HER2 Positive Breast Cancer - PDF Free Download

HER2 Positive Breast Cancer Charles E. Geyer, Jr. MD, FACP Professor of Medicine Division of Hematology, Oncology and Palliative Care Virginia Commonwealth University Associate Director of Clinical Research Massey Cancer Center Heme/Onc Fellows Lecture Series May 1, 2018

HER2/Neu Oncogene Discovery 1984: Neu transforming gene identified in chemically induced rat neuro-glioblastoma 1 1985: HER2 amplification identified in human breast cancer 2 1985: HER2 and c-erbb2 identified and found to be the same gene as neu 3 1986: Neu oncogene had activating point mutation in transmembrane domain 4 1987: HER2/neu amplification associated with worse prognosis in operable breast cancer 5 1 Schecter AL et al. Nature 1984;312:513-516 2 King CR et al. Science 1985;229:974-976 3 Coussens L et al. Science 1985; 230:1132-1139 4 Bargmann CI et al. Cell 1986;45:649-657 5 Slamon DJ et al. Science 1987; 237:177-182

HER Family Receptors and Ligands EGF Epi β-cel HB-EGF HRG (NRG1) Epi HB-GF NRG1 Ligand binding domain Transmembrane Tyrosine kinase domain HER1/ EGFR HER2 HER3 HER4 Herbst. Int J Radiat Oncol Biol Phys. 2004;59(suppl):21 Roskoski. Biochem Biophys Res Commun. 2004;319:1; Rowinsky. Annu Rev Med. 2004;55:433

HER Family of Receptors Ligand Binding, Dimerization, and Phosphorylation HER1 (Open) HER1 (Closed) EGF Dimerization HER2 (Open) EGF Phosphorylation Activation of Downstream Signaling Roskoski. Biochem Biophys Res Commun. 2004;319:1; Herbst. Int J Radiat Oncol Biol Phys. 2004;59(suppl):21

Hierarchy of HER2 Family Dimer Formation and Signal Potency Homodimers ErbB-1 ErbB-1 ErbB-1 ErbB-3 HER2 Heterodimers ErbB-2 ErbB-2 ErbB-1 ErbB-4 ErbB-1 ErbB-2 ErbB-3 ErbB-3 ErbB-4 ErbB-4 ErbB-3 ErbB-4 ErbB-4 ErbB-2 ErbB-3 ErbB-2 Weakest Strongest Holbro T and Hynes N. Annu Rev Pharmacol Toxicol. 2004;44:195-217 Harari D and Yarden Y. Oncogene. 2000;19:6102-6114 Rowinsky E. Horizons in Cancer Therapies: From Bench to Bedside. 2001;2:3-35

HER Family Heterodimer Signaling Pathways Grb2 Sos Shc Grb2 Sos PI3K Ras Raf PTEN Akt MEK1/2 mtor GSK3 FKHR BAD MAPK Cyclin D1, E Cell-cycle progression p27 Survival Proliferation

AC or Paclitaxel alone or with Trastuzumab in HER2+ MBC (2+ and 3+ on IHC) Median TTP 7.4 months vs 4.6 months (P<0.001) Median survival 25.1 months vs 20.3 months (P=0.046) Slamon DJ et al. NEJM 344: 2001;784-792

Trastuzumab with Chemotherapy as First-line Therapy for Metastatic Disease Agent(s) Administered with Trastuzumab Response Rate (%) Median Response Duration (months) Median TTF (months) Median Survival (months) Doxorubucin Cyclophosphamide 1 56 9.1 7.2 26.8 Paclitaxel 1 41 10.5 5.8 22.1 Docetaxel 2 61 11.7 9.8 31.2 Navelbine 3 68 N/P 5.6 N/P * N/P = Not Provided 1 Slamon DJ et al. N Engl J Med 2001;344:783-792 2 Marty M et al. J Clin Oncol 2005;23:4265-4274 3 Burstein HJ et al. J Clin Oncol 2003;21:2889-2895

ASCO-CAP Guidelines Definitions of HER2 Status FDA Positive ASCO-CAP Positive ASCO-CAP Equivocal* ASCO-CAP Negative IHC Membrane staining Intensity Percent staining 3+ Intense >10% 3+ Complete circumferential and intense, >10% of cells 2+ Incomplete or weak/mod > 10%, Strong/complete <10% 0 or 1+ Incomplete and Weak to None FISH Single probe assay HER2 copy number N/A Amplified 6 Equivocal 4 to <6 Non-amplified <4 Dual probe assay with HER2/CEP17 ratio >2.0 >2.0 OR <2.0 with >6 copies per cell <2.0 with >4.0 and <6.0 copies per cell < 2.0 with <4 copies per cell *Reflex testing with alternative method or chromosome 17 probe Wolff AC et al. J Clin Oncol. 2013:31; 3997-4013

