Treatment of Early Stage HER2-positive Breast Cancer (One size does not fit all)

Treatment of Early Stage HER2-positive Breast Cancer (One size does not fit all) 8 November 2014 Edward H. Romond, M.D. Professor of Medicine Lucille Parker Markey Cancer Center University of Kentucky Lexington, KY

Slamon, et al. Science 1987;235:177-182

Focal HER2 Amplified Clones Amplified Not Amplified Not Amplified Amplified

Fig. 2 Epitope binding of HER2 and EGFR therapeutic antibodies.(a) Trastuzumab. M X Sliwkowski, and I Mellman Science 2013;341:1192-1198 Published by AAAS

Large Phase III Adjuvant Trastuzumab Trials B31/N9831 CIRG 006 HERA: Chemo ± XRT AC T AC TH (AC T H) AC T* AC T*H T*C*H Observation H x 1 year H x 2 years A = doxorubicin C = cyclophosphamide T = paclitaxel H = trastuzumab T* = docetaxel C* = carboplatin

Arm 1 Arm 2 NSABP B-31 Control: AC T NCCTG N9831 Arm A Arm B Investigational: AC T+H Arm C = doxorubicin/cyclophosphamide (AC) 60/600 mg/m 2 q 3 wk x 4 = paclitaxel (T) 175 mg/m 2 q 3 wk x 4 = paclitaxel (T) 80 mg/m 2 /wk x 12 = trastuzumab (H) 4mg/kg LD + 2 mg/kg/wk x 51

% Event-Free San Antonio Breast Cancer Symposium, December 4-8, 2012 N9831/B-31 Disease-Free Survival AC P 81.4% 69.5% AC P+H 76.8% 64.9% 73.7% 62.2% 11.5% N Events AC P 2018 680 AC P+H 2028 473 HRadj=0.60 (95% CI: 0.53-0.68) P<0.0001 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, E et al., J Clin Oncol, 2014

% Survival San Antonio Breast Cancer Symposium, December 4-8, 2012 B-31/N9831 Overall Survival AC P 93.2% 89.8% 90.3% 84.3% 87.0% 79.4% AC P+H 84.0% 75.2% 8.8% =2.9% =5.5% =7.6% =8.8% N Events AC P 2018 418 AC P+H 2028 286 HRadj=0.63 (95% CI 0.54-0.73) P<0.0001 No. at risk Years from Randomization 2028 1995 1959 1897 1843 1785 1709 1506 1085 735 439 2018 1962 1883 1806 1730 1640 1534 1336 944 604 353 Perez, E et al., J Clin Oncol, 2014

Age Hormone Receptor Tumor Size Nodal Status Histologic Grade Factor <40 years 40-49 50-59 60+ years OS According to Subgroups ACTH vs. ACT (reference group) ER- and PR- ER+ or PR+ 0-2cm 2.1-5.0cm 5.1cm+ LN 0 LN 1-3 LN 4-9 LN 10+ Good Intermediate Poor N 654 1373 1336 683 1828 2215 1598 2096 345 282 2144 1084 536 76 1123 2801 No. of Events ACT ACTH HR 65 45 0.67 121 87 0.65 129 90 0.68 103 64 0.51 212 206 129 239 50 11 161 133 113 8 108 299 149 137 67 176 42 9 104 103 70 1 59 219 0.65 0.61 0.51 0.68 0.58 0.94 0.59 0.72 0.56 0.11 0.52 0.67 HR with 95% CI 0.0 0.5 1 1.5 2

Cumulative Incidence (%) Years from Randomization San Antonio Breast Cancer Symposium, December 4-8, 2012 B-31/N9831 Cumulative Incidence of Distant Recurrence as a First Event ER and/or PR Positive ER and PR Negative AC P 22.3% AC P 21.5% Δ= 9.6% 12.7% Δ=9.6% 11.9% AC P+H AC P+H N Events AC P 1105 216 AC P+H 1110 124 N Events AC P 911 175 AC P+H 917 103

Does the degree of HER2 amplification correlate with the degree of benefit from trastuzumab?

Hazard Ratio of Benefit to Trastuzumab by HER2 FISH Ratio in NCCTG N9831 Ratio (N) p-value < 2.0 (156) p = 0.12 2.0-5.0 (253) 5.0-8.0 (515) 8.0-11.0 (473) 11.0-15.0 (328) p = 0.05 p = 0.03 p = 0. 04 p = 0.004 15.0 (70) p = 0.96 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 Hazard ratio Reinholz M, SABCS 2007, abstr 36

What is the benefit of using trastuzumab with a non-anthracycline containing regimen?

