Allogeneic Tumor Cells Research Articles

Phase Ib study of ipilimumab alone or in combination with allogeneic pancreatic tumor cells transfected with a GM-CSF gene (vaccine) in pancreatic cancer.

211 Background: Ipilimumab (IPI) at 3mg/kg has been tested in pancreatic ductal adenocarcinoma (PDA) with a low but detectable response rate. This supports a role for immunotherapy in PDA. Melanoma (MEL) studies demonstrate a dose-response relationship with IPI. Preclinical studies show synergy between anti-CTLA-4 antibodies and GM-CSF cell-based vaccines. This study evaluated IPI 10mg/kg alone (Arm 1) versus IPI 10mg/kg + vaccine (Arm 2) in PDA. Methods: 30 subjects with previously treated, locally advanced or metastatic PDA were randomized (1:1) to Arm 1 or 2. Induction treatments were administered every 3 weeks (wk) X 4 doses. Subjects with stable disease (SD) or better between wk 14 and 22 were eligible for maintenance doses every 12 wks. Activity was assessed by response and overall survival (OS). IFN-g Elispots and ELISAs were used to detect induction of mesothelin-specific T cells and galectin-3 antibodies (Abs), respectively. Results: Baseline characteristics were similar (87% metastatic, 100% gemcitabine-treated) with the exception that Arm 1 had a lower % of subjects with > 1 prior therapies (60 vs 100%). Arm 1 had 2 SD (7 and 22 wks). Arm 2 had 3 SD (1 delayed regression starting at wk 14 and maintained until wk 31, 1 delayed stabilization starting at wk 22 and ongoing at wk 57, 1 SD ongoing at wk 64). Transient CA19-9 declines were seen only in Arm 2 (7/15). Median OS was 3.3 vs 5.5 months in Arm 1 vs Arm 2 (p=0.12) with a 12 month OS of 7 vs 27%. 73% (Arm 1) and 80% (Arm 2) of subjects experienced immune related adverse events (IRAE). 20% of subjects on both arms had Grade 3-4 IRAEs including rash (1), colitis (2), Guillain-Barre (1), nephritis (1), and pneumonitis (1). Rash was less frequent in Arm 1 (53 vs 73%). IRAEs (p=0.037), mesothelin T cell responses (p=0.012), and enhancement of the T cell repertoire (p=0.026) were associated with OS in both arms. Galectin-3 Ab responses were associated with OS in Arm 2 (p=0.002). Conclusions: Immunotherapy has potential even in advanced PDA. IRAEs in PDA are similar to IRAEs in MEL. Delayed responses suggest that standard RECIST criteria will underestimate activity and targeting a population with a longer life expectancy may improve efficacy.

Ex vivo expansion of tumor-infiltrating lymphocytes from nasopharyngeal carcinoma patients for adoptive immunotherapy

Establishing Epstein-Barr virus (EBV)-specific cytolytic T lymphocytes (EBV-CTLs) from peripheral blood mononuclear cells (PBMCs) for adoptive immunotherapy has been reported in EBV-associated malignancies including Hodgkin's lymphoma and nasopharyngeal carcinoma (NPC). In the current study, we performed ex vivo expansion of tumor-infiltrating lymphocytes (TILs) obtained from NPC biopsy specimens with a rapid expansion protocol using anti-CD3 monoclonal antibody (OKT3), recombinant human interleukin (IL)-2, and irradiated PBMCs from healthy donors to initiate the growth of TILs. Young TIL cultures comprised of more than 90% of CD3+ T cells, a variable percentage of CD3+CD8+ and CD3+ CD4+ T cells, and less than 10% of CD3−CD16+ natural killer cells, a similar phenotype of EBV-CTL cultures from PBMCs. Interestingly, TIL cultures secreted high levels of the Th1 cytokines, interferon gamma (IFNγ) and tumor necrosis factor-alpha (TNF-α), and low levels of the Th2 cytokines, IL-4 and IL-10. Moreover, young TILs could recognize autologous EBV-transformed B lymphoblast cell lines, but not autologous EBV-negative blast cells or allogeneic EBV-negative tumor cells. Taken together, these data suggest that ex vivo expansion of TILs from NPC biopsy tissue is an appealing alternative method to establish T cell-based immunotherapy for NPC.