Trastuzumab with Alternative Chemotherapy following Progression 54 patients First line Response rate - 43% Stable disease > 6 months - 43% Second line Response rate - 26% Stable disease > 6 months - 43% Median TTP - 6 months Beyond second line Response rate - 30% Stable disease > 6 months - 28% Median TTP - 6 months Bartsch R et al, BMC Cancer 2006;15(6):187-191

GBG 26/BIG-05: Trastuzumab/ Capecitabine vs. Capecitabine in Breast Cancer Progressing during Trastuzumab Eligibility criteria: Progressive MBC or LABC HER2 positive Patients randomized: 156 Prior therapies : 1 st line metastatic setting: T + taxane 111 T ± non-taxane 42 Adjuvant: T + taxane 3 Prior anthracyclines 75 Visceral metastases 119 R A N D O M I Z E Trastuzumab (T) 6 mg/kg day 1 q 21 days Capecitabine 2500 mg/m 2 /day, days 1-14, q 21 days Capecitabine 2500 mg/m 2 /day days 1-14, q 21 days Primary endpoint: TTP Secondary endpoints: OS, ORR, CB Von Minckwitz G, et al. J Clin Oncol 2009; 27:1999-2006

GBG 26/BIG 3-05 Capecitabine vs Capecitabine + Trastuzumab (median follow-up 15.6 months) (accrual closed with registration of lapatinib) Capecitabine Capecitabine + Trastuzumab Number patients 78 78 P value Time to Progression 5.6 months 8.2 months 0.03 Response Rate 27% 48% 0.01 Overall Survival 20.4 months 25.5 months NS Von Minckwitz G, et al. J Clin Oncol 2009; 27:1999-2006

Lapatinib Mechanism of Action Oral dual-tyrosine kinase inhibitor with specificity for the EGFR and HER2 receptors Binds reversibly to the cytoplasmic ATP-binding site of the kinases, preventing receptor phosphorylation and activation Blocks downstream signaling through homodimers and heterodimers of EGFR and HER2 Lapatinib 1+1 2+2 1+2 Downstream signaling cascade Rusnak et al. Mol Cancer Ther 2001;1:85-94 Xia et al. Oncogene 2002;21:6255-6263 Konecny et al. Cancer Res 2006;66:1630-1639

Lapatinib Non-Cross Resistance with Trastuzumab 100 90 Traztuzumab BT474 conditioned 80 70 60 50 percent Cell viability 40 30 20 10 BT474 Lapatinib BT474 conditioned BT474 0 0.016 0.031 0.066 0.125 0.25 0.5 1 2 4 µg/ml Traztuzumab 3.9 7.8 15.6 31.3 62.5 125 250 500 1000 nm Lapatinib Activity of lapatinib in HER2-overexpressing cells selected for long-term growth in the presence of 100ug/mL trastuzumab Konecny, Pegram, et al., Cancer Res 2006;66:1630-9

Comparison with Trastuzumab Activity Trastuzumab 1 Trastuzumab 2 Lapatinib 3 4 mg/kg 2mg/kg weekly n=58 8 mg/kg 4mg/kg weekly n=53 8mg/kg 6mg/kg q3wk n=105 1500 mg QD or 500 mg BID daily n=138 Objective Response (CR/PR), ITT 14 (24%) 15 (28%) 20 (19%) 39 (24%) Clinical Benefit Rate, ITT 20 (34%) 22 (42%) 35 (33%) 43 (31%) Median TTP, ITT, months 3.5 3.8 3.4 - Median TTF, ITT, weeks - - - 16.1 1 Vogel et al J Clin Oncol 2002;20:719-726 2 Baselga et al J Clin Oncol 2005;23:2162-2171 3 Gomez et al J Clin Oncol 2008;26:2999-3005

Progressive, HER2+ MBC or LABC Previously treated with anthracycline, taxane and trastuzumab* No prior capecitabine Measurable disease by RECIST LVEF institution LLN Stratification: Disease sites Stage of disease EGF100151 Study Design N=324 Lapatinib 1250 mg po qd continuously + Capecitabine 2000 mg/m 2 /d po days 1-14 q 3 wk Capecitabine 2500 mg/m 2 /d po days 1-14 q 3 wk Patients on treatment until progression or unacceptable toxicity, then followed for survival *Trastuzumab must have been administered for metastatic disease R A N D O M I Z A T I O N Geyer et al. NEJM 2006;355:2733-2743

Time to Progression - ITT Population % of patients free from progression* 100 90 80 70 60 50 40 30 20 10 No. of pts Progressed or died Median TTP, mo Hazard ratio (95% CI) P-value (log-rank, 1-sided) Lapatinib + Capecitabine 0.00004 Capecitabine 163 161 49 72 8.4 4.4 0.49 (0.34, 0.71) 0 0 10 20 30 40 50 60 Time (weeks) 70 Geyer et al. NEJM 2006;355:2733-2743

