1. Critical Concepts in the Use of Combination Chemotherapy With Targeted Agents Lee M. Ellis, MD The University of Texas MD Anderson Cancer Center

2. Combination Chemotherapy + Targeted Therapy in GI Cancers After all, I only have 20 minutes Scientific rationale and biology Where are we today? –Clinical trial results since ASCO 2006 What to look for at ASCO 2007 Where do we need to go? –Novel targets

3. In the Era of Targeted Therapy How Do We Best Utilize These Agents? Tumors driven primarily by a single molecular event Single agent can be efficacious –RCC –GIST Even tumors driven by a single mutant gene can become refractory –GIST Tumors driven by multiple molecular events Multiple molecular alterations requiring multi-targeted therapies Combination with chemotherapy –CRC –NSCLC –Breast cancer –Pancreatic cancer? Two Basic Molecular Classes of Tumors:

4. Why Combine Targeted Therapy With Chemotherapy? Single-agent, targeted therapy has minimal efficacy in tumors driven by multiple genetic alterations Chemotherapy intended to induce apoptosis –Most targeted therapies are designed to inhibit survival pathways, and thus enhance apoptosis This is the foundation of EGFR targeting Even anti-VEGF therapies may enhance chemotherapy by multiple mechanisms, including inhibition of tumor and endothelial cell survival pathways Targeted therapies are best utilized when you have an “apoptotic hit” –Weaken the tumor cell with targeted therapy in order to maximize the benefit of CTX

5. Current FDA-Approved, Targeted Therapies for GI Malignancies (excluding GIST) EGFR targeting –Cetuximab –Panitumumab –Erlotinib VEGF/R –Bevacizumab

6. EGFR Signalling in Tumor Cells Survival (anti-apoptosis) PI3-K EGFR Ligand PTEN AKT STAT3 MEK Gene transcription Cell cycle progression Upregulation of survival mediators (Bcl-2, etc.) MAPK Proliferation / maturation Chemotherapy / radiotherapy resistance Angiogenesis EGFR-tyrosine kinase domains KK pY RASRAF pY

7. EGFR Inhibition in Cancer: A Pragmatic View The main value of anti-EGFR therapy is to inhibit survival pathways –P-I-3K  Akt  Bcl-2 pathway There is no such thing as an “EGFR-negative” epithelial tumor –We simply cannot detect EGFR in all specimens due to limitations of immunohistochemistry EGFR inhibitors do not work in every tumor or every disease type –Resistance may be due to bypass pathways Tumors driven by other receptors Tumors driven by downstream mutations –Camp et al. Clin Ca Res, 2006

8. Proposed Mechanisms of Action (MOA) of Anti-VEGF Therapy – and Some Comments MOATheoretical OutcomeClinical Observations “Antiangiogenic” Inhibition of vessel growth or regression Should lead to an increase in PFS Improvement in PFS not always seen “Normalization” Anti-VEGF Rx should improve the effects of all cytotoxics Improvement in effects of CTX not always seen Pancreas/melanoma trials VEGFRs on tumor cells Should lead to an increase in PFS Improvement in PFS not always seen Modification of vascular fxn Vasoconstriction  permeability Decreased blood flow Seen on MRI and CT scans Vasoconstriction may lead to toxicities

9. Combination Chemotherapy + Targeted Therapy in GI Cancers Scientific rationale and biology Where are we today? –Clinical trial results since ASCO 2006 CRC Pancreas –What to look for at ASCO 2007 Where do we need to go? –Novel Targets

10. Phase III Trial of FOLFOX4 or XELOX ± Bevacizumab in First-Line mCRC (NO16966) Saltz, et al. GI Cancers Symposium, 2007. Abstract 238. Primary endpoints: PFS (XELOX vs. FOLFOX; bevacizumab + chemotherapy vs. chemotherapy alone) Secondary endpoints: OS, ORR, time to response, DOR, TTF, and safety XELOX + Bevacizumab n=350 XELOX + Placebo n=351 RANDOMIZATIONRANDOMIZATION XELOX n=317 Recruitment June 2003 - May 2004 Recruitment Feb. 2004 – Feb. 2005 FOLFOX4 + Placebo n=350 FOLFOX4 + Bevacizumab n=350 FOLFOX4 n=317 mCRC No prior therapy for advanced disease ECOG PS 0-1