TCL1: A Shared Tumor-Associated Antigen for Immunotherapy Against B-Cell Lymphomas

Abstract 105Rituximab-based chemotherapy regimens have improved complete response rates, progression-free survival, and overall survival of B-cell non-Hodgkin lymphoma patients. However, most patients relapse and die of their lymphoma. To further improve clinical outcome, novel strategies that eradicate minimal residual disease (MRD) after induction therapy are needed. Therapeutic vaccines may induce antitumor antibody and T-cell responses and may eradicate MRD by complementary mechanisms. A recent randomized phase III clinical trial showed that patient-specific idiotype vaccination improves disease-free survival when administered in the setting of MRD in follicular lymphoma (FL), providing proof of principle that therapeutic vaccines can improve clinical outcome (Schuster et al, J Clin Oncol, 2011). However, generation of a custom-made vaccine formulation for each patient can be expensive and time consuming. To overcome these difficulties, identification of novel shared lymphoma-associated antigens is necessary.The T-cell leukemia/lymphoma 1 (TCL1) oncoprotein encoded by the TCL1 gene is a co-activator of Akt and promotes cell proliferation and survival. Ectopic expression of TCL1 in B cells in transgenic mice results in the development of B-cell malignancies and TCL1 was reported to be aberrantly expressed in multiple human B cell malignancies. Here, we determined whether TCL1 can serve as a novel shared tumor-associated antigen in B cell lymphomas. We analyzed the expression pattern of TCL1 in human B cell lymphomas and normal tissues by real-time PCR, flow cytometry, immunohistochemistry, and Western blotting. TCL1 mRNA transcripts were hyperexpressed in multiple types of primary B cell lymphomas [chronic lymphocytic leukemia (CLL), n=7; mantle cell lymphoma (MCL), n=6; FL, n=12, diffuse large B-cell lymphoma (DLBCL), n=5] as compared with B cells derived from normal donors. TCL1 mRNA was not detected in other normal tissues that included T cells, adipose tissue, esophagus, ovary, spleen, bladder, heart, placenta, brain, kidney, prostate, liver, muscle, thyroid, colon, lung, intestine, trachea, thymus, and cervix. Very low TCL1 mRNA was detected in testis. By flow cytometry, immunohistochemistry, and/or Western blotting we observed that the TCL1 protein is hyperexpressed in CLL, MCL, DLBCL, Burkitts lymphoma, and FL, but not splenic marginal zone lymphoma. To determine whether TCL1 is immunogenic, we synthesized overlapping 15-mer peptides spanning the entire length of the TCL1 protein and stimulated PBMC from HLA-A*0201+ (HLA-A2+) normal donors to generate peptide-specific T cells. We found that TCL165–79 peptide (TQIGPSLLPIMWQLY) consistently induced T cells that secreted significant amount of IFN-γ from 3 normal donors. By intracellular cytokine assay, we determined that the TCL165–79 peptide-specific IFN-g was produced by CD8+ T cells but not CD4+ T cells. Using a panel of peptide-pulsed EBV-transformed B-cell lines that were mismatched at the MHC Class I locus and MHC Class I blocking antibodies, we determined that HLA-A2 is the restriction element of the TCL165–79 peptide-specific T cells. Consistent with this, TCL165–79 peptide-specific CD8+ T cells lysed TCL1 expressing HLA-A2+ MCL cell lines but did not lyse, TCL1 expressing HLA-A2− myeloma cell line. Using a panel of peptides truncated progressively by one amino acid at the N- and C-termini of the TCL165–79peptide, we determined that TCL171–78(LLPIMWQL) is the minimal epitope that bound to HLA-A2. Furthermore, cytotoxic T lymphocytes (CTL) specific to this peptide efficiently killed lymphoma cell lines and primary lymphoma cells from CLL, MCL, DLBCL, and FL in an HLA-A2-restricted manner. Using TCL171–78 peptide-specific HLA-A2 tetramers, we found that TCL1 epitope-specific CTLs were present in the peripheral blood and/or tumor-infiltrating lymphocytes of B-cell lymphoma patients (n=8). More importantly, these TCL1 epitope-specific CTLs could be expanded in vitro and lysed autologous and allogeneic tumor cells in an HLA-A2-restricted manner. In conclusion, our results suggest that TCL1 is naturally processed and presented on the surface of primary lymphoma cells for recognition by CTL and can serve as a novel, shared tumor-associated antigen for therapeutic vaccine development against common B-cell lymphomas including CLL, MCL, DLBCL, and FL. Disclosures:Neelapu:Biovest International, Inc.: Research Funding.

