Enhanced Cancer Vaccine Effectiveness with NKTR-214, a CD122-Biased Cytokine

Jonathan ZalevskySVP, Biology and Preclinical Development

Nektar Therapeutics

SMI Cancer Vaccines, September 2017

Biopharmaceutical company leveraging polymer conjugation technologies to develop new therapies in multiple disease areas

Strong heritage of partnership with top biopharma companies

~ 450 employees• R&D Center and Headquarters

in San Francisco, CA

• Pharmaceutical Development & Manufacturing in Huntsville, AL

• R&D support in Hyderabad, India

2

Nektar Therapeutics

San Francisco, CA

Huntsville, AL

Hyderabad, India

100,000-sq.ft.State-of-the-Art

R&D Center

114,000-sq.ft.Manufacturing

Facility

88,000-sq.ft.R&D Support

Facility

Wet macular degeneration

2004

2003

Acromegaly

Evolution of Nektar‘s Polymer Conjugation Technology

3

Hepatitis C

2001

Hepatitis C Chronic kidney disease anemia

2007 2014

2002

Neutropenia

2008

Crohn’s

Opioid inducedconstipation

Hemophilia A

R&D

NKTR-214

NKTR-255

NKTR-262

2015

Small molecule

Biologics

Large Molecule Half-life Extension

Concentration in Diseased Tissue

Small Molecule Compartmental

Distribution

Bias Receptor Activity

NKTR-358

NKTR-181

Overview

An introduction to IO research at Nektar

NKTR-214• CD122 biased agonist based on PEG-conjugation of IL-2

Combination of NKTR-262 + pMEL-1 Melanoma Vaccine • pMEL-1 cell expansion and functional activation in the tumor microenvironment

4

The Immunity Cycle and Multiple Points of Intervention for I-O Therapies

5

4. Trafficking of T cells to tumor

5. Infiltration of T cells

into tumors

6. Recognition of cancer cells

by T cells

7. Killing of cancer cells1. Release of

cancer cell antigens

2. Cancer antigen presentation

3. Priming and

activation

Source:Oncology Meets Immunology: The Cancer-Immunity CycleChen and MellmanImmunity, Volume 39, Issue 1, 1 - 10

4. Trafficking of T cells to tumor (CTLs)

5. Infiltration of T cells into tumors (CTLs, endothelial

cells)

6. Recognition of cancer cells

by t cells (CTLs, cancer

cells)

7. Killing of cancer cells (immune and cancer

cells)

1. Release of cancer cell antigens (cancer

cell death)

2. Cancer antigen

presentation (dendritic

cells/APCs)

3. Priming and activation

(APCs & T cells)

Nektar’s Immuno-Oncology Strategy to Create Therapies that Cover the Immunity Cycle

6

Therapies need to be

accessible as medicines

Target as many steps as possible in the cycle with as few therapies as

possible

3. Priming and activation

(APCs & T cells)

6. Recognition of cancer cells

by t cells (CTLs, cancer

cells)

5. Infiltration of T cells into tumors (CTLs, endothelial

cells)

7. Killing of cancer cells (immune and cancer

cells)

1. Release of cancer cell antigens (cancer

cell death)

2. Cancer antigen

presentation (dendritic

cells/APCs)

Nektar’s Immuno-Oncology Strategy to Create Therapies that Cover the Immunity Cycle

7

4. Trafficking of T cells to tumor (CTLs)

Therapies need to be

accessible as medicines

Target as many steps as possible in the cycle with as few therapies as

possible

NKTR-214 (CD122 Agonist)

Prime, Proliferate, Activate & Increase Tumor-Infiltrating

Lymphocytes (TILs), Increase PD-1 expression

NKTR-214: Biasing Action to CD 122, or IL-2R Beta, to Stimulate T-Cell Production

Biases signaling to favor the CD122 Receptor (IL-2Rβγ complex)

Eliminates over-activation of IL-2 pathway that results in serious safety issues

Achieves antibody-like dosing schedule in outpatient setting

8

CTLs

CD8+ T-Cellsand NK Cells

NKTR-214

Stimulates ImmuneResponse to Kill

Tumor Cells

CD4+ Regulatory T-Cells

Tregs

Down-Regulates Proliferation of CD8+ T-cells

and Suppresses Immune Response

NKTR-214 Is A CD122-biased Cytokine, Designed To Improve Efficacy And Mitigate Toxicity of the IL-2 Pathway

