Emilio Alba

UGCI Oncología Médica

Hosp Univ Regional y Virgen de la Victoria

Dpto de Medicina. Universidad de Málaga. IBIMA

Retos para la aplicación clínica de biopsia

líquida en cáncer de mama

Challenges for liquid biopsy application in

breast cancer

CLINICAL APPLICATIONS

Early diagnosis

Detection MRD

Tracking

The three early cancer detection scenarios

Ellen Heitze et al. npj Precision Oncology 2017

Selected Studies of ctDNA detection

Beaver JA, Clin Cancer Res 2014

Bettegowda C, Sci Transl Med 2014

Kidess E, Oncotarget 2015

Analytic Platform Molecular

Alteration Patients Tumor Stage Sensitivity

Digital PCR (Beaver 2014)

SNV (PIK3CA) 14 Breast I-II 93%

BEAMing (Bettegowda 2014)

SNV (structural

variants)

7 Bladder Localized 57%

19 Breast Localized 53%

40 CCR Localized 78%

14 Gastric-E Localized 57%

9 Ovarian Localized 89%

121 Pancreatic Localized 50%

SCODA (Kidess 2015)

SNV (Kras, BRAF,

PIK3CA, EGFR) 10 CCR I-II 60%

ctDNA as Diagnostic Tool

Correlation

Biopsy NGS: 10 gens more frecuently mutated (Illumina/BEAMING)

Blood ctDNA

Mx: BIRADS 4c- 5

Patients characteristics

Plasma Safe Seq results – 9 Mutations in 8 patients

concordant with tissue NGS

PSS results, VAF and patients characteristics

CLINICAL APPLICATIONS

Early diagnosis

Detection MRD

Tracking

Presence of CTCs and clinical outcome in early breast cancer

Banys-Paluchowski M. Front Oncol 2016

Detection of Residual Disease after Surgery (ctDNA)

Olsson E, EMBO Mol Med 2015

Tie J, Sci Transl Med 2016

García Murillas J, Sci Transl Med 2015

Method Tumor Patients Results

Chromosomal

Rearrangement (Olsson 2015)

Breast 20 ctDNA : Recurrence 0 / 6

ctDNA + : Recurrence 13/14

NGS (Tie 2016)

CRC 178 ctDNA + : Recurrence 11 / 14

ctDNA : Recurrence 16/164

Digital PCR (Garcia Murillas 2015)

Breast 37 ctDNA + v : HR: 25.1

C-TRAK Moderate* and High risk early TNBC post surgery (neoadjuvant group) or completion chemotherapy (adjuvant

group): Tissue screening for somatic mutations

Baseline ctDNA and 3 monthly in year 1+

Intervention Pembrolizumab for 1 year

Monthly plasma samples for 12 months

Clinical relapse prior to +ve ctDNA

Randomize 2:1

Observation Continue standard follow-up

Blinded ctDNA 3 monthly until completed 2 years from study entry

CT staging

+ve ctDNA

Standard treatment

* cap entry of moderate risk to 50% of recruitment + All patients ctDNA negative in the first year have continued blinded ctDNA 3 monthly in year 2 but will not be randomised on the result

Design ctDNA assays

Staging +ve

150 patients

cfcDNA- and ctDNA-concentration evolution during

chemotherapy

F Riva et al. Clinical Chemistry 2017

Correlation between ctDNA detection and survival

F Riva et al. Clinical Chemistry 2017

CLINICAL APPLICATIONS

Early diagnosis

Detection MRD

Tracking

Jeffrey B. Smerage, et al. JCO 2014 ; 32: 3483-90

CTC: SWOG 0500

Integrative heatmap of somatic molecular alterations identified in archived CTCs

and comparison with metastatic tissue in endocrine therapy–resistant

MBCpatients

Paoletti C et al. Cancer Res 2018

Concordance tissue/blood in a clinical trial

Lebofsky R Mol Oncol 2014

Clinical applications

Mechanisms of resistance to therapy: ESR1 and resistance to aromatase inhibitors (AI)

ESR1 mutations: SoFEA

Fribbens C, et al. J Clin Oncol 2016

Fulvestrant containing

(n=45)

Exemestane

(n=18)

Median PFS, months (95% Cl) 5.7

(3.0-8.5)

2.6

(2.4-6.2)

Hazard ratio (95% CI) 0.52 (0.30-0.92)

P-value 0.02

ESR1 mutation(s) detected Fulvestrant

containing (n=59)

Exemestane

(n=39)

Median PFS, months (95% Cl) 5.4

(3.7-8.1) 8.0

(3.0-11.5)

Hazard ratio (95% CI) 1.07 (0.68-1.67)