Overall Survival - ITT Population Cumulative Survival % 100 90 80 70 60 50 40 30 20 10 0 No. of pts Deaths Median OS Hazard ratio (95% CI) P value (log-rank, 2-sided) Lapatinib + Capecitabine 163 36 NR Capecitabine 0.92 (0.58, 1.46) 0.72 0 10 20 30 40 50 60 70 80 90 161 35 NR Time (weeks) Geyer et al. NEJM 2006;355:2733-2743

100 Most Frequent Adverse Events All Grades 90 Severity % of Patients 80 70 60 50 40 30 20 10 0 L+C 1 12 C 20 11 14 27 14 Diarrhea 2 L+C C 2 13 12 29 28 Nausea C L+C 7 11 32 26 10 13 PPE 1 Gr 4 Gr 3 Gr 2 Gr 1 L+C 7 C 20 5 9 Rash 1 L = lapatinib; C = capecitabine Geyer et al. NEJM 2006;355:2733-2743

Activity of Lapatinib and Trastuzumab on HER2+ Breast Cancer Cells Konecny GE et al. Cancer Res 2006;66:1630-1639

Phase III HER2+ Adjuvant Trial: ALTTO Surgery and Chemotherapy Completed Randomize Estimated N = 8,400 3-wkly Trastuzumab 6 mg/kg q3wks (52 wks) Lapatinib 1,500 mg daily (52 wks) Wkly Trastuzumab 2 mg/kg (12 or 18 wks) Washout (6 wks) Lapatinib 1,500 mg daily Lapatinib 1,000 mg daily + 3-wkly Trastuzumab 6 mg/kg (52 wks) (28 or 34 wks) Primary outcome measures: DFS Anti-HER2 therapy can overlap chemotherapy Dose adjustments: Lapatinib reduced to 750 mg daily when given with wkly paclitaxel and trastuzumab, due to high grade 3 toxicities, mainly diarrhea Sep 2011: Independent committee indicated that the lapatinib-alone arm is unlikely to meet the prespecified criteria to demonstrate non-inferiority to trastuzumab alone with respect to DFS - Lapatinibonly arm halted

NCIC MA.31/EGF108919 Women with HER2-positive (central or local lab) MBC and no prior chemotherapy or HER2-targeted therapy in the metastatic setting Experimental Arm Standard Arm 24 Weeks: Lapatinib + Taxane Until PD: Lapatinib 24 Weeks: Trastuzumab + Taxane Until PD: Trastuzumab Primary Outcome: PFS Taxane: Paclitaxel 80 mg/m 2 IV weekly (3 of 4) or Docetaxel 75 mg/m 2 IV every 3 weeks Anti-HER2/neu therapy: Lapatinib (L) 1250 mg PO daily + taxane; monotherapy 1500 mg PO daily Trastuzumab (T): Loading dose, then 6 mg/kg IV every 3 weeks or 2 mg/kg IV weekly Gelmon KA et al. ASCO 2012 Annual Meeting. Abstract LBA671

NCIC MA.31/EGF108919 PFS in Centrally Confirmed HER2 Positive Percent 100 80 60 40 Median PFS TTAX/T = 13.7 months LTAX/L = 9.0 months HR = 1.48 (95% CI,1.15-1.92); P = 0.003 20 No. at Risk TTAX/T LTAX/L 0 TTAX/T LTAX/L 0 5 10 15 20 25 30 35 40 Time (months) 259 266 181 178 93 71 39 30 20 10 8 2 1 0 0 0 0 0 Gelmon KA et al. ASCO 2012 Annual Meeting. Abstract LBA671

Trastuzumab and Pertuzumab Bind to Distinct Epitopes on HER2 Extracellular Domain Trastuzumab (4D5) Pertuzumab (2C4) Activates antibody-dependent cellular cytotoxicity Inhibits shedding and, thus, formation of p95 Inhibits HER2-mediated signaling Inhibits dimerization Potent inhibitor of HER-mediated signaling pathways Activates antibody-dependent cellular cytotoxicity Hubbard SR. Cancer Cell 2005;7:287-288

CLEOPATRA Schema HER2+ MBC N = 800 1:1 randomization Docetaxel + Trastuzumab + Placebo Docetaxel + Trastuzumab + Pertuzumab An international Phase III randomized, double-blind, placebo-controlled study (approximately 250 sites worldwide) Endpoints: Progression-free survival Overall survival Biomarker analysis Baselga J, et al. NEJM 2012;366:109-119

CLEOPATRA Primary Endpoint: Independently Assessed PFS Progression-free survival (%) 100 90 80 70 60 50 40 30 20 10 0 n at risk Ptz + T + D Pla + T + D Ptz + T + D: median 18.5 months Pla + T + D: median 12.4 months 0 5 10 15 20 25 30 35 40 Time (months) 402 345 267 139 83 32 10 0 0 406 311 209 93 42 17 7 0 0 = 6.1 months 433 PFS events HR = 0.62 95% CI 0.51 0.75 p<0.0001 Baselga J, et al. NEJM 2012;366:109-119

