1. Targeted adjuvant systemic therapy: Current status and future directions of Trastuzumab May 25 th 2007 “Highlights in the Management of Breast Cancer” Mediterranean School of Rome Giuseppe Tonini University Campus Bio-Medico of Rome

2. Background Breast cancer is an heterogeneous disease with different tumor subtypes and different natural histories Overexpression of HER2/neu defines one of these subtypes The HER2/neu gene belongs to a family of genes which encode for transmembrane receptors and includes HER1-4 Slamon DJ et al: Science. 1987; 235.

3. HER2/neu gene is a proto-oncogene located on 17q21 HER2/neu is a transmembrane glycoprotein The extracellular domain interacts with other HER proteins allowing the facilitation of signal transduction after ligand binding The intracellular domain has an intrinsic Tyrosine Kinase (TK) activity that regulates various important aspects of the growth and differentiation of cells There is no known ligand for HER2 itself Background Slamon DJ et al: Science. 1987; 235

4. The EGFR/HER Family Valabrega G et al: Ann Oncol 2007

5. Amplification of HER2 occurs in about 20-25% of invasive breast cancers It has been shown to be associated with poorly differentiated cancers, high rates of cell proliferation and lymph node involvement Most clinical studies have shown that patients with HER2 positive tumors have a poorer prognosis The prognostic value is strongest in patients with node positive disease while there is no consensus in its value in node negative patients The prognostic impact appears to be related only to the first 3-4 years after surgery as indicated by the peak of early recurrences HER2 as a prognostic factor Menard et al; Oncogene. 2003; 22, 6570

6. HER2 as a prognostic factor Nodes negative Nodes positive

7. HER2 as a predictive factor Anthracycline based chemotherapy appears to be particularly beneficial HER2 overexpression may be associated with resistance to alkylator based therapy The influence of HER2 on response to taxanes is unclear HER2 may also predict response to endocrine therapy Roughly 50% of HER2 amplified tumors are hormone receptor positive (typically lower levels than HER2 negative tumors) A prospective neoadjuvant study showed that in the HER2 positive patients the RR to letrozole were 88% VS 21% for the tamoxifen arm Ellis et al; JCO 2006; 24 (19): 3019-25

8. Trastuzumab: Humanized Anti-HER2 Antibody

9. Mechanisms of Trastuzumab action and resistance Valabrega G et al: Ann Oncol 2007

10. Adjuvant Trastuzumab The beneficial effects on morbidity and/or mortality are seen in patients with HER2-positive breast cancer with HER2 overexpression at the 3+ level (IHC analysis) and/or HER2 gene amplification (FISH- CISH-positive). Phase III trials in early breast cancer HER-2 +: the addition of Trastuzumab in adjuvant therapy significantly improves DFS Plosker GL and Keam SJ: Drugs 2006

11. Randomized Phase III Trials Adjuvant Trastuzumab Trial HERA NSABP B-31 NCCTG N9831 BCIRG 006 FinHer No. patients 5090 2030 3505 3222 232 a Reference Piccart-Gebhart et al 2005 Smith et al 2007 Romond et al 2005 Slamon et al 2006 Joensuu et al 2006 a HER2-positive subgroup

12. HER2 positive (IHC 3+ / FISH+) Invasive breast cancer resected by lumpectomy/mastectomy Nodal status –node positive (NSABP B-31) –node positive or high-risk node negative (NCCTG N9831, HERA, BCIRG 006) Known hormone receptor status (ER / PgR or ER alone) No previous or current cardiac disease Pivotal adjuvant Herceptin trials: patient characteristics

13. Randomized Phase III Trials

14. Romond et al:N Engl J Med 2005; 353:1673-1684 Combined analysis of B31 and N9831

15. Romond et al:N Engl J Med 2005; 353:1673-1684 Combined analysis of B31 and N9831

16. Romond et al:N Engl J Med 2005; 353:1673-1684 Adding trastuzumab significantly improves DFS !!! P<0.0001

17. Romond et al:N Engl J Med 2005; 353:1673-1684 Adding trastuzumab significantly improves OS!!! P=0.015

18. Romond et al:N Engl J Med 2005; 353:1673-1684 Combined analysis of B31 and N9831

19. Romond et al:N Engl J Med 2005; 353:1673-1684 Sequential trastuzumab does not add nothing !!!

20. Romond et al:N Engl J Med 2005; 353:1673-1684 Early trastuzumab is better than sequential trastuzumab !!!

21. Cardiac Safety 31.4% of patients receiving trastuzumab discontinued radiotherapy before 52 weeks for cardiac events NSABP-31 N9831 Control Group 0.8% Grade III-IV events Trastuzumab Group 4.1% Control Group 0% Trastuzumab Group 2.9% Romond et al:N Engl J Med 2005; 353:1673-1684

