Abstract #3010
Identification of Effective Drug Combinations to
Prevent or Delay Resistance to the EGFR Mutant
Selective Inhibitor Rociletinib (CO-1686)
Andrew D. Simmons, Henry J. Haringsma, Minh Nguyen,
Liliane Robillard, Andrew Allen, and Thomas C. Harding
Disclosure Information
• Andrew Simmons, PhD
• I am an employee and shareholder of Clovis Oncology, Inc.
2
Abstract # 3010: Rociletinib Combinations
The Mechanisms of Resistance to Rociletinib (CO-1686) Are
Under Investigation
• Rociletinib potently inhibits activating EGFR mutations (L858R and Del19) and the
T790M resistance mutation, while sparing wild-type EGFR1
• Clinical data confirm activity of rociletinib in T790M positive NSCLC with minimal
wild-type EGFR related side effects2
• Multiple mechanisms of resistance to EGFR TKIs have been observed in nonclinical
studies3-5
• Clinical studies reveal differences in mechanisms of resistance to 3rd gen TKIs
• C797S has been observed with AZD9291 but not rociletinib6-8
• We used in vivo models to explore acquired resistance to rociletinib
1Walter
5Ichihara,
2Sequist
6Thress
AO, et al. Cancer Discov. 2013;3:1404-1415.
LV, et al. N Engl J Med. 2015;372:1700-1709.
3Chong CR, et al. Nat Med. 2013;19:1389-1400.
4Camidge DR, et al. Nat Rev Clin Oncol. 2014;11:473-481.
E and CM Lovly. Cancer Discov. 2015;5:694-696.
KS, et al. Nat Med. 2015;21:560-562.
7Yu HA, et al. JAMA. 2015;epub.
8Piotrowska Z, et al. Cancer Discov. 2015;5:713-722.
3
Abstract # 3010: Rociletinib Combinations
Rociletinib Prevents the Emergence of T790M Subclones
• Performed continuous dosing of erlotinib and rociletinib in the PC-9 (Del19 EGFR)
NSCLC xenograft model
• Used ddPCR and NGS to evaluate resistant tumors
E r lo tin ib r e s is ta n t tu m o r s
V e h ic le
c o lle c te d fr o m n = 3 m ic e
T u m o r v o lu m e
3
m e an  S E M (m m )
1500
1000
C r o s s o v e r n = 7 m ic e t o
r o c ile tin ib t r e a tm e n t
Vehicle
Del19 EGFR
500
0
0
20
40
60
80
100
D a y o f s tu d y
120
Erlotinib Resistant
Del19/T790M EGFR
v e h ic le
e r lo tin ib ( 5 0 m g /k g Q D )
r o c ile tin ib ( 1 5 0 m g /k g B ID )
4
Abstract # 3010: Rociletinib Combinations
MET Amplification Observed as Mechanism of Resistance
With Continued Dosing of Rociletinib
• Rociletinib resistant tumors are MET amplified and T790M negative
e r lo tin ib / r o c ile tin ib c ro s s o v e r
Vehicle
Del19 EGFR
r o c ile tin ib m o n o th e ra p y
1500
1500
R o c ile tin ib
E r lo tin ib
v e h ic le
T u m o r v o lu m e (m m )
R e s is t a n t
Rociletinib
R o c ile tin ib
R e s is a n t
Resistant
3
3
T u m o r v o lu m e (m m )
v e h ic le
R e s is t a n t
1000
500
0
1000
Erlotinib Resistant
Del19/T790M EGFR
500
0
0
50
e rlo tin ib
( 5 0 m g /k g Q D )
100
ro c ile tin ib
( 1 5 0 m g /k g B ID )
D a y s o f d o s in g
150
200
0
50
100
ro c ile tin ib
( 1 5 0 m g /k g B ID )
D a y s o f d o s in g
150
200
Rociletinib Resistant
Del19 EGFR
MET amp
5
Abstract # 3010: Rociletinib Combinations
Combination of Rociletinib and Crizotinib Restores AntiTumor Activity
Patient-derived LU0858 xenograft
model (EGFR L858R, MET amp)
Consistent theme in nonclinical and
clinical studies is heterogeneity
± SEM)
25
erlotinib
20
15
10
0
5
10
15
20
25
3
D a y s o f d o s in g
(m m
M e a n tu m o r v o lu m e
1000
(g  S E M )
M e a n b o d y w e ig h t
30
rociletinib
100
P < 0 .0 0 0 1
0
5
10
15
20
D a y s o f d o s in g
V e h ic le
R o c ile tin ib ( 1 0 0 m g /k g B ID )
C r iz o tin ib ( 5 0 m g /k g Q D )
C o m b in a tio n
25
rociletinib
Del19
Del19/T790M