Semiallogenic fusions of MSI+tumor cells and activated B cells induce MSI-specific T cell responses

BackgroundVarious strategies have been developed to transfer tumor-specific antigens into antigen presenting cells in order to induce cytotoxic T cell responses against tumor cells. One approach uses cellular vaccines based on fusions of autologous antigen presenting cells and allogeneic tumor cells. The fusion cells combine antigenicity of the tumor cell with optimal immunostimulatory capacity of the antigen presenting cells.Microsatellite instability caused by mutational inactivation of DNA mismatch repair genes results in translational frameshifts when affecting coding regions. It has been shown by us and others that these mutant proteins lead to the presentation of immunogenic frameshift peptides that are - in principle - recognized by a multiplicity of effector T cells.MethodsWe chose microsatellite instability-induced frameshift antigens as ideal to test for induction of tumor specific T cell responses by semiallogenic fusions of microsatellite instable carcinoma cells with CD40-activated B cells. Two fusion clones of HCT116 with activated B cells were selected for stimulation of T cells autologous to the B cell fusion partner. Outgrowing T cells were phenotyped and tested in functional assays.ResultsThe fusion clones expressed frameshift antigens as well as high amounts of MHC and costimulatory molecules. Autologous T cells stimulated with these fusions were predominantly CD4+, activated, and reacted specifically against the fusion clones and also against the tumor cell fusion partner. Interestingly, a response toward 6 frameshift-derived peptides (of 14 tested) could be observed.ConclusionCellular fusions of MSI+ carcinoma cells and activated B cells combine the antigen-presenting capacity of the B cell with the antigenic repertoire of the carcinoma cell. They present frameshift-derived peptides and can induce specific and fully functional T cells recognizing not only fusion cells but also the carcinoma cells. These hybrid cells may have great potential for cellular immunotherapy and this approach should be further analyzed in preclinical as well as clinical trials. Moreover, this is the first report on the induction of frameshift-specific T cell responses without the use of synthetic peptides.

Lung Cancer Vaccines

To date, in lung cancer, early attempts to modulate the immune system via vaccine-based therapeutics have been unsuccessful. An improved understanding of tumor immunology has facilitated the production of more sophisticated lung cancer vaccines. It is anticipated that it will likely require multiple epitopes of a diverse set of genes restricted to multiple haplotypes to generate a truly effective vaccine that is able to overcome the various immunologic escape mechanisms that tumors employ. Other issues to overcome include optimal patient selection, which adjuvant agent to use, and how to adequately monitor for an immunologic response. This review discusses the most promising vaccination strategies for non-small cell lung cancer including the allogeneic tumor cell vaccine belagenpumatucel-L, which is a mixture of 4 allogeneic non-small cell lung cancer cell lines genetically modified to secrete an antisense oligonucleotide to transforming growth factor β2 and 3 other target protein-specific vaccines designed to induce responses against melanoma-associated antigen A3, mucin 1, and epidermal growth factor.

82. A Phase 1-2 Clinical Study of MGN1601, a Tumor Vaccine Comprising Allogeneic, Gene-Modified and Irradiated Tumor Cells in Combination with an Immunomodulator, in Patients with Metastatic Renal Cell Carcinoma (ASET Study) – Preliminary Results

82. A Phase 1-2 Clinical Study of MGN1601, a Tumor Vaccine Comprising Allogeneic, Gene-Modified and Irradiated Tumor Cells in Combination with an Immunomodulator, in Patients with Metastatic Renal Cell Carcinoma (ASET Study) – Preliminary Results

Macrophage activation through phagocytosis of muramyl dipeptide encapsulated in gelatin microspheres.

