1. The story of the ATM gene in CLL:
Bench and Bedside
Tatjana Stankovic
School of Cancer Sciences, University of Birmingham

2. B cell chronic lymphocytic leukaemia
•Occurs in elderly individuals over age of 60
•Incidence 3680 new cases every year in UK
•Prevalence 6.5 in 100 000 individuals
•Currently incurable by chemotherapy

3. Rise in lymphocyte count
B-cell chronic lymphocytic leukaemia (B-CLL)
has a variable clinical course
Progressive leukaemia
Indolent disease
Time from diagnosis
Progressive disease associated with:
Unmutated VH genes
High Zap70, CD38 expression
Del 17p, 11q (loss of single TP53 or ATM allele)
Genomic complexity
Short telomeres

4. VDJ recombination, Irradiation, chemotherapy, Oxidative
Metabolism cause DNA Double strand breaks (DSBs)
Zn2+
Rad50
Mre11
Nbs1
Mre11
Zn2+
Mre11
Nbs1
A
B
Mre11
B A
Rad50
Head
Arm
ATM
Accumulation of
DNA damage
p53
Responsive genes
APOPTOSIS
Chk2
CELL CYCLE
DNA REPAIR
Occurrence
and progression
of lymphoid tumours

5. Complete inactivation of ATM is frequent in
Chronic Lymphocytic Leukaemia:
Up to 40% of patients have ATM mutations in their tumour cells
CLL5
CLL4
CLL3
CLL1
CLL5
CLL4
CLL3
CLL2
CLL1
CLL2
ATM segment VI
ATM segment I
Leukaemia
with intact ATM
Leukaemia
with loss of ATM
1058delGT
Tumour
1058delGT
Skin
1058delGT
Hair
Stankovic et al, Lancet, 1999

6. ATM mutations in CLL alter DNA damage response
1. DNA damage response defect
B-CLL47 B-CLL7 B-CLL35 B-CLL9
IR
ATMdependent
repair
p53
Actin
DSB
p53
P
CLL138 CLL37 CLL109 CLL169
0
24 0
24 0
24 0
24
ATM S1981P
p53 S15P
Mut
WT
WT WT
WT
Mut
p=0.0019
% PARP1 at 24h
11q deletion
and
mutant
ATM allele
WT Mut
2. Defective IR induced apoptosis
In vitro
Fludarabine15µm
urs of treatment
+
Pettit et al, Blood 2001, Stankovic et al, Blood 2002
3. DNA damage response defect
requires inactivation of both ATM alleles
2 wild
type
ATM
alleles
ATM
+ -
TP53 status
Apoptosis
11q deletion
and
wild type
ATM allele
+
+ - DSB -
ATM status
ATM mut
Activation of
cell cycle
check-points
-
100
80
60
40
20
ATM wt ATM mutant
p53
TP53 mutant
Stankovic et al, Blood 2002
Austen et al, JCO 2007
SMC1 S966P
SMC1
Actin
Austen et al, JCO 2007

7. ATM mutations affect patients’ survival
Unselected cohort (18/155) 12%
p<0.0001
TP53 mutant (n=6)
ATM mutant (n=15)
ATM/TP53 wild type
(n=133)
20
40
80 120 160 200
60 100 140 180
Time in months
Proportion of patients alive
11q cohort (26/72) 36%
p=0.0283
1.0
Overall survival
11q deletion and
wild type ATM allele
11q deletion and
mutant ATM allele
0.8
0.6
0.4
0.2
0.0
0
50 100 150 200 250 300 350
Months since diagnosis
Time to First Treatment
90
p=0.0153
80
70
60
50
TP53 mutant (n=6)
40
ATM mutant (n=15)
30
ATM/TP53 wild type
(n=133)
20
10
0
0
20
40
60
80 120 160 200
100 140 180
Time in months
UK CLL4 –First line treatment: Chl vs F vs FC
(36/224) 14.7%
Percentage without progression
Percentage alive
100
90
80
70
60
50
40
30
20
10
0
0
Percentage treatment free
100
Overall survival
Progression Free Survival
<0.001
No TP53 or 11q abnormality
11q deletion
TP53 mutation or 17p deletion
ATM mutation + 11q deletion
TP53 mutation + 17p deletion

8. ATM null leukaemias require alternative, personalized
treatment

9. Survival
ATM defect
DNA
Damage
tion
combina
s Re
mologou
Ho
PARP inhibition (Olaparib)
Single strand break repair
Conversion of Single
Conversion of Single
Strand Breaks to
Strand Breaks to
Double Strand Breaks
Double Strand Breaks

10. Mimicking a clinical trial in patients
Victoria Weston
Tumour size mm 3
2000
Ceri Oldreive
No treatment (n=20)
Olaparib (n=15)
1500
1000
500
0
×××
××
1
3
5
7
9
11
13
15
17
19
21
××
×××
×××
×××
23 25 27 29 31
Time post-treatment initiation (days)
No treatment
Olaparib

11. Guy Pratt
Nicola Fenwick
Phase I/II clinical trial to assess the efficacy
and safety of Olaparib, a PARP-Inhibitor, in
relapsed and refractory Chronic Lymphocytic
Leukaemia patients with an 11q deletion or ATM
mutation and relapsed/refractory patients with TProlymphocytic Leukaemia and Mantle Cell
Lymphoma.

12. PICCLE Trial
Patients with
refractory
CLL and 11q del
Olaparib 200 mg bd->400mg bd
16
Weeks 1
ATM analysis
Clinical and laboratory
assessment
Response rate at
16 weeks

13. Trial Objectives
Primary Objective:
– Phase I:To identify the maximum tolerated dose (MTD) of
olaparib
– Phase II: To assess the efficacy of Olaparib in patients with
ATM-deficient CLL
Exploratory Objective:
– Develop biomarkers for the activity of this agent
Planned Recruitment:
– Phase I: 18 patients (maximum)
– Phase II: 58 patients

14. From ATM gene to leukaemia patients: return to bedside
ATM mutations
in the most frequent
blood cancer
Clinical trial
with Olaparib
Clinical significance of ATM mutations
ATM function
Concept of synthetic lethality
1999
2011

15. Survival
ATM defect
DNA
Damage

16. Acknowledgements
Victoria Weston
Ceri Oldreive
Angelo Agathanggelou
Anna Skowronska
Gulshanara Ahmed
Eliot Marston
Katie Mapp
Belinda Austen
Malcolm Taylor
Phil Byrd
Paul Moss
Guy Pratt
David Oscier
Chris Fegan
Martin Dyer
Pam Kearns
Judy Powell
KuDOS/Astra Zeneca
Pharmaceuticals