9

IL-2: purple IL-2Rα: blueIL-2Rβ: cyan IL-2Rγ: green

Structural model of IL-2docked with IL-2Rαβγ

IL-2

IL-2Rα(CD25)

IL-2Rβ(CD122)

IL-2Rγ(CD132) IL-2 cytokine core

• rhIL-2, same amino acid sequence as clinically validated molecule (aldesleukin)

High molecular weight hydrolyzable polymers located at strategic sites

NKTR-214

NKTR-214: Biased Signaling And Prodrug Design To Improve Risk/Benefit Profile

10

NKTR-214 (essentially inactive)

% P

hosp

ho-S

TAT5

Charych, D., et al. AACR 2013, Abstract #482

NKTR-214: Biased Signaling And Prodrug Design To Improve Risk/Benefit Profile

11

Active Species(Biased signaling, increased potency

with fewer PEGs)

NKTR-214 (essentially

inactive)

% P

hosp

ho-S

TAT5

Charych, D., et al. AACR 2013, Abstract #482

NKTR-214: Biased Signaling And Prodrug Design To Improve Risk/Benefit Profile

12

Active Species(Biased signaling, increased potency

with fewer PEGs)

NKTR-214 (essentially

inactive)

% P

hosp

ho-S

TAT5

Charych, D., et al. AACR 2013, Abstract #482

NKTR-214: Biased Signaling And Prodrug Design To Improve Risk/Benefit Profile

13

Active Species(Biased signaling, increased potency with fewer PEGs)

NKTR-214 (essentially

inactive)

% P

hosp

ho-S

TAT5

Charych, D., et al. AACR 2013, Abstract #482

NKTR-214 Mechanism of Action Delivers a Controlled and Biased Signal to the IL-2 Pathway

14

pSTAT5 is a biomarker of IL-2 receptor target engagement. pSTAT5= signal transducer and activator of transcription 5 p=phosphorylated (activated)

C57BL/6 mice were treated with either one dose of NKTR-214 (blue) or aldesleukin (red); blood samples were collected at various time points post-dose. pSTAT5 in peripheral blood CD3+ T cells was assessed using flow cytometry. Top graph is an inset showing the 0-4 hour time period. Bottom

graph shows the full 10 day time course of the experiment. Histograms on right depict pSTAT5 MFI for IL-2 (red) and NKTR-214 (blue)

In mice, a single dose of NKTR-214 gradually builds and sustains pSTAT5 levels through seven days post-dose. In contrast, IL-2 produces a rapid burst of pSTAT that declines four hours post-dose.

Charych, D., et al. AACR 2013, Abstract #482

B16F10 melanoma, C57Bl/6 mice; N=9-12/groupNKTR-214, 2mg/kg i.v. q9dx3; Aldesleukin, 3mg/kg i.p. bidx5, 2 cycles*, p<0.05, ANOVA with Tukey’s post-test (left) or Log-Rank (right) w.r.t. vehicle‡, p<0.05, Student’s T-test (left) or Log-Rank (right) w.r.t. Aldesleukin

NKTR-214 Increases The Quality And Quantity Of The T-cell Response in Mice

> 400-fold increased ratio of CD8 to Treg cells

15

0 2 4 6 8 10 12 14 16

0

200

400

600

800

1000

1200

1400

1600

Days

*

*

‡

treatment duration

Mouse melanoma model

Tota

l C

D8

/ Tre

g ra

tio

CD8/Treg ratio

NKTR-214 Selectively Grows T Cells, NK Cells in Tumor Microenvironment in Cancer Patients

NKTR-214 drives immune activation in the tumor • Increase in total T cells, NK and CD8 T

cells • No increase in Tregs• Increase in PD-1 positive CD8 T cells• Increase in newly proliferating CD8 T cells• Activation and expression of anti-tumor

genes• Change in T cell clonality in the tumor

16

Fold change expressed as Week 3 / predoseShown are results from N=10 patients

Analysis of T cell Populations in Tumor

0

10

20

30

40

CD8 Tregs

1.6

29.8

3. Priming and activation

(APCs & T cells)

6. Recognition of cancer cells

by t cells (CTLs, cancer

cells)

5. Infiltration of T cells into tumors (CTLs, endothelial

cells)

7. Killing of cancer cells (immune and cancer

cells)

1. Release of cancer cell antigens (cancer

cell death)

2. Cancer antigen

presentation (dendritic

cells/APCs)

Nektar’s Immuno-Oncology Strategy to Create Therapies that Cover the Immunity Cycle