CLEOPATRA Final OS Analysis OS (%) n at risk Ptz + T + D Pla + T + D 100 90 80 70 60 50 40 30 20 10 0 HR 0.68 95% CI = 0.56, 0.84 p = 0.0002 0 10 20 30 40 50 60 70 402 406 371 350 318 289 Time (months) 268 230 Ptz + T + D: median 56.5 months Pla + T + D: median 40.8 months Chemo alone 226 179 104 91 28 23 Δ 15.7 months 1 0 S. Swain et al, N Engl J Med. 2015;372(8):724-34

CLEOPATRA Adverse Events (all grades) 25% incidence or 5% difference between arms Adverse event, n (%) Placebo + trastuzumab + docetaxel (n = 397) Pertuzumab + trastuzumab + docetaxel (n = 407) Diarrhea 184 (46.3) 272 (66.8) Neutropenia 197 (49.6) 215 (52.8) Nausea 165 (41.6) 172 (42.3) Fatigue 146 (36.8) 153 (37.6) Rash 96 (24.2) 137 (33.7) Mucosal inflammation 79 (19.9) 113 (27.8) Asthenia 120 (30.2) 106 (26.0) Peripheral edema 119 (30.0) 94 (23.1) Constipation 99 (24.9) 61 (15.0) Febrile neutropenia 30 (7.6) 56 (13.8) Baselga J, et al. NEJM 2012;366:109-119

Trastuzumab-MCC-DM1 Binds to HER2 with affinity similar to trastuzumab Provides intracellular delivery of mertansine» Derivative of maytansine, a natural-product microtubule polymerization inhibitor» 20-100 more potent than vincristine

T-DM1: Mechanism of Action HER2 T-DM1 Emtansine release Inhibition of microtubule polymerization Lysosome P P P Internalization Nucleus Adapted from LoRusso PM, et al. Clin Cancer Res 2011

T-DM1 vs. Capecitabine + Lapatinib HER2 Positive Metastatic Breast Cancer HER2-positive Locally advanced or metastatic BC Previously received trastuzumab-based therapy Primary end point: PFS Secondary end points: OS, quality of life Allowed crossover at progression T-DM1 (3.6 mg/kg) q3w Lapatinib (1250 mg/day) Days 1 21 + Capecitabine (2000 mg/m 2 ) Days 1 14 q3w Verma S et al. NEJM. 2012;367:1783-1791

EMILIA PFS by Independent Review Proportion progression-free 1.0 0.8 0.6 0.4 0.2 Median (mos) No. events Cap + Lap 6.4 304 T-DM1 9.6 265 Stratified HR=0.650 (95% CI, 0.55, 0.77) P<0.0001 0.0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (mos) No. at risk by independent review: Cap + Lap 496 404 310 176 129 73 53 35 25 14 9 8 5 1 0 0 T-DM1 495 419 341 236 183 130 101 72 54 44 30 18 9 3 1 0 Unstratified HR=0.66 (P<0.0001) Verma S et al. NEJM. 2012;367:1783-1791

EMILIA OS at Second Interim Analysis OS (%) 100 80 60 40 20 85.2% (95% CI, 82.0-88.5) 78.4% (95% CI, 74.6-82.3) Lapatinib/Capecitabine T-DM1 64.7% (95% CI, 59.3-70.2) 51.8% (95% CI, 45.9-57.7) Median PFS Months 25.1 30.9 No. of Events 182 149 Stratified hazard ratio - 0.68 (95% CI) HR was 0.62 at First Interim NS Efficacy stopping boundary, P = 0.0037 or hazard ratio 0.73 No. at Risk Lap + Cap T-DM1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Months 496 471 453 435 403 368 297 240 204 159 133 110 86 63 45 27 17 7 4 495 485 474 457 439 418 349 293 242 197 164 136 111 86 62 38 28 13 5 Verma S et al. NEJM 2012;367:1783-1791

EMILIA Non-Hematologic Adverse Events Grade 3 AEs With Incidence 2% Cap + Lap (n=488) T-DM1 (n=490) Adverse Event All Grades, % Grade 3, % All Grades, % Grade 3, % Diarrhea Hand-foot 79.7 20.7 23.3 1.6 syndrome Vomiting 58.0 16.4 1.2 0.0 Hypokalemia 29.3 4.5 19.0 0.8 Fatigue 8.6 4.1 8.6 2.2 Nausea 27.9 3.5 35.1 2.4 Mucosal inflammation 44.7 2.5 39.2 0.8 19.1 2.3 6.7 0.2 Increased AST Increased ALT 9.4 0.8 22.4 4.3 8.8 1.4 16.9 2.9 Verma S et al. NEJM 2012;367:1783-1791

TH3RESA Study Schema HER2-positive (central) advanced BC (N~600) 2 T-DM1 3.6 mg/kg q3w IV (n~400) PD 2 prior HER2-directed therapies for advanced BC Prior treatment with trastuzumab, lapatinib, and a taxane 1 Treatment of physician s choice (TPC) (n~200) PD T-DM1 (optional crossover) Stratification factors: World region, number of prior regimens for advanced BC, presence of visceral disease Co-primary endpoints: PFS by investigator and OS Key secondary endpoints: ORR by investigator and safety Wildiers H et al. ECCO 2013