Gelatin microspheres containing muramyl dipeptide (MDP) were prepared by crosslinking with glutaraldehyde. They were added to mouse peritoneal macrophages (PMs) to potentiate the tumour growth inhibitory activity. The PMs which had internalized the microspheres exhibited growth inhibitory activity to syngeneic, allogeneic, and xenogeneic tumour cells. A similar effect was observed for PMs incubated with free MDP, but the MDP encapsulated in the microspheres was more efficient in enhancing the PM activity than the free MDP. In addition, PMs were activated in much shorter periods upon incubation with the microsphere-encapsulated MDP. The duration of activity could be controlled for up to 7 days by changing the extent of crosslinking of microspheres. Dose-response experiments established that microsphere-encapsulated MDP is able to activate PMs to inhibit growth of tumour cells at concentrations approximately 2000 times lower than the free MDP present in media. The activity of PMs was also acquired on intraperitoneal injection of the microspheres, in contrast to PMs with the free MDP.

Preliminary safety results of an ongoing phase I/II clinical study of MGN1601, a tumor vaccine comprising allogeneic, gene-modified, and irradiated tumor cells in combination with an immunomodulator in patients with metastatic renal cell carcinoma (ASET study).

392 Background: MGN1601 is a cell-based RCC tumor vaccine MGN1601 consisting of two active pharmaceutical ingredients: genetically modified allogeneic (human) cells transfected with four different MIDGE vectors encoding IL-7, GM-CSF, CD80 and CD154 and a synthetic DNA-based immunomodulator dSLIM-30L1, a TLR-9 agonist. The vaccine is being developed for treatment of patients with advanced RCC. Its prophylactic and therapeutic anti-tumor activity has been shown in several in-vivo models. A good safety profile of MGN1601 was shown in a wide program of acute and chronic toxicity studies. Based on these promising data, this phase 1/2 study was started in patients with advanced RCC. Methods: This multicentric open clinical study for the assessment of safety and efficacy of MGN1601 in patients with advanced RCC was initiated in October 2010. A total of 24 patients have to be recruited into the study. The treatment consists of 8 MGN1601 treatments administered as follows: the first 3 treatments are administered on a weekly basis, and the consecutive 5 treatments on a bi-weekly basis. The treatment dose contains 107 transfected tumor cells and 5 mg dSLIM per administration, which has been proven to be safe with a high safety margin in repeated toxicity studies. The efficacy and safety of the study treatment will be evaluated based on extensive immunological tests, radiological assessment, safety laboratory results and assessments of the quality of life. Here, the first safety data are presented. [Table: see text]

NK cell-based immunotherapy for treating cancer: will it be promising?

The characterization of natural killer (NK) cells initially occurred in the 1970s and 1980s as a result of efforts by investigators such as Rolf Kiessling and Ronald Heberman. It was observed that a certain population of cells, freshly isolated from normal, unimmunized hosts, could lyse allogeneic tumor cells without sensitization. At the time, these cells were just considered to be a population of non-T, non-B lymphocytes. After the introduction of modern technologies such as monoclonal antibody (mAb) production technology and flow cytometry, the population has been identified as NK cells, phenotypically defined as CD56+ CD3-. Nowadays, it is well known that NK cells have a role as killer cells as well as immunoregulatory cells secreting cytokines and chemokines. Contrary to traditional views, NK cells have recently been shown to require a process called licensing or education to acquire full function by recognition of self-MHC class I during maturation. NK cells are derived from CD34+ hematopoietic progenitor cells and have the morphology of large granular lymphocytes. They can directly kill target cells via the perforin-granzyme pathway, antibody-dependent cellular cytotoxicity (ADCC), and death receptor ligand-induced apoptosis. Such ligands include tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas ligand. Human NK cells can be classified into two subsets; CD56dim (90%) and CD56bright (10%). The CD56dim subset has high cytotoxic activity and expresses a low-affinity receptor for the constant region of immunoglobulin G, FcγRIIIa (CD16), while the CD56bright subset has the capacity to produce abundant cytokines.

