Download Preliminary Results of a Proof-of-Concept Trial of

PRELIMINARY RESULTS OF A PROOF-OF-CONCEPT TRIAL OF INTRATUMORAL
ADMINISTRATION OF G100 (GLUCOPYRANOSYL LIPID A IN STABLE EMULSION, GLA-SE), A
TOLL-LIKE RECEPTOR-4 (TLR-4) AGONIST, IN PATIENTS WITH MERKEL CELL CARCINOMA
Shailender Bhatia1, Dafina Ibrani1, Olga Afanasiev1, Natalie Vandeven1, Natalie Miller1, David Byrd1, Upendra Parvathaneni1, Michael
Donahue1, Frank J. Hsu2, Barry Storer1, David M. Koelle1, Paul Nghiem1
of Washington / Fred Hutchinson Cancer Research Center, Seattle, WA; 2Immune Design, Seattle, WA
RESULTS: Immune response
Merkel cell carcinoma (MCC) is a relatively rare, but often very aggressive
neuroendocrine skin cancer.
Investigational agent: G100 (GLA-SE,10ug/ml)
Trial design: 10 MCC pts will be enrolled to receive multiple IT injections
into a superficial injectable tumor. Pts with localized MCC (Cohort A) may
receive 1 cycle of G100 injections (on days 1, 8) followed by definitive
surgery and/or radiation therapy (RT) starting during week 4; pts with distant
metastatic disease (Cohort B) may receive multiple cycles of G100 injections
(days 1, 8, 22) every 6 weeks (up to 4 cycles, may be in conjunction with
RT). Serial tumor biopsies and peripheral blood samples will be collected in
all pts at baseline and post-treatment.
MCPyV serology: Prior studies have shown that MCPyV viral oncoprotein (T-Ag) titer
levels correlate with MCC disease burden. All 4 subjects had detectable MCPyV
antibodies in the blood. Antibody titer levels during the study are shown below (G100
injection timepoints indicated by red arrows).
Subject GLA-001
Subject GLA-002
50,000
45,000
40,000
35,000
30,000
Subject GLA-003
35000
6000
30000
5000
MCPyV Antibody Titer (stu)
METHODS
MCPyV Antibody Titer (stu)
BACKGROUND
MCPyV Antibody Titer (stu)
1University
25000
20000
15000
10000
5000
Primary Endpoints:
• Safety assessed by treatmentrelated adverse events
• Feasibility evaluated by
frequency of dose-interruptions,
treatment discontinuation,
unexpected delays in definitive
management
Screening Phase
• Age over 50
Clinical presentation. MCC typically presents as a rapidly growing red or
purple nodule on sun-exposed skin.
Treatment. Therapy usually includes surgery and radiation for earlier stages of
MCC and chemotherapy for advanced disease. There is an unmet need for
effective therapies. The role of immunotherapy in MCC needs to be explored
further, especially given the strong link of MCC to the immune system.
Merkel cell polyomavirus (MCPYV): Found in ~80% of MCC tumors.
Despite persistent expression of the non-self MCPyV proteins, MCC tumors are
able to evade the immune surveillance mechanisms through multiple
interrelated mechanisms:
1. Down-regulation of MHC class I expression
2. Strikingly sparse intratumoral infiltrates of T cells
3. Immune exhaustion of infiltrating T-lymphocytes (TIL).
Therapeutic immune modulation of the MCC tumor microenvironment
using intratumoral (IT) injections of G100 (GLA-SE), a synthetic TLR-4
agonist, may overcome these evasion mechanisms via immune
responses against the tumor antigens. In preclinical models, TLR4 agonists
have been shown to activate APCs and induce acute inflammatory responses
including production of chemokines and cytokines that mediate leukocyte
infiltration, stimulation of DC maturation and induction of adaptive immune
responses. G100 co-administered with viral antigens has been associated with
quantitative increases in antigen specific IgG and antigen specific gamma
interferon producing CD4+ and CD8+ T cells. This study uses an IT approach,
aimed at local activation of infiltrating APCs and release of cytokines in close
proximity to tumor cells.
Post-treatment tissue * Day 22 after
sample collection
injection
Local disease
Metastatic disease
(Cohort A)
(Cohort B)
Definitive
treatment
Repeat G100
treatment
Follow up phase
Follow up phase
1st
Secondary Endpoints:
• Local efficacy
• Systemic efficacy (response in
non-injected lesions, overall
response)
• Time to relapse or progression
and overall survival
• Immunologic effects:
- cellular immune activation
- HLA class I expression
- tumor-specific immune
responses
0
109
21
43
Day
Study
number
HLA type
GLA-001
A01 A30 B08
B18 Bw6 C05
C07
Post-tx IFNg
responses in
TIL
Pre-tx IFNg
responses in TIL
(to pools with ~20
viral peptides)
Tetramer
positivity?
(to pools with ~20
viral peptides)
1
(Pool 2)
*poor TIL growth
2
(Pool 1 and 2)
No available
tetramer
GLA-002
A02 A24 B15
B44 Bw4 Bw6
C05 C07
1
(Pool 2)
1
(Pool 2)
Yes.
A24-EWW (TIL,
PBMC) &
A02-KLL (TIL)
GLA-003
A03 A24 B07
B51 C07 C07
1
(Pool 2)
1
(Pool 2)
Yes.
