High risk premenopausal Luminal A breast cancer patients derive no benefit from adjuvant chemotherapy: results from DBCG77B randomized trial 1 San Antonio Breast Cancer Symposium - December 8-12, 2015 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. Presenter: Torsten O. Nielsen, MD/PhD, FRCPC University of British Columbia, Canada Maj-Britt Jensen - Statistical Office, Danish Breast Cancer Group Dongxia Gao, Samuel CY Leung, Samantha Burugu and Shuzhen Liu - Genetic Pathology Evaluation Centre, Vancouver Coastal Health Research Institute Charlotte Levin Tykjaer Jorgensen and Eva Balslev - Department of Pathology, Herlev University Hospital Bent Ejlertsen - Medical Oncologist and Director, Danish Breast Cancer Group

2 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. Disclosures Dr. Nielsen: Bioclassifier LLC (ownership interest) Nanostring Technologies (royalty, patent, consultant, fees) Dr. Ejlertsen: Nanostring Technologies (patent, contracted research) San Antonio Breast Cancer Symposium - December 8-12, 2015

Background  Intrinsic subtypes: main biologically-different kinds of breast cancer, as recognized by molecular testing  Proven to be prognostic in many settings; appear promising for predicting benefit of chemotherapy 3 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015

Background Best way to test if intrinsic type predicts value of chemotherapy = interaction test on Phase 3 trial randomized chemo vs. no chemo BUT: such materials difficult to find (trials finished in 1980s, blocks not saved, blocks exhausted, not enough cases) 4 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015

The DBCG77B Trial 5 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 N = 1146 premenopausal women, node (+) / high risk (of any hormone receptor or HER2 status)

The DBCG77B Trial 6 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 treatment: mastectomy + axillary node dissection + RT trial arms: control, levamisole; cyclophosphamide, CMF

The DBCG77B Trial 7 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 Positive study: Both C and CMF improve 10y DFS & 25y OS

Hypothesis “Patients with Luminal A tumors will derive no benefit from chemotherapy” Interaction test between Luminal A status and chemotherapy, for trial’s primary endpoint: 10 yr invasive DFS C and CMF arms = chemotherapy; levamisole + control arms = no chemotherapy 8 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015

Experimental Design Formal prospective-retrospective study Statistics by DBCG central office, executing prespecified plan in signed MTA Staining, scoring and subtype calls by Vancouver team (pathologists with no access to patient data) Intrinsic subtype by IHC performed on TMAs 9 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015

10 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, /- ≤13% >13% - >20% + /-  Triple Negative  (strict) Prat et al. JCO 2013; 31: 203-9

11 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, /- ≤13% >13% - >20% + /- NOT LUMINAL A

Enrolled (n=1146) treated per protocol (n=1072) Tissue available, as TMA (n=709) IHC informative for subtype (n=633) Lum A N = 165 not Lum A N = 468 Lum B (319) HER2E (58) TNP (91), incl. basal (82) San Antonio Breast Cancer Symposium - December 8-12,

Patient characteristics original trial & TMA study set 13 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 nage < 50T > 2 cmN+grade 2-3ductalchemoHazard Ratio original trial %67%83%81%88%74% 0.63 [ ] study set 63370%68%90%81%88%77% 0.56 [ ]

14 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 non-Lum A patients: Hazard Ratio 0.50 interaction test p < 0.05 Main Result: prediction, by subtype

15 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 non-Lum A patients: Hazard Ratio 0.50 Luminal A patients: Hazard Ratio 1.07 interaction test p < 0.05

16 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 non-Lum A patients: Hazard Ratio 0.50 Luminal A patients: Hazard Ratio 1.07 Interaction test: p < 0.05

Caveats  The IHC method we used has limited analytical validity as a clinical test  Tissue microarray study: blocks being recollected for gene profiling analysis  Older trial: higher risk patients, no endocrine tx, no anti HER2, no anthracyclines or taxanes This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12,

18 This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12, 2015 interaction test p < 0.05 Main Result: Women with the common Luminal A subtype of breast cancer get no benefit from chemotherapy even if node positive even with no hormonal therapy

acknowledgements Work developing the intrinsic subtype IHC classifier: Maggie Cheang, Chuck Perou, Aleix Prat Study concept assistance: Zuzana Kos, Jennifer Won, Anne-Vibeke Laenkholm Funding: Canadian Breast Cancer Foundation, IM Daehnfeldt Foundation, Danish Research Council (grant no ) … and our thanks to all the Danish women who participated This presentation is the intellectual property of the author/presenter. Contact for permission to reprint and/or distribute. San Antonio Breast Cancer Symposium - December 8-12,