Allogeneic gene-modified tumor cells (RCC-26/IL-7/CD80) as a vaccine in patients with metastatic renal cell cancer: a clinical phase-I study

Despite novel targeted agents, prognosis of metastatic renal cell cancer (RCC) remains poor, and experimental therapeutic strategies are warranted. Transfection of tumor cells with co-stimulatory molecules and/or cytokines is able to increase immunogenicity. Therefore, in our clinical study, 10 human leukocyte antigen (HLA)-A(*)0201(+) patients with histologically-confirmed progressive metastatic clear cell RCC were immunized repetitively over 22 weeks with 2.5-40 × 10(6) interleukin (IL)-7/CD80 cotransfected allogeneic HLA-A(*)0201(+) tumor cells (RCC26/IL-7/CD80). Endpoints of the study were feasibility, safety, immunological and clinical responses. Vaccination was feasible and safe. In all, 50% of the patients showed stable disease throughout the study; the median time to progression was 18 weeks. However, vaccination with allogeneic RCC26/IL-7/CD80 tumor cells was not able to induce TH1-polarized immune responses. A TH2 cytokine profile with increasing amounts of antigen-specific IL-10 secretion was observed in most of the responding patients. Interferon-γ secretion by patient lymphocytes upon antigen-specific and non-specific stimulation was substantially impaired, both before and during vaccination, as compared with healthy controls. This is possibly due to profound tumor-induced immunosuppression, which may prevent induction of antitumor immune responses by the gene-modified vaccine. Vaccination in minimal residual disease with concurrent depletion of regulatory cells might be one strategy to overcome this limitation.

Ex-vivo expanded human NK cells express activating receptors that mediate cytotoxicity of allogeneic and autologous cancer cell lines by direct recognition and antibody directed cellular cytotoxicity

BackgroundThe possibility that autologous NK cells could serve as an effective treatment modality for solid tumors has long been considered. However, implementation is hampered by (i) the small number of NK cells in peripheral blood, (ii) the difficulties associated with large-scale production of GMP compliant cytolytic NK cells, (iii) the need to activate the NK cells in order to induce NK cell mediated killing and (iv) the constraints imposed by autologous inhibitory receptor-ligand interactions. To address these issues, we determined (i) if large numbers of NK cells could be expanded from PBMC and GMP compliant cell fractions derived by elutriation, (ii) their ability to kill allogeneic and autologous tumor targets by direct cytotoxitiy and by antibody-mediated cellular cytotoxicity and (iii) defined NK cell specific receptor-ligand interactions that mediate tumor target cell killing.MethodsHuman NK cells were expanded during 14 days. Expansion efficiency, NK receptor repertoire before and after expansion, expression of NK specific ligands, cytolytic activity against allogeneic and autologous tumor targets, with and without the addition of chimeric EGFR monoclonal antibody, were investigated.ResultsCell expansion shifted the NK cell receptor repertoire towards activation and resulted in cytotoxicity against various allogeneic tumor cell lines and autologous gastric cancer cells, while sparing normal PBMC. Blocking studies confirmed that autologous cytotoxicity is established through multiple activating receptor-ligand interactions. Importantly, expanded NK cells also mediated ADCC in an autologous and allogeneic setting by antibodies that are currently being used to treat patients with select solid tumors.ConclusionThese data demonstrate that large numbers of cytolytic NK cells can be generated from PBMC and lymphocyte-enriched fractions obtained by GMP compliant counter current elutriation from PBMC, establishing the preclinical evidence necessary to support clinical trials utilizing autologous expanded NK cells, both directly and in combination with monoclonal antibodies in future cell-based immunotherapy in select solid tumors.

Harnessing Naturally Occurring Tumor Immunity: A Clinical Vaccine Trial in Prostate Cancer

BackgroundStudies of patients with paraneoplastic neurologic disorders (PND) have revealed that apoptotic tumor serves as a potential potent trigger for the initiation of naturally occurring tumor immunity. The purpose of this study was to assess the feasibility, safety, and immunogenicity of an apoptotic tumor-autologous dendritic cell (DC) vaccine.Methods and FindingsWe have modeled PND tumor immunity in a clinical trial in which apoptotic allogeneic prostate tumor cells were used to generate an apoptotic tumor-autologous dendritic cell vaccine. Twenty-four prostate cancer patients were immunized in a Phase I, randomized, single-blind, placebo-controlled study to assess the safety and immunogenicity of this vaccine. Vaccinations were safe and well tolerated. Importantly, we also found that the vaccine was immunogenic, inducing delayed type hypersensitivity (DTH) responses and CD4+ and CD8+ T cell proliferation, with no effect on FoxP3+ regulatory T cells. A statistically significant increase in T cell proliferation responses to prostate tumor cells in vitro (p = 0.002), decrease in prostate specific antigen (PSA) slope (p = 0.016), and a two-fold increase in PSA doubling time (p = 0.003) were identified when we compared data before and after vaccination.ConclusionsAn apoptotic cancer cell vaccine modeled on naturally occurring tumor immune responses in PND patients provides a safe and immunogenic tumor vaccine. (ClinicalTrials.gov number NCT00289341).Trial RegistrationClinicalTrials.gov NCT00289341