22. Randomized Phase III Trials

23. Piccart et al:N Engl J Med 2005; 353:1659-1672 Design of the HERA Trial

24. HERA Trial: patient characteristics (%) well balanced arms Piccart et al:N Engl J Med 2005; 353:1659-1672

25. HERA Trial: tumor characteristics (%) well balanced arms Piccart et al:N Engl J Med 2005; 353:1659-1672

26. HERA trial: recent developments Median follow-up more than 2 years Smith et al, 2007

27. HERA Trial: Disease–Free Survival 1703159114341127 742383140 169815351330984 639334127 1 year Herceptin Observation No. at risk Events 218 321 HR 0.64 p value <0.0001 3 year DFS 80.6 74.3 6.3% CI, confidence interval; HR, hazard ratio Months from randomisation 100 80 60 40 20 0 Patients (%) 12123601818 6 2430 95% CI 0.54, 0.76 Smith et al, 2007 Absolute DFS benefit favoring trastuzumab of 6.3%

28. HERA Trial: Overall Survival Smith et al, 2007 2.7% Months from randomisation 100 80 60 40 20 0 Patients (%) 12123601818 6 2430 1 year Herceptin Observation 1703162714981190 794407146 1698160814531097 711366139 No. at risk Deaths 59 90 HR 0.66 p value 0.0115 3 year OS 92.4 89.7 95% CI 0.47, 0.91 Absolute OS benefit favoring trastuzumab of 2.7%

29. HERA trial: DFS subgroup analysis summary No evidence of any subgroup in which there is less efficacy (similar efficacy in each subgroup) No substantial influence of any baseline characteristic on the DFS benefit for Herceptin

30. Summary of Cardiac Toxicity in Three Studies P 0.001 <0.002

31. Slamon D., SABCS 2006 4 x AC 60/600 mg/m 2 4 x Docetaxel 100 mg/m 2 6 x Docetaxel and Carboplatin 75 mg/m2 AUC 6 1 Year Trastuzumab N=3,222 1 Year Trastuzumab AC  T AC  TH TCH Her2+ (Central FISH) N+ or high risk N- 4 x AC 60/600 mg/m2 4 x Docetaxel 100 mg/m2 Stratified by Nodes and Hormonal Receptor Status BCIRG 006: study design

32. Slamon D, SABCS 2006 BCIRG 006: Endpoints Primary Disease-free Survival Secondary Overall Survival Toxicity Pathologic & Molecular Markers Slamon D., SABCS 2006

33. Patient characteristics well balanced arms Randomized (n=3,222) AC-T n=1,073 AC-TH n=1,074 TCH n=1,075 %% Age < 50 years52 54 KPS = 100807980 Mastectomy606360 Radiotherapy636163 Hormonotherapy5051 Enrollment: April 2001 to March 2004 Slamon D., SABCS 2006

34. Tumor Characteristics well balanced arms Randomized (n=3,222) AC-T n=1,073 AC-TH n=1,074 TCH n=1,075 Number of nodes +%% 029 1 – 3393839 4 – 10222423 > 1011910 Tumor Size (cm)%%  2 2 413840 > 2 and  5 535554 > 5 6 7 6 ER and/or PR +54 Slamon D., SABCS 2006

35. Recent developments Median follow-up more than 3 years Slamon D., SABCS 2006

36. Disease Free Survival (1st interim analysis) Median follow-up time = 23 months Year from randomization Slamon D., SABCS 2006

37. Disease Free Survival (2nd Interim Analysis) Median follow-up time = 36 months Absolute DFS benefits (from years 2 to 4): AC  TH vs AC  T: 6% TCH vs AC  T: 5% % Disease Free 0.7 0.8 0.9 1.0 012345 Patients Events 81% 87% 86% 77% 83% 82% 87% 93% 92% 0.5 0.6 1073192AC->T 1074128AC->TH 1075142TCH HR (AC->TH vs AC->T) = 0.61 [0.48;0.76] P<0.0001 HR (TCH vs AC->T) = 0.67 [0.54;0.83] P=0.0003 Year from randomization Slamon D., SABCS 2006 Significant difference between trastuzumab arms and non trastuzumab arm

