EGFR: fundamenteel en klinisch

Transcription

1 EGFR: fundamenteel en klinisch Guido Lammering MAASTRO Clinic Maastricht, NL

2 What is EGFR??

3 The EGFR some facts 1186 amino acids 170 kda Expressed by all cells of epithelial origin Increased activation through: higher levels of ligand, gene amplification, increased transcription, mutations

4 EGFR expression in human tumors Overexpression: normal cells : tumor cells: up to

5 EGFR expression in human tumors High EGFR expression is generally associated with Invasion Metastasis Late-stage diseases Radiotherapy and Chemotherapy resistance Hormonal therapy resistance

6 EGFR expression as a prognostic factor NSCLC Kidney Breast Ovarian Glioma Pancreas Head and Neck Colon Bladder EGFR expression correlated with shorter OS, high rate of met s OS, DFS (only for short follow up (4y.) OS, DFS, chemoresistance grade of differentiation high tumor stage, size, OS significant predictor of DFS, OS (Larynx) prognosis LRR, higher invasiveness

7 The EGFR (ErbB1 / Her 1) Ligands EGF TGFα Cysteine-rich Receptor domain Extracellular Membrane Tyrosine kinase domain K K Intracellular

8 Phosphorylation sites for EGFR

9 The EGFR (erbb( erbb) ) family Ligands EGF TGF- No ligands Heregulins NRG2 NRG3 Heregulins -cellulin Cysteine-rich Receptor domain Extracellular Membrane Tyrosine kinase domain K K K K Intracellular erbb1 HER1 EGFR erbb2 HER2 neu erbb3 HER3 erbb4 HER4

10 EGFR signalling Sharma et al. Nature Reviews Cancer 7, (March 2007) doi: /nrc2088

11 EGFR signalling

12 EGFR response to therapy

13 EGFR expression is prognostic for the outcome of radiotherapy in H&N SCC Ang et al., Cancer Res 62: , 2002

14 Higher EGFR expression = less control with RT

15 EGFR expression predicts benefit from altered fractionation CHART Bentzen et al. JCO 2005

16 EGFR expression predicts benefit from altered fractionation DAHANCA 6/7 Erikson et al. Rad Oncol 2005

17 What is the mechanism How is EGFR responding to radiation

18 ERBB P-Tyr P RESPONSE TO RADIATION (2Gy) MDA-MB-231 C min ErbB-1 ErbB-2 ErbB-3 ErbB-4 fold change fold change fold change fold change Bowers, Schmidt-Ullrich et al., Oncogene, 2001

19 RELATIVE TIME TABLE OF MOLECULAR RADIATION RESPONSES 1 5 min ERBB, IGF-1R (RTKs) / Non-RTKs Oncogenes (H- / K-RAS / RAF) 1-10 min DNA damage recognition ( H2AX / ATM / ATR / DNA-PK / ERCC1 / XRCC1) 5 15 min Protein kinases MAPK, PI3K, AKT JNK, P38, JAK, ATM 30 min 6 hr Transcription factors 6 hrs 72 hrs Cell cycle regulation / proliferation / anti-apoptosis (P21 / P27 / P53 / cyclins D/E / BCL-XL, BAD) MEMBRANE NUCLEUS CYTOPLASM CYTOPLASM / NUCLEUS Schmidt-Ullrich et al., Oncogene (Reviews), 2003

20 P-Tyr EGFR Family and RADIATION-INDUCED INDUCED PROLIFERATION AG IR ERBB1 ERBB3 ERBB2 5 4 IR (2Gy) IR (2Gy) + AG1478 (5 M) 3 2 MAPK PI3K % Control Growth P90S6K P70S6K PROLIFERATION P-P70 IR AG 1478 LY Dose, Gy Contessa, Lammering, et al., Oncogene, 2002

21 EGFR Family and RADIATION-INDUCED INDUCED APOPTOSIS IR ERBB1 ERBB3 ERBB2 P-Tyr (min) PI3K AG 825 AKT + + IR P-Akt C 4 Gy Contessa, Lammering, et al., Oncogene, 2002 Apoptosis Apoptosis + + AG 825

22 EGFR in Cancer Biology Harari PM, Huang S-M, Clin Cancer Res 2000

23 EGFR and the tumor microenvironment

24 EGFR and hypoxia Laderoute et al, 1992: enhanced EGFR mrna & synthesis in A431 scc cells under low oxygen levels Nishi et al, 2002: Egr-1 mediates upregulation of EGFR during hypoxia

25 EGFR in scc xenografts: Highest expression seems mostly restricted to hypoxic regions

26 EGFR and hypoxia in laryngeal cancer biopsies

27 APPROACHES TO EGFR INHIBITION

28 EGFR AS TARGETS FOR CANCER THERAPY Strategy Disruption of EGFR Approaches to EGFR Family Inhibition Blockade of Ligand Binding (mab C225) Chemical Inhibition of the Tyr Kinase Domain Genetic Inhibition through Negative EGFR Species

29 Targeting EGFR in cancer cells

30 EGFR inhibitors Tyrosine Kinase Inhibitors AG 1478 gefitinib/iressa EGFR-TK Astra Zeneca OSI-774 Erlotinib/Tarceva EGFR + EGFRvIII -TK Roche GW Lapatinib EGFR-TK + ErbB2-TK GlaxoSmithKline AEE788 EGFR-TK + VEGFR-TK + ErbB2 Novartis ZD6474 Zactima EGFR-TK + VEGFR-TK Astra Zeneca EKB569 EGFR-TK Wyeth PKI 166 EGFR-TK + ErbB2-TK Novartis CI-1033 canertinib ErbB1-4-TK Pfizer Monoclonal antibodies C225 Cetuximab EGFR / EGFRvIII Merck Germany mab 806 EGFRvIII / EGFR Ludwig Institute EMD7200 EGFR Merck USA ABX-EGF Panitumab EGFR Amgen

