Targeted therapy response in endometrial cancer cells Britta Weigelt Cancer Research UK London Research Institute

Summary •  Background •  Molecular genetic alterations in endometrial cancer •  Targeted therapy response of endometrial cancer cells in vitro •  Targeted therapy response in patients with endometrial cancer •  Outlook

Endometrial cancer •  Most common gynaecological cancer in western world –  UK: 7,835 new cases, 1,937 deaths per year (CRUK) –  US: 47,130 new cases and 8,010 deaths per year (NCI)

•  Increase by over 40% in the UK since 1993 (Evans, BJC 2011) •  Changes in reproductive behaviour, increased life expectancy, overweight/ obesity, hormone replacement therapy Fallopian tube

Ovary Cervix Vagina

Myometrium Endometrium

Classification

Type I and Type II

Histological classification (epithelial tumours) Endometrioid adenocarcinoma Type I (80-90%)

Non-endometrioid adenocarcinoma Type II (10-20%) Serous

Variants - Variant with squamous differentiation - Villoglandular variant - Secretory variant - Ciliated cell variant Mucinous adenocarcinoma

Clear-cell

- Serous (papillary) adenocarcinoma (5-10%) - Clear cell adenocarcinoma (1-5%) - Mixed adenocarcinoma (type I/II) - Squamous cell carcinoma - Transitional cell carcinoma - Small cell carcinoma - Undifferentiated carcinoma

World Health Organisation Classification 2003; Bokhman 1983; Hecht & Mutter, J Clin Oncol 2006

Type I vs Type II Type I

Type II (serous/ clear cell)

Yes

No

ER/PR+

ER/PR-

Hyperplasia

Atrophy

Low

High

Superficial

Deep

Indolent

Aggressive

61.9-63.7 yrs

66.8-69.3 yrs (serous) 64.1-66.4 yrs (clear cell)

Diagnosis

Early stage (FIGO I/II) 86%

Late stage (FIGO III/IV) 41% (serous) and 33% (clear cell)

Prognosis

More favourable 5yr survival by FIGO stage: I 90% II 80% III 68% IV 26%

Poor 5yr survival by FIGO stage: I 80% (serous), 85% (clear cell) II 41% (serous), 63% (clear cell) III 38% (serous), 49% (clear cell) IV† 8% (serous), 6% (clear cell)

Oestrogen associated Hormone receptors Background endometrium Tumour grade* Myometrial invasion Clinical behaviour Mean age/ diagnosis

Weigelt & Banerjee, Curr Opinion Oncol 2012

†4yr

survival

Molecular genetic alterations in endometrial cancer  

Complex molecular/ genetic landscapes •  Morphological/ clinical differences between type I and type II endometrial cancers are mirrored in their genetic alterations (Hecht & Mutter, J Clin Oncol 2006)

•  Harbour many mutations –  Microsatellite instability: 20-45% type I, 0-14% type II

•  Mutational landscape is complex –  Mutations in same pathway are not mutually exclusive –  Different permutations of coexisting mutations

The Cancer Genome Atlas (TCGA) data to be published late 2012

PI3K/AKT/mTOR pathway Alteration

Type I

Type II

57-83%

up to 10%

PIK3CA

50%

30%

PIK3R1

20-40%

5-12%

KRAS

22-43%

2-5%

PIK3CA amp

2-14%

45%

HER2 amp

up to 3%

17-50%

EGFR expr

38-46%

35-56%

FGFR2 mut

16%

2%

2-20%

9-68%

PTEN

TP53

Coexisting mutations

Urick et al, Cancer Res 2011; McConechy et al, J Pathol 2012

Exome sequencing Endometrial cancer cell lines

n=27

•  Exon capture; Agilent Custom SureSelect Target kit (1,651 genes) •  Illumina GAII genome analyser (76 bp paired-end reads)

Institute of Cancer Research •  Exon capture; Agilent SureSelect All Exon kit (~20,000 genes) •  Illumina GAIIx genome analyser (76 bp paired-end reads) •  26 endometrial cancer cell lines Weigelt et al, unpublished data

NO MATCHED NORMAL!

19 cell lines

Exome Seq – endometrial cancer cell lines Broad (27 cell lines)

ICR/ LRI (26 cell lines)

AKT1

7%

8%

AKT2

7%

15%

AKT3

15%

12%

TSC1

8%

11%

TSC2

31%

33%

mTOR

56%

58%

RICTOR

37%

50%

AR

22%

23%

IGFR1

22%

23%

PDGFRA

26%

15%

PDGFRB

19%

35%

Mutation

Rictor

Targeted therapy response of endometrial cancer cells in vitro  

Genotype – drug response associations •  Sensitivity to targeted therapies is associated with genotype –  Oncogene addiction: EGFR mutations – gefitinib; BRAFV600E mutations – vemurafenib, HER2 amplification – trastuzumab/ lapatinib –  Synthetic lethality: BRCA1/2 mutations – PARP inhibitors