BCIRG 006 AC T 4 x AC 4 x Docetaxel 60/600 mg/m 2 100 mg/m 2 Her2+ (Central FISH) N+ or high risk N- AC TH 4 x AC 4 x Docetaxel 60/600 mg/m 2 100 mg/m 2 1 Year Trastuzumab N=3,222 Stratified by Nodes and Hormonal Receptor Status TCH 6 x Docetaxel and Carboplatin 75 mg/m 2 AUC 6 1 Year Trastuzumab

BCIRG 006 Disease Free Survival (median follow-up 65 months) Patients Events HR P AC-TH 1074 185.64 <0.001 TCH 1075 214.75 0.04 AC-T 1073 257 Slamon D, et al. NEJM 365:1273-1283, 2011

What is the benefit of using trastuzumab after chemotherapy is finished?

HERA TRIAL DESIGN Accrual 2001 2005 (n=5102) Women with locally determined HER2-positive invasive early breast cancer Surgery + (neo)adjuvant CT ± RT Centrally confirmed IHC 3+ or FISH+ and LVEF 55% Randomization OBSERVATION n=1698 After ASCO 2005, option of switch to Trastuzumab 1 year Trastuzumab 8 mg/kg 6 mg/kg 3 weekly schedule n=1703 2 years Trastuzumab 8 mg/kg 6 mg/kg 3 weekly schedule n=1701 CT, chemotherapy; RT, radiotherapy

HERA: Disease Free Survival 53% of Observation received trastuzumab Goldhirsch A, et al. Lancet 382:1021-1028,2013

SUMMARY OF DFS ITT ANALYSES FOR 1 YEAR TRASTUZUMAB VS. OBSERVATION ACROSS ANALYSIS TIME POINTS Median follow-up (% follow-up time after selective crossover) 2005 (0%) 1 yr MFU 0.54 DFS benefit No. of DFS events 1 year trastuzumab vs observation 127 vs 220 P<0.0001 2006 (4.3%) 2 yrs MFU 0.64 218 vs 321 P<0.0001 2008 (33.8%) 4 yrs MFU 0.76 369 vs 458 P<0.0001 2012 (48.5%) 8 yrs MFU 0.76 471 vs 570 P<0.0001 Favours 1 year trastuzumab Favours observation 0 1 2 HR (95% CI) Goldhirsch A, et al. Lancet 382:1021-1028,2013

SUMMARY OF OS ITT ANALYSES FOR 1 YEAR TRASTUZUMAB VS. OBSERVATION ACROSS ANALYSIS TIME POINTS Median follow-up (% follow-up time after selective crossover) 2005 (0%) 1 yr MFU 0.76 OS benefit No. of deaths 1 year trastuzumab vs observation 29 vs 37 P=0.26 2006 (4.1%) 2 yrs MFU 0.66 59 vs 90 P=0.0115 2008 (30.9%) 4 yrs MFU 0.85 182 vs 213 P=0.1087 2012 (45.5%) 8 yrs MFU 0.76 278 vs 350 P=0.0005 Favours 1 year trastuzumab Favours observation 0 1 2 HR (95% CI) Goldhirsch A, et al. Lancet 382:1021-1028,2013

So is it better to start trastuzumab sequentially after completion of chemotherapy or concurrently with taxane chemotherapy?

NCCTG N9831 Trial Incorporating Trastuzumab in Adjuvant Therapy Arm A HER2 positive (FISH ratio 2 or IHC 3+ >10%) n=3,505 R A N D O M I Z E T AC Arm B T AC Arm C T AC H H = AC (doxorubicin/cyclophosphamide 60/600 mg/m 2 q3w 4) = T (paclitaxel 80 mg/m 2 /wk 12) = H (trastuzumab 4 mg/kg loading + 2 mg/kg/wk 51)

N9831: Sequential (B) vs. Concurrent (C) Perez EA et al. J Clin Oncol 29:4491-4497, 2011

Efficacy Summary Randomized Adjuvant Trastuzumab Trials TRIAL Pts TREATMENT B31/N9831 2028 2018 CIRG 006 1074 1075 1073 HERA 1703 1698 FinHER 115 116 PACS04 260 268 AC TH AC T AC TH TCH AC T chemo H chemo obs V/T+H FEC V/T FEC FEC/ET H FEC/ET DFS (%) HR P 74* 62 84** 81 75 71* 65 89 78 73* 73 0.60 <0.001 0.64 0.75 <0.001 0.04 0.76 <0.0001 0.42 0.01 0.86 0.42 - at 3 years * - at 8 years ** - at 5.5years OS (%) HR P 84* 75 92** 91 87 83* 77 96 90 92* 93 0.63 <.001 0.63 0.77 0.001 0.038 0.76 0.0005 0.41 0.07 1.27 NR

How long should trastuzumab be given in the adjuvant setting?

