PierFranco Conte

2. HER2: beyond Herceptin

3. “Non esiste vento favorevole per il marinaio che non sa dove andare”(there is no favourable wind for a sailor who does not know where to go) Seneca (5 aC-65 dC)

4. Why targeting HER2 beyond Trastuzumab in Breast Cancer?  Efficacy Primary resistance Secondary resistance Cardiac safety HER2 + molecular subtypes

5. FIRST-LINE SINGLE-AGENT TRIAL RESPONSE ACCORDING TO HER2 STATUS

6. Efficacy data from Phase II and III trials of trastuzumab combined with chemotherapy

9. HER2+ Advanced Breast Cancer ~ 60 – 70% of patients exhibit a primary resistance to Trastuzumab monotherapy ~ 30 – 50% of patients show a primary resistance to Trastuzumab plus chemotherapy Eventually, all the patients become resistant to Trastuzumab within months or years CNS MTS are frequent Trastuzumab is ineffective for CNS MTS ( CSF levels 300-fold lower than in the serum)

10. The Censored DFS analysis, censoring pts switching to delayed trastuzumab at the time of the switch – Also shows a highly significant benefit, very similar to the ITT, with a HR of 0.63 and an absolute 3 yr DFS gain of 6.6%The Censored DFS analysis, censoring pts switching to delayed trastuzumab at the time of the switch – Also shows a highly significant benefit, very similar to the ITT, with a HR of 0.63 and an absolute 3 yr DFS gain of 6.6%

12. HER2+ Early Breast Cancer > 50% of patients do not need HER2 targeted therapy > 50% of patients show a primary resistance to Trastuzumab plus chemotherapy CNS relapse as 1st event is more frequent in patients on adjuvant trastuzumab

13. Management of trastuzumab resistanceLesson # 1 Check HER2 positivity on original tumor blocks Whenever possible, test HER2 status on recurrent disease Trastuzumab and chemotherapy can act synergically on apoptotic pathway Other proteins in the EFGR-mediated signalling pathways are important Other EGFRs (i.e.HER1) can be important

14. Trastuzumab resistance Trastuzumab can induce apoptosis through inhibition of PI3K/Akt pathway PTEN normally opposes PI3K/Akt signaling trastuzumab stabilizes PTEN and downregulates Akt signaling loss of PTEN can induce trastuzumab resistance

15. ErbB2/ErbB3 Expression and Estrogen Receptor Status in Breast Carcinomas Signaling through either the estrogen receptor (ER) or ErbB receptors is often discussed as if they were discrete pathways, but experimental evidence suggests there is considerable interplay between them. Overexpression of ErbB2 has been found to decrease responsiveness to hormonal therapy in patients with breast cancer,1 and estrogen depletion can increase the expression of ErbB1 in breast cancer cell lines.2 This evidence of crosstalk raises the question of the relationship between ER and ErbB expression in primary tumors. In a study conducted by Witton and colleagues, ErbB and estrogen receptor (ER) levels were determined by immunohistochemistry in 220 breast carcinomas.3 An inverse relationship was detected between ER expression and expression of ErbB1, ErbB2, and/or ErbB3. 1. De Placido S, De Laurentiis M, Carlomagno C, et al. Twenty-year results of the Naples GUN randomized trial: predictive factors of adjuvant tamoxifen efficacy in early breast cancer. Clin Cancer Res 2003; 9:1039-46. 2. Yarden RI, Wilson MA, Chrysogelos SA. Estrogen suppression of EGFR expression in breast cancer cells: A possible mechanism to modulate growth. J Cell Biochem 2001; 81:232-246. 3. Witton CJ, Reeves JR, Going JJ, et al. Expression of the HER1-4 family of receptor tyrosine kinases in breast cancer. J Pathol 2003; 200:290-7. Signaling through either the estrogen receptor (ER) or ErbB receptors is often discussed as if they were discrete pathways, but experimental evidence suggests there is considerable interplay between them. Overexpression of ErbB2 has been found to decrease responsiveness to hormonal therapy in patients with breast cancer,1 and estrogen depletion can increase the expression of ErbB1 in breast cancer cell lines.2 This evidence of crosstalk raises the question of the relationship between ER and ErbB expression in primary tumors. In a study conducted by Witton and colleagues, ErbB and estrogen receptor (ER) levels were determined by immunohistochemistry in 220 breast carcinomas.3 An inverse relationship was detected between ER expression and expression of ErbB1, ErbB2, and/or ErbB3. 1. De Placido S, De Laurentiis M, Carlomagno C, et al. Twenty-year results of the Naples GUN randomized trial: predictive factors of adjuvant tamoxifen efficacy in early breast cancer. Clin Cancer Res 2003; 9:1039-46. 2. Yarden RI, Wilson MA, Chrysogelos SA. Estrogen suppression of EGFR expression in breast cancer cells: A possible mechanism to modulate growth. J Cell Biochem 2001; 81:232-246. 3. Witton CJ, Reeves JR, Going JJ, et al. Expression of the HER1-4 family of receptor tyrosine kinases in breast cancer. J Pathol 2003; 200:290-7.

