Tyler J. Curiel, MD, MPHcurielt@uthscsa.edu

Professor of MedicineUT Health Science Center

San Antonio, TX

Reversing Immune Dysfunction in Cancer

Outline• Introduction to tumor immunity

• Limitations of the prevailing cancer drug development approach

• Failures of the prevailing tumor immunotherapy strategies

• The new immunotherapy paradigm and its translational predictions and approaches

Louis Pasteur 1822-1895Louis Pasteur 1822-1895

Germ theory of immunity 1878

First demonstration of acquired immunity with

chicken cholera 1880

Immune surveillance and tumors

Increased cancer in immunosuppressed hosts

Spontaneous cancer remissions, especially in renal cell carcinoma and melanoma

Demonstration of tumor-specific immunityJ Nat CA Inst 1957;18:769

Tumors express antigensNature 304, 165-7 (1983)

● Is there definitive proof of naturally-occurring immunity against cancers?

● Could immune therapy for cancer (of any kind) ever work?

The overarching questions

● For which cancers? At what stages?

● What approaches will work?

Tumor Immune Surveillance Exists.

Shankaran V, Ikeda H, Bruce AT, White JM, Swanson PE, Old LJ, Schreiber RD IFN-γ and lymphocytes prevent primary tumour development and shape tumour immunogenicity. Nature. 2001 410(6832):1107-11

Punch Line:T cells, IFN-γ and adaptive (antigen

specific) immunity are key elements in

defense against tumors

Current tumor immunotherapy paradigms build on infectious disease principles that may not apply to cancer

T. Curiel J Clin Invest, 117(5):1167-1174 2007

One answer: give more T cells

Rosenberg, S.A., Spiess, P. & Lafreniere, R. A new approach to the adoptive immunotherapy of cancer with tumor-infiltrating lymphocytes. Science 233, 1318-21 (1986).

LAK cells. Rosenberg, S.A. et al. N Engl J Med 316, 889-897 (1987)

Morgan, R.A., et al. Cancer regression in patients after transfer of genetically engineered lymphocytes. Science (2006).

Nature Medicine 1996 2(1):52-58 F. Hsu, et al.

B-cell lymphoma, autologous antigen-pulsed dendritic cells

Nature Medicine 1998 4(3):328F. Nestle, et al.Melanoma, peptide- or tumor lysate-

pulsed dendritic cells

Intrinsic tumor strategies• Hide the tumor

– Reduce class I– Reduce TAA– Defective Ag processing– Reduce co-signaling– Grow in privileged sites

• Prevent active immunity– Prevent cell ingress– Promote cell egress– Kill immune cells

• Miscellaneous– Resist apoptosis

- Alter cell differentiation

DC subsets

Tumors reprogram dendritic cells to defeat host immunity, not the tumor

Zou, Curiel, et al., Nature Medicine2001; 7(12):1339-1346

Tumor plasmacytoid DCgenerate IL-10+ T cells

Zou, Curiel, et al.,

Nature Medicine

2001; 7(12):1339-

1346 .

[3H]thymidine incorporation (cpm x 103)

0

10 20 30 40 50 60

Control

+ tumor PDC generated T cells

+ tumor PDC generated T cells + anti-IL-10R

*

**

Tumor myeloid DC induce IL-10+ T cells through B7-H1 signals

Curiel, Zou, et al., Nature

Medicine2003;

9(5):562-567

VEGF and IL-10 from the tumor induce B7-H1 expression

Immune recognition of tumor antigens as self is a significant problem.

Infection: rapidly dividing cells of external origin.

Cancer: rapidly dividing cells of internal origin. The tumor is a part of the host (self).

The big problem

• Anti-tumor immunity is autoimmunity.

• To generate significant anti-tumor immunity requires breaking self tolerance.