Current Trials Assessing Duration of Trastuzumab SOLD (Finland) PHARE (France) Short-HER (Italy) Hellenic Group (Greece) Persephone (Great Britain) HERA Docetaxel + Trast (nine weeks) FEC X 3 Docetaxel + Trast (nine weeks) FEC X 3 Trast (total 1 year) Chemotherapy + Trast X 12 months Chemotherapy + Trast X 6 months Docetaxel + Trast (nine weeks) FEC X 3 AC/FEC X 4 Taxane + Trast X 4 Trast (18 weeks) FEC X 4 Docetaxel + Trast Trast (total 12 months) FEC X 4 Docetaxel + Trast Trast (total 6 months) Chemotherapy + Trast X 12 months Chemotherapy + Trast X 6 months Chemotherapy Trast X 1 year Chemotherapy Trast X 2 years

Disease-free survival (%) HERA: DFS FOR 2 YEARS VS. 1 YEAR TRASTUZUMAB AT 8 YRS MFU 100 80 89.1% 86.7% 81.6% 81.0% 75.8% 76.0% 60 Trastuzumab 2 years 40 Trastuzumab 1 year 20 Pts Events HR (2 vs 1) 95% CI p-value 2 years 1553 367 0.99 (0.85-1.14) 0.86 1 year 1552 367 0 0 1 2 3 4 5 6 7 8 9 Years from randomization No. at risk Trastuzumab 2 years 1553 1553 1442 1361 1292 1223 1153 1051 633 194 Trastuzumab 1 year 1552 1552 1413 1319 1265 1214 1180 1071 649 205 Goldhirsch A, et al. Lancet 382:1021-1028,2013

PHARE* Study design trastuzumab 6 months R Stratification 1. ER pos / neg 2. Chemo: concurrent/sequential trastuzumab up to 12 months 1690 patients stop trastuzumab 1690 patients Clinical exam LVEF 0 3 6 9 12 15 18 21 24 30 mos Mammography Up to 60 mos * Protocol of Herceptin Adjuvant with Reduced Exposure Pivot X, et al, Lancet Oncol 14:741-748, 2013

Probability Disease Free Survival 1.00 97.0 93.8 90.7 87.8 0.75 95.5 91.2 87.8 84.9 0.50 0.25 0.00 Events HR 95%CI p-value H 12m 176 H 6m 219 1.28 (1.05 1.56) 0.29 0 12 24 36 Months 48 60 At risk H-12m 1690 1613 1390 980 544 18 H 6m 1690 1586 1353 939 526 23 H-12m H-6m www.esmo2012.org Pivot X, et al, Lancet Oncol 14:741-748, 2013

Primary endpoint scenarii A Equivalent B 6 month Superior C PHARE trial D 6 month Non Inferior E.85 1 1.15 1.3 1.45 1.6 HR 6 month Inferior Pivot X, et al, Lancet Oncol 14:741-748, 2013

Cardiac Risk Assessment with Anthracycline based regimens

B-31/N9831 LVEF Evaluation Schedule Control AC x 4 Paclitaxel 0 mo. 3 mos. 6 mos. 9 mos. Investigational AC x 4 Trastuzumab + Paclitaxel 18 mos. 0 mo. 3 mos. 6 mos. 9 mos. 18 mos.

Asymptomatic Patients Rules for Trastuzumab Continuation Based on Serial LVEF Relationship of LVEF to LLN Absolute decrease of < 10% Absolute decrease of 10% 15% Absolute decrease of 15% Within normal limits Cont. Cont. Hold * 1% 5% below LLN Cont. Hold * Hold * 6% below LLN Cont. * Hold * Hold * * Repeat LVEF assessment after 4 weeks If criteria for continuation is met then resume trastuzumab If 2 consecutive holds (or a total of 3 holds occur) then discontinue trastuzumab LLN = lower limit of normal.