16. Survival Interrelationship Between ER/PR Status and ErbB Expression Dr. Witton and colleagues reported that there was a significant survival difference among the patients with ER+ tumors depending on ErbB receptor status (P = .0016).1 The 10-year survival rate was lower for the patients with tumors that were ER+ and positive for ErbB1, ErbB2, or ErbB3 (35%) than for those with ER+ tumors that were negative for all ErbB receptors (55%). However, survival rates were significantly higher in the patients with ER+ tumors that were positive for ErbB4 (80%). No significant difference was seen in 10-year survival in the patients with ER– tumors that were either positive or negative for ErbB1, ErbB2, or ErbB3. Witton CJ, Reeves JR, Going JJ, et al. Expression of the HER1–4 family of receptor tyrosine kinases in breast cancer. J Pathol 2003; 200:290-7. Dr. Witton and colleagues reported that there was a significant survival difference among the patients with ER+ tumors depending on ErbB receptor status (P = .0016).1 The 10-year survival rate was lower for the patients with tumors that were ER+ and positive for ErbB1, ErbB2, or ErbB3 (35%) than for those with ER+ tumors that were negative for all ErbB receptors (55%). However, survival rates were significantly higher in the patients with ER+ tumors that were positive for ErbB4 (80%). No significant difference was seen in 10-year survival in the patients with ER– tumors that were either positive or negative for ErbB1, ErbB2, or ErbB3. Witton CJ, Reeves JR, Going JJ, et al. Expression of the HER1–4 family of receptor tyrosine kinases in breast cancer. J Pathol 2003; 200:290-7.

17. Effect on survival of the expression of other EGF-r family members

18. Lapatinib Mechanism of Action Binds to intracellular ATP binding site of EGFR (ErbB-1) and HER2 (ErbB-2) preventing phosphorylation and activation Blocks downstream signaling through homodimers and heterodimers of EGFR (ErbB-1) and HER2 (ErbB-2) Dual blockade of signaling may be more effective than the single-target inhibition provided by agents such as trastuzumab As a dual-kinase inhibitor with specificity for both ErbB1 and ErbB2, lapatinib can block signaling through homodimers composed of either of these receptors.1,2 In theory, lapatinib may also be able to inhibit or decrease signaling through other heterodimer combinations, such as ErbB2/ErbB3. 1. Rusnak DW, Lackey K, Affleck K, et al. The effects of the novel, reversible epidermal growth factor receptor/ErbB-2 tyrosine kinase inhibitor, GW2016, on the growth of human normal and tumor-derived cell lines in vitro and in vivo. Mol Cancer Ther 2001; 1:85-94. Xia W, Mullin RJ, Keith BR, et al. Anti-tumor activity of GW572016: a dual tyrosine kinase inhibitor blocks EGF activation of EGFR/erbB2 and downstream Erk1/2 and AKT pathways. Oncogene 2002; 21:6255-63. Konecny GE, Pegram MD, Venkatesan N, et al. Activity of the dual kinase inhibitor lapatinib (GW572016) against HER-2-overexpressing and trastuzumab-treated breast cancer cells. Cancer Res. 2006;66:1630-1639. As a dual-kinase inhibitor with specificity for both ErbB1 and ErbB2, lapatinib can block signaling through homodimers composed of either of these receptors.1,2 In theory, lapatinib may also be able to inhibit or decrease signaling through other heterodimer combinations, such as ErbB2/ErbB3. 1. Rusnak DW, Lackey K, Affleck K, et al. The effects of the novel, reversible epidermal growth factor receptor/ErbB-2 tyrosine kinase inhibitor, GW2016, on the growth of human normal and tumor-derived cell lines in vitro and in vivo. Mol Cancer Ther 2001; 1:85-94. Xia W, Mullin RJ, Keith BR, et al. Anti-tumor activity of GW572016: a dual tyrosine kinase inhibitor blocks EGF activation of EGFR/erbB2 and downstream Erk1/2 and AKT pathways. Oncogene 2002; 21:6255-63. Konecny GE, Pegram MD, Venkatesan N, et al. Activity of the dual kinase inhibitor lapatinib (GW572016) against HER-2-overexpressing and trastuzumab-treated breast cancer cells. Cancer Res. 2006;66:1630-1639.

