Download Serum Antibodies in Ovarian Cancer

Serum autoantibodies in ovarian cancer
Isabel K
1Oncimmune
1*
Macdonald ,Celine
1
Parsy-Kowalska ,
Jane
1
McElveen ,
1
Allen ,
Jared
Caroline
2
Chapman
& Andrea
1
Murray
Ltd, Nottingham, United Kingdom; 2 Division of Medical Sciences and Faculty of Medicine & Health Sciences, University of Nottingham Graduate Entry Medicine, Nottingham, UK
*Corresponding author; [email protected]
1. Ovarian Cancer
4. Methodology
 Patient Population:  225,000 new cases & 140,000 deaths per year worldwide
 Recombinant
Proteins:
 1-2% life time risk in developed world
 High risk groups?:
 Early Detection:
 Current Clinical
path:
 Tumour associated antigens
 Identified through literature review and scoring
 >50 years old
 Human cDNA sequences
 Family History
 Gibson cloned into vector (assay and His6 purification tags)
 Genetic risk groups e.g. BRCA1&2
 >70% present at late stage
 Recombinant proteins overexpressed in E.coli
 FPLC purification & characterisation
 >90% 5 year survival for Stage I&II
 ELISA:
 10-30% 5 year survival for Stage III&IV
 Symptomatic presentation, no screening programme
 5 point titration of antigen; captures sera autoantibodies
 Pilot Study I:
 NY-ESO-1, CAGE, p53, SOX2, GBU4-5 & Annexin I
 63 malignant Ovarian Cancer samples10
 High risk offered CA125 &/or HE4 on request
 Imaging for patients with abnormal Hx, exam or CA125/HE4:
 Diagnosis by surgery/removal of ovaries (6% mortality)
 68% early stage (I&II)
 Pilot Study II:
 22 antigens including NY-ESO-1, CAGE, p53 & SOX2
 78 malignant ovarian cancer sera samples10
 Disease monitoring following treatment (CA125/HE4)
 78 age matched healthy control sera samples
 68% early stage (I&II)
2. Autoantibodies
 Antibodies raised against ‘self’ proteins by host immune response:
5. Results
 Autoimmune disorders: abnormal immune response to normal protein
 Pilot Study I:
 Tumours: abnormal proteins detected
 Panel Sensitivity for ovarian Cancer of 33%
 Panel Specificity set at 90%
N y e s o - 1 B IR A : 5 0 ( c ir c le ) & 1 6 0 n M ( s o lid c ir c le )
Normal
cell
2 .0
Normal host protein
Tumour
Cell
Abnormal ‘tumour associated’
antigen
Tumour
genesis
O D @ 650nm
1 .5
Autoantibodies specific for TAA
 Produced early in tumour genesis prior to clinical symptoms
1 .0
0 .5
 Biological amplifiers :
 Increase the detectable signal for the corresponding tumour antigen
0 .0
 Absent or low concentrations in healthy & benign cohorts
 Stable unlike antigens which can degrade rapidly
 Half-lives ≤ 30 days
N
l
r
r
n
n
a
e
e
Ovarian
Benign
Healthy
g
g
i
i
c
c
n
n
rm
n
n
e
e
a
a
o
Cancer
B
.B
.cohort
.C
. Ncontrol . C
O
O
O
O
O
S
S cohortS
S
S cohort
E
E
E
E
E
Y
Y
Y
Y
N
N
Y
N
N
Y
E
S
O
.N
o
rm
a
l
N
Dot plots of ELISA signal for NY-ESO-1: separated by cohort
 Detection is minimally invasive and cost effective
A n t ig e n ( S a m p le G r o u p )
 Pilot Study II:  Confirmed pilot study I findings
 Identified additional markers with high sensitivities of 8-16% per
marker
3. EarlyCDT
 Diagnostic aid for lung cancer already in clinical use (EarlyCDT-Lung1-5)
 Autoantibody levels for a benign cohort (n=66) were comparable to
healthy control populations
 ELISA to measure a panel of 7 tumour associated serum autoantibodies
Substrate binding; colorimetric output
Enzyme (HRP)
6. Conclusions
Anti-human antibody
Patient sera autoantibody
Tumour associated antigen
ELISA plate
 Highly reproducible