% 0 1 2 3 4 5 NSABP B-31: 7 year cumulative incidence of cardiac events ACPH arm; 4.0% HR=3.30;P-value- =0.00038 ACP arm; 1.3% 0 1 2 3 4 5 6 7 Years Post Day 1 Cyc 5 Romond et al. J Clin Oncol 30:3792-3799, 2012

B-31: Potential Risk Factors for Congestive Heart Failure Risk Factors No. of Pts No. with CHF (%) P value Relative risk (95% CI) Age < 50 486 11 (2.3%) Ref. group 50-59 313 16 (5.1%) 0.03 2.3 (1.1-4.9) 60+ 148 8 (5.4%) 2.4 (1.0-6.0) Hypertension medications No 732 22 (3.0%) Yes 192 13 (6.8%) 0.02 2.3 (1.2-4.6) Baseline LVEF <54 70 9 (12.9%) Ref. group 55-64 452 17 (3.8%) 0.0003 0.3 (0.1 0.6) 65+ 425 9 (2.1%) 0.2 (0.1 0.4) Left-sided tumor & radiation No 587 23 (3.9%) Yes 351 12 (3.4%) 0.71 0.9 (0.4-1.8)

Cardiac Risk Score (based on evaluable cohort in NSABP B-31) [7.0 + (0.04 x Age in years) (0.1 x Baseline percent LVEF)] x 100 4.76 Romond et al. J Clin Oncol 30:3792-3799, 2012

Predicted Probability of CE 0.0 0 % 10 0.1 % 20 0.2 % 30 0.3 % 40 0.4 % NSABP B-31 Cardiac Risk Assessment 0 20 40 60 80 100 Cardiac Risk Score Romond et al. J Clin Oncol 30:3792-3799, 2012

Examples: (a)age 45, LVEF=65%, CRS=48.3 (b)age 65, LVEF=55, CRS=86.1

Predicted Probability of CE 0 0.0 % 10 0.1 % 20 0.2 % 30 0.3 % 40 0.4 % NSABP B-31: Examples of Cardiac Risk Assessment b a 0 20 40 60 80 100 Cardiac Risk Score

Summary of Cardiac Dysfunction in the Large Adjuvant Trastuzumab Trials Trial Median Follow-up (years) Treatment Arms Class III/IV CHF (%) Cardiac Deaths NSABP B- 31 7 AC P + Trast AC P 4.0 1.3 1 1 NCCTG N9831 5 AC P+Trast AC P Trast AC P 3.3 2.8 0.3 1 0 0 HERA 8 Chemo Trast Chemo Observation 0.8 0 0 1 BCIRG 006 5 AC D+Trast D+Carboplatin+Trast AC D 2.0 0.4 0.7 0 0 0 A: doxorubicin; C: cyclophosphamide; P: paclitaxel; D: docetaxel

Low Risk and Node Negative Cancers

British Columbia Tumor Registry HER2 status Stage I Only (T1N0) n 10 yr RFS (%) HER2-1128 78.7 HER2+ 117 71.6 P=0.21 Chia S et al. J Clin Oncol 2008 26:5697-5704

BCIRG 006 Node Negative Patients Valero et al, ASCO 2011, Abstr 553

BCIRG 006 Disease Free Survival Valero et al, ASCO 2011, Abstr 553

US Oncology Phase II Adjuvant Trial Docetaxel + Cyclophosphamide + Trastuzumab Open label, Phase II 493 patients registered Low risk HER2 positive operable breast cancer: T1-2, N0-1a LVEF 50% by MUGA or echo Treatment regimen: (4 chemotherapy cycles) Docetaxel 75 mg/m² day 1 Cyclophosphamide 600 mg/m² day 1 Trastuzumab 4 mg/kg (loading) then 2mg/kg day 1,8,15 Following completion of chemo: trastuzumab 6mg/kg q 21 days to complete 1 year targeted therapy Jones SE, et al. Lancet Oncol 14:1121-1128, 2013

Baseline Patient Characteristics Jones SE, et al. Lancet Oncol 14:1121-1128, 2013

US Oncology Phase II Adjuvant Trial Docetaxel + Cyclophosphamide + Trastuzumab Disease-free Survival Overall Survival Jones SE, et al. Lancet Oncol 14:1121-1128, 2013

Study Design (APT Trial) HER2+ ER+ or ER- Node Negative < 3 cm Enroll P P P P P P P P P P P T T T T T T T T T T T PACLITAXEL 80 mg/m 2 + TRASTUZUMAB 2 mg/kg x 12 P T Planned N=400 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)* *Dosing could alternatively be 2 mg/kg IV weekly for 40 weeks ** Radiation and hormonal therapy was initiated after completion of paclitaxel Tolaney S, et al. SABCS 2013, abstr S1-04

San Antonio Breast Cancer Symposium- Cancer Therapy and Research Center at UT Health Science Center--December 10-14, 2013 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 50% 50% Tolaney S, et al. SABCS 2013, abstr S1-04

San Antonio Breast Cancer Symposium- Cancer Therapy and Research Center at UT Health Science Center- December 10-14, 2013 Recurrence-Free Survival (Probability) 0.0 0.2 0.4 0.6 0.8 1.0 Recurrence-Free Interval 3-year RFI 95% Conf. Interval 99.2% 98.3% to >99.9% Recurrence Free Interval= Invasive Local/Regional Recurrence Distant Recurrence Death from Breast Cancer All patients 0 12 24 36 48 60 Time (Months) Number at risk 406 390 382 307 126 27 Tolaney S, et al. SABCS 2013, abstr S1-04

What about really small node negative breast cancers 1.0 cm (T1a/b)?