19. Dual kinase inhibitor lapatinib against HER-2 overexpressing and trastuzumab-treated breast cancer cell lines

20. Combined effect of Trastuzumab and Lapatinib

21. Phase Ib Trial: EGF10004Overview Study objectives: Determine a dose or range of biologically active doses Evaluate safety and tolerability Examine dose pharmacokinetics and pharmacodynamics Study design: Patients randomized to doses of 500, 650, 900, 1200, or 1600 mg/day Clinical response evaluated every 8 weeks Biological effects examined by comparing biomarker results from biopsy samples obtained pretreatment and following 21 days of therapy The phase Ib trial EGF10004 was designed to determine the range of biologically effective doses for lapatinib. Additional goals of this study included evaluating safety and tolerability as well as pharmacokinetics and pharmacodynamics at different doses. Patients were required to have tumors with documented overexpression or activation of ErbB1 or ErbB2 (immunohistochemical data) or evidence of amplification of the ErbB2 gene. Tumors or ascites also needed to be amenable to baseline and repeat biopsies. In addition, patients were required to have adequate organ function with an LVEF >40%. Eligible patients were randomized to 5 dose levels, with skin and tumor biopsies obtained prior to the start of the study and again on day 21. Clinical responses were determined every 8 weeks. The biological effects of lapatinib on skin and tumor tissue were evaluated by quantitative immunohistochemistry. The phase Ib trial EGF10004 was designed to determine the range of biologically effective doses for lapatinib. Additional goals of this study included evaluating safety and tolerability as well as pharmacokinetics and pharmacodynamics at different doses. Patients were required to have tumors with documented overexpression or activation of ErbB1 or ErbB2 (immunohistochemical data) or evidence of amplification of the ErbB2 gene. Tumors or ascites also needed to be amenable to baseline and repeat biopsies. In addition, patients were required to have adequate organ function with an LVEF >40%. Eligible patients were randomized to 5 dose levels, with skin and tumor biopsies obtained prior to the start of the study and again on day 21. Clinical responses were determined every 8 weeks. The biological effects of lapatinib on skin and tumor tissue were evaluated by quantitative immunohistochemistry.