A24-EWW (TIL)
GLA-004
A02 A26 B14
B38 C08 C12
1
(Pool 1)
2
(Pool 1 and 3)
No.
Day 0
Four patients have been enrolled to date (2 in each Cohort). Treatment has
been tolerated well with no grade 3/4 or serious adverse events (AEs).
Treatment-related AEs have all been grade 1 (injection-site reaction, pain and
bruising at the injection site), except transient grade 2 injection-site reaction at
the injected inguinal lymph node in patient 002 (in Cohort A), who interestingly
also had a pathologic complete remission of the involved node after only
two G100 injections. Both pts in Cohort A successfully completed definitive
GLA-002
therapy without any delays. Both pts in Cohort B successfully completed cycle
TIL
1, but had progressive disease at the first restaging evaluation.
Age
Sex
GLA-001
B
68
M
GLA-002
A
70
M
GLA-003
B
82
M
GLA-004
A
67
M
Pre-treatment biopsy (Day 0)
Race/
ethnicity
White/
non-Hispanic
Tetramer schematic
(A2-KLL- &
A24-EWW-tetramer neg.)
Post-treatment
Day 7
Day 24
Negative control
Day 46
White/
non-Hispanic
White/
non-Hispanic
White/
non-Hispanic
GLA-002
TIL
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Day 0
Pre-treatment
Post-treatment
Nearby node
7
24
PD1 expression
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Pre-tx
Post-tx
Nearby node
Pre-tx
Post-tx
Nearby node
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
CD8
DISCUSSION / CONCLUSIONS
Post-treatment biopsy (Day 24)
H&E
H&E
PD1 expression
CD8
Status
Progressive disease after
cycle 1
Completed treatment;
currently progressionfree and in surveillance
Progressive disease after
cycle 1
Completed treatment
and in surveillance
86
Viral peptide pools:
GLA-002
PBMC
Study
Study number
Cohort
65
Cellular immunity: Infiltrating CD8 T cells are known to correlate with improved survival.
MCPyV-specific CD8 T cells in the blood have also been shown to track with disease
burden, while upregulating immune checkpoint markers such as PD1. We have identified
MCPyV-specific CD8 T cells isolated from TIL and peripheral blood. Below are the
correlative immune studies tracking frequency and functional status of these cells.
Pre-treatment
RESULTS: clinical response
46
PD1 expression
(% tet-pos cells)
• Infection with Merkel cell
polyomavirus (MCPyV)
* IT G100 injections
on days 1, 8 (22)
24
Day
PD1 expression
(% tet-pos cells)
• Immune suppression
Treatment phase
7
A24-EWW tetramer
• Caucasian ethnicity
0
A02-KLL tetramer
• Ultraviolet Radiation
Pre-treatment biopsy
41
1000
A24-EWW tetramer
Etiology and Pathogenesis. Molecular pathogenesis has not been firmly
established, but risk factors include:
21
Day
2000
0
0
0
3000
PD1 expression
(% tet-pos cells)
Merkel cell
carcinoma diagnosis
25,000
4000
Preliminary results indicate that IT immunotherapy with G100 injections in MCC patients
is well tolerated. The inflammatory response in a G100-injected tumor was associated
with pathologic complete remission in one patient. MCPyV-specific CD8 T-cells without
any MCC cells were identified in a lymph node proximal to the injected tumor, suggesting
adaptive immune responses to cancer (viral) antigens.
FUTURE DIRECTIONS
CK20
CK20
This trial is still accruing patients and we are continuing to follow each cohort in terms of
clinical and immunological responses. Future studies could include assessment of tumorspecific T cell persistence, function and cytokine responses to viral peptides. It would be
interesting to explore the mechanisms of action of GLA in MCC tumors (such as
correlation of responses with certain TLR-4 polymorphisms). The protocol has been
amended to allow palliative RT in cycles 2 and beyond in Cohort B, which may increase
the effectiveness of the approach by the release of antigens from dead or apoptotic tumor.
REFERENCES
1. Lemos, B, Nghiem, P. Merkel cell carcinoma: more deaths but still no pathway to blame. J Invest Dermatol 127 (9), 2100 (2007)
2. Feng H, Shuda M, Chang Y, Moore PS. Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science. 2008 Feb 22;319(5866):1096-100
3. Carter JJ, Paulson KG, et al. Association of Merkel cell polyomavirus-specific antibodies with Merkel cell carcinoma. J Natl Cancer Inst. 2009
4. Shuda, M et al. Human Merkel cell polyomavirus infection I. Int J Cancer. 2009 Sep 15;125(6):1243-9.
5. *Iyer, *Afanasiev, McClurkan, Paulson, Nagase, Jing, Marshak, Dong, Carter, Lai, Farrar, Byrd, Galloway, Yee, Koelle, Nghiem. Merkel cell
polyomavirus-specific CD8+ and CD4+ T-cell responses identified in Merkel cell carcinomas and blood. Clin Cancer Res. Sep 2011
OBJECTIVES
This proof-of-concept trial (NCT02035657) is a single center study to test the safety,
clinical efficacy and immunologic effects of IT administration of G100 in MCC patients
(pts).
MCC present
MCC absent
ACKNOWLEDGEMENTS
*We graciously thank MCC patients and family members for their participation in our research studies.
*This work was supported by the Life Sciences Discovery Grant and CCSG grant
46