Subset DFS and OS results US Oncology Phase II Trial of TC + Trastuzumab Jones SE, et al. Lancet Oncol 14:1121-1128, 2013

T1abN0M0 HER2+ Breast Cancers Kaiser Permanente Northern California 3.3 million members 16,975 new Breast Cancers diagnosed from 1/1/2000 to 12/31/2006 HER2, ER, PR IHC mandatory on all cases 2,168 HER2+ (IHC 3+ or FISH ratio >2.0) 237 T1a or T1b Fehrenbacher L, et al. J Clin Oncol 32:2151-2158, 2014

Recurrences:T1a+bN0 HER2+ Median F/U 5.8 yrs N# T1aN0 116 T1bN0 121 T1abN0 237 Invasive Cancer Recurrence (%) (4) 3.5% (11) 9.1% (15) 6.3% Invasive Cancer Local Recurrence Only (%) (3) 2.6% (4) 3.3% (7) 2.9% Invasive Cancer Distant Recurrence (%) (1) 0.9% (7) 5.8% (8) 3.4% 5 year Relapse Free Interval (K-M) 97.4% (95% CI, 92.1.,99.1) 91.1% (95% CI,83.2,95.3) 94.2% (95% CI, 89.9, 96.7) 5 year Distant Relapse Free Interval (K-M) 99.1% (95% CI,93.9, 99.9) 94.0% (95% CI, 87.1, 97.3) 96.5% (95% CI, 92.8, 98.3) Fehrenbacher L, et al. J Clin Oncol 32:2151-2158, 2014

Treatments Received by T1abN0M0 Received Chemo Received Trastuzumab Distant Recur No Chemo Distant Recur with Chemo All T1abN0 59/237 (24.9%) 20/237(8.4%) 5/178 (2.8%) 3/59 (5.1%) Pre 2005 4/153 (2.6%) 2005-2006 16/84 (19.0%) T1aN0* 15/116 (12.9%) 8/116 (6.8%) 1/101 (1.0%) 0/15(0%) T1bN0 44/121 (36.3%) 12/121 (9.9%) 4/77 (5.2%) 3/44(6.8%) *Note:48% ER negative Fehrenbacher L, et al. J Clin Oncol 32:2151-2158, 2014

NCCN Breast Cancer Guidelines (v.1.2011) T1/N0, HER2-positive Tumor Size Recommendation > 1cm Chemotherapy + trastuzumab* 0.6-1.0 cm 0.5cm Consider chemotherapy + trastuzumab* No adjuvant therapy* * endocrine therapy if HR +

Recently Reported Adjuvant Trials

BETH TRIAL Node-Positive or High Risk Node- Negative Breast Cancer HER2 Positive by Central Testing STRATIFICATION Number of positive Nodes (0, 1-3 4+) Hormone Receptor Status NSABP/CIRG CONTACT TCH ± B FEC TH ± B

Does improved neo-adjuvant response predict improved disease-free and overall survival?

Collaborative Trials in Neoadjuvant Breast Cancer (CTNeoBC): Association of pcr with EFS in Her2+ Subtype HR=0.39, P* < 0.001 HR=0.58, P* = 0.001 HR=0.25, P* < 0.001 pcr=ypt0/is ypn0 Cortazar P, et al. Lancet 384:164 72,2014

Lapatinib Lapatinib is an oral small-molecule dual inhibitor of ERBB1 and ERBB2 tyrosine kinase: 1 + 1 2 + 2 1 + 2 Works intracellularly Binds reversibly to the cytoplasmic ATP-binding site of the kinase, thereby preventing receptor phosphorylation and activation Downstream signaling cascade

Phase III NeoALTTO Trial Eligibility criteria: Operable HER2 + breast cancer T > 2 cm LVEF 50% Stratify by: Tumor size ( 5 cm vs. > 5 cm) HR status (positive vs. negative) N status (0/1 vs. 2) R A N D O M I Z E (n = 455) Lapatinib a 1000 mg/day Trastuzumab 2 mg/kg/week (4-mg/kg loading dose) 18 cycles Paclitaxel 80 mg/m 2 /week 12 cycles starting at week 7 Lapatinib 1500 mg/day Paclitaxel 80 mg/m 2 /week 12 cycles starting at week 7 Trastuzumab 2 mg/kg/week (4-mg/kg loading dose) 18 cycles Paclitaxel 80 mg/m 2 /week 12 cycles starting at week 7 a 750 mg/day with paclitaxel S U R G E R Y Baselga J et al. Lancet 379: 633 40,2012