Type‐1 polarized dendritic cells loaded with apoptotic prostate cancer cells are potent inducers of CD8+ T cells against prostate cancer cells and defined prostate cancer‐specific epitopes

In order to develop improved vaccines for patients with recurrent prostate cancer (PCa), we tested the feasibility of using type-1 polarized dendritic cells (αDC1s) to cross-present antigens from allogeneic PCa cells and to induce functional CD8(+) T cell responses against PCa cells and against defined MHC class I-restricted PCa-relevant epitopes. Monocyte-derived DCs from PCa patients were matured using the "standard" cytokine cocktail (IL-1β/TNFα/IL-6/PGE₂) or using the αDC1-polarizing cocktail (IL-1β/TNFα/IFNα/IFNγ/poly-I:C), loaded with UV-irradiated LNCaP cells, and used to sensitize autologous CD8(+) T cells. αDC1s from PCa patients secreted 10-30 times higher levels of IL-12p70 than sDCs. Importantly this elevated capacity for IL-12p70 secretion was not inhibited by loading with apoptotic tumor cells. Compared to standard DCs, αDC1s induced higher numbers of CD8(+) T cells capable of recognizing both the original PCa cells as well as another PCa cell line, DU145, in MHC class I-restricted fashion. Furthermore, αDC1s induced higher numbers of CD8(+) T cells recognizing defined PCa-specific class I-restricted peptide epitopes of prostate-specific antigen and prostatic acid phosphatase: PAP(135-143) (average 49-fold higher), PAP(112-120) (average 24-fold), PSA(141-150) (average 5.5-fold), and PSA(146-154) (average 11-fold). Type-1 polarization of GM-CSF/IL-4-generated DCs enhances their ability to present allogeneic tumor cells and to induce CD8(+) T cells recognizing different PCa cells and multiple defined PCa-specific epitopes. These observations help to develop improved immunotherapies of PCa for patients with different HLA types and lacking autologous tumor material.

When do I (not) release cellular products?

Harvest, production, storage and release of cellular products are regulated by international guidelines like the EU guidelines 2004/23/EC or 2006/17/EC. In addition, worldwide effective guidelines exist with the FACT‐JACIE standards. As cellular products such as haematopoietic progenitor cells (HPC) are usually applied to critically ill patients requirements for release must be well defined and high.The determination of criteria for release requires a prior definition of specifications of parameters for the product. Such specifications and the question of product release with parameters out of specification will be addressed here exemplarily for autologous and allogeneic HPC grafts.The harvest of cellular products must be preceded by an examination of the healthy donor or in case of an autologous transplantation of the patient. Apart from the medical history and the clinical condition of the donor, results of the testing of infectious disease markers (IDM) (HCV, HBV, HIV1,2 and syphilis at the minimum) are decisive for the judgment on the donor’s eligibility for donation. In case of an autologous donor, even positive test results for the IDM do not necessarily exclude a donation. After harvest and processing of the cellular product, the processing records must be complete and parameters like the content of the active pharmaceutical ingredient, i.e. CD34+ cells for HPC grafts, the content of possible cellular contaminants such as CD3+ cells in the allogeneic setting or tumour cells in the autologous setting, are relevant and need to be specified. For CD34+ cells, a minimum amount of 2 × 106 cells/kg of body weight for autologous or 4 × 106 cells/kg of body weight for allogeneic grafts is required. This may sometimes only be achieved by more than one harvest. Regarding CD34+ cells, the quality of the cells defined by viability and optional by analysis of clonogenic growth has to be evaluated. Such parameters need to be measured especially after manipulations such as cryopreservation or selection or depletion procedures. In addition, microbial contaminations, i.e. potential contaminations by aerobe or anaerobe bacteria or fungi for HPC products, have to be detected. Cellular grafts undergoing incubation steps need to be examined for contaminations by mycoplasma or viruses in addition. Furthermore, incubation or activation steps of cellular products require examinations regarding functionality, genomic stability and potential malignant transformation of the cultivated cells.The final decision to release a cellular product in case of parameters being out of the specifications should be guided by the consideration that benefits outweigh potential risks for the recipient when administering the product. Furthermore, the type of the product, HPC or other product like donor lymphocyte infusions, and its importance in a given medical situation of the patient, the documented urgent medical need, will influence the decision of release.

