Patient Selection for PARP Inhibitors: Purpose and Practicalities Presenter Charlie Gourley, MBChB, PhD, FRCP Professor of Medical Oncology University of Edinburgh Edinburgh, Scotland, United Kingdom Abbreviations: BRCA = breast cancer gene 1

Topics for Discussion Rationale for BRCA testing to inform decision making in patients with cancer Who should be tested and when? Germline or somatic testing? Barriers to testing 2

BRCA1/2 Mutation Status in Ovarian Cancer Identification of unaffected mutation carriers Prognostic importance Tells us how the disease might behave Impact on patient treatment Platinum sensitivity Sensitivity to intraperitoneal chemotherapy Sensitivity to other chemotherapy Pegylated liposomal doxorubicin Trabectedin PARP inhibition Abbreviations: PARP = poly (ADP-ribose) polymerase 3

Identification of Unaffected Mutation Carriers Abbreviations: BBC = bilateral breast cancer ca = cancer OS = overall survival Patients with BRCA1 and BRCA2 mutations had a better survival vs patients with wild-type BRCA until ~5 years At around 5 years, OS between patients with BRCA1 mutations and patients with wild-type BRCA was similar However, patients with BRCA2 mutations continue to have improved OS at 10 years Kadouri L, et al. BMC Cancer. 2007;7:14. 4

BRCA1/2 Impact on Disease Behavior: Ovarian Cancer Abbreviations: hered = hereditary met = metastasis P = .153 Site of Mets Site of Mets Gourley C, et al. J Clin Oncol. 2010;28:2505-2511. 5

Impact on Patient Treatment, Platinum Sensitivity: Ovarian Cancer Second-Line Response Rate Chemotherapy for Relapse BRCA Mutant BRCA Wild-Type Platinum-based 92 41 Non-platinum 20 33 Third-Line Response Rate 100 14 29 6 Tan DS, et al. J Clin Oncol. 2008;26:5530-5536. 6

BRCA1/2 Status: Impact on PLD Sensitivity 87 Edinburgh patients evaluable for PLD response 83 HGS, 4 non-HGS 19.3% response rate in HGS (16/83) BRCA1/2 wild-type: 12.1% (7/58) BRCA1/2 aberrant: 36% (9/25) Rs1799950 only: 50% (3/6) BRCA1/2 mutant (no rs1799950-only patients) Abbreviations: HGS = high-grade serous PLD = pegylated liposomal doxorubicin Hollis et al., unpublished data, 2017. 7

BRCA1/2 Status: Impact on Trabectedin Sensitivity Ova-301 phase 3 study In patients with recurrent ovarian cancer PLD ± trabectedin The PFS and OS benefit of the combination appears to be confined to the BRCA1-mutant population Abbreviations: PFS = progression-free survival Monk BJ, et al. Ann Oncol. 2015;26:914-920. 8

Cellular DNA Repair Pathways Enzymes involved PARP XRCC1 LIGASE 3 BER DSBs SSBs Repair Pathway DNA-PK KU70/80 BRCA1/2, PALB2 CHEK1/2, RAD51 HRR NHEJ DSB repair ATM MSH2 MLH1 Mismatch repair ERCC1 ERCC4 NER Bulky adducts Base mismatches, insertions and deletions Abbreviations: DSB = double-strand break SSB = single-strand break BER = base excision repair NER = nucleotide excision repair NHEJ = non-homologous end joining HRR = homologous recombination repair Lord CJ, Ashworth A. Nature. 2012;481:287-293. O'Connor MJ. Mol Cell. 2015;60:547-560. 9

Olaparib Monotherapy Content no longer available Abbreviations: bid = twice daily gBRCAm = germline breast cancer gene mutation Reprinted from Lancet, 376 /9737, Audeh MW, et al., Oral poly(ADP-ribose) polymerase inhibitor olaparib in patients with BRCA1 or BRCA2 mutations and recurrent ovarian cancer: a proof-of-concept trial, 245–251, Copyright 2010, with permission from Elsevier. Reprinted from Lancet Oncol., 12 /9, Gelmon KA et al., Olaparib in patients with recurrent high-grade serous or poorly differentiated ovarian carcinoma or triple-negative breast cancer: a phase 2, multicentre, open-label, non-randomised study, 852–861, Copyright 2011, with permission from Elsevier. 10

Olaparib Maintenance, Study 19: PFS Analysis Content no longer available Abbreviations: BRCAm = breast cancer gene mutation BRCAwt = breast cancer gene wild-type CI = confidence interval HR = hazard ratio BRCAwt includes patients with no known BRCAm or a mutation of unknown significance Reprinted from Lancet Oncol., 15 /8, Ledermann J, et al., Olaparib maintenance therapy in patients with platinum-sensitive relapsed serous ovarian cancer: a preplanned retrospective analysis of outcomes by BRCA status in a randomised phase 2 trial, 852–861, Copyright 2014, with permission from Elsevier. 11

