Targeting the Cell Cycle in Lymphoma Therapy
Selina Chen-Kiang
Weill Cornell Medical College
CDK Inhibitors
Non-Selective CDK4/CDK6 inhibitors
Targeting multiple CDKs, some are transcription factors
• Flavopiridol CDK9
• Daniciclib
CDK7
Selective CDK4/CDK6 inhibitors
• PD 0332991 (palbociclib)
Lymphoma, Myeloma
Solid tumors-Breast Cancer (ER+/HER-)
–Breakthrough therapy, combination with letrozole, Phase 3
• LEE011
Breast Cancer –combination with letrozole and BYL719,
Phase 3
Melanoma
• LY2835219
Non-Small Cell Lung Carcinoma
Breast Cancer
The Cell Cycle
Positive
Negative
Go
Cyclin D + CDK4/6
M
G1
G2
pS-Rb-E2F
Cyclin E + CDK2
S
pST-Rb
CDK: Cyclin-Dependent Kinase
p18INK4c (CDKN2C)
E2F release
p16
p15
p18
p19
p21
p27
p57
mid-G1
checkpoint
Targeting CDK4/6 with PD 0332991 (palbociclib)
•
•
•
•
•
•
Selective CDK4/CDK6 inhibitor (IC50 11 nM)
Orally bioavailable pyridopyrimidine
Competing with ATP for binding to the kinase site of CDK4/CDK6
Induces early G1 arrest
Reversible
Low in toxicity
• Selectively and potently inhibits CDK4/6 phosphorylation of Rb in
primary human myeloma cells (IC50 60 nM )
• Inhibits tumor growth in the NOD-SCID human myeloma xenograft
models and the immune-competent mouse 5T models
Fry et al., 2004, Mol Cancer Ther
Baughn et al., 2006, Cancer Research
Menu et al., 2008, Cancer Research
Targeting CDK4/CDK6 in combination therapy
CDK4/6 Inhibitor
Partner agent (low dose, selective )
Weill-Cornell
Mantle cell lymphoma
Multiple Myeloma
Mantle cell lymphoma
Phase I single agent
Phase I/II PD-bortezomib-Dex
Phase I PD 0332991-bortezomib
2014
Mantle cell lymphoma
Phase I PD 0332991-Ibrutinib
Multiple myeloma Phase I PD 0332991-Lenalidomide-Dex
Prolonged early G1 arrest (pG1) Hypothesis
Go
Cyclin D + CDK4/6
M
G1
G2
PD 0332991
pS-Rb
S
Prolonged inhibition of CDK4/6
Prolonged early G1 arrest (pG1)
Expression of only genes programmed for early G1
Sensitizing tumor cells to cytotoxic killing
pG1 Hypothesis
Go
Cyclin D + CDK4/6
M
G1
G2
PD 0332991
Reversible
pS-Rb
S
Release of prolonged early G1 block
Cell cycle synchronization
incomplete restoration of scheduled gene expression
Further sensitizing tumor cells to cytotoxic killing
Targeting CDK4/CDK6 in Recurrent MCL
Single agent PD 0332991 Phase I study
• Inhibition of CDK4/CDK6 by PD 0332991 leads to prolonged
G1 arrest (pG1) and increased tumor-specific cell death in
MCL (n=17)
• PD 0332991 (125 mg/d orally 21 of 28 d) is generally well
tolerated with neutropenia, fatigue and diarrhea as most
common adverse events
• 1 complete response, 2 partial response, 5 SD > 1 year
Leonard, et al Blood 2012
Phase I study of PD 0332991 + bortezomib in patients
with recurrent MCL
Biopsy
★
★
pG1
★
pG1-S
Martin, Di Liberto, Leonard, et al, unpublished
Phase I study of PD 0332991 + bortezomib
in patients with recurrent MCL
% change in tumor size (by patient)
Martin, Leonard, unpublished
Inhibition of CDK4/6 induces early G1 arrest in
MCL cells of both responders and non-responders
initially.
Can we identify genes that
differentiate sensitivity from
resistance to targeting CDK4 in
combination with bortezomib?
M. Di Liberto, D. Chiron, C. Mason,
P. Martin, J. Leonard, S. Ely, unpublished
Prolonged early G1 arrest (pG1) Hypothesis
Go
Cyclin D + CDK4/6
M
G1
G2
PD 0332991
pS-Rb
S
Prolonged inhibition of CDK4/6
Prolonged early G1 arrest (pG1)
Expression of only genes programmed for early G1
Sensitizing tumor cells to cytotoxic killing
Longitudinal Integrative analysis of whole
exome-sequencing (WES) and whole
transcriptome-sequencing (WTS) of serial
biopsies, using cheek swab as a control.