“Oncogene addiction” Hits Normal Cancer cell cell

Signal intensity

Time

Synthetic lethality Genes A

B

Survival

A

B

Survival

A

B

Survival

A

B

Death

Targeting HER2/ EGFR Lapatinib * *

*

*

* * *

* * *

Lapatinib response correlates with EGFR/HER2/HER3 expression, PTEN-independent. Konecny et al, BJC 2008

Targeting FGFR2 AN3CA

MFE-296

N550K FGFR2 mutation

EC cell lines with activating FGFR2 mutations may be addicted to FGFR, PTEN-independent. Byron et al, Cancer Res 2008

Targeting the PI3K pathway 1 PI3K inhibitor CH5132799

Mouse xenograft

Tumour volume (mm3)

In vitro

Days after implantation

PI3K inhibitor shows potent anti-tumour activity. Tanaka et al, Cancer Res 2011

Targeting the PI3K pathway 2 PI3K inhibitor GDC-0941

PIK3CA mutant endometrial cancer cells are preferentially sensitive to PI3K inhibition. Weigelt et al, unpublished

Targeting the PI3K pathway 3 mTOR inhibitor Temsirolimus

PTEN mutations are associated with Temsirolimus response in endometrial cancer cells. Weigelt et al, unpublished

Targeting PARP PARP inhibitor KU0058948

PTEN deficient endometrial cancers may be homologous recombination DNA repair defective and sensitive to PARP inhibition. Dedes et al, Science Transl Medicine 2010

Clinical trials testing targeted therapies for patients with endometrial cancer  

HER2/ EGFR inhibitors Trastuzumab

“Trastuzumab as a single agent did not demonstrate activity against endometrial carcinomas with HER2 overexpression or HER2 amplification”

Fleming et al, Gynecol Oncol 2010

HER2/ EGFR inhibitors Trastuzumab

“Trastuzumab as a single agent did not demonstrate activity against endometrial carcinomas with HER2 overexpression or HER2 amplification”

Fleming et al, Gynecol Oncol 2010

Erlotinib

- Objective response rate of 12.5% - No correlation between EGFR mutations/ amplifications and response Oza et al, J Clin Oncol 2008

PI3K/AKT/mTOR inhibitors Temsirolimus – allosteric mTORC1 inhibitor Chemotherapy-naïve (n=29)

Prior chemotherapy (n=25)

Partial Response

Stable Disease

Partial Response

Stable Disease

14%

69%

4%

48%

Median PFS

5.1 mths

9.7 mths

4.3 mths

3.7 mths

Endometroid

2/19

12/19

1/10

5/10

Serous/ clear cell

2/6

3/6

0/10

6/10

RECIST response

Oza et al, J Clin Oncol 2011

PI3K/AKT/mTOR inhibitors Temsirolimus – allosteric mTORC1 inhibitor Chemotherapy-naïve (n=29)

Prior chemotherapy (n=25)

Partial Response

Stable Disease

Partial Response

Stable Disease

14%

69%

4%

48%

Median PFS

5.1 mths

9.7 mths

4.3 mths

3.7 mths

Endometroid

2/19

12/19

1/10

5/10

Serous/ clear cell

2/6

3/6

0/10

6/10

RECIST response

No correlation between response and PTEN, p-mTOR, p-AKT, p-S6 kinase protein expression or PTEN mutations. Oza et al, J Clin Oncol 2011

PI3K/AKT/mTOR inhibitors PI3K pathway inhibitors alone or in combination (Temsirolimus, Sirolimus, PX866)

PIK3CA mutant cancers

A subset of PIK3CA mutant endometrial cancers may be sensitive to PI3K pathway inhibitors. Janku et al, J Clin Oncol 2012

PARP inhibitors

week 10 week 20

week 20

week 10

baseline

baseline

Nat Rev Clin Oncol 2011

Clinical trials to evaluate the efficacy of Olaparib in endometrial cancer patients with PTEN-deficient tumours are warranted.

Angiogenesis inhibitor

Patients (n)

%

Complete response

1

1.9

Partial response

6

11.5

Stable disease

26

50

Increasing disease

17

32.7

Indeterminate

2

3.8

PSF ≥ 6 months

21

40.4

Responses seen across all types of endometrial cancer J Clin Oncol 2011

Conclusions •  Endometrial cancers heterogeneous group of tumours with distinct –  –  –  – 

risk factors histopathological features clinical outcome genetic aberrations

•  Genetic heterogeneity –  between type I and type II cancers –  within type I and type II cancers

•  Epistatic interactions in PI3K pathway not understood •  Clinical trails: modest activity of single agent targeted therapeutics

Ongoing clinical trials

Dedes et al, Nat Rev Clin Oncol 2011

Outlook: towards a predictive classification •  Identification of drivers and therapeutic targets of subgroups of endometrial cancer •  Robust predictive markers of targeted therapy response •  Integration: translational biomarker studies within clinical trial design

Acknowledgements

Maryou Lambros Alan Mackay Charlotte Ng Konstantin Dedes Lina Chen Iwanka Kozarewa Chris Lord Alan Ashworth Jorge Reis-Filho

Patricia Warne Julian Downward