22. EGF10004 Results: Frequency of Achieving = 75% Inhibition of p-EGFR, p-ErbB2, p-ERK1/2, or p-AKT Expression in Tumors at Day 21 In order to determine the range of biologically effective doses of lapatinib, a panel of tumor biomarkers was examined by quantitative immunohistochemistry.1 Tumor samples were taken at day 0 and at day 21 following initiation of treatment. Potent inhibition of the phosphorylation of ErbB1, ErbB2, ERK1/2 or Akt occurred at dose levels greater than or equal to 650 mg/day. The greatest frequency of inhibition was observed in patients receiving 1600 mg daily (80%). 1. Burris H, Hurwitz H, Dees C, et al. EGF 10004: a randomized, multicenter, phase Ib study of the safety, biologic activity and clinical efficacy of the dual kinase inhibitor GW572016 [abstract #39]. (SABCS Oral Presentation) Breast Cancer Res Treat. 2003;82 (suppl1):S18 In order to determine the range of biologically effective doses of lapatinib, a panel of tumor biomarkers was examined by quantitative immunohistochemistry.1 Tumor samples were taken at day 0 and at day 21 following initiation of treatment. Potent inhibition of the phosphorylation of ErbB1, ErbB2, ERK1/2 or Akt occurred at dose levels greater than or equal to 650 mg/day. The greatest frequency of inhibition was observed in patients receiving 1600 mg daily (80%). 1. Burris H, Hurwitz H, Dees C, et al. EGF 10004: a randomized, multicenter, phase Ib study of the safety, biologic activity and clinical efficacy of the dual kinase inhibitor GW572016 [abstract #39]. (SABCS Oral Presentation) Breast Cancer Res Treat. 2003;82 (suppl1):S18

23. EGF10004: Clinical Characteristics of Responders––Breast Cancer Subset Sixty-seven patients with various solid tumors were entered on study with the largest proportion (n=30) having breast cancer. The patients were heavily pretreated having received a median of 5 prior lines of treatment (range, 1-14). Four patients (of 59 evaluable) achieved a partial response, all of whom had breast cancer. Twenty-four patients showed stable disease (10 breast cancer, 5 NSCLC, 3 colorectal cancer, 3 SCCHN, and 1 each of ovarian, adenocarcinoma of unknown primary, and granular cell carcinoma). Details of the 4 breast cancer patients who responded were assessed in detail so as to understand clinical parameters which may influence responsiveness. Two of the patients had inflammatory breast cancer. Among these 4 patients all overexpressed ErbB2 (3+ by IHC) and histological evaluation of the tumor sample revealed that ErbB2 activity was inhibited by lapatinib. Three of the patients also overexpressed EGFR/ErbB1. All patients had received prior therapy with trastuzumab, 3 had received taxanes and 3 had received anthracyclines. Burris H, Hurwitz H, Dees EC et al. Phase I Safety, Pharmacokinetics, and Clinical Activity Study of Lapatinib (GW572016), a Reversible, Dual Inhibitor of Epidermal Growth Factor Receptor Tyrosine Kinases in Heavily Pretreated Patients With Metastatic Carcinomas J Clin Oncol 2005; 23:1-9 Sixty-seven patients with various solid tumors were entered on study with the largest proportion (n=30) having breast cancer. The patients were heavily pretreated having received a median of 5 prior lines of treatment (range, 1-14). Four patients (of 59 evaluable) achieved a partial response, all of whom had breast cancer. Twenty-four patients showed stable disease (10 breast cancer, 5 NSCLC, 3 colorectal cancer, 3 SCCHN, and 1 each of ovarian, adenocarcinoma of unknown primary, and granular cell carcinoma). Details of the 4 breast cancer patients who responded were assessed in detail so as to understand clinical parameters which may influence responsiveness. Two of the patients had inflammatory breast cancer. Among these 4 patients all overexpressed ErbB2 (3+ by IHC) and histological evaluation of the tumor sample revealed that ErbB2 activity was inhibited by lapatinib. Three of the patients also overexpressed EGFR/ErbB1. All patients had received prior therapy with trastuzumab, 3 had received taxanes and 3 had received anthracyclines. Burris H, Hurwitz H, Dees EC et al. Phase I Safety, Pharmacokinetics, and Clinical Activity Study of Lapatinib (GW572016), a Reversible, Dual Inhibitor of Epidermal Growth Factor Receptor Tyrosine Kinases in Heavily Pretreated Patients With Metastatic Carcinomas J Clin Oncol 2005; 23:1-9

24. EGF20009:A Phase II, Randomized Trial Using the Small Molecule Tyrosine Kinase Inhibitor Lapatinib as a First-Line Treatment in Patients with FISH Positive Advanced or Metastatic Breast Cancer H. L. Gomez, M. A. Chavez, D. C. Doval, L. W. Chow, B. Newstat, S. H. Stein, M. S. Berger, G. W. Sledge ASCO 2005

