1. No category

Pretreatment and serial plasma
assessments of EGFR mutations in
NSCLC patients treated with
rociletinib (CO-1686)
Jonathan Goldman, Chris Karlovich, Elaina Mann, Lindsey Rolfe,
Shannon Matheny, Darrin Despain, Philipp Angenendt, Claudia
Stamm, Heather Wakelee, Jean-Charles Soria, Benjamin Solomon,
D. Ross Camidge, Rafal Dziadziuszko, Leora Horn, Shirish
Gadgeel, Mitch Raponi, Andrew Allen, Lecia Sequist
2
Disclosure Information: Jonathan Goldman, MD
AACR Annual Meeting 2015
I have the following financial relationships to disclose:
• Consultant for: Clovis
• Grant/Research support from: Clovis, MedImmune, BMS, Lilly, Astra
Zeneca
3
Lung adenocarcinoma is increasingly treated
according to driver mutation
• Activating mutations (eg, del 19, L858R) in
EGFR found in ≈15% of all NSCLC
–
Lung adenocarcinoma
oncogene drivers
Twice as common in East Asian populations
• A first-generation EGFR inhibitor (EGFRi) is
often used as first- or later-line therapy after
chemotherapy
• T790M found in >60% of acquired
resistance to first-generation EGFRi
• Rociletinib (CO-1686) is a novel, oral,
selective covalent inhibitor of EGFR
mutations in NSCLC
–
Inhibits key activating and T790M mutations
–
Spares wild-type (wt) receptor signaling
EGFR=epidermal growth factor receptor; NSCLC=non-small cell lung cancer.
Blakely CM, Bivona TG. Cancer Discov. 2012;2:872-875; Yu HA, et al. Clin
Cancer Res 2013;19:2240–2247
4
TIGER-X clinical dose group responses
Change from Baseline (%)
100
Best Response for Evaluable T790M+ Patients
67% ORR
(per RECIST v1.1)
89% DCR
80
60
40
20
0
-20
-40
-60
-80
-100
• US FDA breakthrough therapy designation granted May 2014
• Several global phase 2/3 trials are underway or about to start in both first-line and later-line
Soria et al. Presented at EORTC-NCI-AACR; November 18–21, 2014; Barcelona, Spain.
5
Mutations missed by tissue test because of tumor
heterogeneity may be captured by a blood test
EGFR-mutant NSCLC
Response
T790M-mediated relapse:
candidate for rociletinib
First-generation
EGFRi
EGFR-activating mutation
EGFR-activating mutation plus
T790M resistance mutation
blood
•
Adapted from N. Rosenfeld/D. Tsui
Reservoir for cancer genome in
circulating tumor (ct)DNA
biopsy
•
May miss T790M
6
An EGFR blood test would be advantageous but needs
high sensitivity/specificity for use in clinical practice
• Why blood?
–
Tumor heterogeneity
–
Biopsies can be difficult/insufficient
–

Inadequate/insufficient material for
molecular analysis in 10%–20% of
clinical cases