11. Phase III Trial of FOLFOX4 or XELOX ± Bevacizumab in First-Line mCRC (NO16966): PFS Response Rates (P=NS) FOLFOX4/XELOX + bevacizumab47% FOLFOX4/XELOX + placebo*49% FOLFOX + placebo/XELOX + placeboN=701; 547 events FOLFOX + bevacizumab/XELOX + bevacizumabN=699; 513 events HR=0.83 [97.5% CI, 0.72-0.95] (ITT) P=0.0023 8.09.4 Saltz, et al. GI Cancers Symposium, 2007. Abstract 238

12. Phase III Trial of FOLFOX4 or XELOX ± Bevacizumab in First-Line mCRC (NO16966): Subgroup PFS XELOX subgroup HR=0.77 [97.5% CI 0.63-0.94] (ITT) P=0.0026 9.37.4 1.0 0.8 0.6 0.4 0.2 0 0510152025 Months PFS Estimate XELOX + placeboN=350; 270 events XELOX + bevacizumab N=350; 258 events FOLFOX subgroup HR=0.89 [97.5% CI 0.73-1.08] (ITT) P=0.1871 9.48.6 FOLFOX + placebo N=351; 277 events FOLFOX + bevacizumab N=349; 255 events 1.0 0.8 0.6 0.4 0.2 0 0510152025 Months Saltz, et al. GI Cancers Symposium, 2007. Abstract 238

13. Primary endpoint: survival Secondary endpoints: PFS, RR, DCR, safety, QoL Sample size: 1,298 patients in 221 centers Sobrero, et al. AACR 2007. Randomized Phase III Trial of Cetuximab Plus Irinotecan vs. Irinotecan Alone for mCRC After Failing Prior Oxaliplatin-Based Therapy: The EPIC Trial Stratified by: Study site ECOG PS (0-1, 2) Cetuximab/Irinotecan Irinotecan Failure of Oxaliplatin-Based Therapy Survival N=648 N=650

14. Cetuximab + irinotecan; N=648 Irinotecan alone; N=650 Proportion Progression Free 0.0 0.2 0.4 0.6 0.8 1.0 03691215 4.0 mo 2.6 mo Months HR=0.692 95% CI=0.617–0.776 Stratified Log Rank P Value = < 0.0001 PFS 18 Randomized Phase III Trial of Cetuximab Plus Irinotecan vs. Irinotecan Alone for mCRC After Failing Prior Oxaliplatin-Based Therapy: The EPIC Trial

15. Post-Hoc Survival Analysis: Subjects Who Received Post-Study Cetuximab Were Excluded Survival Probability 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Survival Time (months) 036912151821242730 10.2 mo 6.2 mo |||| | || | | | | | || | | | | | | | | ||| | ||| | | | | ||| | | | | | | | | | || | | | ||| | | | | || | || ||||| ||||| || | | | | ||| | | ||| | | || ||| | | || || | || || |||| | | | || | || | ||||| | || | |||| || || | ||||| | ||| | | | |||| | | ||| || | | | ||| ||| || | |||||||||||||| || || | | | | | | | | | | | | | | | | | | | |||| || | | | || | | | | ||| | | || | || || || | | || | | || | | | || | ||| | | | | || | | | || | |||| |||| Irinotecan; N=345 Cetuximab + Irinotecan; N=575 47% of pts subsequently received cetuximab

