Transcript PDX - Flasca

Bench to Bedside Translation
Patient Derived Xenograft (PDX) Models and Case Study
S. S. Gail Eckhardt, M.D.
University of Colorado Cancer Center
September 2014
Schema: Patient Derived Xenograft Model (PDX)
These are the logistical steps that need to be worked out:
consenting patients and getting tumor from pathology in OR
Note: Tumors are never grown on plastic
Response of Colorectal PDX to a Range of Targeted Agents
150.00%
100.00%
50.00%
IGF1Ri
MEKi
STI
Pro-apoptotic
0.00%
AurAi
PLKi
Irinotecan
Cetuximab
-50.00%
-100.00%
-150.00%
GSI
Individual Tumor Growth Curves Reveal Heterogeneity
Drug A/2500 mm3 scale
Drug A
Drug B/2500 mm3 scale
Drug A/600 mm3 scale
Colorectal (CRC) PDX
Preservation of histopathologic diversity
Stromal evolution to mouse
PDX
(Similar to primary)
ALU probe in situ
hybridization
stromal cells negative at
8th passage
Julien S et al. Clin Cancer Res 2012;18:5314-5328
Circos plots for the 1° tumor, metastasis and xenograft genomes
PDX and metastasis
look similar
Met
PDX
Ding L, et al Nature Vol
464 April 2010
Sorafenib in RCC PDX:
Efficacy Recapitulated in PDX Models
Yuen JSP et al
BJC 2011 104: 941-947
Cetuximab (EGFR Ab) Treatment in Unselected Metastatic
CRC Xenopatients: Prediction of KRAS Status Effect
WT KRAS
PDX
responded
(regression)
If this had been known prior to
phase III development, literally
thousands of patients could
have avoided ineffective and
toxic therapy
Bertotti A et al. Cancer Discovery 2011;1:508-523
©2011 by American Association for Cancer Research
Using PDX to Develop Rational Combinations
Case Study: MEK Combination in CRC
Synthetic Lethality: Functional Screen for Actionable Resistance Pathways
Identifying genes which when suppressed potentiate cell death with Drug X
WNT signaling pathway
Legend
SL genes
GSEA core genes
Common in GSEA and SL genes
3/5 R CRC PDX had >50% increase in FZD2 (Wnt receptor)
post-treatment with a MEK inhibitor
CUCRC006
CUCRC007
CUCRC012
CUCRC021
CUCRC027
4
2
1
CUCRC027 post-T
CUCRC027 pre-T
CUCRC021 post-T
CUCRC021 pre-T
CUCRC012 post-T
CUCRC012 pre-T
CUCRC007 post-T
CUCRC007 pre-T
CUCRC006 post-T
0
CUCRC006 pre-T
relative expression
3
FZD2
PDX Models Enable Validation of Cell-Line Derived Hypotheses
EOS
End of treatment
CUCRC006
3000
vehicle
additional time point
selumetinib
CsA
combo
Rational
Combination:
selumetinib+CsA
CsA+selumetinib
MEK inhibitor + Wnt
inhibitor
Percent Day 1
2000
Tested in PDX model
1000
We were also
able to test the
robustness of the
response and
durability
0
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220
Days
single agents vs combo
combos vs vehicle
regrowth
Clinical Translation: NCI/CTEP Approved Trial
Note: PDX will be utilized to determine
which are the most effective
biomarkers to assess in patient’s
tumors on the study
Three Dose Levels
Dose
Level
-1
1
2
MTD
No.
Patients
3-6
3-6
3-6
20
AZD6244
(orally)
50 mg QD
50 mg BID
75 mg BID
TBD
Cyclosporin A
(orally)
2 mg/kg BID
2 mg/kg BID
2 mg/kg BID
TBD
Treatment Plan (dose escalation)
• In Cycle 1 (dose-escalation)
– AZD6244 alone on Day -7
• plasma sampling at baseline, 0.5, 1, 2, 4, 8, and 24 hours
– Cyclosporin A alone on Day -3,
• plasma sampling at baseline, 0.5, 1, 2, 4, 8, and 24 hours
• On Day 1 all patients will receive both AZD6244 and cyclosporin A with
plasma sampling at baseline, 0.5, 1, 2, 4, 8, and 24 hours
• Cyclosporin A levels will be checked 6-8 days later and at least every other
week while patients are taking cyclosporin A
• The dose of cyclosporin A will be adjusted accordingly for a goal of steadystate trough levels of 125 to 250 ng/mL
Treatment Plan (dose expansion)
• Total of 20 patients with CRC – all required to have a baseline
tumor biopsy
• A cohort of seven patients will have a 7-day AZD6244 alone run-in
– Biopsy before AZD6244 and after the 7-day run-in
– Assessing up-regulation of resistance (Wnt) pathway(s)
– Biopsy at the time of progression
• AZD6244 and Cyclosporin A will be given together on day 1
• No PKs in the expansion cohort
This was the First activated Experimental
Therapeutics – Clinical Trials Network (ET-CTN)
(UM1) clinical trial!
PETT Lab
Program for the Evaluation
of Targeted Therapy (PETT)
Lab
S. Gail Eckhardt, M.D.
Aik-Choon Tan, Ph.D.
John Tentler, Ph.D.
Todd Pitts, M.S.
Steve Leong, M.D.
Jiyhe Kim, Ph.D.
Jennifer Diamond, M.D.
Anastasia Ionkina
Stacey Bagby, BA, AAS, CVT
Peter Klauck
Lindsey Davis, M.D.
Chris Lieu, M.D.
Kit Wong, M.D.