Olaparib Maintenance, SOLO 2: PFS Content no longer available 5.5 19.1 Median follow-up was 22.1 months in the olaparib group and 22.2 months for placebo Reprinted from Lancet Oncol., 18 /9, Pujade-Lauraine EA, et al., Olaparib tablets as maintenance therapy in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA1/2 mutation (SOLO2/ENGOT-Ov21): a double-blind, randomised, placebo-controlled, phase 3 trial, 1274-1284, Copyright 2017, with permission from Elsevier. 12

Niraparib, NOVA: Second-Line Maintenance Content no longer available Abbreviations: HRD = homologous recombination deficiency From N Engl J Med., Mirza MR, et al., Niraparib Maintenance Therapy in Platinum-Sensitive, Recurrent Ovarian Cancer, 375, 2154-2164. Copyright © 2016 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society. 13

Which Patients (Non-Ovarian)? Study 42 Olaparib monotherapy tested in gBRCA1/2 mutation carriers with advanced cancers Breast cancer with ≥ 3 prior lines of chemotherapy for metastatic disease Pancreatic cancer with prior gemcitabine Prostate cancer progressed on hormone and 1 prior systemic treatment Platinum-resistant ovarian cancer Tumor Response Rate (RECIST) Breast (62 patients) 13% Pancreatic (23 patients) 22% Prostate (8 patients) 50% Ovarian (193 patients) 31% Abbreviations: RECIST = Response Evaluation Criteria In Solid Tumors Kaufman B, et al. J Clin Oncol. 2015;33:244-250. 14

Olaparib vs Physician's Choice: Phase 3 OlympiAD Study in MBC Content no longer available Abbreviations: MBC = metastatic breast cancer No. = number From N Engl J Med., Robson R, et al., Olaparib for Metastatic Breast Cancer in Patients with a Germline BRCA Mutation, 377, 523-533. Copyright © 2017 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society. 15

Which Patients (Prostate Cancer)? TOPARP Study Olaparib monotherapy in metastatic, castration- resistant prostate cancer (49 evaluable patients): Heavily pre-treated 33% response rate (16/49) by RECIST 1.1, PSA response, or fall in circulating tumor cells 16 patients found to have aberrations in DNA repair genes; 88% response rate (14/16) in these patients All 7 patients with BRCA2 loss had a PSA response and all 5 with measurable disease had a RECIST response PSA = prostate-specific antigen Mateo J, et al. N Engl J Med. 2015;373:1697-1708. 16

Clear evidence of 'super responders' Why a Breakthrough? Clear evidence of 'super responders' Gourley C, et al. J Clin Oncol. 2017;35:5533.

Non mucinous ovarian cancer patients (n = 1001) Australian Population-Based Study of BRCA Mutations in Patients With Ovarian Cancer Non mucinous ovarian cancer patients (n = 1001) BRCA mutations: 14% overall 16.6% of serous cancer 22.6% of HGS Alsop K, et al. J Clin Oncol. 2012;30:2654-2663. 18

Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) Data (528 BRCA1 & 176 BRCA2) n = 704 (813 BRCA1 & 272 BRCA2) n = 1085 % % Histology Grade Mavaddat N, et al. Cancer Epidemiol Biomarkers Prev. 2012;21:134-147. 19

Do Patients With Non-Serous Histology Associate With BRCA Mutations? Study Serous HGS Endometrioid Clear cell Borderline/ Mucinous Risch, 2006 18% 7% 0% Malander, 2004 8% 13% Soegaard, 2008 5.4% 9% Alsop, 2012 17% 8.4% 6% Excluded Song, 2014 11% 5% - Hirsh-Yechezkel G, et al. Gynecol Oncol. 2003;89:494-498. Risch HA, et al. J Natl Cancer Inst. 2006;98:1694-1706. Malander S, et al. Eur J Cancer. 2004;40:422-428. Soergaard M, et al. Clin Cancer Res. 2008;14:3761-3767. Alsop K, et al. J Clin Oncol. 2012;30:2654-2663. Song H, et al. Hum Mol Genet. 2014;23:4703-4709. 20