NeoALTTO: Efficacy Lapatinib/ Trastuzumab (n = 152) Lapatinib (n = 154) Trastuzumab (n = 149) Pathologic CR, Breast 51% 25% 29.5% By hormone receptor status Positive 42% 16% 23% Negative 61% 34% 36.5% Total Pathologic CR, Breast +Nodes (n = 145) (n = 150) (n = 145) 47% 20% 28% Objective Response (n = 152) (n = 154) (n = 149) At week 6 67% 53% 30% At surgery 80% 74% 70.5% All differences between lapatinib/trastuzumab and trastuzumab alone are significant (P <.05). Baselga J et al. Lancet 379: 633 40,2012.

ALTTO Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization WILL DUAL ANTI-HER2 BLOCKADE IMPROVE DISEASE-FREE AND OVERALL SURVIVAL IN THE ADJUVANT SETTING?

DESIGN 1: SEQUENTIAL ANTI-HER2 THERAPY AFTER ALL CHEMOTHERAPY (N= 4,613) 3-weekly Trastuzumab Lapatinib* All (neo)adjuvant chemo prior to anti-her2 therapy Weekly Trastuzumab wash out Lapatinib 12 weeks 6 wks 34 weeks 12 weeks Lapatinib + 3-weekly Trastuzumab 6 wks 34 weeks All patients: radiotherapy, if indicated (concomitant with targeted therapy). Hormone receptor-positive patients: endocrine therapy for at least 5 years. *The L alone arm was closed on 18 Aug 2011 following IDMC recommendation 52 weeks Tras alone: 8 mg/kg 6 mg/kg iv, q21 days Lap alone: 1500 mg po qd Tras Lap: T 4 mg/kg 2 mg/kg iv q7 days; L 1500 mg po qd Tras + Lap: T 8 mg/kg 6 mg/kg iv, q21 days; L 1000 mg po qd

DESIGN 2: CONCURRENT ANTI-HER2 THERAPY AFTER ANTHRACYCLINE-BASED CHEMOTHERAPY (N= 3,337) w-p or 3-w D 3-weekly Trastuzumab w-p or 3-w D Lapatinib* Anthracyclinebased chemo first Weekly w-p or 3-w D Trastuzumab wash out Lapatinib 12 weeks 6 wks 34 weeks w-p or 3-w D 12 weeks Lapatinib + 3-weekly Trastuzumab 6 wks 34 weeks w-p: weekly paclitaxel (80 mg/m 2 ); 3-w D: q3 weeks docetaxel (75-100 mg/m 2 ) All patients: radiotherapy, if indicated (concomitant with targeted therapy). Hormone receptor-positive patients: endocrine therapy for at least 5 years. *The L alone arm was closed on 18 Aug 2011 following IDMC recommendation 52 weeks Tras alone: 4 mg/kg 2 mg/kg iv, q7 days 6 mg/kg iv, q21 days Lap alone: 750 mg po qd 1500 mg qd Tras Lap: T 4 mg/kg 2 mg/kg iv q7 days; L 1500 mg po qd Tras + Lap: T 4 mg/kg 2 mg/kg iv, q7 days 6 mg/kg iv, q21 days; L 750 mg po qd 1000 mg qd

DESIGN 2B: CONCURRENT ANTI-HER2 THERAPY WITH A NON-ANTHRACYCLINE CHEMOTHERAPY (N= 431) 3-w D + carbo 3-weekly Trastuzumab Nonanthracyclinebased chemo with anti-her2 therapy 3-w D + carbo Weekly 3-w D + carbo Trastuzumab Lapatinib* wash out Lapatinib 18 weeks 6 wks 28 weeks 3-w D + carbo 18 weeks Lapatinib + 3-weekly Trastuzumab 6 wks 28 weeks 3-w D: q3 weeks docetaxel (75 mg/m 2 ); carbo: carboplatin (AUC 6) All patients: radiotherapy, if indicated (concomitant with targeted therapy). Hormone receptor-positive patients: endocrine therapy for at least 5 years. *The L alone arm was closed on 18 Aug 2011 following IDMC recommendation 52 weeks Tras alone: 4 mg/kg 2 mg/kg iv, q7 days 6 mg/kg iv, q21 days Lap alone: 750 mg po qd 1500 mg qd Tras Lap: T 4 mg/kg 2 mg/kg iv q7 days; L 1500 mg po qd Tras + Lap: T 4 mg/kg 2 mg/kg iv, q7 days 6 mg/kg iv, q21 days; L 750 mg po qd 1000 mg qd

