Molecular Targeted Therapy Of Cancer

6th Latin American Medical Education Workshop

MOLECULAR TARGETED THERAPY OF CANCER Brain Tumors Mauricio Lema Medina

Glioblastoma 

Most frequent malignant glioma: 2/3



Worst median survival: 12 mo



Two groups  Primary GBM  De novo  >50 years  Secondary GBMs  Progression of lower grade gliomas  <50 years

Glioblastoma - Pathology 

Dense cell proliferation



Extensive nuclear polymorphism,



High mitotic activity



Necrosis  Serpentine  Pseudopalisade formation.



Vascular endothelial cell proliferation  Double layer of endothelial cell

Cell-of-origin: Gliomas Olig2 expression (100%)

Olig2 expression (100%)

p53 mutated (>65%) PDGFA/PDGFR (60%)

Low-Grade Astrocytoma LOH19q (50%) RB mutated (25%) CDK4 amplified (15%) MDM2 overexp. (10%) p16 loss (4%) LOH 11p (30%)

EGFR amplified (40%) EGFR overexpressed (60%) EGFR mutated (20%) MDM2 amplified (10%) MDM2 overexpressed (>50%) LOH 10q (70%) PTEN mutated (40%) PI3K mutated/amplified (20%) RB mutated

LOH 1p, 4q, 19q EGFR overexpressed PDGF/PDGFR overexpressed

Low-Grade Oligodendroglioma

Anaplastic Astrocytomas

p16 loss RB mutated (65%) P53 mutated PTEN loss LOH 9p, 10q CDK4/EGFR/Myc amplified

LOH 10q (70%) DCC Loss (50%) PDGFRa amplified (10%) PTEN mutated (10%) PI3K mutated/amplified (10%)

VEGF overexpressedVEGF overexpressed Secondary GBM

Olig2 expression (100%)

Primary GBM

VEGF overexpressed

Anaplastic Oligodendroglioma

Wen PY, Kesari S. Malignant Gliomas in Adults. N Engl J Med 2008 359: 492-507

Angiogenesis is central to GBM 

Driven by VEGF



Blood vessels in GBM  Dilated  Abnormal  Hyperpermeable



Restoration of vascular integrity  Decreases permeability  Improves oxygen delivery  Increase chemo-sensitiviy  Increas radio-sensitivity

Therapy of Malignant Gliomas Glioblastoma

Maximal surgical resection

RT + TMZ, followed by TMZ Carmustine wafers + RT

Anaplastic astrocytoma

Maximal surgical resection

RT + TMZ, followed by TMZ

Anaplastic Oligodendrogliomas

Maximal surgical resection

TMZ RT RT + TMZ, followed by TMZ RT, followed by TMZ PCV +/- RT TMZ +/- RT

NCCN

TMZ + RT in GBM

RT Maximal surgical resection

R Chemo-RT Temozolomide (TMZ) 75 mg/m2 every day while on radiotherapy, followed by single-agent temozolamide 150-200 mg/m2 for 5 days, q28d, for 6 months

Stupp R, Mason WP, van den Bent MJ, et al. the National Cancer Institute of Canada Clinical Trials Group, Radiotherapy plus Concomitant and Adjuvant Temozolomide for Glioblastoma. N Engl J Med 2005 352: 987-996

TMZ+RT in GBM N=573 OS: 14.6 vs 12.1 2-yr S: 26% vs 10

Stupp R, Mason WP, van den Bent MJ, et al. the National Cancer Institute of Canada Clinical Trials Group, Radiotherapy plus Concomitant and Adjuvant Temozolomide for Glioblastoma. N Engl J Med 2005 352: 987-996

Silenced MGMT improves survival in GBM 

MGMT (O6-MethylguanineDNA-Methyltransferase)  Removes alkyl groups  Restores DNA integrity



Epigenetic silencing of MGMT  Frequent in GBM (45%)  By promoter methylation



Silenced MGMT results in  Improves survival  Chemosensitivity to TMZ

N=92

Hegi ME, Diserens AC, Gorlia T, et al. MGMT Gene Silencing and Benefit from Temozolomide in Glioblastoma. N Engl J Med 2005 352: 997-1003

Silenced MGMT improves chemo-sensitivity

Hegi ME, Diserens AC, Gorlia T, et al. MGMT Gene Silencing and Benefit from Temozolomide in Glioblastoma. N Engl J Med 2005 352: 997-1003

Second-line therapy in GBM  Only 5% survive >5 years  6-month progressión-free survival after progression is < 25%  TMZ: 21%  No established second-line therapy  Opportunity for targeted-therapy  15% 6-month PFS cut-off for “active” strategies

Second-line therapy in GBM

Wong ET, Hess KR, Gleason MJ, et al. Outcomes and Prognostic Factors in Recurrent Glioma Patients Enrolled Onto Phase II Clinical Trials. J Clin Oncol 1999 17: 2572

