Epigenetics and Epigenetics and CancerCancer

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Nilofer Azad, MDNilofer Azad, MDAssistant Professor, Gastrointestinal Oncology/Phase I ProgramAssistant Professor, Gastrointestinal Oncology/Phase I Program

Sidney Kimmel Comprehensive Cancer CenterSidney Kimmel Comprehensive Cancer CenterOctober 19, 2010October 19, 2010

CMAJ 2006;174(3):341-8

Simplified Model of Epigenetic Regulation of Gene Expression

Promoter Coding section Non-coding section Coding section

Protein Complex

How do genes get turned on and off?

DNAofGene X

M M M

Gene is transcribed = ON

Gene blocked from being transcribed = OFF

Histone Histone

Protein Complex

DNA Methyltransferase inhibitors

• Two currently FDA approved agents

• 5-azacytidine(Vidaza)

• 5-aza-2'-deoxycytidine (decitabine, Dacogen)

5-azacitidine

• FDA approved in 2004 for myelodysplasia

• Dose: 75 mg/m2 SQ daily x 7 d / 28 d cycle

• Mechanism of action: Incorporated into DNA → suicide inhibitor of DNMTInduces global hypomethylation

• Time to clinical response: Average = 4 months

Histone deacetylase inhibitors• Three currently FDA approved agents

• Vorinostat (Pan-HDACi)(SAHA, Zolinza) Oral agentApproved for cutaneous T-cell lymphoma

• Depsipeptide (Pan-HDACi)(Istodax) Intravenous agent

Approved for cutaneous T-cell lymphoma

• Valproic acid (weak inhibitor) anti-seizure

LUNG CANCER

Rationale for double epigenetic blockage in lung cancer

• Epigenetic gene silencing mediated by DNA methylation and histone deaceylation is a key contributor to lung carcinogenesis

• Preclinical studies suggest that combining DMNTi with HDACi synergistically enhances expression of silenced tumor suppressor genes

• Clinical studies combining DMNTi and HDACi have shown remarkable clinical activity in MDS/AML

• Hypothesis: similar effect in NSCLC

Trial Schema

• 5AC Dosing = 40 mg/m2 SQ daily on days 1-6 and 8-10• SNDX-275 dosing = 7 mg PO (fixed dose) days 3 and 10• Cycle length = 28 days

MS275

5-Aza

Day 1 8 15 22 29 36

SNDX-275

5-AC

Day 1 8 15 22 29 36

Phase I Toxicity Data

0 2 4 6 8 10

Number of Patients

Injection Site ReactionNausea / Vomiting

ConstipationAnorexia

Lower Extremity EdemaHyperglycemia

Low ElectrolytesFatigue

NeuropathyNeutropenia

LymphopeniaAnemia

Thrombocytopenia

Phase I Toxicities

Grade 1

Grade 2

Grade 3

Updated Response Data28 Evaluable Patients

• 1 Complete Response – On treatment for 14 months

• 1 Partial Response

Responded for 8 months – then new SCLC

Still no progression of his NSCLC 9 months off epigenetic therapy

• 8 Stable Disease One on treatment for 18 months; Five treated for 4 months

One treated for 3 months then stopped due to schedule

One still being treated (on cycle 12 now)

• 17 Progressive Disease

• 8 Not evaluable (finished less than 1 cycle)

• 5 Actively being treated

Overall Survival

Median OS: 8.2 months

Images of Patient with Complete Response

56 year old woman with stage I lung cancer that was resected and treated with adjuvant chemotherapy.She progressed after salvage chemotherapy with radiation at relapse.She had a response after 2 cycles, continued improvement after 4; 14 cycles were given. She had 3 prior therapies for advanced disease.

Images of patient withPartial Response

58 year old male treated with 3 prior therapies; Chemotherapy refractory disease. He completed 8 cycles.