25. EGF20009: Phase II Randomized Trial of Lapatinib as First-line Treatment in FISH-Positive Metastatic Breast Cancer EGF20009 was undertaken to evaluate single agent lapatinib in previously untreated ErbB2-overexpressing MBC. Based upon activity observed with lapatinib in heavily pre-treated patients, it was hypothesized that greater activity would be observed in a chemotherapy-naïve population of MBC patients. Target accrual for this trial was 130 patients and the patients were required to have ErbB2 positive disease as determined by FISH. Patients were randomized to treatment with lapatinib 1500 mg/day or 500 mg PO BID. Treatment in either arm was administered for 12 weeks. Efficacy was assessed at 8 and 12 weeks and those benefiting from therapy were permitted to continue therapy. The primary endpoint for this study was objective response rates, with secondary endpoints of clinical benefit, time to response, duration of response, and time to treatment failure. EGF20009 was undertaken to evaluate single agent lapatinib in previously untreated ErbB2-overexpressing MBC. Based upon activity observed with lapatinib in heavily pre-treated patients, it was hypothesized that greater activity would be observed in a chemotherapy-naïve population of MBC patients. Target accrual for this trial was 130 patients and the patients were required to have ErbB2 positive disease as determined by FISH. Patients were randomized to treatment with lapatinib 1500 mg/day or 500 mg PO BID. Treatment in either arm was administered for 12 weeks. Efficacy was assessed at 8 and 12 weeks and those benefiting from therapy were permitted to continue therapy. The primary endpoint for this study was objective response rates, with secondary endpoints of clinical benefit, time to response, duration of response, and time to treatment failure.

26. Efficacy in All Patients

27. EGF20009: Lapatinib Monotherapy for First-line FISH-Positive Metastatic Breast CancerSafety

28. Patient C: Brain Lesion Baseline

29. Patient C: Brain Lesion Week 12

30. Lapatinib + Trastuzumab in Advanced Pretreated Metastatic Breast Cancer Phase I Study: EGF10023 Study objectives: Safety of lapatinib in combination with trastuzumab Optimally tolerated regimen of combination Pharmacokinetic parameters Clinical activity Eligibility criteria: Advanced ErbB2+ MBC Prior treatment with trastuzumab allowed but not required Treatment consisted of escalating doses of lapatinib 750, 1000, 1250, or 1500 mg/day with trastuzumab (4-mg/kg loading dose; 2 mg/kg/week) Responses to single agent lapatinib in patients with heavily pretreated MBC are limited, according to studies EGF20008 and EGF20002.1,2 In preclinical studies, the combination of lapatinib and trastuzumab demonstrated enhanced activity against an ErbB2-overexpressing cell line compared to either agent alone.3 Thus, to augment activity in these patients, combining lapatinib with trastuzumab may lead to enhanced responsiveness. A phase I trial (EGF10023) was undertaken to assess the feasibility and to define an optimal regimen for treatment of advanced pretreated MBC using trastuzumab and lapatinib.4,5 Patients had ErbB2+ disease and prior therapy with trastuzumab was allowed but not required. Treatment with trastuzumab was administered with lapatinib in escalating doses of 750, 1000, 1250 or 1500 mg/day. Forty-six patients were enrolled of whom 45 (94%) were pretreated with trastuzumab 1. Blackwell et al. ESMO 2004; Abstract 103 Burstein et al. ESMO 2004; Abstract 104 Konecny et al. Proc AACR 2002; 42 (abstract 4974) Storniolo A, et al. ECCO 2005; Abstract 278 Storniolo A, et al. SABCS 2005; Abstract 1075Responses to single agent lapatinib in patients with heavily pretreated MBC are limited, according to studies EGF20008 and EGF20002.1,2 In preclinical studies, the combination of lapatinib and trastuzumab demonstrated enhanced activity against an ErbB2-overexpressing cell line compared to either agent alone.3 Thus, to augment activity in these patients, combining lapatinib with trastuzumab may lead to enhanced responsiveness. A phase I trial (EGF10023) was undertaken to assess the feasibility and to define an optimal regimen for treatment of advanced pretreated MBC using trastuzumab and lapatinib.4,5 Patients had ErbB2+ disease and prior therapy with trastuzumab was allowed but not required. Treatment with trastuzumab was administered with lapatinib in escalating doses of 750, 1000, 1250 or 1500 mg/day. Forty-six patients were enrolled of whom 45 (94%) were pretreated with trastuzumab 1. Blackwell et al. ESMO 2004; Abstract 103 Burstein et al. ESMO 2004; Abstract 104 Konecny et al. Proc AACR 2002; 42 (abstract 4974) Storniolo A, et al. ECCO 2005; Abstract 278 Storniolo A, et al. SABCS 2005; Abstract 1075