31 DN-EGFR mechanism of action Kinase Dom CD533 Kinase Dom CD533 Kinase Dom CD533 Kinase Dom CD533

32 Inhibition of EGFR function Time after 2 Gy Rad (min) EGFR Tyr-P Fold Change control EGFR inhibition C C EGFR Tyr-P 1 5,0 2,5 2,3 2,1 Fold Change 1 1,1 0,8 0,8 1,0 MAPK activity (2 Gy) CELL PROLIFERATION CELL SURVIVAL IR(2Gy) +Ad-LacZ +IR(2Gy) +Ad-CD Relative Cell Growth Radiation - CD533 + CD533 DER: Surviving fraction (log 10) CD533 + CD533 DER: x2 2x2 3x2 Repeated Dose of 2 Gy Days Contessa, et al., Clin Cancer Res, 1999 Lammering, et al. Clin Cancer Res 2001, IJRBP 2001.

33 Preclinical studies glioblastoma tumor xenografts (DN-EGFR) 8 7 C 3 x 3 Gy Relative tumor volume DN-EGFR DN-EGFR, 3 x 3 Gy days Lammering et al., Clin Cancer Res, 2004

34 EGFR strategies in cancer therapy

35 Cetuximab monoclonal antibody

36 Cetuximab in squamous cancer tumors

37 tumor xenografts RT + / - Cetuximab 1 x 8 Gy 4 x 8 Gy Huang, Harari, Clin Cancer Res inhibition of radiation damage repair (redistribution of DNA-PK) -inhibition of tumor angiogenesis -effects on tumor cell migration and invasion capacity

38 Phase III (anti( anti-egfr mab) patients Locoregionally advanced SCC of H&N RT alone RT + Cetuximab weekly

39 Phase III (anti( anti-egfr mab) metastatic CRC

40 Skin toxicity anti- EGFR therapy

41 Preclinical studies ZD1839 in colon xenograft tumors Single dose Vehicle ZD1839 Vehicle + 5 Gy ZD Gy Fractionated dose Vehicle ZD1839 ZD x 2 Gy Vehicle + 3 x 2 Gy Tumour volume (mm 3 ) Time post-treatment treatment (days) Time post-treatment treatment (days) Williams KJ et al. Proc AACR 2001; 42: 715 (poster 3840)

42 Preclinical studies CI-1033 in colon cancer xenografts only minimal radiosensitization in vitro significant radiosensitization in vivo C C CI x 2 Gy CI x 2 Gy 15 x 2 Gy + CI x 2 Gy + CI-1033 Colon cancer Nygati, Lawrence et al, Clin Cancer Res., 2004

43 EGFR Tyr kinase inhibitor NSCLC cancer Tarceva Monotherapy pancreatic cancer Tarceva + Gem Subgroup: EGFR +; non-smokers No benefit for tarceva with Chemo

44 Cetuximab treatment Biomarkers for efficiency

45 Colorectal cancer Cetuximab response independent of EGFR expression

46 Cetuximab response correlates with Kras and PTEN mutation

47 EGFR mutations: -Kinase mutations -Truncated ectodomain

48 Lung cancer responders to anti-egfr Three groups have reported an important association between somatic mutations in the EGFR gene at the tyrosine kinase domain and a dramatic response to gefitinib and erlotinib.8,9,10

49 EGFR gene mutations in the Gefitinib responsive tumors The EGFR domain mutations frequently involved either in-frame deletions in exon 19, single missense mutations in exon 21, or in-frame duplications/insertions in exon 20

50 EGFR gene mutations lead to active tyr kinases

51 these mutations were statistically more frequent in never smokers than in smokers (51% v 14%), in adenocarcinomas than in other histological types (40% v 3%), in patients of East Asian ethnicity (30% v 8%), and in women than in men (42% v 14%). In total 5 10% lung carcinomas

52 EGFR mutation extracellular - EGFRvIII

53 EGFR viii mutation EGF TGF EGF TGF EGFR EGFRvIII Kinase Dom P Kinase Dom P naturally occurring during malignant progression constitutively phosphorylated expressed in malignant gliomas, prostate, NSCLC, breast etc.

54 EGFR mutations in Head and Neck Cancer unlike NSCLC EGFR kinase mutations are rare in H & N Chen et al., CCR 2005 but EGFRvIII mutations are common in H & N (42%) Sok et al., CCR 2006

55 EGFRvIII- mediates better survival after radiation EGFRvIII % survival Gy parental EGFRvIII MAPK Akt fold activation fold activation Time (min). AG AG1478 AG1478 AG AG C U Time (min) Lammering, et al. CCR 2004

56 CONCLUSIONS Inhibition of the EGFR- (ErbB) signaling offers promise in cancer therapeutics heterogeneity in ErbB expression and compensatory responses might limit broad clinical application (ErbB3, PTEN, IGF1R, kras..) mutant EGFR variants play an important role response to inhibitors different (EGFRvIII, EGFR kinase mut)

57 FUTURE DIRECTION Better predictors of response: imaging, proteomics, gene arrays Evaluation of combined anti-egfr targeting approaches Combination of upstream and downstream targeting

58 Its not just the one receptor