16. FOLFIRI: 5-FU: 400 mg/m 2 as bolus and 2400 mg/m 2 over 46 h Folinic acid: 400 mg/m 2 Irinotecan: 180 mg/m 2 Cetuximab:400 mg/m 2 initial dose (week 1) 250 mg/m 2 weekly dose (starting week 2) CRYSTAL: Phase III FOLFIRI ± Cetuximab in First-Line mCRC * Press Release - PFS top line data; detailed data will be presented at ASCO 2007. Tuesday 11:00 AM - 11:15 AM Randomized phase III study of irinotecan and 5-FU/FA with or without cetuximab in the first- line treatment of patients with metastatic colorectal cancer (mCRC): The CRYSTAL trial. Abstract 4000. Presenter: Eric Van Cutsem, MD, PhD N=1080; primary endpoint: PFS – statistically improved over chemo alone* EGFR-expressing mCRC; no previous chemotherapy except adjuvant FOLFIRI FOLFIRI + Cetuximab PFS, OS, ORR, duration of response, safety, QoL

17. Is More Better? If you use all of your agents up front, what do you use second line after progression/resistance? Simultaneous targeting of multiple pathways may lead to increased toxicity –Remember, these targets also play a role in physiology

18. PACCE Phase III Trial in First-Line mCRC FOLFOX FOLFIRI N=1,000 RANDOMIZATIONRANDOMIZATION Bevacizumab + Panitumumab

19. Phase III Trial CTX + Bev +/- Panitumumab in mCRC: PACCE Study Preliminary announcement in January 2007 reported an increased incidence of grade 3 diarrhea, dehydration, and infections in the panitumumab arm In March 2007, Amgen announced discontinuation of panitumumab treatment based on pre-planned interim analysis showing PFS and OS in favor of the control arm Not Presented at ASCO Will be presented at the World Congress on GI Cancers, Barcelona, Spain, June 2007

21. CALGB/SWOG 80405: Study Design Primary endpoint: OS Secondary endpoints: PFS, RR Patients with untreated metastatic colorectal cancer (N=2,289) Cetuximab Bevacizumab Cetuximab Bevacizumab Patient/physician choice: mFOLFOX6 or FOLFIRI

22. Combination Chemotherapy + Targeted Therapy in GI Cancers Scientific rationale and biology Where are we today? –Clinical trial results since ASCO 2006 CRC Pancreas –What to look for at ASCO 2007 Where do we need to go? –Novel Targets

23. Phase III Trial of Gemcitabine ± Bevacizumab in First-Line Metastatic Pancreatic Cancer (CALGB 80303) Primary endpoint: OS Secondary endpoints: PFS, ORR, DR, toxicity Kindler, et al. GI Cancers Symposium, 2007. Abstract 108. RANDOMIZATIONRANDOMIZATION Gemcitabine + placebo Unresectable pancreatic adenocarcinoma No prior chemotherapy for metastatic disease No prior VEGF inhibitors ECOG PS 0-2 Gemcitabine + bevacizumab N=602 n=300 n=302

24. Response Rates (P=NS) Gemcitabine + bevacizumab13.1% Gemcitabine + placebo11.3% Phase III Trial of Gemcitabine ± Bevacizumab in First-Line Metastatic Pancreatic Cancer (CALGB 80303): PFS and OS HR=1.00 P=0.99 Gemcitabine + bevacizumab Gemcitabine + placebo PFS HR=1.09 P=0.40 Gemcitabine + bevacizumab Gemcitabine + placebo OS 0 0.2 0.4 0.6 0.8 1.0 05101520 Months From Study Entry 0 0.2 0.4 0.6 0.8 1.0 05101520 Months From Study Entry Kindler, et al. GI Cancers Symposium, 2007. Abstract 108.