32. Lapatinib + Trastuzumab in Advanced Pretreated Metastatic Breast Cancer: Results Optimally tolerated dose and dose-limiting toxicities: Lapatinib 1000 mg/day with standard trastuzumab was defined as optimally tolerated regimen (OTR). The most frequent adverse at OTR were diarrhea, rash, fatigue, nausea, anorexia, and vomiting. Pharmacokinetics: No effect on PK of lapatinib or trastuzumab was observed during coadministration. Synergism of action of lapatinib and trastuzumab similar to preclinical studies reported. Based on the prevalence of dose limiting toxicities and need for dose reduction, 1000 mg/day was identified as the dose for further study in combination with trastuzumab. Among 10 patients treated at 1250 mg/day, there were 2 DLTs and 3 dose reductions, and among 3 patients treated at 1500 mg/day, there were 2 DLTs and 2 dose reductions. Storniolo A, et al. ECCO 2005; Abstract 278, and SABCS 2005; Abstract 1075Based on the prevalence of dose limiting toxicities and need for dose reduction, 1000 mg/day was identified as the dose for further study in combination with trastuzumab. Among 10 patients treated at 1250 mg/day, there were 2 DLTs and 3 dose reductions, and among 3 patients treated at 1500 mg/day, there were 2 DLTs and 2 dose reductions. Storniolo A, et al. ECCO 2005; Abstract 278, and SABCS 2005; Abstract 1075

33. Management of trastuzumab resistanceLesson # 2 Combining two MoAbs binding at different epitopes of HER2 receptor can inhibit more efficiently HER2-driven signalling (trastuzumab+Pertuzumab) Combining an anti-ErbB2 antibody with small molecule tyrosine kinase inhibitor, that act at different sites of the receptor with distinct mechanisms of action, might enhance the efficacy of both drugs (trastuzumab +Lapatinib) Inhibition of multiple EGFR-family receptors can be important (lapatinib)

34. A Phase III Randomized, Open-Label, International Study Comparing Lapatinib and Capecitabine vs. Capecitabine in Women with Refractory Advanced or Metastatic Breast Cancer (EGF100151) C.E. Geyer, D. Cameron, D. Lindquist, S. Chan, T. Pienkowski, C.G. Romieu, A. Jagiello-Gruszfeld,J. Crown, B. Kaufman, A. Chan, J.K. Forster Allegheny General Hospital, Pittsburgh, PA; Western General Hospital, Edinburgh, UK; US Oncolgy Research Network, Houston,TX; Nottingham City Hospital, Nottingham, UK; Cancer Center, Warsaw, Poland; CRCC Val d’Aurelle Paul Lamarque, Montpellier, France; ZOZ MSWiA, Olsztyn, Poland; St. Vincent’s University Hospital, Dublin, Ireland; Sheba Medical Center, Tel Hashomer, Israel; Mount Medical Centre, Perth, Australia; GlaxoSmithKline, Greenford, UK

35. Study Design

36. EGF 100151 - Study Objectives Primary TTP Secondary Overall survival Progression free survival 6-month progression free survival Overall tumor response rate Clinical benefit (complete, partial response or stable disease for at least 6 months) Time to response Duration of response

