1. Pertuzumab e Trastuzumab-DM1. Filippo Montemuro, M.D. Divisione di Oncologia Medica 1 Fondazione del Piemonte per l’Oncologia/Istituto per la Ricerca e la Cura del Cancro, Candiolo

2. HER2 targeting has changed the natural history of HER2-positive advanced breast cancer Dawood et al, J Clin Oncol 28;92, 2009 1991-2007

3. Proposed Mechanisms of Action of Trastuzumab Spector, J Clin Oncol 27;5838, 2009

4. From linear cascades to integrated networks Evolutionary processes:  Gene Duplication  Subfunctionalization (i.e. HER2 no known ligands, HER3 no tyrosine kinase activity) Amit I, Wides R, Yarden Y, Molecular Systems Biology 2007 1 ligand10 ligands

5. Targeting key pathways in HER signalling…and beyond Lapatinib Neratinib BIBW 2992 Canertinib Erlotinib Gefitinib Trastuzumab/DM1 Pertuzumab MM-111 Pertuzumab Cixitumumab Everolimus Temsirolimus ADAM 17 inhibitors HDAC inhibitors Endothelial Cell VEGFR PDGFR PDGF VEGF Bevacizumab Sorafenib Sunitinib Pazopanib HSP90 Inhibitors

6. HER2:HER3 dimers may provide an escape mechanism from trastuzumab + + + + + + + + + ++ Signaling activity + + + + HomodimersHeterodimers HER1:HER1 HER2:HER2 HER3:HER3 HER4:HER4 HER1:HER2 HER1:HER3 HER1:HER4 HER2:HER3 HER2:HER4 HER3:HER4 Tzahar, et al. Mol Cell Biol 1996 Tzahar et al. Mol Cell Biol 1996; Sergina et al. Nature 2007

7. Different mechanisms of action of trastuzumab and pertuzumab on heterodimers

8. Activity of pertuzumab in HER2-negative breast cancer Gianni et al. J Clin Oncol, 28; 1131, 2010

9. Toxicity profile of pertuzumab Gianni et al. J Clin Oncol, 28; 1131, 2010 8 patients experienced drops in LVEF ≥10% to <50%, including 1 CHF

10. Pertuzumab, demonstrates synergistic activity with trastuzumab ● Preferentially inhibits ligand-independent HER2 signaling ● Prevents shedding of HER2 ECD ● Flags cells for destruction by the immune system ● Inhibits formation of HER2 dimer pairs ● Suppresses multiple HER signalling pathways, leading to a more comprehensive blockade of HER2-driven signalling ● Flags cells for destruction by the immune system HER2 receptor Trastuzumab Pertuzumab Subdomain IV of HER2 Dimerization domain of HER2 Junttila et al. Cancer Cell 2009

11. Activity of trastuzumab and pertuzumab in HER2 positive xenografts Scheuer et al, Cancer Res 2009

12. Phase II trial of pertuzumab + trastuzumab in HER2-positive MBC patients progressing during trastuzumab-based therapy Pertuzumab + trastuzumab (n=66) Cohorts 1 and 2 1 HER2-positive MBC Progressed on trastuzumab + chemotherapy (Cohorts 1 and 2, n=66) HER2-positive MBC Progressed on trastuzumab + chemotherapy (n=29) Pertuzumab (n=29) Pertuzumab + trastuzumab (n=15) Cohort 3 2 Primary objectives ● Safety and efficacy Population ● ≤3 prior lines cytotoxic therapy (including adjuvant treatment) 1. Baselga et al. JCO 2010; 2. Baselga et al. SABCS 2009

13. Pertuzumab / trastuzumab combination therapy more active than treatment with either agent alone Cohorts 1 and 2 1,2 (P + H) (n=66) Cohort 3 3 (P) (n=27*) Cohort 3 3 (P  P + H) (n=11 † ) CR, % 7.60.0 PR, % 16.73.4 21.4 ORR, %24.23.4 21.4 SD  6 months, % 25.86.9 21.4 CBR, % (CR + PR + SD  6 months) 50.0 ‡ 10.3 37.5 PD, %50.082.8 57.1 1. Gelmon et al. ASCO 2008; 2. Baselga et al. JCO 2010; 3. Baselga et al. SABCS 2009 CR, complete response; PR, partial response; SD, stable disease *n=27, as at data cut-off 2/29 patients had not reached overall best response endpoint (8 cycles of assessment during this phase); † n=11, as at data cut-off 4/15 patients had not reached overall best response endpoint (8 cycles of assessment during this phase); ‡ at data cut-off, 21 (31.8%) patients had not experienced PD