TH3RESA PFS by Investigator Assessment Proportion progression-free 1.0 0.8 0.6 0.4 0.2 TPC (n=198) T-DM1 (n=404) Median (months) 3.3 6.2 No. of events 129 219 Stratified HR=0.528 (95% CI, 0.422, 0.661) P<0.0001 0.0 No. at risk: TPC T-DM1 0 2 4 6 8 10 12 14 Time (months) 198 120 62 28 13 6 1 0 404 334 241 114 66 27 12 0 Median follow-up: TPC, 6.5 months; T-DM1, 7.2 months. Unstratified HR=0.521 (P<0.0001). Wildiers H et al. ECCO 2013

1.0 TH3RESA First Interim OS Analysis Observed 21% of targeted events Proportion surviving No. at risk: TPC T-DM1 0.8 0.6 0.4 0.2 0.0 0 2 4 6 8 10 12 14 Time (months) 198 404 169 381 125 316 80 207 TPC (n=198) 44 patients in the TPC arm received crossover T-DM1 treatment after documented progression. Unstratified HR=0.57 (P=0.004). Wildiers H et al. ECCO 2013 51 127 T-DM1 (n=404) Median (months) 14.9 NE No. of events 44 61 Stratified HR=0.552 (95% CI, 0.369, 0.826); P=0.0034 Efficacy stopping boundary HR<0.363 or P<0.0000013 30 65 9 30 3 7 16 0 0

First-Line Treatment With T-DM1 vs Trastuzumab + Docetaxel Phase II N = 137 MBC patients (never received chemotherapy or HER2-targeted therapy for locally advanced or metastatic HER2- positive breast cancer) R a n d o m i z e 1:1 T-DM1 3.6 mg/kg IV q3wk Trastuzumab 6 mg/kg IV (8 mg/kg in cycle 1) + Docetaxel 75 or 100 mg/m 2 IV q3wk until disease progression or unacceptable toxicity, and then followed for survival Hurvitz S et al. European Multidisciplinary Cancer Congress 2011 Abstract 5001 38

First-Line Treatment of HER2-Positive MBC With T-DM1 vs D + T Docetaxel + Trastuzumab T-DM1 Comparison No. Patients 70 67 Efficacy Median PFS (months) 9.2 14.2 ORR n (%) (95% CI) Toxicity 58.0% (45.5, 69.2) 64.2% (51.8, 74.8) Grade 3-4 events 89.4% 46.4% Treatment discontinuation due to adverse events 28.8 % 7.2% HR 0.59 (0.36-0.97, P = 0.035) Hurvitz S et al. European Multidisciplinary Cancer Congress 2011 Abstract 5001

MARIANNE Initiated Prior to Report of CLEOPATRA HER2-positive (central) LABC or MBC No prior chemotherapy for LABC/MBC >6 months from prior (neo)adjuvant vinca alkaloid or taxane chemotherapy Trastuzumab + docetaxel (8 mg/kg LD then 6 mg/kg + 100 or 75 mg/m 2 q3w) OR Trastuzumab + paclitaxel (4 mg/kg LD then 2 mg/kg + 80 mg/m 2 qw) T-DM1 + placebo (3.6mg/kg + 840 mg LD then 420 mg q3w) T-DM1 + pertuzumab (3.6mg/kg + 840 mg LD then 420 mg q3w) N = 1095 Stratification factors: World region, Prior neo-/adjuvant therapy (if Yes: prior trastuzumab/ lapatinib), Visceral disease Primary end point: PFS by independent review facility (IRF), non-inferiority and superiority assessed Key secondary end points: OS, PFS by investigator, ORR, Safety, Patient-reported outcomes Ellis P, et al. ASCO 2015

MARIANNE Progression-Free Survival by IRF Progression-Free Survival (%) 100 80 60 40 20 No. at Risk HT T-DM1 T-DM1+P 0 365 367 363 HT T-DM1 T-DM1+P HT T-DM1 T-DM1+P Median PFS (mo.) 13.7 14.1 15.2 Events (no.) 231 236 217 Stratified HR (97.5% CI) vs HT Stratified HR (97.5% CI) vs T-DM1 0.91 (0.73 1.13) P=0.31 0.87 (0.69 1.08) P=0.14 0.91 (0.73 1.13) 0 6 12 18 24 30 36 42 48 54 Time (mo.) 265 163 107 75 50 21 257 176 133 104 67 28 261 177 135 109 75 25 5 3 5 1 Non-inferiority: Established if the upper limit of the 97.5% CI for the HR is below 1.1765 (non-inferiority margin). Ellis P, et al. ASCO 2015

Innate and Adaptive Immunity of Trastuzumab Dependent on Functional FcγR Adaptive Immunity Innate immunity Bianchini G and Gianni L. Lancet Oncol 2014;15:58-68