Targeted therapy in GBM

Slide No. 13

Ligand Anti EGFR

PIP2

Anti VEGF

PIP3 RTK inhibitors Anti VEGF

mTOR p70S6k

Cytoskeleton Integrin

FAK

Integrin Inhibitors

Farnesyl-transferase inhibitors

Grb2/mSOS

AKT

ECM

RTK inhitors anti PDGF

PI3K inhibitors

PDK1

mTOR inhibitors

PI3K

MoAbs

RTK inhibitors anti EGF RAS

Protein synthesis Raf & MEK

Activated Transcription factors

inhibitors

Raf

GAP

MEK ERK1/2

AP-1(Jun-Fos) Serum Response Factor

Activated kinases

c-Src STAT

Cell-Cycle regulation

JAK PLC-γ PIP2

PKC Ca2+

MYC CiclinaD Ciclinas/cdks

Nucleus

HDAC inhibitors Steroid hormone receptors

DAG

Wen PY, Kesari S. Malignant Gliomas in Adults. N Engl J Med 2008 359: 492-507

Ligand

Bevacizumab Afibercept

Cetuximab Panitumumab

PIP2

Anti VEGF

PIP3

RTK inhibitors Anti VEGF

Cediranib ECM FAK

AKT

Lonafarnib Tipifarnib

RTK inhibitors anti EGF RAS

ProteinGefitinib synthesis Erlotinib

Activated Transcription factors

Raf

Lapatinib

GAP

MEK

Vandetanib ERK1/2 AP-1(Jun-Fos) Serum Response Factor

Activated kinases

c-Src

Cilengitide

Grb2/mSOS

p70S6k Temsirolimus Everolimus Sirolimus

Farnesyltransferase inhibitors

RTK inhitors anti PDGF

PI3K inhibitors

PDK1

Cytoskeleton

Integrin Inhibitors

PI3K

BEZ325 mTOR inhibitorsmTOR XL765

Sunitinib Sorafenib Vandetanib

Integrin

Anti EGFR

Imatinib Dasatinib Tandutinib

STAT

Cell-Cycle regulation

JAK PLC-γ PIP2

PKC Ca2+ DAG

MYC CiclinaD Ciclinas/cdks

Nucleus

HDAC inhibitors Steroid hormone receptors Depsipeptide

Vorinostat

Wen PY, Kesari S. Malignant Gliomas in Adults. N Engl J Med 2008 359: 492-507

Anti-angiogenic therapy of GBM  Bevacizumab  Anti VEGF antibody  Cediranib  Oral pan VEGF tyrosine kinase inhibitor  Cilengitide  Anti integrin agent

Bevacizumab in recurrent malignant gliomas

 Bevacizumab + Irinotecan  57-63% response rate  6-month PFS: 46% (vs 21% with TMZ)  Combination superior to single-agent Irinotecan



Vredenburgh JJ, Desjardins A, Herndon JE II, et al. Bevacizumab plus irinotecan in recurrent glioblastoma multiforme. J Clin Oncol 2007;25:4722-4729.

Bevacizumab in GBM  Bevacizumab + Irinotecan  57-63% response rate  6-month PFS: 46%  Combination superior to singleagent Irinotecan

N Engl J Med 2008 359: 492-507

Vredenburgh JJ, Desjardins A, Herndon JE II, et al. Phase II trial of bevacizumab and irinotecan in recurrent malignant glioma. Clin Cancer Res 2007;13:1253-1259; Vredenburgh JJ, Desjardins A, Herndon JE II, et al. Bevacizumab plus irinotecan in recurrent glioblastoma multiforme. J Clin Oncol 2007;25:4722-4729.

Cediranib in recurrent GBM  AZD2171  Pan VEGFR, PDGFRa, PDGFRb TKI  Oral  Median half-life: 12-35 hours  Dose: 45 mg QD

Wikipedia

Cediranib in recurrent GBM  NCI Phase II trial  31 patients with recurrent GBM  Daily Cediranib PO  Primary End-Point: 6 mo – PFS  Secondary End-Points:  Radiographic response  Overall survival  Toxicity  Correlative biomarker and imaging studies Gerstner ER, Duda DG, di Tomaso E, et al. Cediranib, an Oral Pan-VEGF Tyrosine Kinase Inhibitor, in the Treatment of Glioblastoma. Current Treatment Options in Oncology (2008) 9:1-2

Cediranib in recurrent GBM

Batchelor TT, Sorensen AG, di Tomaso E, et al. (2007). AZD2171, a pan-VEGF receptor tyrosine kinases inhibitor, normalizes tumor vasculature and alleviates edema in glioblastoma patients. Cancer Cell 11(1), 83-95; Gerstner ER, Duda DG, di Tomaso E, et al. Cediranib, an Oral Pan-VEGF Tyrosine Kinase Inhibitor, in the Treatment of Glioblastoma. Current Treatment Options in Oncology (2008) 9:1-2

Cediranib in recurrent GBM 

Median PFS: 117 days



Median OS: 227 days in 31 patients enrolled in the trial, respectively.

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6-month PFS: 26%

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Serial MRI scans:  Vascular normalization  Decrease in brain edema  Steroid-sparing effect

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Toxicity  Diarrhea  Hypertension  Fatigue (2 patients stopped the intervention due to fatigue).  No intracerebral hemorrhages in any patients.

