1. Progression-Free Survival Times Overall Survival Times
Ligand expression of the EGFR ligands amphiregulin, epiregulin, and amplification of the EGFR gene to predict for treatment efficacy in KRAS wild-type mCRC patients treated with cetuximab plus CAPIRI and CAPOX: Analysis of the randomized AIO CRC-0104 trial
#3519
S. Stintzing1, A. Jung², C. Kapaun1, J. Reiche², D.P. Modest1, C.A. Giessen1, U. Vehling-Kaiser3, M. Stauch4, H. Hass5, L. Fischer von Weikersthal6, T. Kirchner2, V. Heinemann1
1Department of Medicine III, LMU University of Munich; ²Institute of Pathology, LMU University of Munich Munich; ³Onkologische Praxis Landshut; 4Onkologische Praxis Kronach; 5Marienhospital Stuttgart; 6Health Center St. Marien, Amberg.
Background:
We investigated the expression of the EGFR ligands amphiregulin (AREG) and epiregulin (EREG) as well as the amplification of the EGFR-gene in tumor specimens of mCRC patients (pts) treated first-line with anti-EGFR targeted cetuximab together with CAPOX or CAPIRI. Expression levels were correlated with overall response rate (ORR), progression free survival (PFS) and overall survival (OS) to determine their relationship with effectiveness in this setting.
Methods:
A total of 185 mCRC pts were randomized to cetuximab (400mg/m² day 1, followed by 250mg/m² weekly) plus CAPIRI (irinotecan 200mg/m², day 1; capecitabine 800mg/m² twice daily days 1-14, every 3 weeks; 20% dose reduction of both agents for pts older than 65 years) or plus CAPOX (oxaliplatin 130mg/m² day 1; capecitabine 1000mg/m² twice daily days 1-14, every three weeks). The primary study endpoint was ORR. KRAS mutational status did not correlate with treatment outcome. The cut-offs for EGFR-amplification using FISH, AREG and EREG levels determined by RT-qPCR were calculated using ROC analysis for ORR.
Results:
Within the subgroup of KRAS wildtype tumors, analysis of EREG- and AREG-expression was possible in 99 pts and of EGFR-amplification in 63 pts. Higher AREG levels correlated significantly with higher ORR (83% vs 46%, p=0.006, OR 0.31), longer PFS (9.6mo vs 4.9, p<0.001, HR 0.35) and longer OS (39.9mo vs 17.2mo, p<0.001, HR 0.36). Higher EREG levels showed a significant correlation with ORR (74% vs 47%, p=0.036, OR 0.54), longer PFS (7.9mo vs 4.9mo, p=0.026, HR 0.57) and OS (33.0mo vs 20.2mo, p=0.041, HR 0.57). EGFR-amplification correlated significantly with higher ORR (71% vs 33%, p=0.004, OR 0.49), longer PFS (8.4mo vs 4.6mo, p=0.004, HR 0.50) and longer OS (30.5mo vs 15.2mo, p=0.001, HR 0.44).
Primary Study Results
Study Objectives
Progression-Free Survival Times
Overall Survival Times
Amphiregulin (AREG)
Amphiregulin (AREG)
Survival Times by KRAS Status
Laser- microdissection of FFPE tumor-cells
Amphiregulin (AREG)
3´-cggagaatgcaaatatatagagcac-5´
3´-caccgaaatattcttgctgaca-5´
Epiregulin (EREG)
3´-tggtctcttcactcaggtctca-5´
3´-cgtgagttggcatagggaac-5´
Houskeeping RNA´s:
ß-actin and GAPDH
1.0
0.8
0.6
0.4
0.2 12 24 36 48 6 18 30 42
AREG high: 8.4 (6.1 – 13.1)
AREG low: 4.9 (3.8 – 6.0)
logrank p < 0.001
HR: 0.35 (0.21 – 0.60)
months since randomisation
probability of PFS
n=30
n=39
1.0
0.8
0.6
0.4
0.2 12 36 72 24 48 60
AREG-high: (30.8 – 49.0)
AREG low: 17.1 (13.8 – 20.5)
logrank p <
HR: 0.36 (0.20 – 0.63)
months since randomisation
probability of OS
n=30
n=39
ROC-Analysis for ORR
Epiregulin (EREG)
Epiregulin (EREG)
1.0
0.8
0.6
0.4