Comorbidities prevent biopsies in
≤20% of patients
blood
Minimally invasive
• In January 2015, EMA approved
blood testing for activating mutations
(L858R and del 19) to guide
treatment decisions with gefitinib
EGFR-activating mutation
EMA=European Medicines Agency.
EGFR-activating mutation plus
T790M resistance mutation
7
Quantitative and sensitive BEAMing test (Sysmex Inostics)
is being used for EGFR mutation detection in plasma
Pre-amplification
Emulsion PCR & hybridization
Flow cytometry
Magnetic beads
coated with primer
DNA isolation
Amplified DNA
Water-in-oil
emulsion
Plasma
Tumor DNA
Wild-type DNA
dNTPs
Polymerase
Primer
Oil-emulsifier mixture
• BEAMing is digital PCR followed by flow cytometry
–
EGFR test identifies L858R, del 19, and rare activating mutations plus T790M
dNTPs=deoxynucleotide triphosphates; PCR=polymerase chain reaction.
Dressman D et al. Proc Natl Acad Sci U S A. 2003;100:8817-8822; Diehl F et al. Proc Natl Acad Sci U S A. 2005;102:16368-16373.
8
Low mutant EGFR levels in substantial fraction of NSCLC
patients support need for highly sensitive detection
mutant molecules/mL plasma
Pretreatment plasma
1000000
100000
• EGFR testing performed on
matched pretreatment tissue and
plasma (BEAMing) for 247 patients
from TIGER-X trial
10000
1000
• 20 (8.1%) not evaluable in tissue
due to low/no tumor content or
poor sample quality
100
10
1
0.1
EGFR molecules/mL in
plasma by BEAMing
Activating
mutations
T790M
Median = 93
Range = 0–324,399
N = 251
Median = 24
Range = 0–227,994
N = 235
• Plasma and tissue collections
matched in time
9
Comparison of plasma and tissue: BEAMing shows very
good sensitivity and identifies patients missed by tissue test
Tissue
Activating mutations
T790M
Positive
Negative
Inadequate
tissue
Positive
193
4
14
211
155
23
12
190
Negative
28
2
6
36
37
12
8
57
221
6
20
247
192
35
20
247
Plasma
Total
Tissue as reference:
Positive percent agreement
Total
Positive
Activating
87% (193/221)
Negative
Inadequate
tissue
Total
T790M
81% (155/192)
• T790M plasma+/tumor- patients very likely true positives and reflect tumor heterogeneity
– 5 of 7 tested were confirmed plasma+ by Cobas or Boreal tests
• BEAMing plasma test almost identified as many T790M+ patients (190) as did tissue
test (190) when inadequate tissue specimens (n=20) were included in analysis (n=247)
10
Comparative data suggest ≈20%–30% of T790M tissue
positives are not detected in plasma by any method
Patient
1
2
3
4
5
6
7
8
9
10
11
12
13
Tissue
T790M
ND
ND
Detected
Detected
Detected
Detected
Detected
Detected
Detected
Detected
Detected
Detected
ND
BEAMing
Plasma Copies/
T790M
mL
%
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Detected
1
0.05
Detected
1
0.07
Detected
6
0.35
Detected
9
1.1
Detected
14
0.4
Detected
29
0.9
Cobas
Plasma
T790M
ND
ND
ND
ND
ND
ND
Detected
ND
Detected
Detected
Detected
Detected
Detected
ddPCR
Plasma Copies/
T790M
mL
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Detected
32
Detected
12
Detected
20.5
Detected
275
%
ND
ND
ND
ND
ND
ND
ND
ND
ND
1.1
0.5
0.3
1.1
Boreal OnTarget
Plasma Copies/
T790M
mL
%
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Detected
3
0.15
Detected
2
0.08
Detected
15
0.38
Detected
18
1.4
Detected
11
0.2
Detected
10
0.4
• The various platforms performed similarly for most samples
• NSCLC biology, rather than sensitivity of detection method, is likely limiting factor
ddPCR=Droplet Digital PCR; ND=not detected.
11
Mutations are more readily detected in plasma of patients with
distant metastatic (M1b) vs intrathoracic (M1a) disease
Mutation
Mutation detected
Disease
in tissue and/or
classification
plasma
M0/M1a
63
Subset with
mutation in plasma
by BEAMing
Percentage
40
63%
T790M
<0.001
M1b
Mutation
Activating
Mutations
P value
170
Mutation detected
Disease
in tissue and/or
classification
plasma
M0/M1a
60
161
95%
Subset with
mutation in plasma
by BEAMing
Percentage
30
50%
P value
<0.001
M1b
164
151
91%
12
Change in EGFR-activating mutation plasma levels by
day 21 may predict clinical benefit to rociletinib
1000
100
10
21
ay
as
e
B
D
ay
lin
e
8
1
21
ay
lin
e
B
as
e
ay
D
Plasma Collection Day
Activating Mutation
10000
D
EGFR act mut (molecules/mL)
1
21
8
ay
D
lin
e
1
10
D
10
100
8
100
1000
ay
1000
10000
D
EGFR act mut (molecules/mL)
10000
as
e
PD
SD
B
EGFR act mut (molecules/mL)
PR
Plasma Collection Day
Activating Mutation
Plasma Collection Day
Activating Mutation
• A drop to <10 copies/mL in EGFR-activating mutation levels was observed
by day 21 in all but 1 patient who went on to have PRs
• A similar drop was seen in T790M plasma levels in patients with PRs
• EGFR-activating mutation levels remained high in most patients with PD
PD=progressive disease; PR=partial response; SD=stable disease.
13
Changes in ctDNA mirror clinical response to rociletinib;
progression may or may not be preceded by reemergence of plasma mutEGFR
50
100
40
30
10
20
10
1
N/D
0
-30
0
60 120 180 240 300 360 420 480 540
80
1000
60
100
40
10
20
1
N/D
0
-30
0
60
Study Day
SLD
T790M
120
180
240
300
50
10000
40
1000
30
100
20
10
10
360
1
N/D
0
-30
0
60 120 180 240 300 360 420 480
Study Day
Del 19
 Still on study
SLD

T790M
Copies/mL Plasma
1000
60
10000
Sum of Target Lesions (mm)
70
100
Copies/mL Plasma
10000
Sum of Target Lesions (mm)
80
Best Overall Response: PR
Best Overall Response: PR
Copies/mL Plasma
Sum of Target Lesions (mm)
Best Overall Response: PR
Study Day
L858R
Re-emergence of mutEGFR 17 ½
wks prior to clinical progression
SLD

T790M
Del 19
M1a pt with no re-emergence
of mutEGFR in plasma
14
Tissue negative/plasma positive patient with
excellent outcome
• 30 yr old male
• Progressed on front line gefitinib (15 months) immediately before rociletinib
•
Tumor in thorax, brain, supraclavicular nodes (readily accessible for bx)
• Negative T790M by local and central tissue testing
• Plasma T790M positive by BEAMing
• RECIST PR at cycle 2 (including biopsied node), maintained for 10 cycles
BASELINE
CYCLE 4
15
Summary
• Low plasma T790M level in many NSCLC patients supports the
use of sensitive technologies such as BEAMing for mutation
detection
• BEAMing plasma test identified almost as many T790M+ patients
as the tissue test when inadequate tissue specimens were included
in the analysis
• Plasma testing and tissue testing appear to be complementary
techniques for identifying patients for T790M inhibitors
–
Reflex testing of plasma before tumor could be considered
• Mutations were more readily detectable in the plasma of patients
with M1b rather than M1a disease
• Change in EGFR-activating mutation plasma levels by day 21 may
predict clinical benefit to rociletinib
16
Acknowledgments
All of the Phase I and TIGER-X
Investigators
Qiagen
Sysmex/Inostics
Clovis Oncology
Jonathan Perkins
Philipp Angenendt
Chris Karlovich
Judith Finlayson
Claudia Stamm
Mitch Raponi
Sheila Smart
Sarah Clausdorf
Andrew Allen
Vishal Sikri
Elaina Mann
Roche Molecular Systems
Rachel Fernald
Onkar Dha
Wen Wei
Frank Diehl
Lindsey Rolfe
Lin Wu
Jason Litten
Patrick O’Donnell
Shannon Matheny
Sean Chien
Darrin Despain
Jeff Isaacson
Andy Simmons
Tom Harding
Cynthia Voong
Lisa Caunt
17