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Several phase I-II trials have been initiated with cediranib with lomustine in relapsed GBM, and cediranib plus temozolamide and radiation therapy in newly diagnosed GBMs.

Gerstner ER, Duda DG, di Tomaso E, et al. Cediranib, an Oral Pan-VEGF Tyrosine Kinase Inhibitor, in the Treatment of Glioblastoma. Current Treatment Options in Oncology (2008) 9:1-2

Cediranib in recurrent GBM

Batchelor TT, Sorensen AG, di Tomaso E, et al. (2007). AZD2171, a pan-VEGF receptor tyrosine kinases inhibitor, normalizes tumor vasculature and alleviates edema in glioblastoma patients. Cancer Cell 11(1), 83-95

Slide No. 23

Integrin α vβ

3

expression in glioblastomas

* 100 µm

Integrin α vβ 3

100 µm

CD31 (endothelial cells)

100 µm

Integrin α vβ 3/CD31 fluorescent Schnell et al, Brain Pathol overlay 2008

Cilengitide in GBM 

Mechanismo of action  Selective alphavbeta3 and alphavbeta5 integrin antagonist



Intravenous formulation



Integrins  Cell surface receptors  Endothelial cell proliferation  Endothelial cell migration



Blocking the ligation of integrins by antagonists  Apoptosis of proliferative angiogenic cells

Wikipedia

Cilengitide studies in glioblastoma

Study 0101,a

Radiatio n therapy

+

Biopsy Unresectable

Cilengitide second-line

Chemotherapy

Study 0092,b

ec nerr uc e R

Symptoms

si s ongai D

Resectable

Cilengitide first-line

erck–Serono-sponsored trials: Study 010=EMD 121974–010; bStudy 009=EMD 121974–009 1. Stupp R, et al. Society for Neuro-Oncology, 12th Annual Meeting, Dallas, TX, USA, November 2007, Abstract No. MA-10;

Cilengitide single agent: Study 009

Survival distribution function Cohort to which subject is assigned 500 mg 1.0 2000 mg 0.9 0.8 0.7 2000 mg: median OS 9.9 months 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 6 12 18 24 30 36 42 Time (months)

Study design

Concomitant phase +

Adjuvant phase

(6 months)

C i l e n g i t i d e (twice weekly IV) Temozolomide (TMZ) daily x 6 weeks RT (30 x 2 Gy)



TMZ 75 mg/m2 daily (7/7) during RT  Maintenance 150–200 mg/m2 x 5 days for 6 cycles

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RT 60 Gy (30 x 2 Gy), to start 3–5 weeks post surgery

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Cilengitide 500 mg flat dose twice weekly IV to start 1 week before TMZ/RT, continue throughout chemoradiotherapy, optional single-agent maintenance after completion of 6 cycles of TMZ



Primary endpoint: PFS rate after 6 months of treatment

Stupp R, et al. Society for Neuro-Oncology, 12th Annual Meeting, Dallas, TX, USA, November 2007, Abstract No. MA10;

Overall survival: ITT population n=52 Died 28 (54%)

1.0 0.9 0.8

Median OS: 16.1 months (95% CI 13–NA)

Survival

0.7 0.6

12-month OS: 64% (95% CI 49–76)

0.5 0.4 0.3 0.2 0.1 0.0 0

2

4

6

8 10 12 14 16 18 20 22 24

Time (months)

Stupp R, et al. Society for Neuro-Oncology, 12th Annual Meeting, Dallas, TX, USA, November 2007, Abstract No. MA10

Overall survival according to MGMT status 1.0 0.9

— Methylated (n=23)

0.8

Median OS: not reached 15-month OS: 77.4% (95% CI 54–90)

Survival

0.7 0.6 0.5

— Unmethylated (n=22)

0.4

Median OS: 13.1 months (95% CI 9.7–18) 15-month OS: 41% (95% CI 20–61)

0.3 0.2 0.1 0.0 0

2

4

6

8 10 12 14 16 18 20 22 24

Time (months) Stupp R, et al. Society for Neuro-Oncology, 12th Annual Meeting, Dallas, TX, USA, November 2007, Abstract No. MA10

Cilengitide phase III for GBM Diagnosis

Registration

Step 1: Central MGMT methylation status assay

MGMT unmethylated

New agent: to be defined To be defined

Radiothera py Concomitant phaseAdjuvant (maintenance) phase

}

MGMT methylated Randomization Step 2: Randomization

+

}

R

versus

control

+

cilengitide TMZ

Radiothera py Adjuvant (maintenance) phase Concomitant phase

Conclusions  TMZ+RT remains one SOC for newly diagnosed GBM  Promoter methylation of MGMT identifies alkylator-sensitive disease  MGMT status not routinely available, though  Anti angiogenic agents are promising therapeutic strategies in GBM with favorable 6-mo PFS.  Aiming at other targets has been disappointing, so far  Further studies are needed Slide No. 32