NSABP B-31 - Adjuvant Trastuzumab DFS Outcome by FCGR2A and FCGR3A SNPs Genotype by treatment interaction test adjusted for ER and nodal status indicates association between FCGR3A-158 and benefit from trastuzumab (p=0.0002) Gavin PG et al, JAMA Oncol. 2017;3:335-341

NRG BR-004 Schema HER2-Positive, First-line Metastatic Breast Cancer STRATIFICATION Prior adjuvant or neoadjuvant trastuzumab (yes; no) Prior adjuvant or neoadjuvant pertuzumab (yes; no) Estrogen receptor status (positive; negative) PD-L1 status (positive; negative) RANDOMIZATION Arm 1 Weekly Paclitaxel + Trastuzumab + Pertuzumab every 3 weeks until progression + Placebo every 3 weeks until progression or 2 years Arm 2 Weekly Paclitaxel + Trastuzumab + Pertuzumab every 3 weeks until progression + Atezolizumab 1200 mg every 3 weeks until progression or 2 years Weekly Paclitaxel (WP): 80 mg/m 2 IV Days 1, 8 and 15 every 3 weeks for 9 cycles

Stimulatory and Inhibitory Factors in Adaptive Cancer-Immunity Cycle Traz/Pert Atezolizumab Chemotherapy Chen DS and Mellman I. Immunity 2013;39:1 10

Cross-Talk Between Signal Transduction and Endocrine Pathways Growth factor Estrogen IGFR EGFR / HER2 Plasma membrane P P P P ER Cell survival Akt PI3-K P p90 RSK P P P MAPK SOS RAS RAF MEK P P Cytoplasm P P P ER P ER p160 CBP Basal transcription machinery Cell growth Nucleus ERE ER target gene transcription Adapted from Johnston S. Clin Cancer Res. 2005;11:889S-899S.

TAnDEM PFS - Anastrozole vs Anastrozole plus Trastuzumab Probability 1.0 0.8 0.6 0.4 Events 87 99 Median PFS 4.8 months 2.4 months 95% CI 3.7, 7.0 2.0, 4.6 p value 0.0016 0.2 No. at risk A+H A 0.0 0 5 10 15 20 25 30 35 40 45 50 55 60 2.4 months Months 103 48 31 17 14 13 11 9 4 1 1 0 0 104 36 22 9 5 4 2 1 0 0 0 0 0 Mackey J et al; SABCS 2006, Abstract 3

EGF 30008 Progression-Free Survival: HER2+ Population Letrozole (N = 108) Letrozole + Lapatinib (N = 111) Progressed or died 89 (82%) 88 (79%) Median PFS, mo 3.0 8.2 Hazard ratio (95% CI) 0.71 (0.53, 0.96) p-value 0.019 Johnston et al, SABCS 2008, Abstract 46

NSABP B-31/NCCTG N9831 Long Term DFS 81.4% AC Ú P+H 76.8% 73.7% % Event-Free AC Ú P N Events AC P 2018 680 AC P+H 2028 473 69.5% 64.9% 62.2% HRadj=0.60 (95% CI: 0.53-0.68) P<0.0001 11.5% No. at risk Years from Randomization 2028 1959 1848 1747 1675 1611 1514 1293 910 619 350 2018 1887 1689 1529 1423 1329 1232 1027 705 449 255 Perez EA, et al. J Clin Oncol. 2014;32(33):3744-52

NSABP B-31 ACàPaclitaxel with or without trastuzumab HER2+ node-positive breast cancer Initial study entry criteria included FISH+ > 2.0 or IHC 3+ HER2 testing performed at local lab site A tissue specimen sent to NSABP for later testing NSABP B-31: Central HER2 status performed as quality check after 529 patients enrolled

NSABP B-31 Central HER2 Assay Result Central HER2 FISH negative Central IHC negative (0-2+) Both Negative Before amendment 103/529 (19.5%) 122/528 (23.1%) 87/529 (16.4%) (any lab) After amendment (qualified lab) 104/1266 (8.2%) 177/1259 (14.1%) 87/1266 (6.8%) Total Final 207/1795 (11.5%) 299/1787 (16.7%) 174/1795 (9.7%)

RR of ACTH/ACT for DFS (NSABP B-31) FISH+ (1588) Categories (N) FISH- (207) IHC 3+ (1488) IHC <3 (299) FISH- & IHC <3 (174) Interaction p=0.60 for FISH Interaction p=0.26 for IHC 0.00 0.25 0.50 0.75 1.00 1.25 1.50 RR Note: RR adjusted for ER and nodal status