Images of patient with partial response: liver metastases

Pre-treatment Cycle 2 Cycle 4 Cycle 8 Pre-treatment Cycle 2 Cycle 4 Cycle 8

Hypotheses for biology of the complete responder

• Fewer number of previous therapies…

• Higher serum level of 5-azacitidine…

• Epigenetics…• Responding patient was a previously resected stage

I NSCLC patient

• Analysis of her tumor and mediastinal lymph nodes found a methylation pattern that predicted she was at high risk for early recurrence

Response

PD NE SD CR

5A

C C

ma

x (n

g/m

L)

0

500

1000

1500

2000

14500

15000

15500

0 1 2 3 4 5

0.00

0.25

0.50

0.75

1.00

Negative (U)n=79

Positive (M)N=11

P<0.0001

Stage 1

Stage 3

Gene DNA Hypermethylation Markers Are Better for Prognosis than Standard Staging

Prop

ortio

n D

isea

se-F

ree

Years After Surgery

OR = 25 fold

p16 and H-cadherin

Brock et al, 2008

Molecular Re-staging

Epigenetic Therapy Study Design: Treatment Epigenetic Therapy Study Design: Treatment SchemaSchema

2

1

5-Azacitidine 40 mg/m2 SQ Day 1-5, 8-10Entinostat 7mg PO Day 3 and 10

Every 28 days, for 6 cycles

Intended Accrual: 172 patients

5-Azacitidine 40 mg/m2 SQ Day 1-5, 8-10Entinostat 7mg PO Day 3 and 10

Every 28 days, for 6 cycles

Intended Accrual: 172 patients

Stage IA or IB NSCLC s/p surgery with curative intent

Stage IA or IB NSCLC s/p surgery with curative intent

RANDOMIZE

RANDOMIZE Standard Care

Intended Accrual: 86 patients

Standard Care

Intended Accrual: 86 patients

Within 4-8 weeks of completing surgery

COLON CANCER

Men294,120

Women271,530

Available at: http://www.cancer.org.

Colorectal Cancer is Common 2009 Estimated U.S. Cancer Deaths

Colorectal cancer represents 2nd leading cause of death

Lung and bronchus 31%

Prostate 10%

Colon and rectum 8%

Pancreas 6%

Leukemia 4%

Liver/bile duct 4%

Esophagus 4%

Urinary bladder 3%

Non-Hodgkin Lymphoma 3%

Kidney 3%

All other sites 24%

26% Lung and bronchus

15% Breast

9% Colon and rectum

6% Pancreas

6% Ovary

4% Non-Hodgkin lymphoma

3% Leukemia

3% Uterine corpus

2% Brain/other nervous system

2% Liver/bile duct

25% All other sites

Available at: http://www.cancer.org.

Colorectal Cancer Staging

AdenomaPre-cancer lesion

Stage Ilocalized, not through “muscularis”(muscle wall in the colon)

Stage IIthrough muscularis, but no lymph nodes

Stage IIIcancer in nodes, but not other organs

Stage IVmetastatic (liver, lung, etc)

Stage III

Stage I-II

IV

Stage I 15%

Stage II 20%–30%

Stage III 30%–40%

Stage IV 20%–25%

Disease Stage at Time of Diagnosis

Hamilton IM, Grem JL. Current Cancer Therapeutics. 3rd ed. 1998;157.

Copyright © American Society of Clinical Oncology

Sargent, D. et al. J Clin Oncol; 27:872-877 2009

Risk of recurrence after primary resection in Stage II and III Colon

Cancer

85% recur within 3 years

85%

Metastatic Disease

History of Treatment for Colorectal CancerHistory of Treatment for Colorectal Cancer

• ~1960: 5-FU is a cornerstone of first-line therapy; bolus/infusion

• ~1985: Addition of LV (biomodulator) to 5-FU bolus regimens

• 1998: Irinotecan as single agent approved as second-line

• 2000: Irinotecan approved as first-line in CRC (bolus IFL)

• 2001: Capecitabine approved as first-line in CRC in selected pts

• 2002: Oxaliplatin approved as second-line agent (FOLFOX)

• 2004: Oxaliplatin approved as first-line agent in infusional regimen

• 2004: Approval of Cetuximab (Erbitux) & Bevacizumab (Avastin)

• 2006: Approval of Panitumumab (Vectibix)

• 2008: KRAS mutations predict lack of benefit of EGFR mAb’s

Incremental Survival Advantage in First-LineMetastatic Colorectal Cancer

No active drug

0 6 12 18 24Median OS (mo)

~4-6 mo

12-14 mo

~ 15-16 mo

20.3 mo

?