Erratum: The cancer vaccine roller coaster

Nat. Biotechnol. 27, 129–139 (2009); published online 7 February 2009; corrected after print 7 June 2010 In the version of this article initially published, the Mologen product description in Table 5, page 139, was incomplete and its status incorrectly stated to be compassionate use in India. The product description should have read: Genetically modified allogeneic (human) tumor cells for the expression of IL-7, GM-CSF, CD80 and CD154, in fixed combination with a DNA-based double stem loop immunomodulator (dSLIM).

Safety data of MGN1601, a tumor vaccine, made of allogeneic, transfected, and irradiated tumor cells in combination with an immunomodulator for the treatment of metastatic renal cell carcinoma.

e15104 Background: The cell-based tumor vaccine MGN1601 for the treatment of renal cell carcinoma (RCC), consists of two active pharmaceutical ingredients: First, genetically modified allogeneic (h...

Preclinical efficacy data of MGN1601, a tumor vaccine comprising 4-fold gene-modified and irradiated allogeneic tumor cells in combination with a DNA-based immunomodulator for the treatment of metastatic renal carcinoma.

e15067 Background: MGN1601 is a cell-based tumor vaccine for the treatment of mRCC. MGN1601 consists of two active pharmaceutical ingredients. One consists of allogeneic, human tumor cells, derived from RCC tissue, and transfected in-vitro with four different MIDGE vectors for transient expression of human IL-7, GM-CSF, CD80 and CD154. The other ingredient is the DNA-based immunomodulator dSLIM-30L1, mainly a TLR-9 agonist. Methods: Murine tumor models were used to evaluate the efficacy of a murine homologue of MGN1601 (mMGN1601). mMGN1601 was set up from Renca cells and transfected with 4 different MIDGE vectors for transient expression of mouse IL-7, GM-CSF, CD80 and CD154. For tumor inoculation in syngenic BALB/c mice Renca cells were used. For efficacy of the vaccine in a prophylactic setting, mice were vaccinated with mMGN1601 and thereafter challenged with Renca cells. In therapeutic settings Balb/c mice first received naïve Renca cells and were subsequently vaccinated four times with different test items, either the complete mMGN1601 or one out of three lacking different components. To address the mode of action, modulations of the immune system were monitored in NMRI mice (allogeneic setting). Results: Prophylactic setting: None of the vaccinated mice showed tumor growth, whereas all of the tumor-bearing mice of the control group died due to the tumor growth. Efficacy evaluation in the therapeutic setting revealed, that the complete tumor vaccine clearly achieved the most pronounced effects in tumor reduction, showing a survival of 92%, compared to 25% survival in the control group. The incomplete derivatives led to less pronounced therapeutic efficacy. The immunomodulatory effects of mMGN1601 in allogeneic NMRI mice generated a more than 3-fold increase of the cytotoxic activity of spleen cells, an augmented T-cell proliferation (> 6-fold) and an increase of CD4+, CD8+ and CD86+ cells at the site of vaccination (up to 20-fold). Conclusions: The murine homologue of MGN1601 showed excellent antitumor efficacy and significant pharmacological effects in murine models. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration MOLOGEN AG MOLOGEN AG MOLOGEN AG

Current status of immunological therapies for prostate cancer.

