La caratterizzazione molecolare alla progressione di malattia
Nicola Normanno
ISTITUTO NAZIONALE PER LO STUDIO E LA CURA DEI TUMORI FONDAZIONE G. Pascale – NAPOLI
SC Biologia Cellulare e Bioterapie
CENTRO RICERCHE ONCOLOGICHE MERCOGLIANO (AV)
Laboratorio di Farmacogenomica
Camidge Nat Rev Clin Oncol 2014
Mechanisms of acquired resistance to TKIs in
oncogene-addicted cancers
Resistance to anti-EGFR agents
Normanno Nat Rev Clin Oncol 2009
EGFR alterations:
T790M (1st/2nd generation TKI) C797S,L798I (3rd generation TKI) CNV (~10%)
T790M C797S
• A substitution of methionine for threonine at position 790 (T790M) in the kinase domain in exon 20 increases the ATP affinity of the EGFR
• ~ 50% of patients with acquired resistance to EGFR TKIs develop the T790M mutation
• Among 155 lung tumor specimens only 1 had pre-existing T790M without prior EGFR-TKI exposure
Pao PLos Med 2005; Kobayashi NEJM 2005; Yun PNAS 2008
Secondary Mutation in Gefitinib/Erlotinib-
Resistant NSCLC
Resistance to anti-EGFR agents
ERBB2 MET AXL
Normanno Nat Rev Clin Oncol 2009
Activation of other receptors:
ERBB2 (CNV; ~10%) MET (CNV; ~5%)
AXL/GAS6 (↑ expression; ~20%)
Resistance to anti-EGFR agents
Normanno Nat Rev Clin Oncol 2009
Activation of signalling proteins:
MAPK1 (CNV; ~5%) BRAF (SNV; ~1%) PIK3CA (SNV; ~1-2%)
EGFR TKI resistance mechanisms in NSCLC:
transformation in SCLC
Sequist Sci Transl Med 2011
EGFR TKI resistance mechanisms in NSCLC:
EMT
Sequist Sci Transl Med 2011
HE Vimentin E-cadherin
Camidge Nat Rev Clin Oncol 2014
Mechanisms of acquired biological resistance to
EGFR TKIs in NSCLC
Clonal Evolution and Drug Resistance
Burrell & Swanton Mol Oncol 2014
EGFR Mutations Detected by Higly Sensitive Techniques
Su JCO 2012
Preexistence of MET
Amplification in EGFR Mutant
NSCLC
Turke Cancer Cell 2010
Model for the development of EGFR T790M-determined acquired resistance
Hata Nat Med 2016
Janne NEJM 2015
Response to AZD9291 in NSCLC patients
ORR* = 64%
(69/107; 95% Cl 55%, 73%) Overall disease control rate (CR+PR+SD) = 94% (101/107;
95% CI 88%, 98%)
ORR* = 22%
(11/50; 95% Cl 12%, 36%) Overall disease control rate (CR+PR+SD) = 56% (28/50;
95% CI 41%, 70%)
EGFR T790M testing on patient progression:
tissue or liquid biopsy?
Tissue biopsy
• Techniques for tissue testing are well established
• Re-biopsy at progression is not a common practice in many
countries
• Invasive procedure with
potential risks for the patient
• Sampling limited to a single disease site
Liquid biopsy
• Liquid biopsy is a non-invasive procedure
• Analysis is more rapid as compared with tissue biopsy
• Liquid biopsy may provide a more complete picture of the tumor molecular portrait
• Methods for analysis of liquid biopsy have not been
standardized yet and have some limitations
Normanno WCLC 2015
EGFR T790M is difficult to test!
• The EGFR T790M mutation is within a CG rich DNA region in which it is difficult to design primers
• As a consequence, most of the available testing methods usually show a sensitivity for the T790M that is lower as compared with canonical
activating EGFR mutations (exon 19 deletions or p.L858R)
• Highly sensitive, REAL-TIME PCR based techniques are recommended for EGFR T790M tissue and plasma testing
Performance of four different plasma assays (38 plasma samples from the AURA trial)
Thress Lung Cancer 2015
Performance of four different plasma assays (72 plasma samples from the AURA trial)
Thress Lung Cancer 2015
Discordant results with two different plasma assays for
detection of the EGFR T790M mutation from circulating tumor
DNA
Thress Lung Cancer 2015
Clinical response to AZD9291 according to EGFR T790M mutation at baseline
Thress Lung Cancer 2015
In patients with plasma positive but tumor negative for T790M, the clinical ORR was 38% (3/8 patients) and the disease
control rate was 75% (6/8 patients).
T790M Plasma Testing is a Viable Alternative to Tissue Testing
Presented By Lecia Sequist at 2015 ASCO Annual Meeting
T790M Mutation Heterogeneity of NSCLC with Squamous Histology
Leone JCO 2014 Lung before TKI Lung after TKI Liver after TKI
T790M Mutation Heterogeneity
Suda Sci Rep 2015
Slide 7
Presented By Jacob Chabon at 2016 ASCO Annual Meeting
Heterogeneity Underlies the Emergence of EGFR T790 Wild-Type Clones Following
Treatment with 3 rd Generation TKIs
Piotrowska Cancer Discov 2015
TREATMENT OF NSCLC WITH TARGET BASED AGENTS INCREASES
TUMOR HETEROGENEITY
Mitsudomi Nat Rev Clin Oncol 2013
Liquid biopsy can represent temporal and spatial heterogeneity in cancer progression
Burrell & Swanton Mol Oncol 2014
EGFR T790M testing on patient progression:
tissue or liquid biopsy?
• Some tumors are heterogenous with regard to the presence of the T790M mutation
• Liquid biopsy will allow to identify T790M mutation in heterogenoeus tumor that might be negative at tissue biopsy
• However, liquid biopsy still suffers from a relative low sensitivity: a fraction of cases that are positive on tissue might result negative on plasma
• Liquid biopsy and tissue biopsy are complementary in
providing information on T790M status of patients at
progression following EGFR TKI treatment
Algorithm for T790M testing
Plasma sample mutation testing
EGFR T790M mutation detected No EGFR mutation detected
Re-biopsy mutation testing
T790M plasma testing:
clnical interpretation
Sensitizing T790M Interpretation
+ + T790M positive: start treatment with 3°
generation TKI
+ - T790M negative: tissue biopsy recommended
- + T790M positive?: confirm with an orthogonal technique
- - Non informative: tissue biopsy strongly recommended
Plasma EGFR mutations during treatment with EGFR TKIs
Sorensen Cancer 2014
T790M
In clinical practice, plasma testing for the T790M should be
performed at the same time when tissue biopsy is indicated (i.e. at
clinical progression of the disease)
Acquired resistance to EGFR TKIs
Sequist Sci Trasl Med 2011