N9831 Outcomes by HER2 Status Perez EA, et al. J Clin Oncol. 2010;28:4307-15

B-47: Adjuvant Trastuzumab in HER2 Low Breast Cancer STRATIFICATION HER2 IHC Score (1+, 2+) Number of Positive Nodes (0-3, 4-9, 10+) ER / PgR Status Intended ChemoRx regimen (ACàWP, TC) RANDOMIZATION GROUP 1 ChemoRx* GROUP 2 ChemoRx* + Trastuzumab x 1year Hormonal therapy and radiation as indicated. Chemotherapy by MD Choice: *ACàWP: Doxorubicin 60mg/m2 and Cyclophosphamide 600mg/m2 q2 or 3 wks x 4 followed by qwk paclitaxel x 12 or TC: Docetaxel 75mg/m2 + Cyclophosphamide 600mg/m2 q3wk x 6

San Antonio Breast Cancer Symposium, December 5-9, 2017 B-47: Selected Eligibility Criteria High-risk Node Negative T2 and ER/PR negative (TNBC) T2 and ER positive and Grade 3 or RS 25 Node Positive with T1-3 IHC must be 1+, or 2+ If 2+ then ISH must be negative for gene amplification, with ratio <2.0, and HER2 gene copy of <4 per nucleus. Exclusion: Active Cardiac Disease, Hx of MI, CHF, cardiomyopathy If TC planned -- LVEF <50%, No uncontrolled HTN >150/>90 If ACx4àWP planned -- LVEF <55% 50 yr and HTN Dx (controlled or not)

San Antonio Breast Cancer Symposium, December 5-9, 2017 B-47: Invasive Disease-Free Survival HR 0.98 (95% CI 0.77-1.26) P=0.90 Treatment N Events 5 year EFS ChemoRx 1603 134 89.2% ChemoRx+Trast 1599 130 89.6% No. at Risk ChemoRx ChemoRx+Trast 1603 1599 1558 1528 1423 1403 1003 1009 595 591 140 117

B-47: Overall Survival HR 1.33 (95% CI 0.91-1.94) P=0.14 Treatment N Deaths 5 Year OS ChemoRx 1604 49 96.2% ChemoRx+Trast 1599 62 94.8% No. at Risk ChemoRx 1604 ChemoRx+Trast 1599 1577 1563 1507 1497 1099 1113 703 683 Be cautious with TCHP in HER2 equivocal patients 169 149

TRYPHAENA trial Study design All 3 arms were experimental Study dosing q3w: FEC: 500 mg/m 2, 100 mg/m 2, 600 mg/m 2 Carboplatin: AUC 6 Trastuzumab: 8 mg/kg loading dose, 6 mg/kg maintenance Pertuzumab: 840 mg loading dose, 420 mg maintenance Docetaxel: 75 mg/m 2 Schneeweiss A, et al. Ann Oncol 2013:24;2278-2284

TRYPHAENA Pathologic Complete Responses Schneeweiss A, et al. Ann Oncol 2013:24;2278-2284

TRYPHAENA pcr by hormone receptor status Schneeweiss A, et al. Ann Oncol 2013:24;2278-2284

APHINITY: Trial Design S U R G E R Y Central confirmation of HER2 status (N = 4805) R Randomisation and treatment within 8 weeks of surgery Chemotherapy* + trastuzumab + pertuzumab Chemotherapy* + trastuzumab + placebo Anti-HER2 therapy for a total of 1 year (52 weeks) (concurrent with start of taxane) Radiotherapy and/or endocrine therapy may be started at the end of adjuvant chemotherapy F O L L O W - U P 10 Y E A R S *A number of standard anthracycline-taxane-sequences or a non-anthracycline (TCH) regimen were allowed von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 63

APHINITY: Intent-to-Treat Primary Endpoint Analysis Invasive Disease-free Survival expected: 89.2% von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 64

APHINITY: Node-positive Subgroup von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 65

APHINITY: Node-negative Subgroup von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 66

APHINITY: Hormone Receptor-negative Subgroup von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 67

APHINITY: Hormone Receptor-positive Subgroup von Minckwitz G, et al. N Engl J Med 2017;377(2):122-131 The slides are the property of BIG. Permission required for reuse 68

APT: Study Design HER2+ ER+ or ER- Node Negative < 3 cm P P P P P P P P P P P P Enroll T T T T T T T T T T T T WEEKLY PACLITAXEL 80 mg/m 2 + TRASTUZUMAB 2 mg/kg x 12 N=410 T T T T T T T T T T T T T FOLLOWED BY 13 EVERY 3 WEEK DOSES OF TRASTUZUMAB (6 mg/kg)* Presented by: Sara M. Tolaney

Patient Characteristics Age <50 50-70 70 Size of Primary Tumor T1a 0.5 cm T1b >0.5-1.0 T1c >1.0-2.0 T2 >2.0-3.0 Histologic Grade I Well differentiated II Moderately differentiated III Poorly differentiated HR Status (ER and/or PR) Positive Negative N % 132 233 41 77 124 169 36 44 131 228 272 134 33 57 10 19 31 42 9 11 32 56 67 33 Presented by:

Disease-Free Survival All patients Disease-Free Survival 0.0 0.2 0.4 0.6 0.8 1.0 Point Est. 95% Conf. Interval No. of events 3-yr DFS 98.5% 97.2% to 99.7% 6 5-yr DFS 96.3% 94.4% to 98.2% 14 7-yr DFS 93.3% 90.4% to 96.2% 23 0 12 24 36 48 60 72 84 96 Time (Months) Number at risk 406 388 385 378 362 347 247 120 34 Presented by:

Disease-Free Survival Events DFS Event N (%) Time to event [months; mean(range)] Any recurrence or death 23 (5.7) Local/Regional Recurrence* Ipsilateral axilla (HER2+) Ipsilateral breast (HER2+) New Contralateral Primary Breast Cancer HER2+ HER2- Unknown 5 (1.2) 3 2 6 (1.5) 1 3 2 29 (12-54) 51 (37-65) 56 36 (12-59) 87 (84-90) Distant Recurrence 4 (1.0) 49 (27-63) Death Non-breast cancer related 8 (2.0) 58 (13-71) Presented by:

ATEMPT Trial Schema San Antonio Breast Cancer Symposium- Cancer Therapy and Research Center at UT Health Science Center--December 10-14, 2013 Stage I HER2+* ER+ or ER- PS 0-1 Adequate organ fx N=500 R 3 1 Trastuzumab-DM1 q3weeks X17 N=375 Paclitaxel + Trastuzumab x12à Trastuzumab q3weeks x13 N=125 *HER2-positive defined as IHC 3+ or FISH 2.0; will be confirmed by central HER2 testing prior to study enrollment Adjuvant endocrine therapy can be initiated after completion of 12 weeks of therapy Adjuvant radiation therapy can be administered concurrently with study treatment. Presented by: Sara M. Tolaney

Neratinib (irreversible pan-her inhibitor) after trastuzumab-based adjuvant therapy in HER2-positive breast cancer (ExteNET): 5- year analysis of a randomised, doubleblind, placebo-controlled, phase 3 trial

ExteNET Overall Five Year IDFS Martin M, et al. Lancet Oncology 2017;18:1688-1700

ExteNET Five Year IDFS by Hormone Receptor Status HR Positive HR Negative Martin M, et al. Lancet Oncology 2017;18:1688-1700

KATHERINE Post Neoadjuvant Residual Disease Study Residual Invasive HER2 Positive Breast Cancer in Breast and/or Axillary Nodes after Neoadjuvant Chemotherapy and Trastuzumab STRATIFICATION - Clinical presentation: inoperable vs. operable - Hormone receptor: ER or PR positive vs. ER and PR negative - Preoperative therapy: Trastuzumab vs. dual HER2 targeting - Path nodal status after preoperative therapy: +/- Trastuzumab 6 mg/kg q3wk x 14 doses T-DM1 3.6 mg/kg q3wk x 14 doses Accrual - 1484 patients

Intrinsic Subtypes of Breast Cancer in HER2+ BC Unsupervised Hierarchical Clustering Analysis Perou CM. The Oncologist 2011:16(suppl 1):61-70

Intrinsic Subtypes within HER2+ BC Eroles P et at. Cancer Treatment Reviews 2012:38:698-707

Intrinsic Subtypes within HER2 Negative BC Eroles P et at. Cancer Treatment Reviews 2012:38:698-707

PAMELA TRIAL 92% T1/2 65% Node Negative Llombart-Cussac A et al. Lancet Oncol 2017

PAMELA TRIAL Distribution of intrinsic subtypes at baseline All patients N=151 HR+ N=77 HR - N=74 The study determined how pcr might be impacted by the intrinsic subtype. IMPLICATION: some patients with low-risk disease, might not need chemotherapy if treated with dual HER2 blockade + endocrine therapy Llombart-Cussac A et al. Lancet Oncol 2017

CDK4/6 inhibitors and HER2 positive disease Cyclin D1-CDK4 pathway can mediate resistance to anti-her2 targeted therapy This resistance can be overcome using CDK4/6i Inhibition of CDK4/6 suppresses Rb phosphorylation, reduces TSC2 phosphorylation and partially attenuates mtorc1 activity à relieves feedback inhibition of upstream EGFR family kinases, resensitizing tumors to EGFR/ HER2 blockade. Dual inhibition of EGFR/HER2 and CDK4/6 invokes a more potent suppression of mtorc1/ S6K/S6RP activity. BT474 tumors PDX tumor Goel, Cancer Cell 2016

Single arm phase II study Breast cancer T 3 cm N0 M0 HR+(> 10%) HER2+ Translational: Tissue from Dx PAM50 #1 & Blood sample TPLR Neoadjuvant treatment: 18 weeks Double anti-her2 therapy TP (Trastuzumab and Pertuzumab) Uniform Endocrine Deprivation Letrozole +/- goserelin CDK 4/6 inhibitor Ribociclib 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Clinical evaluation/us: if concerns for PD, patient goes off trial as non-pcr Translational: Blood sample with US at wk #6 pcr rate S U R G E R Y Adjuvant treatment per physician discretion Translational: Tissue from Sx (PAM50 #2) & Blood sample 84