Del19/MET amplification
6
Abstract # 3010: Rociletinib Combinations
MEK and Aurora A Inhibitors Can Restore Activity in
Rociletinib-Resistant Cells
• Developed PC-9 resistant cell line (designated 2A10) by in vitro and in vivo selection
with rociletinib
• Used resistant cell line for compound library combination screening
200
175
175
150
150
% v ia b ility
125
100
75
50
25
r o c ile tin ib
m ean ± STD EV
% v ia b ility
m ean ± STD EV
• MEK (trametinib) and Aurora A inhibitors (alisertib) can restore rociletinib activity
125
100
75
50
25
tra m e tin ib
0
0 .2
0 .5
2
5
r o c ile tin ib
a lis e rtib
14
41
123
370
1111 3333 10000
d o s e (n M )
0
0 .2
0 .5
2
5
14
41
123
370
1111 3333 10000
d o s e (n M )
PC-9 2A10 maintained and screened in 1mM rociletinib
7
Abstract # 3010: Rociletinib Combinations
Trametinib Combination Can Overcome MAPK Pathway
Reactivation
• The MAPK pathway plays a key
role in EGFR pathway signaling
2000
25
20
15
10
20
60
40
80
D a y s o f d o s in g
1500
3
± SEM)
0
1000
500
0
0
• Resistant cells maintain
dependence on EGFR pathway
(g  S E M )
M e a n b o d y w e ig h t
2500
(m m
• Trametinib combination restores
activity in rociletinib resistant
2A10 model
30
M e a n tu m o r v o lu m e
• Resistance to EGFR inhibitors
results from MAPK pathway
reactivation1-3
10
20
30
40
50
60
70
80
D a y s o f d o s in g
V e h ic le
R o c ile tin ib ( 1 0 0 m g /k g B ID )
T r a m e tin ib ( 0 .5 m g /k g Q D )
C o m b in a tio n
1Ercan
D, et al. Cancer Discov. 2012;2:934-947.
CA, et al. Cancer Res. 2015;75:2489-2500.
3Tricker EM, et al. Cancer Discov. 2015;epub.
2Eberlein
8
Abstract # 3010: Rociletinib Combinations
Rociletinib Resistant Cells Exhibit Increased Sensitivity to
Aurora A Kinase Inhibitors
100
r o c ile tin ib
80
a lis e rtib
60
c o m b in a tio n
40
% v ia b ility
100
20
a lis e rtib
60
c o m b in a tio n
40
20
0
0
10
100
1000 10000
lo g d o s e ( n M )
5
0
P C -9 2 A 1 0
10
100
1000 10000
lo g d o s e ( n M )
5
PC-9 2A10 cell cycle (48hr)
C aspase
100%
120
80%
100
% caspase
r o c ile tin ib
80
0
• Combination results in increased
apoptosis (caspase) and cell
cycle arrest
• Mechanism under investigation
120
m ean  S T D E V
• Combination active in both
parental and resistant cells
P C -9 2 A 1 0
C e ll V ia b ility
120
m ean  S T D E V
% v ia b ility
P C -9 P a re n ta l
C e ll V ia b ility
m ean  S T D E V
• Increased single agent activity of
the Aurora A kinase inhibitor
alisertib (MLN8237) observed in
PC-9 2A10 cells
r o c ile tin ib
80
60%
a lis e rtib
60
c o m b in a tio n
40%
40
20%
20
0%
no drug
0
0
10
100
1000 10000
lo g d o s e ( n M )
5
rociletinib
G0
G1
alisertib
S
G2
combination
>4N
9
Abstract # 3010: Rociletinib Combinations
Conclusions
• We have broadly explored mechanisms of acquired resistance to rociletinib in nonclinical studies
• MET amplification has been observed as a mechanism of acquired resistance to rociletinib
• Heterogeneity is a common theme in preclinical and clinical studies
• Combination of rociletinib and the MEK inhibitor trametinib restores activity in rociletinib resistant
models
• Clinical evaluation of rociletinib in combination with trametinib is ongoing
• Combination of rociletinib and the Aurora A inhibitor alisertib restores activity in rociletinib-resistant
models
• Clinical evaluation of rociletinib in combination with other agents is ongoing or planned
• Understanding differences between mechanisms of resistance to 3rd generation TKIs will help define
optimal treatment paradigms
10
Abstract # 3010: Rociletinib Combinations