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 3rd 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

Conclusions

• Liquid biopsy has a relevant role for the molecular profiling of recurrent disease

• Liquid biopsy has the advantage to provide a comprehensive molecular portrait of the disease and, therefore, to represent tumor heterogeneity

• Testing of liquid biopsy still needs standardization (low sensitivity)

• In patients with recurrent disease tissue biopsy and liquid biopsy can provide complementary information