplantation• Rich source of stem cells• ~50,000 units banked, immediately available

for transplantation• Immunologically immature- less prone to

produce GVHD• Less risk of transmitting infection• Can successfully transplant across HLA

mismatch• Major concern- low stem cell dose, longer

time to engraftment- may be overcome by ex vivo expansion

• Results comparable to MUD BMTs

Mesenchymal Stem Cells (MSC)

• MSC are a stromal componentof the hematopoietic microenvironment.

• They provide cellular and extracellular components of the stem cell “niche”.

• When isolated and used in vitroin combination with cytokines, MSC markedly increase the expansion of CB hematopoietic progenitors.

Day 14 hematopoietic output from liquid culture of CD133+ (solid bar) vs.co-culture of non-selected CB cells with MSC (striped bar)

x13 x25 x7 x14 x200 x44

Co-culture with MSC significantly enhancesex vivo expansion of CB cells

Robinson et al. Bone Marrow Transplantati

Fold increase

Median time to engraftment (range)

Neutrophil (>500/µl) 15 days (range 9-42)Platelet (>20,000/µl) 40 days (range 13-62)

Cumulative Incidence of Engraftment

Neutrophil (>500/µl) 97% (n=31)Platelet (>20,000/µl) 81% (n=26)

- One patient died before engraftment

MSC-CB Expansion Trial Engraftment Data

de Lima et al. Blood (ASH Annual Meeting Abstracts), 2010; 116: 362

Post Transplant Cyclophosphamide for Haploidentical Transplantation

NST for Haploidentical Transplantation

Luznick et al 2008

Cell Therapy +/- HSCT

36

T-cell Immune Response

T-Cell Activation and Proliferation

Chimeric antigen receptors (CARs)

vL

vH

CH1

CL

Antibody

Fab

vH vL

Chimeric antigen receptor

α βTCR-complex

γ ε ε δ ζ ζ

(Eshhar et al; PNAS 1993)

Chimeric Antigen Receptors

Cooper et al

Lysis

Lysisleukemia

DC

NK

DC

DC

NK

NK

Donor alloreactiveNK cells

Lysis

T T T

Kill recipient APCs =protection from GvHD

Kill recipient T cells =improved engraftment

Kill leukemia =GvL effect

Ruggeri et al. Science 2002

Allo NK-based conditioning:Ablation of recipient targets

T T

Busulfan Fludarabine

HaploidenticalAllo reactive NK Cells

ATG

Allo matchPBPC

Addition of NK cells to HSCT

Phase I/II study to determine toxicity and efficacy of addition of alloreactive NK cells to high dose chemotherapy and allogeneicstem cell transplantation for myeloid leukemias

Champlin et al

Hematopoiesis

Stem Cells

Granulocytes

Monocytes

Eosinophils

Basophils

Erythrocytes

Megakaryocytes

Platelets

T-lymphocytes

B-lymphocytes

Immune System

BloodStem Cell

Nervous System

Liver and other organs

MesenchymalBlood vesselsFibrous tissue

GlandsGI tract, islet cells

Heart

Approach to Abrogate GVHD

Suicide Switch- Prevention of GVHD

45

Modified Caspace 9- Self Destruct Switch

46

If We Can Prevent GVHD • Dramatically expand use of allogeneic

SCT• Bone marrow failure/immune deficiency/metabolic

diseases of hematopoietic cells• Non malignant hematologic/metabolic/immune

mediated diseases– Thalassemia, Hemoglobinapathies– Autoimmune diseases

» Arthritis, Diabetes, Rheumatologic diseases, ……• Tolerance for Organ Transplants• Malignant Diseases

– Eliminates major toxicity of highly effective treatment

HSCT

Vaccine or ImmuneEffector cells

DD

DRLRLR

RR

R

RLR

R DD

D

D

D DD

D

D

D

D

DD

Complete ChimeraRecipient Donor TolerantMixed Chimera

Ideal Nonablative Hematopoietic Transplant

PreparativeRegimen

No GVHD, Immune Reconstitution, GVL for malignancy