NcXHF

AHMAD A. TARHINI
addition, HDI regulated mitogen-activated protein kinase
(MAPK) signaling differentially in melanoma tumor cells
and host lymphoid cells. HDI signifıcantly downregulated
pSTAT3 (p 0.008) and phospho-MEK1/2 (p 0.008) levels
in tumor cells. Phospho-ERK1/2 was downregulated by
HDI in tumor cells (p 0.015) but not in lymphoid cells.
HDI downregulated epidermal growth factor receptor
(EGFR; p 0.013), but pSTAT3 activation did not appear
associated with EGFR expression and the MEK/ERK MAPK
pathway, which indicates that STAT3 activation is independent
of the EGFR/MEK/ERK signaling pathway. 34 Clinical responders
had signifıcantly greater increases in endotumoral CD11c
and CD3 cells and signifıcantly greater decreases in endotumoral
CD83 cells than nonresponders. 30
Neoadjuvant ipilimumab was tested in locoregionally advanced
melanoma to evaluate safety and to defıne markers of
activity and toxicity in the blood and tumor of patients at
baseline and early on-treatment times. 35 Patients were
treated with ipilimumab (10 mg/kg intravenously every 3
weeks for two doses) that bracketed surgery. Tumor and
blood samples were obtained at baseline and at the defınitive
surgery time. Thirty-fıve patients were enrolled; diseases
were stages IIIB (three patients; N2b), IIIC (32 patients; N2c,
N3), and IV (two patients). The worst toxicities included
grade 3 diarrhea/colitis (fıve patients; 14%), hepatitis (two
patients; 6%), rash (one patient; 3%), and elevated lipase
(three patients; 9%). The median follow-up was 19 months.
Among 33 evaluable patients, the preoperative radiologic assessment
by PET-CT scans at 6 to 8 weeks after the initiation
of ipilimumab revealed that three patients (9%) had objective
responses (two patients, complete response; one patient, partial
response). Twenty-one patients (64%) had stable disease,
and eight patients (24%) experienced disease progression
identifıed with PET-CT. [ 18 F]-fludeoxyglucose PET/CT parameters
at baseline (T0) and at the fırst scan after two doses
of ipilimumab (T1) were unable to predict recurrence after
surgery (at a signifıcance level of 0.05). 36 The number of lesions
at T1 showed a trend toward predicting a higher chance
of disease recurrence (p 0.06). The median recurrence-free
survival was 11 months (95% CI, 6.2 to 19.2 months). The
probability of 12-month overall survival was 96%. Based on
preliminary data from a study that tested HDI and tremelimumab
in patients with metastatic disease and on recent data
in the literature, we evaluated candidate biomarkers linked to
the proinflammatory immune response and markers of immunosuppression
as assessed in the tumor microenvironment
(TME) and in circulation that may have therapeutic
predictive roles in relation to immunotherapy for melanoma.
37 The underlying hypothesis was that our quest for a
predictive biomarker signature in patients with metastatic
melanoma who are treated with immunotherapy may be rewarded
by evaluating candidate biomarkers in the TME and
in circulation simultaneously, on the basis of the common
systems of biology. 38
Neoadjuvant ipilimumab leads to a signifıcant potentiation
of type I CD4 and CD8 tumor-specifıc T cells that may play a
therapeutic predictive role. 35 Here, multicolor flow cytometry
that used overlapping peptide pools (gp-100, MART-1,
NY-ESO-1) showed baseline evidence of spontaneous in vivo
cross-presentation that resulted in type I CD4 and CD8
antigen-specifıc T-cell immunity. 35 Ipilimumab induced a
signifıcant increase in type I CD4 and CD8 (fully activated
and IFN gamma–producing) antigen-specifıc T cells. Both
CD4 and CD8 T cells were activated (upregulated CD69)
on their stimulation with individual antigen peptide pools,
and a subset secreted IFN gamma. High increases (3- to 10-
fold) in CD3 /CD4 /IFN gamma T cells were seen only in
patients who were progression free at 6 months, which suggests
a potential early on-treatment therapeutic predictive
value. A signifıcant modulation of circulating regulatory T
cells (Treg) and myeloid-derived suppressor cells (MDSC)
also was seen. A signifıcant increase in the frequency of circulating
Treg (CD4 /CD25hi /Foxp3 [p 0.02] and
CD4 /CD25hi /CD39 [p 0.001]) from baseline to 6
weeks was observed. Signifıcant decreases in circulating
MDSC were seen. A decrease in the circulating monocyte
gate MDSC Lin1-/HLA-DR-/CD33 /CD11b was associated
with improved progression-free survival (PFS; p
0.03). Increases in Treg were associated with improved PFS
(hazard ratio 0.57; p 0.034). In the tumor, Treg (CD4 /
CD25hi , CD4 /CD25hi /Foxp3 ) appeared higher at
week 6 in the progressive-disease group but the opposite occurred
in the disease control group (p 0.09). Tumor samples
obtained at baseline and after ipilimumab were tested by
immunohistochemistry and showed signifıcant increases in
CD8 tumor-infıltrating lymphocytes after ipilimumab (p
0.02). By flow, trends were observed in examination of the
change in Treg and disease control (p 0.09). Treg were
higher at week 6 in the progressive-disease group, whereas
the opposite was seen in the disease control group. This was
unlike what we observed in the circulation. Ipilimumab also
induced T-cell activation, as evidenced by CD69 without in
vitro stimulation. There was evidence of induction/potentiation
of T-cell memory (CD45RO ) but not naive status
(CD45RO - ) in the tumor, which also supported further testing
as a predictive marker, as suggested from data by Galon et
al in colorectal tumors. 39 Gene expression profıling was performed
on the tumor biopsies and identifıed immune-related
genes that were signifıcantly differentially expressed on the
basis of clinical outcome. A baseline gene signature that resulted
from this analysis was signifıcantly associated with clinical benefıt
of neoadjuvant ipilimumab. 40 These data have laid the
groundwork for a series of subsequent studies that are evaluating
potentially therapeutically predictive biomarkers of a proinflammatory
immune response and of immunosuppression both
in the TME and in circulating blood in patients with melanoma
who are receiving immunotherapy.
Neoadjuvant Efforts Using Molecularly Targeted
Agents
Driver oncogenic mutations identifıed in melanoma have defıned
clinically relevant melanoma molecular subsets that
can be targeted therapeutically, leading to giant leaps in metastatic
melanoma management. 41,42 Signifıcant clinical activ-
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