Autologous Cell Vaccine Research Articles

Final outcomes analysis of the cell product SQZ-PBMC-HPV Phase 1 trial in incurable HPV16+ solid tumors shows improved overall survival in patients with increased CD8+ T cell tumor infiltration.

Cancer vaccines strive to induce robust, antigen-targeted, T-cell-mediated immune responses but have struggled to produce meaningful regression in solid tumors. An autologous cell vaccine, SQZ-PBMC-HPV, was developed by SQZ Biotechnologies using microfluidic squeezing technology to load PBMCs with HPV16 E6 and E7 antigens in HLA-A*02+ patients. The SQZ-PBMC-HPV-101 Phase 1 trial (NCT04084951) enrolled patients with incurable HPV16+ cancers. Here, we present a post hoc analysis of the relationship between Posttreatment CD8+ T cell infiltration and patient outcomes. SQZ-PBMC-HPV was administered as monotherapy every 3 weeks. Tumor samples were collected pre-dose and post-dose 4 weeks after treatment start. Biomarkers including CD8, MHC-I, E6, E7, GZMB, and Ki67 were evaluated by immunohistochemistry, immunofluorescence, and RNA in situ hybridization, and were correlated with clinical response, survival, and drug product composition. Eighteen patients had paired pre- and post-dose biopsies. Six (33%) had an increase in CD8+ T cell density in tumor parenchyma between screening and C2D8. Patients with increased CD8+ T cell density had improved disease control rate (66.7% vs 16.7%) and median overall survival (606.5 days vs 170.0 days, p = 0.0078). Drug product was significantly enriched for higher T cells and lower monocytes in the increased CD8+ T cell density group. In patients with incurable HPV16+ solid tumors treated with SQZ-PBMC-HPV, an increase in CD8+ T cell density within the tumor parenchyma was associated with superior disease control rate and overall survival. The product composition for patients with increased CD8+ T cell density was enriched for T cells.

Long-Term Survival and Immune Response Dynamics in Melanoma Patients Undergoing TAPCells-Based Vaccination Therapy.

Cancer vaccines present a promising avenue for treating immune checkpoint blockers (ICBs)-refractory patients, fostering immune responses to modulate the tumor microenvironment. We revisit a phase I/II trial using Tumor Antigen-Presenting Cells (TAPCells) (NCT06152367), an autologous antigen-presenting cell vaccine loaded with heat-shocked allogeneic melanoma cell lysates. Initial findings showcased TAPCells inducing lysate-specific delayed-type hypersensitivity (DTH) reactions, correlating with prolonged survival. Here, we extend our analysis over 15 years, categorizing patients into short-term (<36 months) and long-term (≥36 months) survivors, exploring novel associations between clinical outcomes and demographic, genetic, and immunologic parameters. Notably, DTHpos patients exhibit a 53.1% three-year survival compared to 16.1% in DTHneg patients. Extended remissions are observed in long-term survivors, particularly DTHpos/M1cneg patients. Younger age, stage III disease, and moderate immune events also benefit short-term survivors. Immunomarkers like increased C-type lectin domain family 2 member D on CD4+ T cells and elevated interleukin-17A were detected in long-term survivors. In contrast, toll-like receptor-4 D229G polymorphism and reduced CD32 on B cells are associated with reduced survival. TAPCells achieved stable long remissions in 35.2% of patients, especially M1cneg/DTHpos cases. Conclusions: Our study underscores the potential of vaccine-induced immune responses in melanoma, emphasizing the identification of emerging biological markers and clinical parameters for predicting long-term remission.

Safety and efficacy of autologous cell vaccines in solid tumors: a systematic review and meta-analysis of randomized control trials

We conducted a systematic review and meta-analysis of randomized control trials to formally assess the safety and efficacy of autologous whole cell vaccines as immunotherapies for solid tumors. Our primary safety outcome was number, and grade of adverse events. Our primary efficacy outcome was clinical responses. Secondary outcomes included survival metrics and correlative immune assays. We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published between 1946 and August 2020 using any autologous whole cell product in the treatment of any solid tumor. The Cochrane Randomized Controlled Trial risk of bias tool was used to assess risk of bias. Eighteen manuscripts were identified with a total of 714 patients enrolled in control and 808 in vaccine arms. In 698 patients receiving at least one dose of vaccine, treatment was well tolerated with a total of 5 grade III or higher adverse events. Clinical response was reported in a minority (n = 2, 14%) of studies. Autologous cell vaccines were associated with improved overall (HR 1.28, 95% CI 1.01–1.63) and disease-free survival (HR 1.33, 95% CI 1.05–1.67) over thirteen and ten trials respectively. Where reported, immune assays correlated well with clinical outcomes. Our results suggest that autologous whole cell vaccination is safe and efficacious in increasing survival in patients undergoing treatment for solid tumors.Registration: PROSPERO CRD42019140187.