DISTRIBUTION OF THE STRATIFICATION Hormone Receptor Status FACTORS BY TREATMENT ARM L + T (N = 2,093) T L (N = 2,091) T (N = 2,097) Positive 1,203 (57%) 1,205 (58%) 1,200 (57%) Negative 890 (43%) 886 (42%) 897 (43%) Timing of chemotherapy Sequential (Design 1) 1,155 (55%) 1,143 (55%) 1,147 (55%) Concurrent (Design 2 and 2B) 938 (45%) 948 (45%) 950 (45%) Lymph Node Status Not applicable (neoadjuvant chemotherapy) 168 (8%) 170 (8%) 181 (9%) Node negative 845 (40%) 842 (40%) 844 (40%) 1-3 positive nodes 617 (29%) 617 (30%) 603 (29%) >=4 positive nodes 463 (22%) 462 (22%) 469 (22%)

DISTRIBUTION OF PATIENT CHARACTERISTICS BY TREATMENT ARM L + T (N = 2,093) T L 76 T (N = 2,097) (N = 2,091) Menopausal Status Premenopausal 908 (43%) 929 (44%) 908 (43%) Postmenopausal or male 1,185 (57%) 1,162 (56%) 1,189 (57%) Pathological primary tumor size - largest diameter of invasive component Missing 27 41 38 2cm 937 (45%) 938 (46%) 942 (46%) > 2cm to 5cm 1,002 (49%) 980 (48%) 990 (48%) > 5cm 127 (6%) 132 (6%) 127 (6%) Histologic grade Missing 10 7 9 Gx: Differentiation cannot be assessed 79 (4%) 61 (3%) 59 (3%) G1: Well differentiated 51 (2%) 59 (3%) 48 (2%) G2: Moderately differentiated 774 (37%) 793 (38%) 744 (36%) G3: Poorly differentiated/undifferentiated 1,179 (57%) 1,171 (56%) 1,237 (59%)

DISEASE-FREE SURVIVAL (DFS) ANALYSIS MFU = 4.5 yrs * ** * 97.5% CI **p-value 0.025 required for statistical significance Piccart-Gebhart M. ASCO 2014, LBA 4

Fig. 2 Epitope binding of HER2 and EGFR therapeutic antibodies.(b) Pertuzumab. M X Sliwkowski, and I Mellman Science 2013;341:1192-1198 Published by AAAS

Randomized Phase II Study of Neoadjuvant Pertuzumab Plus Trastuzumab: NeoSphere Eligibility criteria: Operable or locally advanced/ inflammatory HER2 + breast cancer Chemonaive Primary tumors > 2 cm R A N D O M I Z E Docetaxel (T) Trastuzumab (H) (n = 107) Docetaxel (T) Trastuzumab (H) Pertuzumab (P) (n = 107) Trastuzumab (H) Pertuzumab (P) (n = 107) Docetaxel (T) Pertuzumab (P) (n = 96) All q 3 weeks 4 Primary endpoint: pcr rates Secondary endpoints including: clinical response S U R G E R Y FEC q 3 weeks 3 H q 3 weeks, cycles 5-17 FEC q 3 weeks 3 H q 3 weeks, cycles 5-17 T q 3 weeks 4 FEC q 3 weeks 3 H q 3 weeks, cycles 5-17 FEC q 3 weeks 3 H q 3 weeks, cycles 5-21 FEC: 5-fluorouracil/epirubicin/ cyclophosphamide Gianni et al. SABCS 2010; abstract S3-2.

NeoSphere: Efficacy of Neoadjuvant Pertuzumab Plus Trastuzumab Pathologic Complete Response TH (n = 107) THP (n = 107) HP (n = 107) TP (n = 96) pcr in Breast 29% 46% 17% 24% By Hormone Receptor Status ER + /PgR + 20% 26% 6% 17% ER /PgR 37% 63% 29% 30% By Nodal Status Node negative 21.5% 39% 11% 18% Node positive 7.5% 6.5% 6% 6% CR + PR + SD a 107 (100%) 106 (99%) 99 (92.5%) 94 (98%) a Investigator assessed T = docetaxel H = trastuzumab P = pertuzumab Gianni et al. SABCS 2010; abstract S3-2.