38. Overall Survival ( 2nd Interim Analysis) Median follow-up time = 36 months Year from randomization Slamon D., SABCS 2006 % Survival 0.7 0.8 0.9 1.0 HR (AC->TH vs AC->T) = 0.59 [0.42;0.85] P=0.004 HR (TCH vs AC->T) = 0.66 [0.47;0.93] P=0.017 0.5 0.6 0 1 2345 Patients Events 107380AC->T 107449AC->TH 107556TCH 97% 99% 98% 93% 97% 95% 92% 91% 86% Significant difference between trastuzumab arms and non trastuzumab arm

39. Grade 3/4 Non-Hematological toxicity AC-T n=1,050 % AC-TH n=1,068 % TCH n=1,056 % Arthralgia 3.23.31.4 Myalgia 5.2 1.8 Fatigue 7.07.37.2 Hand-foot syndrome 1.91.40.0 Stomatitis 3.63.11.4 Diarrhea 3.05.75.5 Nausea 6.05.74.8 Vomiting 6.16.83.4 Irregular menses 27.124.226.4 * * * * * Yellow = numerically less events AC-TH or TCH *Statistically significant AC-TH or TCH Slamon D., SABCS 2006

40. Grade 3/4 Hematological Toxicity AC-T n=1,050 % AC-TH n=1,068 % TCH n=1,056 % Neutropenia63.371.366.2 Leucopenia51.560.248.2 Febrile neutropenia9.111.09.8 Neutropenic infection11.312.011.0 Anemia2.53.15.8 Thrombocytopenia1.01.25.4 Leukemia (%)3 pts (0.3)1 pt (0.1)0 pts * * * * Yellow = numerically less events AC-TH or TCH *Statistically significant AC-TH or TCH Slamon D., SABCS 2006

41. AC-T n=1,050 AC-TH n=1,068 TCH n=1,056 Cardiac related death 0 / 0 Cardiac left ventricular function (CHF) Grade 3 / 4 3 / 417 / 20 4 / 4 first interim analysis second interim analysis P = 0.0015 Slamon D., SABCS 2006 Safety analysis population: cardiotoxicity Statistically significant increase in cardiac events in the AC-TH arm

42. TOPO IIa Amplification as a Predictor of Anthracycline Response in Breast Cancer StudyYrN Park et al.2006284 Tanner et al.2006525 Knoop at al.2005805 Park et al.2003188 Coon et al.200235 Di Leo et al.2002354 Since 2002, at least 6 studies have been published demonstrating the association between topo II alpha amplification and improved anthracyline response.

43. Year from randomization % Disease Free 0.5 0.6 0.7 0.8 0.9 1.0 012345 Patients EventsTopo II 1044119 1904325 94% 88% 82% 84% 78% Co-Amplified Non Co-amplified HR (Co-Amp vs Non Co-Amp) = 1.44 [1.16;1.78] P<0.001 Co-Amplified Non Co-amplified DFS Topo II Co-Amplified vs.... Non Co-Amplified (2nd Interim Analysis) Slamon D., SABCS 2006

44. DFS Co-Amplified Topo II by Arm (2nd Interim Analysis) Year from randomization % Disease Free 0.5 0.6 0.7 0.8 0.9 1.0 012345 Patients Events 32842AC->T 35735AC->TH 35942TCH 92% 95% 94% 87% 89% 87% 85% 83% P=0.336 P=0.648 Slamon D., SABCS 2006 In co-amplified Topo II patients trastuzumab does not add nothing in term of DFS to anthracycline based therapy

45. Year from randomization % Disease Free 0.5 0.6 0.7 0.8 0.9 1.0 012345 Patients Events 643146AC->T 64387AC->TH 61892TCH 83% 91% 90% 78% 85% 84% 71% 83% 81% P<0.001 DFS Non Co-Amplified Topo II by Arm (2nd Interim Analysis) Slamon D., SABCS 2006 In NOT co-amplified Topo II patients trastuzumab INCREASES DFS compared to anthracycline based therapy

