Bench to Bedside TranslationPatient 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

Drug A

Drug A/2500 mm3 scale Drug A/600 mm3 scale

Drug B/2500 mm3 scale

Individual Tumor Growth Curves Reveal Heterogeneity

Colorectal (CRC) PDXPreservation of histopathologic diversity

Stromal evolution to mouse

Julien S et al. Clin Cancer Res 2012;18:5314-5328

ALU probe in situ hybridization

stromal cells negative at 8th passage

PDX(Similar to primary)

Circos plots for the 1° tumor, metastasis and xenograft genomes

Ding L, et al Nature Vol 464 April 2010

PDX and metastasislook similar

Met

PDX

Sorafenib in RCC PDX:Efficacy Recapitulated in PDX Models

Yuen JSP et alBJC 2011 104: 941-947

Cetuximab (EGFR Ab) Treatment in Unselected Metastatic CRC Xenopatients: Prediction of KRAS Status Effect

Bertotti A et al. Cancer Discovery 2011;1:508-523

©2011 by American Association for Cancer Research

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

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

3/5 R CRC PDX had >50% increase in FZD2 (Wnt receptor) post-treatment with a MEK inhibitor

PDX Models Enable Validation of Cell-Line Derived Hypotheses

CUCRC006

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 2200

1000

2000

3000vehicle

selumetinib

CsA

combo

selumetinib+CsA

CsA+selumetinib

single agents vs combo combos vs vehicle regrowth

additional time point

EOS End of treatment

Days

Per

cen

t D

ay 1

Rational Combination:

MEK inhibitor + Wnt

inhibitor

Tested in PDX model

We were also able to test the

robustness of the response and

durability

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

Dose Level

No. Patients

AZD6244 (orally)

Cyclosporin A (orally)

-1 3-6 50 mg QD 2 mg/kg BID

1 3-6 50 mg BID 2 mg/kg BID 2 3-6 75 mg BID 2 mg/kg BID MTD 20 TBD TBD

Three Dose Levels

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 steady-state 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 Evaluationof Targeted Therapy (PETT)LabS. 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 IonkinaStacey Bagby, BA, AAS, CVTPeter KlauckLindsey Davis, M.D.Chris Lieu, M.D.Kit Wong, M.D.