P-value 0.77

ESR1 WT

Interaction effect

for treatment

p=0.07

100

75

50

25

0

0 6 12 18 24 Number at risk (events)

Exemestane 18 (12) 6 (4) 2 (2) 0 (0) 0 Fulvestrant-containing 45 (23) 22 (10) 12 (5) 6 (5) 1

Time from randomization (months)

Exemestane

Fulvestrant containing

PF

S (

%)

Number at risk (events)

Exemestane 39 (18) 21 (9) 12 (5) 5 (0) 3 Fulvestrant-containing 59 (31) 27 (7) 19 (8) 8 (2) 5

100

75

50

25

0

0 6 12 18 24 Time from randomization (months)

Exemestane

Fulvestrant containing

PF

S (

%)

PlasmaDNA AI study of sequential plasma DNA sampling during

first line aromatase inhibitor therapy for advanced breast cancer

C. Fribbens et al. Ann Oncol 2018

BELLE-2: Efficacy by PIK3CA Mutation in ctDNA

Baselga J, et al. SABCS 2015. Abstract S6-01

PIK3CA mutation analysis in ctDNA by BEAMing method (N = 587 pts) Buparlisib + fulvestrant extended PFS in pts with PIK3CA mutations vs fulvestrant alone

Median PFS, Mos (95% CI)

Buparlisib + Fulvestrant

Placebo + Fulvestrant

HR (95% CI)

P Value

ctDNA PIK3CA mutant (n = 200)*

7.0 (5.0-10.0) 3.2 (2.0-5.1) 0.56 (0.39-0.80) < .001

ctDNA PIK3CA non-mutant (n = 387)† 6.8 (4.7-8.5) 6.8 (4.7-8.6) 1.05 (0.82-1.34) .642

*n = 87 buparlisib + fulvestrant; n = 113 placebo + fulvestrant.

†n = 199 buparlisib + fulvestrant; n = 188 placebo + fulvestrant.

ORR higher with buparlisib + fulvestrant in pts with PIK3CA mutations vs fulvestrant alone (18.4 % vs 3.5%) but similar in pts with non-mutant PIK3CA (11.6% vs 10.6%)

Locally Assessed PFS by Tissue or Plasma ctDNA-determined

Mutation Status

ctDNA, circulating tumor DNA; HR, hazard ratio; PFS, progression-free survival; QD, once daily.

This presentation is the intellectual property of Dejan Juric. Contact Juric.Dejan@mgh.harvard.edu for permission to reprint and/or distribute.

ALP + FUL PBO + FUL

HR Event n/N (%) Median

PFS Event n/N

(%) Median

PFS

Patients with PIK3CA

mutation: tissue 103/169 (60.9) 11.0 129/172 (75.0) 5.7 0.65

Patients with PIK3CA

mutation: plasma 57/92 (62.0) 10.9 75/94 (79.8) 3.7 0.55

Patients without PIK3CA

mutation: tissue 49/115 (42.6) 7.4 57/116 (49.1) 5.6 0.85

Patients without PIK3CA

mutation: plasma 92/181 (50.8) 8.8 103/182 (56.6) 7.3 0.80

Number of patients still at risk

92 87 80 77 68 61 54 52 44 43 41 38 34 31 29 24 23 19 18 16 9 8 6 2 2 1 1 1 0 94 90 58 53 42 41 37 34 30 30 26 22 20 19 18 14 14 11 10 9 6 6 5 2 2 1 1 1 0 Placebo + ful

Alpelisib + ful

Time (months)

0

20

40

60

80

100

Alpelisib + fulvestrant

Placebo + fulvestrant

Censoring times

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Even

t-fr

ee p

rob

ab

ilit

y (

%)

PIK3CA mutant patients determined by ctDNA

Clinical applications

Patient stratification: UK PlasmaMATCH

- To assess whether ctDNA is a feasible multi-centre screening tool for detecting aberrations in advanced breast cancer. - To generate proof of principle efficacy of targeted agents in patients with targetable mutations identified by ctDNA screening.

CONCLUSIONS

• CTCs ARE PROGNOSTIC MARKERS IN EARLY AND METASTATIC DISEASE

• CTCs AND ctDNA DETECT MRD

• HIGH CONCORDANCE TISSUE/BLOOD

• PREDICTIVE FACTORS FOR SOME ANTITARGET THERAPY

FACTS

• ctDNA AS SCREENING TOOL

• CTCs AND ctDNA AS SURROGATE MARKERS OF ALL TUMOR POPULATIONS (heterogeneity)

• CLINICAL UTILITY OF EARLY DIAGNOSIS OF MRD

• CLINICAL UTILITY AS PREDICTIVE FACTORS

PROMISES