14. Toxicity, non cardiac Baselga et al, J Clin Oncol, 28;1138, 2010

15. Cardiac toxicity Baselga et al, J Clin Oncol, 28;1138, 2010

16. Further development of this combination Accrual completed HER2-positive MBC No prior chemotherapy for MBC (except 1 prior hormonal regimen) (n=800*) Trastuzumab + docetaxel + placebo Trastuzumab + docetaxel + pertuzumab 1:1 Cleopatra HER2-positive MBC 2nd line, progressed on prior trastuzumab (n=450) Trastuzumab + capecitabine + placebo Trastuzumab + capecitabine + pertuzumab 1:1 125 centers, 20 countries Pherexa

17. The NEOSPHERE trial Trastuzumab + Docetaxel Trastuzumab + Docetaxel + Pertuzumab Trastuzumab + Pertuzumab Docetaxel + Pertuzumab SurgerySurgery FEC X 3 trastuzumab q3w until week 52 Trastuzumab + Docetaxel FEC X 3 trastuzumab q3w until week 52 HER2+ LABC 400 patients FEC X 3 trastuzumab q3w until week 52 End Points: -pCR -Biomarker analysis

18. Gianni et al. SABCS 2011

24. PI3K inhibition

25. Multiple targeting with trastuzumab, pertuzumab and GDC-0941

26. Trastuzumab-DM1

27. T-DM1 selectively delivers a highly toxic payload to HER2-positive tumor cells Receptor-T-DM1 complex is internalized into HER2-positive cancer cell Potent antimicrotubule agent is released once inside the HER2-positive tumor cell T-DM1 binds to the HER2 protein on cancer cells Trastuzumab-like activity by binding to HER2 Targeted intracellular delivery of a potent antimicrotubule agent, DM1

28. Phase I study in patients with HER2- positive advanced breast cancer

30. Clinical Study Descriptions Study TDM4258g (n=112)Study TDM4374g (n=110) Study designMulti-institutional, single-arm Phase II US studies Patient population (all with locally confirmed HER2- positive MBC) Received prior chemotherapy for MBC Progressed after exposure to at least one HER2-directed therapy (trastuzumab) Previously treated with an anthracycline, a taxane, capecitabine, lapatinib and trastuzumab Received at least two HER2- directed regimens for MBC, and progressed on the last regimen received Prior systemic therapy Received a median of 3 prior chemotherapy agents for MBC (range 1– 12) All received prior trastuzumab; 67/112 (60%) patients had also received prior lapatinib Received a median of 7 prior chemotherapy agents for MBC (range 1–15) All received prior lapatinib and trastuzumab Study treatment T-DM1 (3.6 mg/kg) was given by IV infusion over 30–90 minutes every 3 weeks (q3w) until disease progression Primary objectives Objective response rate (ORR) per RECIST by independent review facility (IRF)

31. Antitumor Activity, All Treated Patients TDM4374g* (n=110) TDM4258g † (n=112) ORR,% (95% CI) ‡ 32.7 (24.1–42.1)25.9 (18.4–34.4) Clinical benefit rate, % (95% CI) § 38.8 (38.8–57.9)39.3 (30.3–48.3) ORR=objective response rate. * Approximately 9 months minimum follow-up from last patient in (LPI) † Approximately 12 months minimum follow-up from LPI ‡ Complete or partial response determined by 2 tumor assessments ≥ 28 days apart § Includes patients who achieved an ORR, partial response, or stable disease of ≥ 6 months Both Phase II studies demonstrated clinically meaningful ORR for single-agent T-DM1.

32. Prior Chemotherapy and Anti-HER2 Therapy: TDM4258g

33. Summary of activity as a single agent: TDM4258g

34. Activity according to HER2 status

35. Adverse events

36. Patients treated with TDM1 retain sensitivity to further antiHER2-based therapy

37. Randomized, phase II, international, open-label study HER2-positive, measurable disease required Stratification factors  World region, prior adjuvant trastuzumab therapy, disease-free interval Primary endpoints: PFS by INV, safety Key Secondary endpoints: ORR, clinical benefit, OS, QOL, symptom control Study Design 1:1 HER2-positive, recurrent locally advanced BC or MBC (n=137) T-DM1 3.6 mg/kg Q3W until PD Trastuzumab 8 mg/kg dose; 6 mg/kg Q3W + Docetaxel 75 or 100 mg/m 2 Q3W Crossover T-DM1 PD Perez EA, et al. Abstr LBA3. ESMO 2010