~ 20 mo

5-FU/LV

FOLFOX4

IFL + bevacizumab

IFL

21.5 moFOLFOX/FOLFIRI

FOLFOX/FOLFIRI

+ biologics

Are we hitting a wall with current drugs?

Therapy for Advanced Colorectal Cancer: Response rates and survival

First Line Second Line Third Line- FOLFOX or - FOLFOX or - Irinotecan +- CAPOX or - FOLIRI or Cetuximab - FOLFIRI - Irinotecan alone - Cetuximab +/- Bevacizumab - Irinotecan/Cetuximab - Panitumumab

+/- Bevacizumab

Response Rates in Randomized Trials:

50-60% 15% 10%Survival Benefit in Randomized Trials:

Yes Yes Yes

Epigenetics in CRC• Many genes have silenced expression due to epigenetic

changes

• Targeting epigenetically abnormal tumors may be more effective than targeting abnormal mutations in genes

• CRC may be uniquely appropriate for this strategy

• A subset of colon cancer have more gene promoter methylation

Ahuja et al.

Combination Epigenetic Therapy• First study of epigenetic therapy in CRC

• Primary Objective:

• To determine the preliminary efficacy via tumor shrinkage rate of the combination of 5-azacitadine and entinostat in patients with metastatic colorectal cancer

• Secondary Objective:

• To see what is happening in the tumor itself and circulating cells in blood before and after treatment with these drugs

Study Schema28 days

C2d1C1d3entinostat

C1d1 C1d10entinostat

C2d3entinostat

C2d10entinostat

C3d1

= plasma sampling for research purposes

= tumor sampling for research purposes

5-aza days 1-5 and 8-10 q cycle5-aza days 1-5 and 8-10 q cycle

Ongoing and Upcoming Studies

• Lung Cancer– New schedule– Adjuvant treatment of early stage disease

• Breast– Same schedule in triple negative and hormone

resistant metastatic cancer

Conclusions

• Despite progress, colon cancer is a still leading source of death

• Epigenetic therapy offers a novel way to approach treating cancer, based on the abnormal gene expression seen in cancers compared to normal cells

• We are presently enrolling a trial of patients with late-stage colon cancer an treating them with epigenetic agents, 5-azacitidine and entinostat

BREAST CANCER

Epigenetics and breast cancer

• Multiple genes are methylated and thus silenced in breast cancer1

• ER, RAR beta, cyclin D, Twist, RASSF1A, and HIN-1

1 Pu RT. Mod Pathol 2003;16(11):1095-101.

Zebularine inhibits growth of MDA-MB-231 cell lines alone

or in combination

Billam M. BCRT 2010

Clinical studies: Vorinostat in MBC

• Phase 2

SKCCC J0785/TBCRC 008A Multi-Institutional Randomized Phase II Study Evaluating Response and Surrogate Biomarkers to

Carboplatin and nab-Paclitaxel (CP) with or without Vorinostat (SAHA) in HER2- Negative Breast

Cancer

Principal Investigator: Vered Stearns, MDFellow: Roisin Connolly, MB.BCh

Eligible patients with locally advanced or metastatic breast cancer (up to 60)

Cohort A (up to 30)Triple-negative

5-AZA + entinostat

Cohort B (up to 30)Hormone-resistant5-AZA + entinostat

Disease Progression at Any Time Cohort A or Cohort B

5-AZA + etinostat + hormonal therapy

Event Monitoring

MD discretion

Study schema

Conclusions

• Epigenetics is a new way to look at cancer biology and therapy

• Ongoing trials in major tumor types in the metastatic setting

• Plans to move therapy into earlier stage disease may be even more successful

Acknowledgements

• First and foremost, our patients

• SU2C researchers

• Research support staff at all our institutions