191P Preliminary biomarker and safety results of SQZ-PBMC-HPV at RP2D in monotherapy and combination with checkpoint inhibitors in HLA A*02+ patients with recurrent, locally advanced, or metastatic HPV16+ solid tumors

Cancer vaccines strive to produce robust, antigen-targeted, T cell-mediated anti-tumor responses, but have struggled to induce tumor regression in patients. The Cell Squeeze® system achieves efficient antigen presentation by delivering target antigens directly into the cytosol of a patient’s PBMCs. SQZ-PBMC-HPV is an autologous cell vaccine that presents epitopes of HPV16 viral oncoproteins on HLA-A*02 to induce CD8 T cell activation. Monotherapy data showed tumor inflammation markers that may indicate correlation with clinical response motivating expansion of the monotherapy and combination with immune checkpoint inhibitors (ICIs).

48MO SQZ-PBMC-HPV-101: Preliminary results of a first-in-human, dose-escalation study of a cell-based vaccine in HLA A*02+ patients with recurrent, locally advanced, or metastatic HPV16+ solid tumors

Cancer vaccines aim to generate antigen-specific anti-tumor immune responses. However, their efficacy has been hampered by inefficient cross-presentation of the target antigens. Cell Squeeze® technology delivers target antigens directly into the PBMC’s cytosol via temporary cell membrane disruption through a microfluidic chip, which can achieve more efficient MHC-I antigen presentation compared to conventional cancer vaccines. SQZ-PBMC-HPV is an autologous cell vaccine targeting HPV16 viral oncoprotein E6 and E7 using the Cell Squeeze platform.

Allogeneic tumor cell line-based vaccines: A good alternative to autologous and cancer stem cell vaccines in colorectal cancer.

Objective(s):Besides the uncertainty about colorectal cancer stem cell (CCSC) markers, isolating, purifying, and enriching CCSCs to produce CCSC vaccines is highly challenging. However, allogeneic vaccines developed from CRC cell lines can provide universal, comprehensive, inexpensive, simple, and fast approach to cancer treatment. Materials and Methods:CCSCs were isolated from human CRC tissue using the in vitro sphere formation assay and then characterized through gene expression analysis, in vivo and in vitro tumor formation assay, karyotyping, and surface marker detection. Subsequently, CCSCs and two CRC cell lines (HT-29 and SW-480) were inactivated with cisplatin (CDDP) and administrated as vaccines to the three groups of athymic C57BL/6 nude mice. Afterward, tumorigenesis was challenged with HT-29 cells. The antitumor effect of vaccines was evaluated by tumor and spleen examination and immune response analysis. The cytotoxic activity of splenocytes and serum levels of TGF-β and IFN-γ were measured by Calcein-AM cytotoxicity assay and enzyme-linked immunosorbent assay (ELISA), respectively.Results:The results of gene expression analysis showed that CCSCs are CD44+CD133-LGR5-. All vaccinations resulted in decreased tumor growth, spleen enlargement, enhanced serum level of IFN-γ and TGF-β, and increased cytotoxic activity of natural killer (NK) cells. The antitumor efficacy of the CCSC vaccine was not more than CRC cell line-based vaccines. Interestingly, the allogeneic SW-480 vaccine could effectively inhibit tumorigenesis.Conclusion:Despite the great challenge in developing CCSC vaccines, allogeneic vaccines based on CRC cell lines can efficiently induce antitumor immunity in CRC.

Safety and efficacy of autologous whole cell vaccines in hematologic malignancies: A systematic review and meta-analysis.