17

4. Trafficking of T cells to tumor (CTLs)NKTR-214 (CD122 Agonist)

Prime, Proliferate, Activate & Increase Tumor-Infiltrating

Lymphocytes (TILs), Increase PD-1 expression

CheckpointInhibitors

NKTR-214: Combination With Anti-PD-1 Consistently Produces Durable Responses in Mice

NKTR-214 + anti-PD-1 is superior to anti-CTLA-4 + anti-PD-1

18

0 20 40 60 800

25

50

75

100

Days

*NKTR-214 + anti-PD-1

anti-CTLA-4 + anti-PD-1

0 20 40 60 80 1000

25

50

75

100

Days

*

*

VehicleAnti-CTLA-4Anti PD-1

NKTR-214

Anti CTLA-4 + Anti PD-1

NKTR-214 + Anti PD-1

CT26 colon carcinoma, Balb/c mice, N=10/groupAnti-CTLA-4, 100µg i.p., twice-weekly; Anti-PD-1, 200µg i.p., twice weeklyNKTR-214, 0.8mg/kg i.v. q9dx3*, p<0.05, ANOVA with Tukey’s post-test (left) or Log-Rank (right) w.r.t. vehicle

Long-term survivalColon Cancer Model

Long-term survivalBreast Cancer Model

EMT6 breast carcinoma, Balb/c mice, N=10/groupAnti-CTLA-4, 100µg i.p., twice-weekly; Anti-PD-1, 200µg i.p., twice weekly NKTR-214, 0.8mg/kg i.v. q9dx3*, p<0.05, ANOVA with Tukey’s post-test (left) or Log-Rank (right) w.r.t. vehicle

NKTR-214 Drives Greater T-cell Expansion And T-Cell Clonality in Mice

19

Vehicle

aPD-1

aCTLA-4

NKTR-214

aCTLA4 + aPD-1 NKTR-214 + aCTLA4

NKTR-214 + aPD-1

ImmunoSeq Data(in collaboration with Adaptive Biotechnologies)

0 5 10 15 20 25 30 35

0

200

400

600

800

1000

1200

1400

1600

1800

Days

Mea

n Tu

mor

Vol

ume

(mm

3 )

0 5 10 15 20 25 30 35

0

200

400

600

800

1000

1200

1400

1600

Days

NKTR-214 + aPD-1

NKTR-214 + aCTLA4

aCTLA4 + aPD-1

Harnessing the IL-2 Pathway the Right Way to Increase TILs

20

Prodrug design to enable safe, outpatient dosing Q2w or Q3w

Active cytokine species bias signaling through the heterodimeric IL-2 receptor pathway (IL-2Rβγ)

Biased and sustained signaling to preferentially activate and expand effector CD8+ T and NK cells over Tregs in the tumor microenvironment

Prodrug (inactive)

Currently in multiple clinical trials• NKTR-214 + checkpoint

‒ Combo with nivolumab: 14 tumor types‒ Combo with pembrolizumab in 2 tumors‒ Combo with atezolizumab in 2 tumors

• Other NKTR-214 combination trials to begin 2018

3. Priming and activation

(APCs & T cells)

6. Recognition of cancer cells

by t cells (CTLs, cancer

cells)

5. Infiltration of T cells into tumors (CTLs, endothelial

cells)

7. Killing of cancer cells (immune and cancer

cells)

1. Release of cancer cell antigens (cancer

cell death)

2. Cancer antigen

presentation (dendritic

cells/APCs)

Nektar’s Immuno-Oncology Strategy to Create Therapies that Cover the Immunity Cycle

21

4. Trafficking of T cells to tumor (CTLs)

Therapies need to be

accessible as medicines

Target as many steps as possible in the cycle with as few therapies as

possible

NKTR-214 (CD122 Agonist)

Prime, Proliferate, Activate & Increase Tumor-Infiltrating

Lymphocytes (TILs), Increase PD-1 expression

Vaccine Model

Provide Antigens Activate Dendritic

Cell Response

CheckpointInhibitors

Melanoma Vaccine Mouse Model to Study NKTR-214

Pmel-1 cancer vaccine developed by Overwijk and Rosenberg• Pmel-1 cells adoptive transfer + peptide

vaccination for killing B16F10 tumors• IL-2 is essential for driving anti-tumor pMEL-1

response

Pmel-1 are genetically marked killer T cells• Easy to track in tumor and blood• Responsive to anti-melanoma vaccine• Kill melanoma cells

