Abstracts for the 25th Annual Scientific Meeting of the International ...

J Immunother Volume 33, Number 8, October 2010
Abstracts
TABLE 1.
E75
E39
¾1 Stim ¾2 Stim ¾1 Stim ¾2 Stim
IFN-g
KLE 170 ± 55 165 ± 80 204 ± 58 126 ± 100
MEF 224 ± 82 153 ± 99 348 ± 87 235 ± 125
Granzyme
KLE 338 ± 228 220 ± 92 367 ± 181 146 ± 90
MEF 447 ± 250 142 ± 74 502 ± 218 202 ± 100
All results are spots/1 10 6 PBMCs.
IFN indicates interferon; PBMC, peripheral blood mononuclear cell.
Introduction: We conducted a pre-clinical study to assess the ability
of two HLA-A2 (A2) restricted peptides, E75 (Her2: aa369-377)
and E39 (FBP: aa191-199), to generate anti-tumor immune
responses in endometrial cancer (EnCa) patients. We measured
ex-vivo peptide-induced cytokine secretion and cytotoxic activity in
peripheral blood mononuclear cells (PBMC) from EnCa patients.
In addition, PMBC stimulated with peptide-loaded dendritic cells
(DC) were tested for their ability to elicit inflammatory and lytic
activity against EnCa cell lines expressing Her2/neu and FBP.
Methods: PBMC samples obtained from 16 EnCa patients were
tested for A2 expression. A2 positive samples were analyzed for
peptide-specific stimulation of IFN-g and granzyme secretion ex
vivo via the ELISPOT assay with subtracted negative controls. DC
(monocyte-derived using GM-CSF and IL4) pulsed with E75 or
E39 were used to stimulate PBMC cultures that were not (1 stim)
or were (2 stim) previously stimulated with E75 or E39 peptides.
These cultures were studied for IFN-g and granzyme secretion
against HLA-A2+ EnCa cell lines (KLE and MEF280) using the
ELISPOT assay with subtracted negative controls. Results are
reported at spots/1 106 PBMCs.
Results: Twelve of the sixteen (75%) EnCa patients were found to
be A2 positive. In ex-vivo ELISPOT assay the mean specific
response against E75 was 95 ± 42 spots for IFN and 43 ± 22 spots
for granzyme and against E39 was 28 ± 17 spots for IFN and 2 ± 2
spots for granzyme. PBMC cultures stimulated once or twice with
peptide-pulsed DC showed peptide-specific cytotoxic activity
against HLA-A2+ EnCa cells by IFN-g and granzyme (Table 1).
Conclusion: The peptides E75 and E39 are capable of inducing antitumor
specific immune responses in the PBMC of EnCa patients.
These peptides are being evaluated for use in vaccines in Phase I
clinical trials for endometrial cancer.
Artificial Neural Network (ANN) and Immune Monitoring
Analysis for Patients with Progressive Castration-Resistant
Prostate Cancer Undergoing Therapeutic Tumor Cell
Vaccination
Heike Pohla*w, Thomas H. Brillz, Alexander Buchner*, Hubert
R. Ku¨ blery, Birgit Stadlbauer*, Michael Osthoff*, Udo BaronJ,
Sven OlekJ, Tibor Schusterz, Bernd Eisele#, Falko Fend**,
Rudolf Hartungy, Dolores J. Schendelw, Bernd Gansbacherz.
*Laboratory of Tumor Immunology, LIFE Center, Ludwig-Maximilians
University; w Institute of Molecular Immunology and
Clinical Cooperation Group Immune Monitoring, Helmholtz Zentrum
München, German Research Center for Environmental Health;
zInstitute for Experimental Oncology and Therapeutic Research,
Technical University; yDepartment of Urology, Technical University;
zInstitute of Medical Statistics and Epidemiology; **Department of
Pathology, Technical University, Munich; JEpiontis GmbH, Berlin;
#VPM GmbH, Hannover, Germany.