Autologous cell vaccines use a patient's tumor cells to stimulate a broad antitumor response in vivo. This approach shows promise for treating hematologic cancers in early phase clinical trials, but overall safety and efficacy remain poorly described. We conducted a systematic review assessing the use of autologous cell vaccination in treating hematologic cancers. Primary outcomes of interest were safety and clinical response, with secondary outcomes including survival, relapse rate, correlative immune assays and health-quality related metrics. We performed a search of MEDLINE, Embase and the Cochrane Register of Controlled Trials including any interventional trial employing an autologous, whole cell product in any hematologic malignancy. Risk of bias was assessed using a modified Institute of Health Economics tool. Across 20 single arm studies, only 341 of 592 enrolled participants received one or more vaccinations. Primary reasons for not receiving vaccination included rapid disease progression/death and manufacturing challenges. Overall, few high-grade adverse events were observed. One death was reported and attributed to a GM-CSF producing allogeneic cell line co-administered with the autologous vaccine. Of 58 evaluable patients, the complete response rate was 21.0% [95% CI, 10.4%-37.8%)] and overall response rate was 35.8% (95% CI, 24.4%-49.0%). Of 97 evaluable patients for survival, the 5-years overall survival rate was 64.9% (95% CI, 52.6%-77.2%) and disease-free survival was 59.7% (95% CI, 47.7%-71.7%). We conclude that, in hematologic malignancies, based on limited available data, autologous cell vaccines are safe and display a trend towards efficacy but that challenges exist in vaccine manufacture and administration.

A Systematic Review of Evidence Supporting the Use of Autologous Cell Vaccines in the Treatment of Hematological Malignancies

By presenting a patient's own tumor antigens to their immune system, autologous cancer cell vaccines can drive a robust polyclonal adaptive response. In this systematic review and meta-analysis, we investigated the safety and efficacy of these vaccines administered to patients with hematologic malignancies. Our primary outcomes of interest were safety and clinical response, with secondary outcomes including overall, disease-free and progression-free survival, relapse rate, correlative immune assays and health-quality related metrics. We identified 14 studies with 332 patients enrolled, of which 200 were ultimately treated with at least one dose of the vaccine. While we identified both patient-related and technical issues that might limit the feasibility of these trials, very few serious adverse events (AEs) were reported overall, with only 31.5% of patients suffering any AEs. Grade II or lower AE was observed in 10 (71.4%) of the 14 studies. Of the 3 (21.4%) reporting grade IV AEs, two observed the AE in one patient only, and one reported a 20% incidence of grade II-IV AEs. Of 58 evaluable patients, the complete response rate was 21% [95% CI, 10%-38%)] and overall response rate was 36% [95% CI, 24%-49%]. Analysis of individual patient level data (n=50) revealed a 5-year overall survival of 68.7% (SE 7.1%) and disease-free survival of 67.4% (SE 8.1%). Despite the clear safety and a signal towards efficacy, our review has identified several factors limiting administration of these vaccines, which should be considered when developing future clinical trials. PROSPERO registration number CRD42019140187 Disclosures Diallo: Virica Biotech: Other: Owner and Executive. Auer:Imugene: Other: Scientific Advisory Board. Kekre:Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria.

Safety and efficacy of autologous tumour cell vaccines as a cancer therapeutic to treat solid tumours and haematological malignancies: a meta-analysis protocol for two systematic reviews

IntroductionAutologous cancer cell vaccines are promising personalised immunotherapeutic options for solid and haematological malignancies that uses the patient’s own cells to arm an immune response. Evidence suggests that among patients...

Pilot study on outcome and antitumor efficacy of an autologous cancer cell vaccine applied in patients with advanced solid tumors.