Use model to study effect of NKTR-214

22

Vaccine Vaccine + IL-2

Overwijk et al. JEM 2003

o Adoptive transfer of gp100-specific Pmel-1 cells

o Gp100 peptide (50 ug/mouse)-L-tyr (adjuvant)

o anti –CD40 (50 ug/mouse)

o TLR-7 agonist (Imiquimod- 5 mice/pack)

o Recombinant IL-2 (100,000 IU X 5 doses_ Day 0, D1 and D2) or

NKTR-214 (0.2mg/kg)

Evaluation of NKTR-214 in Pmel-1 Vaccine Model

23

1. No treatment

2. Aldesleukin

3. NKTR-214

4. Vaccine

5. Vaccine + Aldesleukin (IL-2)

6. Vaccine + NKTR-214

Pmel-1 Cell Transfer

Vaccine = gp100 peptide + anti-CD40 + TLR-7 agonist

Aldesleukin (IL-2) – 100,00 IU b.i.d_D0,D1,D2_q8d

NKTR-214- 0.2 mg/kg_q8d

Collaboration with Meenu Sharma, Willem

Overwijk Laboratory, MD Anderson Cancer Center

NKTR-214 More Effective that Aldesleukin to Delay Tumor Growth in Mouse Melanoma Vaccine Model

24M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

NKTR-214 Promotes Massive Pmel-1 Cell Expansion After Vaccination

25

NKTR-214-vaccine significantly enhanced Pmel-1 T cell response as compared to Aldesleukin-vaccine

p= <0.001

M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

D3 D5 D7 D100

200000

400000

600000 Untreated

Vaccine + NKTR-214 Vaccine + Aldesleukin Vaccine

***

Days after vaccination

Num

ber o

f Thy

1.1+

CD8

T c

ells

/ gr

am o

f tum

orNKTR-214 Vaccine Combination Superior to Aldesleukin for Pmel-1 CD8 T Cell Expansion in Tumor and Spleen

26

Tumor

D3 D5 D7 D100

500000

1000000

1500000

2000000

No Tx

Vaccine + NKTR-214 Vaccine + Aldesleukin Vaccine

Days after vaccination

Num

ber o

f Thy

1.1+

CD8

T c

ells

/Spl

een ***Untreated

Vaccine + NKTR-214 Vaccine + Aldesleukin Vaccine

***

Untreated

Vaccine + NKTR-214 Vaccine + Aldesleukin Vaccine

***Spleen

M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

NKTR-214 Promotes Higher Pmel-1/Treg Ratio than Aldesleukin in Tumor and Spleen

27

0 1000 2000 3000 4000

Day 10

Day 7

Day 5

Day 3

Pmel-1/Tregs (Tumor)

No TreatmentVaccineVaccine + AldesleukinVaccine + NKTR-214

0 50 100 150

Day 10

Day 7

Day 5

Day 3

Pmel-1/Tregs (Spleen)

ure 5

B

M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

NKTR-214 Preferentially Drives Pmel-1 Proliferation

28

As compared to Vaccine alone and aldesleukin-vaccine combination, NKTR-vaccine treatment

significantly maintained higher proliferation of Pmel-1 T cells and lower proliferation of Tregs in

tumor as well as in spleen

Day 7

M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

NKTR-214 Preferentially Promotes Pmel-1 Survival

In tumor, addition of NKTR-214 to vaccine reduced annexin V expression on Pmel-1 and enhanced it on Tregs though no significant change was exhibited in Aldesleukin-Vaccine treatment group

In contrast to tumor, Annexin V expression in spleen was reduced on both Pmel-1 T cells and Tregs, in NKTR-vaccine group as compared to vaccine alone

29

Day 7

M. Sharma, Willem Overwijk Laboratory, MD Anderson Cancer Center

Summary and Conclusions

NKTR-214 is a CD122-biased agonist that effectively activates the IL-2 receptor pathway in preclinical and clinical settings

Addition of NKTR-214 to peptide vaccine drives enhanced Pmel-1 T cells in tumor as well as in spleen

• NKTR-214 is better than Aldesleukin in stably maintaining high CD8+ (Pmel-1 cells) and low Treg numbers in tumor

At the peak of Pmel-1 response on day 7, number of Tregs dramatically reduced in tumor of NKTR-vaccine treated group

Relative expression of Ki67 and Annexin V indicated that NKTR-vaccine treatment supports proliferation and survival of Pmel-1 T cells in tumor as well as in spleen

Reduced proliferation and moderately enhanced apoptosis in intratumoral Tregs, seem to contribute to observed low number of Tregs in tumor of NKTR-vaccine treated mice

30