Integrative WES and WTS analysis
Lymph node biopsy
CD5+CD19+ isolation
WES (50ng DNA)
CNV
SNVs
WTS (100-100ng RNA)
mRNA abundance
Alternative
splicing
Only 1% of the genes that were repressed in (pG1, day 8) in
clinically responding patients (R) were up-regulated in pG1 nonresponding patients (NR).
Candidate biomarkers for the PD 0332991-bortezomib therapy?
Differential regulated genes
• Glucose homeostasis
• Redox homeostasis
• Cell migration
Chiron, Di Liberto, Mason, Martin, et al,
unpublished
Targeting CDK4 in combination with bortezomib in MCL
• At the optimal PD 0332991 concentration and reduced bortzomib
1 CR, 1 PR, 2 near PR (43% reduction), 1 SD, 1 PD.
• Inhibition of CDK4 induces early G1 arrest that controls
cell cycle gene expression in all MCL patients initially.
• MCL cells express CDK4 but not CDK6, cyclin D1 but not D2 or D3
• CDK4 is a stable target- no mutation in CDK4 detected
• A small number of genes are oppositely regulated in pG1
(day 8 vs day 0) in responders vs non-responders – candidate
biomarkers for targeting CDK4 in combination with bortezomib.
Glucose homeostasis
Redox homeostasis
Cell migration
pG1 reprogramming MCL cells for ibrutinib inhibition of
Bruton Tyrosine Kinase (BTK)
Ibrutinib is effective in MCL. However, relapse is frequent and
associated with aggressive proliferation and poor prognosis
Relapse-specific C481S mutation in BTK in MCL
--Longitudinal integrative WES and WTS analysis
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
Relapse-specific C481S mutation in BTK in MCL
--Longitudinal integrative WES and WTS analysis
BTK C481S mutation undetected before Ibrutinib relapse
At least two mechanisms of Ibrutinib relapse -
• BTKC481S mutation is detected in durable ibrutinib response
(>14 or 30 months, 2/2.
• However, BTKC481S mutation is absent in transient ibrutinib response
(< 5months) or primary resistance (6/6)
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
• BTK is inactivated by ibrutinib in MCL cells of both
sensitive and resistant patients in vivo
• PI3K-AKT is activated in ibrutinib resistance
BTK
Sensistive Resistant
BTKC481S
Sensitive Relapse
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
Induction of pG1 by CDK4 inhibition reprograms MCL cells
for killing by ibrutinib via inhibition of BTK and AKT
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
pG1 inhibits NF-kB activation in BCR signaling
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
Overriding ibrutinib resistance by cell cycle reprogramming
• Integrative WES/WTS identified a BTK481S mutation at relapse
from ibrutinib after a durable response in MCL
• BTK481S mutation is absent in transient ibrutinib response or
primary resistance, suggesting addition mechanisms for resistance.
• BTK and AKT are concurrently activated in ibrutinib resistance.
• Ibrutinib inactivates BTK in MCL cells of resistant patients.
• Enhanced proliferation of MCL cells at relapse
• pG1 sensitizes resistant MCL cells to Ibrutinib killing via cooperative
inactivate BTK and AKT, and inactivation of NF-kB.
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
pG1 reprogramming of MCL cells for PI3K inhibition
regardless of C481S BTK mutation
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
pG1 reprograms MCL cells for PI3K inhibitor killing
PI3Kd inhibitor
GS-1101
(idelalisib)
D. Chiron, M. Di Liberto, et al, Cell Cycle, 2013
Induction of pG1 sustains the inactivation of AKT by
PI3Kd inhibitor in MCL cells
D. Chiron, M. Di Liberto, et al, Cell Cycle, 2013
pG1 reprogramming for PI3K inhibition eradicates
ibrutinib-resistant lymphoma cells independent of BTK
mutation
Cell death
Live cells
Chiron, Di Liberto, Martin et al, Cancer Discovery, 2014
pG1 reprogramming of MCL cells for PI3K inhibition
independent of C481S BTK mutation in MCL
Future Directions• Mechanism of pG1 sensitization
Cancer metabolism
• Mechanism-based combination therapy for MCL
Targeting CDK4 with PD 0332991(palbociclib) in
combination with ibrutinib
Targeting CDK4 in combination with PI3K inhibitor
• Mechanism of resistance
• Identification of biomarkers via longitudinal integrative
WES/WTS and targeted sequencing
The Team
Maurizio Di Liberto Xiangao Huang
David Chiron
David Jayabalan
Selina Chen-Kiang
John Leonard
Peter Martin
Adriana Rossi
Ruben Niesvizky
Tomer Mark
Lewis Cantley
Chris Mason
Olivier Elemento
Jihye Paik
Scott Ely
Steve Gross
Tim McGraw
Jeff Sharman
Patients
NIH/NCI
V Foundation
Lymphoma Research Foundation
Leukemia and Lymphoma Society
Starr Cancer Consortium