Background: Prostate cancer has been historically regarded as a
non-immunogenic cancer but several clinical trials using different
vaccine strategies have induced anti-tumor immunity and moderate
response rates. Here, a clinical phase I trial was established to
determine the safety and efficacy of the allogeneic, gene-modified
LNCaP cell line, expressing recombinant IL-2 and IFN-g.
Methods: In a dose-escalating study patients (n = 30) were
scheduled to receive four intradermal injections bi-weekly and a
boost at day 92, and in the absence of disease progression every
3 months. Primary objectives were safety and toxicity, the
determination of the PSA doubling-time (PSA-DT), and secondary
objective was the immune monitoring together with ANN analysis.
Results: No dose-limiting or autoimmune toxicity was seen and
during vaccination there was a significant prolongation of the PSA-
DT (63 to 114 d, P50% decrease
in PSA versus baseline. By ELISPOT analysis an increase in
antigen-specific T cells of at least 2-fold was observed. As no
correlation could be drawn by simple comparison between PSA
course and immune monitoring data, ANN analysis in addition to
conventional statistical methods was performed. Patients were
devided into two groups, with group 1 (n = 12) showing a PSA
plateau for at least 12 weeks together with stable metastatic state
and group 2 (n = 18) showing a shorter or no PSA plateau. For
these two groups a significant difference in their reactivity against
survivin (P = 0.007) was observed after the third vaccination. In all
patients the frequency of natural regulatory T cells (Tregs) was the
same as in normal healthy persons.
Conclusion: In summary, our vaccination approach with an
allogeneic tumor vaccine can prolong the PSA-DT. The impact
of this type of vaccination on the survival of the patients must be
further studied.
Frequency of Circulating Regulatory T Cells and Tumor-
Specific Effector T Cells in Patients with Metastatic Renal
Cell Carcinoma Undergoing Therapeutic Tumor Cell Vaccination
Heike Pohla*w, Alexander Buchner*z, Bernhard Frankenbergerw,
Birgit Stadlbauer*, Udo Barony, Sven Oleky, Ronald FrankJ,
Alfons Hofstetter*, Ralph Obernederz, Antonio Pezzutto#,
Thomas Blankenstein**, Dolores J. Schendelw. *Laboratory of
Tumor Immunology, LIFE Center, Ludwig-Maximilians University;
w Institute of Molecular Immunology and Clinical Cooperation Group
Immune Monitoring, Helmholtz Zentrum München, German Research
Center for Environmental Health; zDepartment of Urology, Ludwig-
Maximilians University, Munich; yEpiontis GmbH; #Department of
Hematology, Oncology, and Tumor Immunology, Charite´-University
Medicine, Campus Virchow, Berlin; JDepartment of Chemical
Biology, Helmholtz Center for Infection Research, Braunschweig;
zUrological Clinic, Munich-Planegg; **Institute of Immunology,
Charite´-University Medicine, Berlin, Germany.
Background: New classes of angiogenesis inhibitors were applied
for patients with metastatic renal cell carcinoma (mRCC). Some
tumors show regression in imaging, but most patients develop
resistance over time. Therefore, there is still an important need for
therapeutic generic vaccines that could be applied to many patients.
For vaccine development we used a well-characterized allogeneic
gene-modified RCC-26 tumor cell line that showed strong
immunogenic potential in extensive preclinical studies through
expression of CD80 and IL-2.
Methods: The vaccine RCC-26/CD80/IL-2 was tested in a clinical
phase I trial to evaluate safety and feasibility with stage IV mRCC
patients matched for HLA-A*0201 allotype. Fifteen patients were
enrolled in this study and the vaccine was applied s.c./i.d. in
increasing doses of up to 40 mio. cells over 22 weeks.
Results: 50% of the progressing patients showed a stable disease for
time periods ranging from 23 to 187 weeks. Median time to
r 2010 Lippincott Williams & Wilkins www.immunotherapy-journal.com | 907