25. Phase III Trial of Gemcitabine ± Cetuximab in First-Line Advanced Pancreatic Cancer (SWOG 0205) Sunday, 06/03/2007, 3:15 PM - 3:30 PM Phase III study of gemcitabine [G] plus cetuximab [C] versus gemcitabine in patients [pts] with locally advanced or metastatic pancreatic adenocarcinoma [PC]: SWOG S0205 study. Abstract LBA4509. Presenter: Philip A. Philip, MD, PhD, FRCP Primary endpoint: OS; completed accrual at N=760 Secondary endpoints: TTF, RR, safety, QOL, EGFR + tumors and compare survival in EGFR + subset Tumor samples to SWOG central lab for EGFR IHC; registration independent of EGFR status Gemcitabine + placebo Stratify Stage Prior pancreatectomy PS Gemcitabine + cetuximab RANDOMIZATIONRANDOMIZATION N=~760

26. What’s Next As targeted therapies become the mainstay of therapy in the frontline setting, we need to be prepared for resistance –Is resistance to chemo or targeted therapies or both –We use 5-FU through multiple lines of therapy –Should targeted therapies continue after progression on a regimen? We need therapies for subsequent lines of therapy Association between exposure to bevacizumab (BV) beyond first progression (BBP) and overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC): Results from a large observational study (BRiTE). Abstract No: 4036 Presenter: Axel Grothey, MD Saturday, 2:00 PM - 6:00 PM Poster Display Location:S403

27. Functions of Cell Surface Receptors ProliferationInvasionMigrationSurvivalAngiogenesis EGFR √√√√ √ IGFR √√√√ √ c-MET √√√√√ VEGFR1 √√√ uPAR √√√√√ Integrins √√√ √ The most efficacious targeted therapies may be those that mediate cell survival

28. IGF-IR as a Central Mediator of Cellular Functions EGFR Survival PI-3-K/Akt Mitogenic Ras MAPK Migration/ Invasion Angiogenesis VEGF P P P P P P P P IGF-1R

29. Effect of an IGF-IR MoAB +/- Oxaliplatin on Growth of Liver Tumors Treatment: MoAB IGFR oxaliplatin Groups: 1. control 2. Oxaliplatin 3. MoAB IGFR 4. MoAB IGFR + oxali 5. MoAB IGFR + oxali (start d 19) (“delayed”) Days 0 4 7 10 11 13 14 16 18 19 21 22 25 28 54 Direct Liver Injection (1 x 10 6 HT29 cells) Liver harvested (3/12 mice moribund) IGF-IR MoAB oxaliplatin Bauer et al. Ann Surg Onc, In press, 2007

30. Effect of MoAB IGF-IR and Oxaliplatin on Colon Cancer Growth in the Liver 1 cm Bauer et al. Ann Surg Onc, In press, 2007

31. IGF-IR Inhibitors in Development Description IMC-A12 Human MoAB CP-751,871 Human MoAB AVE1642 Humanized MoAB h7C10 (F50035) Humanized MoAB 19D2 Humanized MoAB NVP-ADW742 NVP-AEW541 TKI* BMS 536924 BMS-554417 TKI* PPP TKI* INSM18 TKI* *All TKIs (tyrosine kinase inhibitors) have the potential to inhibit the insulin receptor (kinase homology = 84%, ATP-binding pocket homology 100%). Hofmann, DDT 10, 2005. Insulin-like Growth Factor Receptor Targeting: An Exciting New Strategy for Cancer Therapeutics: Monday AM- Location: S100a

32. Other Promising Targets NF  B HDAC Src* Akt/PKB MAPK (MEK, JNK, Raf) HSP90 * mTOR* Proteosome cMET* uPAR* * Ongoing studies in the lab with promising results in combination with chemotherapy

33. Conclusions: CTX and Targeted Therapies Anti-EGFR and anti-VEGF MoABs have lead to incremental improvements in RR and PFS in metastatic CRC At the present time, combining multiple targeted therapies simultaneously with CTX has not been shown to be of benefit –Detriment? Little progress has been made in pancreatic cancer with the addition of targeted therapies to CTX –Is gemcitabine the right foundation? We urgently need predictive markers of efficacy, toxicity, and resistance