0.2 12 24 36 48 6 18 30 42
EREG high: 7.9 (6.1 – 10.0)
EREG low: 4.9 (3.0 – 6.8)
logrank p = 0.026
HR: 0.58 (0.34 – 0.94)
months since randomisation
probability of PFS
n=39
n=30
1.0
0.8
0.6
0.4
0.2 12 36 72 24 48 60
EREG-high: (18.7 – 47.3)
EREG low: 20.2 (15.0 – 25.4)
logrank p =
HR: 0.57 (0.33 – 0.98)
months since randomisation
probability of OS
n=39
n=30
ROC analysis was carried out, using
EREG and AREG mRNA expression levels
in relation to the housekeeping RNA
(ß-actin and GAPDH) and EGFR copy
number in relation to chromosome 7 as
continious test variables and ORR as
state variable
1.0
0.8
0.6
0.4
0.2
EREG:
AUC = 0.615
cut-off: 31.66
sensitivity: 62.1%
specificity: 73.2%
1- specificity
sensitivity
ROC-curve
Design of Investigation
Moosmann et al JCO 2011
RECIST Response by KRAS Status
AIO CRC-0104 trial recruited patients during the years , independent of the KRAS mutational status
tumor specimen of 99 KRAS wildtype patients were available for investigation
Retrospective analyses of tumor material was done, looking for molecular factors predictive for response to Cetuximab- based treatment
AREG:
AUC = 0.661
cut-off: 8.855
sensitivity: 56.9%
specificity: 75.6%
1.0
0.8
0.6
0.4
0.2
1- specificity
sensitivity
ROC-curve
EGFR-FISH:
AUC = 0.651
cut-off: 1.055
sensitivity: 67.9%
specificity: 57.8%
1.0
0.8
0.6
0.4
0.2
1- specificity
sensitivity
ROC-curve
EGFR-FISH
EGFR-FISH
1.0
0.8
0.6
0.4
0.2 12 24 36 48 6 18 30 42
EGFR-high: 8.4 (6.8 – 10.0)
EGFR low: 4.6 (3.1 – 6.2)
logrank p =
HR: 0.49 (0.30 – 0.81)
months since randomisation
probability of PFS
n=41
n=34
1.0
0.8
0.6
0.4
0.2 12 36 72 24 48 60
EGFR-high: (15.1 – 45.9)
EGFR low: 15.2 (9.3 – 21.1)
logrank p =
HR: 0.44 (0.26 – 0.74)
months since randomisation
probability of OS
n=41
n=34
AIO CRC-0104 Study Design
Moosmann et al JCO 2011
CAPIRI + Cetuximab
Response Data
Metastatic
colorectal cancer
EGFR-FISH
commercialy available test staining chromosome 7 (528nm orange) and EGFR (572nm green) to evaluate the frequency of EGFR per cell („gene copy number“) and the relative frequency in relation to chromosome 7 R
amphiregulin (AREG)
epiregulin (EREG)
EGFR-FISH
low
(n=35)
high
(n=24) p
(n=28)
(n=31)
(n=27) PD
17% 0%
0.072
14% 7%
0.409
19% 6%
0.223 SD
37%
0.143
39%
0.149
48%
23%
0.058 PR
46%
67%
0.183
61%
0.302
33%
60%
0.044* CR
0.023*
13%
0.114
11%
0.125
ORR
83%
0.006*
74%
0.036*
71%
0.004*
DCR
100%
86%
94%
82%
CAPOX + Cetuximab
CAPIRI + Cetuximab (*)
Capecitabine 800 mg/m² oral BID day 1-14, q 3wks
Irinotecan 200 mg/m² iv, 30 min day 1, q 3wks
Cetuximab initial dose 400 mg/m² iv, 120 min, then 250 mg/m² iv,60 min, wkly
CAPOX + Cetuximab Capecitabine 1,000 mg/m² oral BID day 1-14, q 3wks
Oxaliplatin 130mg/m² iv, 120 min day 1, q 3wks
* 20% dose reduction for patients > 65 years in the XELIRI + Cetuximab arm.
Conclusions
In the treatment setting of cetuximab combined with CAPIRI or CAPOX, AREG, EREG and EGFR-amplification predicted treatment efficacy.
Within the subgroup of pts with KRAS wildtype tumors, EGFR-FISH and AREG expression have the strongest relationship with treatment efficacy.
significant differences are indicated by * and italic and bold writing; PD (progressive disease), SD (stable disease), PR (partial remission) and
CR (complete remission) were evaluated using RECIST criteria. ORR (objective response rate = CR + PR) and DCR (disease control rate = ORR + SD)
were calculated