38. Objective Response by Investigator (ITT) Randomized Patients T-DM1 (n=67) Trastuzumab + Docetaxel (n=70) Patients with an Objective Response,* n (%)32 (47.8)29 (41.4) 95% CI(35.4, 60.3)(30.2, 53.8) Patients with Clinical Benefit, † n (%)37 (55.2)40 (57.1) 95% CI(43.1, 67.2)(44.8, 68.9) Objective Responses, n (%) Complete Response3 (4.5)1 (1.4) Partial Response29 (43.3)28 (40.0) Stable Disease ‡ 22 (32.8)29 (41.4) Progressive Disease8 (11.9)4 (5.7) Unable to Evaluate4 (6.0)4 (5.7) * Objective response = complete or partial response based on RECIST 1.0 determined on two consecutive tumor assessments at least 4 weeks apart † Clinical benefit = objective response or maintained stable disease for at least 6 months from start of study treatment ‡ Stable disease includes 11 patients with unconfirmed partial response (5 in T-DM1 arm and 6 in the trastuzumab + docetaxel arm) Perez EA, et al. Abstr LBA3. ESMO 2010

39. AE Summary Safety Evaluable Patients T-DM1 (n=67) Trastuzumab+Docetaxel (n=68) Any AE, n (%)63 (94.0)68 (100.0) Grade ≥3 AE25 (37.3)51 (75.0) Serious AE*13 (19.4)15 (22.1) Three most common AEs (any grade) in T-DM1 arm Nausea Fatigue Pyrexia 32 (47.8) 31 (46.3) 24 (35.8) 27 (39.7) 29 (46.2) 14 (20.6) Three most common AEs (any grade) in trastuzumab + docetaxel arm Alopecia Neutropenia Diarrhea 1 (1.5) 5 (7.5) 7 (10.4) 45 (66.2) 39 (57.4) 31 (45.6) * AEs that result in death, are life-threatening, require inpatient hospitalization or prolongation of existing hospitalization, result in persistent or significant disability/incapacity, or are congenital anomalies/birth defects Perez EA, et al. Abstr LBA3. ESMO 2010

40. Phase Ib/II trial of T-DM1 + pertuzumab in patients with locally-advanced and MBC who were previously treated with trastuzumab Phase Ib: 3+3 dose escalation Cohort I: T-DM1 3.0 mg/kg; pertuzumab (840 mg loading dose, 420 mg maintenance dose) Cohort II: T-DM1 3.6 mg/kg; pertuzumab (840 mg loading dose, 420 mg maintenance dose) Phase II Expansion at dose level established in Phase Ib Dose escalation phase (completed) Expansion phase (completed) Phase Ib/II: HER2-positive MBC in all therapeutic lines (n=67) T-DM1 + pertuzumab (n=9) T-DM1 + pertuzumab (n=58, including 22 first line) Primary endpoints: Safety ORR by RECIST 1.0 Secondary endpoints: PFS DoR Heavily pretreated population: Median of 6 prior therapeutic agents in the metastatic setting Miller et al. ASCO 2010

41. T-DM1 + pertuzumab shows promising efficacy in patients pretreated with trastuzumab + lapatinib Cohort I, n (%) (n=3) Cohort II, n (%) (n=25) Total, n (%) (n=28) PR2 (66.7)8 (32.0)10 (35.7) SD1 (33.3)12 (48.0)13 (46.4) PD04 (16.0)4 (14.3) Missing01 (4.0)1 (3.6) ORR was 35.7% (10/28 patients), per investigator assessment  All responses were confirmed PRs  1/13 patients with SD had an unconfirmed response Miller et al. ASCO 2010

42. T-DM1 + pertuzumab has an encouraging safety and tolerability profile Key AE, %Grade 3, %Grade 4, %Total (all grades), %* Any Events36.44.5100 Fatigue13.6052.3 Nausea4.505.0 Thrombocytopenia6.84.527.3 Diarrhea2.3025.0 Vomiting4.5022.7 AST increase6.8020.5 Dyspnea † 2.3020.5 AST, aspartate aminotransferase Miller et al. ASCO 2010 *One Grade 5 AE was reported (pneumonia) in a patient who died before her first tumor assessment. This AE was considered to be unrelated to study treatment † Primarily attributed to pneumonia or the disease under study (lung metastases & pleural effusions)

43. First-line T-DM1 + pertuzumab vs trastuzumab + docetaxel Clinicaltrials.gov Primary endpoints ● PFS (independent assessment) ● Safety Secondary endpoints ● ORR (independent assessment) ● OS ● 1-year survival ● PFS ● ORR (investigator assessment) ● CBR ● TTF ● DoR ● Safety and tolerability HER2-positive MBC No prior chemotherapy (n=1092) Trastuzumab + taxane T-DM1 + placebo T-DM1 + pertuzumab Global study starts summer 2010 332 centers in 40 countries