TRYPHAENA Cycles 1 3 4 6 A FEC Docetaxel HER2-positive EBC centrally confirmed (n = 225) B C Pertuzumab + trastuzumab FEC Docetaxel Docetaxel Pertuzumab + trastuzumab Pertuzumab + trastuzumab S u r g e r y Trastuzumab to complete 1 year Carboplatin 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 (escalating to 100 mg/m 2 if tolerated, in Arms A and B only) Schneeweiss, et al. Annals Onc 24:2278-2284,2013

Pathologic complete response (%) TRYPHAENA: Pathologic complete response ypt0/is ypt0 ypn0 61.6 50.7 57.3 45.3 66.2 51.9 FEC+H+P x3 T+H+P x3 (n = 73) FEC x3 T+H+P x3 (n = 75) TCH+P x6 (n = 77) FEC, 5-fluorouracil, epirubicin, cyclophosphamide; H, trastuzumab; P, pertuzumab; T, docetaxel; TCH, docetaxel/carboplatin/trastuzumab Schneeweiss, et al. Annals Onc 24:2278-2284,2013

Pathologic complete response (%) Pathologic complete response by hormone receptor status ypt0/is ER- and PR-negative ER- and/or PR-positive 79.4 83.8 65.0 46.2 48.6 50.0 FEC+H+P x3 T+H+P x3 (n = 73) FEC x3 T+H+P x3 (n = 75) TCH+P x6 (n = 77) ER, estrogen receptor; FEC, 5-fluorouracil, epirubicin, cyclophosphamide; H, trastuzumab; P, pertuzumab; PR, progesterone receptor; T, docetaxel; TCH, docetaxel/carboplatin/trastuzumab Schneeweiss, et al. Annals Onc 24:2278-2284,2013

Fig. 2 Epitope binding of HER2 and EGFR therapeutic antibodies.(d) T-DM1. M X Sliwkowski, and I Mellman Science 2013;341:1192-1198 Published by AAAS

NSABP B-50-I/GBG 77/Roche BO27938 Katherine: Study Schema Residual Invasive HER2 Positive Breast Cancer in Breast and/or Axillary Nodes after Neoadjuvant Taxane/Trastuzumab ± Anthracycline Randomization Trastuzumab 6 mg/kg q3wk x 14 doses T-DM1 3.6 mg/kg q3wk x 14 doses Radiation per standard guidance; hormone therapy if ER or PgR pos Accrual goal - 1484 patients

A Final Question: Does the standard definition of HER2 positivity mean the same thing as a predictor of response to trastuzumab + chemotherapy in the adjuvant setting as it does for metastatic breast cancer?

B-31: distribution of cases according to central HER2 assay IHC=0 IHC=1 IHC=2 IHC=3 unk FISH- 25 87 62 31 2 Central assay negative FISH+ 9 32 84 1457 6 Paik, ASCO 2007, abstr 511

% Disease-Free 0 20 40 60 80 100 NSABP B-31 Updated 2009 Disease Free Survival FISH Negative, IHC 0, 1+, 2+ Breast Cancer Pts. NSABP B-31:FISH Negative, IHC 0,1+,2+ ACT ACTH N #Event HR p-value 92 25 0.64 0.16 81 19 HR=0.64, p=0.16 0 1 2 3 4 5 6 7 Time from Randomization

HER2 expression is a continuous variable HER2 by RT-PCR (relative to ref genes; log2) 15 14 13 12 11 10 9 8 7 6 Hard to imagine that these two tumors respond differently to trastuzumab Cut-off Based on IHC/FISH 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Case Slide courtesy of S Paik

Summary of take-home messages Virtually all invasive breast cancers should be tested for HER2. HER2 testing must be done in laboratories with rigorous quality controls. Addition of one year of trastuzumab to adjuvant chemotherapy decreased the rate of breast cancer events by 25-40% in the large adjuvant trials. Focally positive cancers also derive similar benefit. The inclusion of pertuzumab along with trastuzumab and chemotherapy in pre-operative treatment of early stage disease is now a FDA approved standard of care. NCCN 2014 guidelines also provide for option to include pertuzumab concurrent with chemotherapy and trastuzumab in the adjuvant AC-TH and TCH regimens.

Summary of take-home messages Cardiac monitoring must be done in all patients treated with adjuvant trastuzumab with appropriate holds when indicated. Most patients recover normal ejection fractions if holding rules are followed. In B-31 the combination of age and baseline LVEF correlates with risk of CHF when trastuzumab/paclitaxel is used following AC. Radiation and hormone therapy may be given after chemotherapy concurrently with trastuzumab. Neo-adjuvant trials are appropriate for studying new targeted agents for specific patient subsets but appropriate patient selection for incorporating new agents in adjuvant trials is critical. The criteria of HER2 positivity for discerning adjuvant trastuzumab benefit is being studied further in a prospective randomized trial (NSABP B=47).

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