46. Adjuvant Herceptin trials: summary of DFS data to date Romond et al 2005; Joensuu et al 2006; Slamon et al 2006; Smith et al 2007 a Relapse-free survival; V, vinorelbine 0 HERA (n=5090) 2 years Combined analysis (n=3351) 2 years Median follow-up BCIRG 006 DCarboH (n=1075) 3 years BCIRG 006 AC  DH (n=1074) FinHer VH / DH a (n=232) 3 years 12 Favours Herceptin Favours no Herceptin HR

47. St. Gallen guidelines: update on adjuvant treatments for Early Breast Cancer Herceptin provides substantial benefit to patients with HER2-positive tumours at high risk of early recurrence Herceptin should be added either with or after chemotherapy for HER2-positive patients, irrespective of endocrine responsiveness and nodal status Goldhirsch et al 2006

48. Adjuvant Herceptin: answering some key questions Optimal duration of Herceptin treatment? - HERA (1 year versus 2 years Herceptin) Effect of delayed switching to Herceptin? - HERA Is concurrent or sequential Herceptin administration optimal? - NCCTG N9831

49. Future directions 1) EGFR family inhibitors associated with trastuzumab Because HER2 and EGFR coexpression occurs in 30% of breast cancers, blockage of both receptors is a rational strategy which may improve RR to trastuzumab. Such combination may also be considered for trastuzumab-resistant tumours, in which compensatory signalling by EGFR may inhibit the response to trastuzumab. - Lapatinib, Gefitinib, Pertuzumab Valabrega G et al: Ann Oncol 2007

50. Future directions 2) Association with agents targeting other pathways and modified anti-HER2 antibodies It is under early clinical investigation for breast cancer after promising results in a preclinical setting. - inhibitors of mTOR (kinase located downstream the PI3K-AKT pathway): CCI-779 and RAD001 - trastuzumab + bevacizumab (NCI-sponsored phase I/II trial ongoing in HER2-overexpressing metastatic breast cancer patients) - recombinant molecules in which the antibody-combining site is fused directly to the toxin have been developed and show strong selectivity for HER2 binding Valabrega G et al: Ann Oncol 2007

51. Ongoing large clinical phase III trials: 1) The TEACH trial (3,000 patients) - it compares lapatinib and placebo after completion of any chemotherapy (anthracycline, taxane or CMF regimen) 2) ALTTO (Adjuvant lapatinib and/or trastuzumab treatment optimization) (to begin): -it will investigates the benefit of trastuzumab 1 year vs lapatinib 1 year vs trastuzumab 12 ws  lapatinib 34 ws vs combination trastuzumab+lapatinib 1 year (after chemotherapy) -it expects an ultimate enrollment of 8,000 patients Lapatinib (Tykerb) in early stage HER2-overexpressing breast cancer Ito Y et al: Breast Cancer 2007

52. Co-amplification of c-myc and HER2: benefit of trastuzumab C-MYC/HER2Regimen PatientsEventsHR2p Non co-amplifiedAC T AC TH 540 538 82 55 0,630,007 Co-amplifiedAC T AC TH 234 237 51 13 0,240,0001 Relationship between amplification of HER2 and c-myc in NSABP-B31 trial Kim et al Breast Cancer Research Treat 2005

53. Co-amplification of c-myc and HER2: benefit of trastuzumab Patients with co-amplification of c-myc and HER2 have worse outcome when treated with chemotherapy alone, whereas the addition of Trastuzumab reverses this trend Patients treated with trastuzumab achieved recurrence-free survival of over 90% HER2 amplification could represent an antiapoptotic signal for the pro-apoptotic function of c-Myc Trastuzumab could promote the apoptotic function of c-myc Kim et al Breast Cancer Research Treat 2005

54. Results from four major randomised trials provide level 1 evidence for OS benefit of adjuvant Herceptin Adjuvant Herceptin greatly increases the chance of Survival for patients with HER2-positive Early Breast Cancer Adjuvant Herceptin should be considered for all patients with HER2-positive breast cancer Close cardiac monitoring is mandatory Sequential vs.... concurrent vs.... chemotherapy regimen? Role of Topo II α testing? Role of c-myc testing? Take-Home Messages

55. Adjuvant Herceptin approval Chile Columbia Dominican Republic Ecuador Norway USA Guatemala Iceland India Israel Bosnia- Herzegovina Mexico New Zealand Nicaragua Pakistan Philippines Russia South Korea Switzerland Australia EU