Predictors of BRCA Mutations? Age? BRCA1/2 - BRCA1+ BRCA2+ Alsop, 2012[a] 60 y 53 y Soegaard, 2008[b] 61 y 49 y Malander, 2004[c] 59 y 57 y Song, 2014[d] 52 y Approximately 25% of BRCA1/2 mutation carriers are older than 60 y[e] Family History? Frequency of BRCA in the Presence of Family History Frequency of BRCA in the Absence of Family History Percentage of BRCA Mutation Carriers who Lack a Family History Alsop, 2012[a] 39% 8% 44% Song, 2014[d] 19% 5% 35% to 50% of BRCA1/2 mutation carriers do not have a family history a. Alsop K, et al. J Clin Oncol. 2012;30:2654-2663; b. Soergaard M, et al. Clin Cancer Res. 2008;14:3761-3767; c. Malander S, et al. Eur J Cancer. 2004;40:422-428; d. Song H, et al. Hum Mol Genet. 2014;23:4703-4709; e. Risch HA, et al. J Natl Cancer Inst. 2006;98:1694-1706. 21

Test Early (at Diagnosis) or Test Late (at Relapse or Later)? Prognostic information High Low Inform first-line therapy decision ☑ ☒ Inform access to first-line PARP inhibitor trials Identification for PARP inhibitor at relapse Identification of family carriers ☑ (early and complete) ☑ (late and less complete) Timing for patient Lot of other considerations Come to terms with disease Family discussion time Less More Genetic counsellor time 22

Ideal Scenario All women with non-mucinous epithelial ovarian cancer (or at least HGS ovarian cancer) know their BRCA status shortly after a diagnosis of ovarian cancer This information is used to: Guide therapeutic decisions Reduce the morbidity and mortality from BRCA-associated cancer for the patient and their family members 23

Germline or Somatic Sequencing? Maintenance Studies Study Agent sBRCA PFS HR (95% CI) gBRCA PFS HR (95% CI) Study 19[a] Olaparib vs placebo 0.23 (0.04, 1.12) 0.17 (0.09, 0.34) NOVA[b] Niraparib vs placebo 0.27 (0.08, 0.90) (0.17, 0.41) Treatment Study Study Agent sBRCA Response Rate gBRCA Response Rate ARIEL2[c] Rucaparib 88% 81% Abbreviations: gBRCA = germline breast cancer gene mutation sBRCA = somatic breast cancer gene mutation a. Ledermann J, et al. N Engl J Med. 2012;366:1382-1392; b. Mirza MR, et al. N Engl J Med. 2016;375:2154-2164; c. Swisher EM, et al. Lancet Oncol. 2017;18:75-87; d. Hollis RL, et al. Cancer Biol Med. 2016;13:236-247; e. Patch AM, et al. Nature. 2015;521:489-494. 24

Germline or Somatic Sequencing? (cont) Easy to acquire and process sample Interpretation of sequence data straightforward Low false negative rate (2%) False positive signals not an issue Tissue heterogeneity not an issue If want to detect all BRCA patients, will need to sequence 100% of germline and 85% of somatic (if do germline first) In some countries, patients required to see a genetic counsellor before testing can be done Somatic More samples processing required Interpretation of sequence data complicated False negative rate unclear False positive signals are an issue (FFPE artefact) Tissue heterogeneity may be an issue If want to detect all BRCA patients, will need to sequence 100% of somatic and 15% of germline (if do somatic first) In many countries, patients not required to see a genetic counsellor before the testing is done Abbreviations: FFPE = formalin-fixed paraffin-embedded 25

Barriers to Testing Financial Genetic counsellor availability Ethical Cost of test Cost of insurance if positive test Genetic counsellor availability Ethical Technological Cultural 26

Summary Approximately 10% of invasive epithelial non-mucinous ovarian cancers are associated with germline BRCA1/2 mutations[a-c] BRCA germline mutations are not restricted to serous histology, but it is the most frequent type[d] Around one-third of BRCA carriers with ovarian cancer do not have a family history of breast/ovarian cancer, or have been diagnosed > 60 y BRCA germline testing should be considered in all patients with epithelial invasive non-mucinous ovarian cancer Knowledge of BRCA status informs therapeutic decisions including access to PARP inhibitors RCOG = Royal College of Obstetricians and Gynaecologists Royal College of Obstetricians and Gynaecologists. The distal fallopian tube as the origin of non-uterine pelvic high-grade serous carcinomas (Scientific Impact Paper No. 44). https://www.rcog.org.uk/globalassets/documents/guidelines/scientific-impact-papers/sip44hgscs.pdf. Published November 2014. Accessed November xx , 2017. a. Risch HA, et al. J Natl Cancer Inst. 2006;98:1694-1706; b. Malander S, et al. Eur J Cancer. 2004;40:422-28; c. Alsop K, et al. J Clin Oncol. 2012;30:2654-2663; d. RCOG. Scientific Impact Paper No 44. 27

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