Epigenetics and Cancer

+ Nilofer Azad, MD Assistant Professor, Gastrointestinal Oncology/Phase I Program Sidney Kimmel Comprehensive Cancer Center October 19, 2010

Simplified Model of Epigenetic Regulation of Gene Expression CMAJ 2006;174(3):341-8

How do genes get turned on and off?

Protein Complex

M M

Protein Complex

M Promoter Coding section Non-coding section Coding section

DNA of Gene X

Histone Histone

Gene is transcribed = ON Gene blocked from being transcribed = OFF

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/m 2 SQ daily x 7 d / 28 d cycle • Mechanism of action: Incorporated into DNA → suicide inhibitor of DNMT Induces global hypomethylation • Time to clinical response: Average = 4 months

Histone deacetylase inhibitors

• Three currently FDA approved agents • Vorinostat (Pan-HDACi) (SAHA, Zolinza) Oral agent Approved 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

Phase I Toxicity Data

Phase I Toxicities

Injection Site Reaction Nausea / Vomiting Constipation Anorexia Lower Extremity Edema Hyperglycemia Low Electrolytes Fatigue Neuropathy Neutropenia Lymphopenia Anemia Thrombocytopenia 0 Grade 1 Grade 2 Grade 3 2 4 6

Number of Patients

8 10

Updated Response Data 28 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 with Partial 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

Hypotheses for biology of the complete responder 15500 14500 • Higher serum level of 5-azacitidine… • Responding patient was a previously resected stage I 1000 NSCLC patient found a methylation pattern that predicted she was at 0 high risk for early recurrence SD CR Response

Gene DNA Hypermethylation Markers Are Better for Prognosis than Standard Staging

1.00

p16 and H-cadherin Negative (U) n=79

P<0.0001

0.75

0.50

Positive (M) N=11 Stage 1 OR = 25 fold

0.25

Molecular Re-staging Stage 3

0.00

0 1 2 3

Years After Surgery

4 5 Brock et al, 2008

Epigenetic Therapy Study Design: Treatment Schema

Stage IA or IB NSCLC s/p surgery with curative intent R A N D O M I Z E 2 1 Within 4-8 weeks of completing surgery 5-Azacitidine 40 mg/m 2 SQ Day 1-5, 8-10 Entinostat 7mg PO Day 3 and 10 Every 28 days, for 6 cycles Intended Accrual: 172 patients Standard Care Intended Accrual: 86 patients

COLON CANCER

Colorectal Cancer is Common

2009 Estimated U.S. Cancer Deaths

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

Men 294,120 Women 271,530

Lung and bronchus 31% 26% Lung and bronchus Prostate 10% 15% Breast

Colon and rectum 8% 9% Colon and rectum

Pancreas 6% 6% Pancreas Leukemia 4% 6% Ovary Liver/bile duct 4% 4% Non-Hodgkin lymphoma Esophagus 4% 3% Leukemia Urinary bladder 3% 3% Uterine corpus Non-Hodgkin Lymphoma 3% 2% Brain/other nervous system Kidney 3% 2% Liver/bile duct All other sites 24% 25% All other sites Colorectal cancer represents 2 nd leading cause of death Available at: http://www.cancer.org.

Colorectal Cancer Staging Adenoma Pre-cancer lesion Stage I localized, not through “muscularis” (muscle wall in the colon) Stage II through muscularis, but no lymph nodes Stage III cancer in nodes, but not other organs Stage IV metastatic (liver, lung, etc)

Stage I-II Stage III IV

Disease Stage at Time of Diagnosis

Stage I Stage II Stage III Stage IV 15% 20%–30% 30%–40% 20%–25% Hamilton IM, Grem JL. Current Cancer Therapeutics. 3rd ed. 1998;157.

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

85% recur within 3 years 85%

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

Copyright © American Society of Clinical Oncology

Metastatic Disease

History 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 2001 2002 2004 : Irinotecan approved as first-line in CRC (bolus IFL) : Capecitabine approved as first-line in CRC in selected pts : Oxaliplatin approved as second-line agent (FOLFOX) : Oxaliplatin approved as first-line agent in infusional regimen 2004: 2006: 2008: Approval of Cetuximab (Erbitux) & Bevacizumab (Avastin) Approval of Panitumumab (Vectibix) KRAS mutations predict lack of benefit of EGFR mAb’s

Incremental Survival Advantage in First-Line Metastatic Colorectal Cancer No active drug 5-FU/LV IFL FOLFOX4 IFL + bevacizumab FOLFOX/FOLFIRI FOLFOX/FOLFIRI + biologics 0

~4-6 mo 12-14 mo ~ 15-16 mo ~ 20 mo 20.3 mo 21.5 mo ?

6 12 18 Median OS (mo) 24

Are we hitting a wall with current drugs?

Therapy for Advanced Colorectal Cancer: Response rates and survival First Line - FOLFOX or - CAPOX or - FOLFIRI +/- Bevacizumab Second Line - FOLFOX or - FOLIRI or - Irinotecan alone Third Line - Irinotecan + Cetuximab - Cetuximab - Irinotecan/Cetuximab - Panitumumab +/- Bevacizumab Response Rates in Randomized Trials:

50-60% 15%

Survival Benefit in Randomized Trials:

Yes Yes 10% 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

28 days

Study Schema

C1d1 C1d3 C1d10 entinostat entinostat 5-aza days 1-5 and 8-10 q cycle C2d1 C2d3 entinostat C2d10 entinostat C3d1 5-aza days 1-5 and 8-10 q cycle = plasma sampling for research purposes = tumor sampling for research purposes

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 cancer

1

• 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 008 A 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, MD Fellow: Roisin Connolly, MB.BCh

Study schema

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

Cohort B (up to 30)

Hormone-resistant 5-AZA + entinostat

Cohort A (up to 30)

Triple-negative 5-AZA + entinostat

Disease Progression at Any Time

Cohort A or Cohort B MD discretion 5-AZA + etinostat + hormonal therapy Event Monitoring

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