Considerable progress has been made in prostate cancer immunotherapy over the last year, and two agents have completed phase III testing. This review will discuss the most promising immune-directed strategies in development for prostate cancer, outlining interventions that mitigate tumor-induced tolerance and highlighting several combination immunotherapy approaches. A pivotal phase III study using Sipuleucel-T, an autologous prostatic acid phosphatase (PAP)-loaded dendritic cell immunotherapy, in men with metastatic castration-resistant prostate cancer (CRPC) demonstrated a survival advantage over placebo. By contrast, two phase III studies of GVAX, an allogeneic tumor cell vaccine, in a similar patient population failed to show a survival benefit of GVAX or GVAX/docetaxel over standard docetaxel/prednisone. Other strategies currently in clinical development include the ProstVac poxviral vaccine, a PAP-encoding DNA vaccine, and immune checkpoint inhibitory approaches. Although Sipuleucel-T may receive FDA approval for patients with metastatic CRPC, challenges remain in identifying immunotherapy strategies that overcome immune tolerance, especially when disease burden is substantial. An emerging paradigm focuses on using immunotherapy together with checkpoint antagonists or in combination with conventional therapies in patients with early-stage disease. Such approaches are likely to yield optimal results, but must carefully be explored in well designed phase II studies before moving forward.

822. Preclinical Efficacy Data of MGN1601, a Tumor Vaccine Comprising 4-Fold Gene-Modified and Irradiated Allogeneic Tumor Cells in Combination with a DNA-Based Immunomodulator for the Treatment of Metastatic Renal Carcinoma

822. Preclinical Efficacy Data of MGN1601, a Tumor Vaccine Comprising 4-Fold Gene-Modified and Irradiated Allogeneic Tumor Cells in Combination with a DNA-Based Immunomodulator for the Treatment of Metastatic Renal Carcinoma

Abstract 1926: Adoptive γδ T cell transfer therapy for non-small cell lung cancer

Abstract Human peripheral blood γδ T cells can recognize and kill tumor cells by their Vγ9Vδ2 T cell receptor and/or NKG2D. We have established large-scale ex vivo expansion of γδ T cells from peripheral blood mononuclear cells (PBMC) by zoledronate and IL-2. A clinical study of adoptive γδ T cell transfer therapy has been conducted for the treatment of non-small-cell lung cancer (NSCLC) patients to evaluate the safety profile and potential anti-tumor effects of γδ T cells. Prior to beginning the study, it was registered on a University hospital Medical Information Network Clinical Trials Registry (UMIN-CTR : http://www.umin.ac.jp/ctr/index.htm) on March 1, 2006 (UMIN ID: C00000036). PBMC were isolated from 67.5 ml of peripheral blood and stimulated with zoledronateand IL-2 for 14 days to obtain γδ T cells. The cultured cells on day 14 consisted mostly of γδ T cells. The predominant populations in fresh peripheral blood were cells with the CD45RA−CD27+ memory phenotype or a CD45RA+CD27− naïve phenotype. In contrast, most γδ T cells were shown to have the CD45RA−CD27− effector memory phenotype after 14 days culture. They expressed NKG2D and up-regulated the expression of activation marker CD69, and had cytotoxicity against allogeneic tumor cell lines. Upon stimulation, γδ T cells produced IL-2, TNF-α and IFN-γ. Though certain patients were refractory to zoledronate stimulation, γδ T cells from patients demonstrated comparable cytotoxic effector activity once they were successfully expanded. Cultured cells were intravenously administered every 2 weeks for 6 injections. Fifteen patients who were resistant to current standard therapy were enrolled this study. The treatment was well tolerated and no severe adverse events related to γδ T cell therapy were observed. Two patients came off the study at the early stage of the treatment due to the aspiration pneumonia (grade 3) and radiation pneumonitis (grade3). The responses according to RECIST guideline were SD for 7 patients, PD for 6 patients and 2 inevaluable for response due to early drop off the study (The disease control rate was 46.7 %). Transferred γδ T cells gradually accumulated in peripheral blood in patients who received more than 1×109 γδ T cells per injection and accounted for 10 % of PBMC even 2 weeks after the final injection. When PBMC were stimulated with PMA/ionomycin or zoledronate-pulsed Daudi cells, IFN-γ production and surface expression of CD107 were detected on γδ T cells, suggesting that transferred γδ T cells sustained their effector function in vivo. These results indicated that γδ T cell therapy was well tolerated and feasible for the treatment of NSCLC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1926.