37. Prior Therapy

38. Prior Trastuzumab for Metastatic Disease

39. Issued – Monday 3 April 2006, London, UK & Philadelphia, US - LSE Announcement GlaxoSmithKline Receives Positive Data and Halts Enrolment in Phase III Trial of Tykerb® (Lapatinib) in Advanced Breast Cancer  First Regulatory Filings now Planned for 2nd Half of 2006 Based on the unanimous recommendation of an Independent Data Monitoring Committee (IDMC), GlaxoSmithKline (GSK) announced today that it has halted enrolment in its Phase III clinical trial evaluating the combination of Tykerb (lapatinib ditosylate) and capecitabine (Xeloda®) versus capecitabine alone. The trial evaluated women with refractory advanced or metastatic breast cancer who have documented ErbB2 (HER2) overexpression and whose disease progressed following treatment with trastuzumab (Herceptin?) as well as other cancer therapies. A pre-planned interim analysis of 321 patients in the study yielded statistically significant results, exceeding the primary endpoint.

40. EGF100151: Phase III Trial of Capecitabine ± Lapatinib in Advanced or Metastatic Breast Cancer Efficacy

41. Time to Progession – ITT Population

42. EGF100151: Phase III Trial of Capecitabine ± Lapatinib in Advanced or Metastatic Breast CancerBrain Metastases as Site of Progression

43. EGF 100151-Most Frequent Adverse Events  All Grades

44. EGF 100151-Mean LVEF at Scheduled Assessments

45. Conclusions Lapatinib with capecitabine is an effective new regimen for advanced HER2+ breast cancer and should be considered a new standard of care for women meeting eligibility criteria of this trial

46. Summary: Cardiac Effects Associated with Lapatinib Therapy (n = 3558) 1097 pts with > 6 mo exposure to lapatinib In 598 patients pre-treated with A but no H 1.2% LVEF decrease; 0.3% symptomatic In 759 patients pre-treated with H and chemotherapy 1.7% LVEF decrease; 0.1% symptomatic In 2201 A and H naïve patients 1.7% LVEF decrease; 0.2% symptomatic

47. Effect of tumor selection and treatment selection on response

48. EGF109085/CHERLOBSTUDY DESIGN

49. DOSES AND TREATMENT REGIMENS Arm A: Paclitaxel 80 mg/m2 weekly for 12 weeks ? FE75C q 21 X 4 courses plus trastuzumab 4 mg/kg loading dose followed by 2mg/kg weekly Arm B: Paclitaxel 80 mg/m2 weekly for 12 weeks ? FE75C q 21 X 4 courses plus Lapatinib 1500 mg po daily Arm C: Paclitaxel 80 mg/m2 weekly for 12 weeks ? FE75C q 21 X 4 courses plus trastuzumab 4 mg/kg loading dose followed by 2mg/kg weekly plus Lapatinib 1000 mg po daily Lapatinib and trastuzumab administration will start on the same day of the 1st infusion of CT, will continue throughout all the duration of the treatment and will be discontinued 1 week before surgery

50. EGF109077/LET-LOBSTUDY DESIGN

51. BIOMARKER EVALUATION The following biomarkers will be evaluated, to define the inhibition of the down-stream pathways of EGFR-family: - EGFR, HER2 - pTEN, pAKT, pMAPK - Apoptosis with TUNEL Test - Ki 67 These parameters will be evaluated by IHC, on paraffin-embedded specimens obtained from diagnostic core biopsy of the primary lesion and from surgical specimens. Fresh tumor tissue from core-biopsy must be snap frozen, to perform a microarray analysis of the gene expression profile before treatment and to evaluate its correlation with response.

53. Molecular subtypes of breast cancer and clinical management Her2+ represents a distinct molecular subtype Her2+ tumors have a unique clinical behaviour (shorter DFI, more visceral and CNS metastases) Her2 + tumors exhibit a peculiar pattern of sensitivity to chemo and hormonal therapy Her2 targeting agents have dramatically changed the course of this disease and represent now the foundation of treatment in early and advanced disease