ThymusNegative selectionCentral tolerance

Self-reactive

Normal repertoire

Blood, LN, BM, spleenPeripheral tolerance

CD4+CD25+

Treg

Naïve thymocytes

Regulatory T cells (Tregs) are CD4+CD25hi T cells

Treg depletion improves endogenous immunity

Shimizu, J., et al. J Immunol 163, 5211-8 (1999)

Treg depletion improves actively-induced immunity

Steitz, J., et al. Cancer Res 61, 8643-6 (2001)

Sutmuller, et al. J Exp Med 194, 823-32 (2001)

In tumors, many pathways generate TregsT. J. Curiel 2007 J Clin Invest 117(5):1167-1174

Evading apoptosis

Self-sufficiencyin growth

signals

Insensitivity to anti-growth signals

Tissue invasionand metastasis

Limitless replicativepotential

Sustained angiogenesis

Six fundamental hallmarks of cancer Hanahan and Weinberg 2000. Cell 100:57-70

The seventh fundamental hallmark of cancer Dunn, G.P., Old, L.J., and Schreiber, R.D. 2004. Annu Rev Immunol 22:329-360.

Zitvogel, L., Tesniere, A., and Kroemer, G. 2006. Nat Rev Immunol 6:715-727.T. J. Curiel. 2007 J Clin Invest, 117(5):1167-1174.

Lack of immune rejection

Self-sufficiencyin growth

signals

Insensitivity to anti-growth

signals

Tissue invasionand metastasis

Limitless replicativepotential

Sustained angiogenesis

Evading apoptosis

FOXP3+ Tregs in tumors

Curiel, Zou, et al. Nature Medicine 10, 942-949 (2004)

Tumor Tregs allow tumor growth despite otherwise sufficient numbers of functional anti-tumor effectors cells

IL-2

IFN

- 6 40

24

8 24

17

Treg

40% 17%C

ou

nts

Annexin-V-APC

- + - +

IL-2

Curiel, Zou, et al. Nature Medicine 10, 942-949 (2004)

Tumor Tregs allow tumor growth despite otherwise sufficient numbers of functional anti-tumor effector cells

IL-2

IFN

- 6 40

24

8 24

17

Treg

40% 17%C

ou

nts

Annexin-V-APC

- + - +

IL-2

Curiel, Zou, et al. 2004Nature Medicine 10, 942-949

Months

0 20 40 60 80 1000.0

0.2

0.4

0.6

0.8

1.0

low Treg

medium Treg

high Treg

Sur

viva

l

Elevated tumor CD4+CD25+ T cells predict poor survival in ovarian cancer

Low Treg66.4 mos

High Treg12.8 mosP<0.0001

Curiel, Zou , et al. Nature Medicine 10, 942-949 (2004)

CD4+CD25+

CTCL cellCD4+CD25+

Treg

Patient DT μg/kg

Age in

years

Gender Tumor

type

Prior treatments

1 9 59 F ovarian S, C

2 9 41 F breast HT, C

3 9 50 M lung C, RT

4 12 53 F ovarian C, RT, S

5 12 31 F ovarian C, S

6 12 36 F ovarian C, S

7 12 72 M pancreatic C, HT, S

Denileukin diftitox depletesTregs in cancer patients

Denileukin diftitox increases blood IFN-γ-producing T cells in cancer patients

Patient 4

• Stage IV (metastatic) ovarian cancer.

• First recipient of the dose-escalated 12 µg/kg, with significant immune response.

• Because she had measurable disease, she received six additional denileukin diftitox doses to test clinical efficacy.

Denileukin diftitox reduces metastatic tumor in treatment-refractory ovarian cancer

4 months

Corroborating trials

• Ovarian: Barnett, B., Kryczek, I., Cheng, P., Zou, W. & Curiel, T.J. Am J Reprod Immunol 54:369-377; 2005

• Renal cell: Dannull, J., et al. The Journal of Clinical Investigation 115:3623-3633; 2005

• Melanoma: Mahnke, K., et al. Int J Cancer 120: 2723-33; 2007

• Melanoma: Rasku, M. A, et al. J. Translational Med, 6:12;2008

Even when the system works,tumors can develop:

“The Three Es of Cancer Immunoediting”R. Schreiber Annu Rev Immunol 33:329 2004

Fig: L. Zitvogel et al., Nature Reviews Immunology 6, 715-727 (October 2006)