 Both pilot studies strongly support previous findings suggesting autoantibodies are
suitable biomarkers for ovarian cancer
 Early stage disease detected
 Patients with benign tumours, like healthy patients, have low levels of autoantibodies
compared to those with malignant ovarian tumours
 A preliminary EarlyCDT-Ovary panel of 6 autoantibody assays was determined resulting
in a combined sensitivity of 41% and specificity of 93.6% for malignant ovarian cancer
 Detection up to 4 years before CT (current diagnosis pathway)
 Technically & clinically validated on numerous high risk case control cohorts6&7
 92% accuracy
 ~40% sensitivity & 93% specificity for all stage disease
 Launched 2012 & clinical performance as expected:
 >100,000 tests performed in US
 Diagnostic aid for high risk patients
 Patient stratification of nodules identified by CT8
 NHS prospective randomised controlled clinical screening trial ongoing (UK)9
 US health insurance companies reimburse use
7. Future perspectives
 Autoantibody panels can detect early stage ovarian cancer, distinguishing malignant from
benign disease with a very high specificity
 Research is ongoing at Oncimmune to identify additional autoantibody markers to
improve EarlyCDT-Ovary test performance
 Identifying suitable cohorts is a major obstacle to this work: several large independent
cohorts containing a high proportion of early stage disease are needed. Aggressive and
treatment resistant sub types must also be represented.
 Autoantibody panels have the potential to meet requirements for nationwide
screening programmes for ovarian cancer
References
1. Lam, S., et al. EarlyCDT-Lung: an immunobiomarker test as an aid to early detection of lung cancer. Cancer Prev Res (Phila) 4, 1126-1134 (2011); 2. Healey, G.F., et al. Signal stratification of autoantibody levels in serum samples and its application to the early detection of lung cancer. J Thorac Dis
5, 618-625 (2013); 3. Chapman, C.J., et al. EarlyCDT(R)-Lung test: improved clinical utility through additional autoantibody assays. Tumour Biol 33, 1319-1326 (2012); 4. Macdonald, I.K., et al. Application of a high throughput method of biomarker discovery to improvement of the EarlyCDT((R))Lung Test. PLoS One 7, e51002 (2012); 5. Boyle O, W.D., Khuu A, Jett J, Detterbeck F, Kennedy T, Miller D, Fritsche H, Wood W, Hamilton-Fairley G, Robertson J, Edelsberg J. An autoantibody test to aid in early detection of lung cancer in high-risk patients is likely to be cost-effective. in CHEST, Vol.
138 4 (2010). Tammemagi, C.M., et al. Lung cancer risk prediction: Prostate, Lung, Colorectal And Ovarian Cancer Screening Trial models and validation. Journal of the National Cancer Institute 103, 1058-1068 (2011); 6. Boyle, P., et al. Clinical validation of an autoantibody test for lung cancer. Ann
Oncol 22, 383-389 (2011); 7. Murray, A., et al. Technical validation of an autoantibody test for lung cancer. Ann Oncol 21, 1687-1693 (2010); 8. Massion, P. Biormarker-driven programs for lung cancer screening. in World Conference of Lung Cancer, Vol. 8 S6 (Journal of Thoracic Oncology, Sydney,
Australia, 2013); 9. Hume, C. Detection in Blood of Autoantibodies to Tumour Antigens as a Case-finding Method in Lung Cancer using the EarlyCDT-Lung test (ECLS). in ClinicalTrials.gov [Internet]. Bethesda (MD): National Library of Medicine (US), Vol. 2014 (University of Dundee, 2014); 10. Clinical
Research Centre Cape Cod.
For more information: www.oncimmune.com or +44(0)1158231869