Salvaging DT failure in ovarian cancer

Patient SAOC03

S. Wall, S. Thibodeaux, T. Curiel, et al., in preparation

Interferon-α improves Treg depletion and DT efficacy in ovarian cancer

Patient SAOC03

S. Wall, S. Thibodeaux, T. Curiel, et al., in preparation

How IFN-α boostsTreg depletion effects

• Directly activates CD8+ T cells

• Boosts T cell-activating capacity of dendritic cells

• Increases T cell trafficking into tumor

• Does NOT appear to affect Treg function or regeneration after depletion

Special cases

• Sex

• Age

WT + isotype

WT + isotype

WT + αB7-H1

WT + αB7-H1

c

Pen

tam

err

CD8

0.25% 0.24% 0.27%

0.36% 0.35% 0.29%

0.38% 0.42% 0.46%

0.56%0.52%0.55%

Mouse 1 Mouse 2 Mouse 3

68.0%

90.8%

a

Tum

or v

olum

e (m

m3)

Days post B16 challenge

WT + isotype

WT + B7-H1

WT + isotype

0 2 64 8 10 12 14 16

800

600

400

200

0

1200

1400

1000

WT + B7-H1

Sup

pres

sion

(%

)

Eff:Treg ratio

b

p=0.017

1:1 1:0.5

60

40

20

0

80

Tot

al n

umbe

r of

tum

or-

spec

ific

CD

8+ c

ells

(10

5 )

p=0.009

p=0.013

p=0.028

6

4

2

0

WT + isotype

WT + B7-H1

WT + isotype

WT + B7-H1

Females respond better to anti-B7-H1 blockade in B16 melanoma

WT + isotype

WT + B7-H1

WT + isotype

WT + B7-H1

Sex differences in female Tregs

• B7-H1-dependent reduction in Treg function

• B7-H1 effects are estrogen-dependent

• Functional differences are due to defective mTOR/PTEN signaling

• Treg function is rescued with dendritic cell B7-H1 signals, estrogen withdrawal or rapamycin

Treg depletion does not work in aged female mice with B16

tum

or

volu

me

(m

m3)

day after challenge

young

aged

PBS

DT

PBS

DT

Aged female mice have more CD11b+Gr-1+ myeloid suppressors that

are more suppressive than young

p=0.01

CD

11b+

Gr-

1+ c

ells

in s

plee

n (%

)

6

4

2

0

PBS DT PBS DTno tumor no tumor

young aged

1:1 ratio of MDSC from Spleen

p=0.10

p=0.02

p=0.01

80

60

40

20

0

100

supp

ress

ion

by

CD

11b+

Gr-

1+

from

sp

leen

at

1:

1 r

atio

(%

)

PBS DT PBS DTno tumor no tumor

young aged

Depleting Gr-1+ cells improves tumor immunity and slows B16 in aged females

tum

or

volu

me

(m

m3)

day after challenge

anti-Gr1

control mAb

anti-Gr1

young

aged

control mAb

B

Per

cent

IFN

γ+ o

f CD

8+ T

ce

lls in

spl

een

0

1

2

3

4

no tumor control mAb -Gr-1 mAb -Gr-1 mAb

young aged

control mAb

p=0.21

p=0.019

Summary and conclusions

• Cancers are immunogenic and thus should be amenable to effective immune therapies in the new paradigm.

• Immune therapies are adjuncts in multi-modal treatment approaches.

• Immune therapy is not appropriate for all patients.

Ways forward

• Identify patients with relatively intact immune systems for trials

• Test available agents: DT, anti-CTLA-4

• Test reversing immune dysfunction with immunization or immune boost (e.g., anti-CTLA-4 or DT plus a vaccine)

Final Thoughts

• We need a better understanding of immune dysfunction in cancer.

• We need a better understanding of the immune effects of current agents.

• Willingness of investigators to try immune therapies will help, but they have to be convinced.

Acknowledgements• Curiel lab members

• National Cancer Institute

• Hayes, Voelcker, Rippel Foundations and Trusts, Eisai

• UTHSCSA endowments

• Cancer Therapy & Research Center