3000 Background: In the last decade cancer immunotherapy has emerged as the most promising anti-tumor approach. The most commonly used immunotherapies are vaccines and checkpoint inhibitors. An autologous cell vaccine is made with the patient's own tumor cells processed in vitro, which may elicit a cytotoxic T-lymphocytic immune response against tumor cells antigens, resulting in tumor cell death. We performed a pilot study to evaluate the clinical relevance and general outcome of an autologous vaccine as a treatment in different types of cancer. Methods: A total of 31 patients (n=31) with advanced solid tumors and the lack of standard treatments were treated with an immunotherapy protocol consisting of 6 intradermal doses of the vaccine, given the first two doses at day 1 and 2, and the rest every two weeks. All patients signed an informed consent form. Response evaluation was assessed by PET/CT identified as metric (iRECIST) response and in some cases tumor markers where available. Results: Out of 31 patients treated, 2 patients suffered from pancreatic cancer, 2 from sarcoma, 1 from lung cancer, 13 from breast cancer, 2 from ovarian cancer, 1 from prostate cancer, 1 from cholangiocarcinoma, 4 from colorectal cancer, 1 from non-Hodgkin lymphoma, 1 from gastric cancer, 1 from laryngeal and hypopharyngeal cancer, 1 from fallopian tube cancer, 1 from peritoneal cancer. Side effects related to the therapy were rare including light redness in the area of injection and in one case inflammation of the tumor area. 26 patients were evaluated for metric response and 5 for tumor marker response assessment. For tumor marker follow up 9.6 % had a SD of &gt; 3 month and 6.5 % a PD. For metric follow up 12.9 % had a CR, 6.5 % a PR, 25.8 % a SD of &gt; 3 month and 38.7 % a PD. Conclusions: This study have confirmed an anti-tumor response in the majority of patients treated, with none to very low side effects and a good quality of life during the treatment. To obtain more detailed and significant data on the efficacy of this therapy, a further controlled clinical phase study should be performed.

Abstract B71: Phase 1b/2 prospective randomized trial of four autologous cell vaccine dose cohorts for initial treatment of glioblastoma

Abstract Introduction: We present a novel autologous cell vaccine therapy designed to treat patients with newly diagnosed glioblastoma (Trial Registration: IND 14379, NCT01550523). Methods: This phase 1b trial has a phase 2 design with 4 randomized vaccine dose cohorts in 33 patients with the objective being safety assessment but also including clinical, radiographic, and immune analyses. Eligibility criteria included age &amp;gt; 18 and Karnofsky score of &amp;gt; 60; neither bihemispheric disease nor extent of resection were exclusion criteria but autoimmune diseases were. During craniotomy for tumor resection, if frozen section confirmed GBM, incisions were made in the lower abdomen through the rectus sheath and pockets created between the sheath and the muscle and the wounds closed with a temporary three-layer closure. Tumor resection involved an aspirator that collected morselized viable tumor tissue in sterile traps. The tissue was processed by overnight culture with 0.2 mg of an IGF-1R antisense oligodeoxynucleotide/gm. The next (first postoperative) day, treated tumor cells were harvested, encapsulated in either ten or twenty small biodiffusion chambers along with 4 micrograms of the IGF-1R antisense, irradiated and then implanted at bedside in the abdominal acceptor sites as previously described (1). Chambers were explanted 24 or 48 hours later, depending on randomization. Standard of care according to Stupp (2) was initiated at 6 weeks. Studies included 3T MRI imaging and analysis of serial blood samples for T cell function and cytokine levels. Disease progression was assessed using RANO (3) and iRANO (4) criteria with a data cutoff of March 1 (N=30) used for this analysis. Results: The trial opened September 1, 2015 and completed accrual on March 1, 2018. A midpoint interim analysis revealed significantly more robust cytokine responses at the highest vaccine dose. Randomization was therefore stopped at subject 23 and amended to treat using only the highest dose. Progression-free survival (PFS) was compared to three historic SOC comparators (Stupp [2], Kong [5], and an antecedent cohort of 37 consecutive patients treated with SOC at our institution [TJUH]). PFS was significantly improved at 10.5 mo v. SOC comparators: 6.9 mo (Stupp, p = .003), 5.3 mo (Kong, p = .002) and 7 mo (TJUH, p = .013). Seventy-five percent of the 14 patients in the highest-dose cohort had robust proinflammatory and early evidence of sustained immune reactivity associated with tumor regression or no recurrence after surgery. Conclusion: These data reflect a therapeutic benefit defined as significant improvement in PFS without increased safety risk compared to three different SOC cohorts. Since GBM remains one of the most challenging solid tumors, this treatment design invites investigator collaboration in a multicenter phase 2 trial.

Abstract CT038: Results of a Phase Ib trial of an autologous cell vaccine for newly diagnosed glioblastoma

Abstract Background: We evaluated an autologous cell vaccine, a combination of GBM tumor cells and an antisense molecule against insulin-like growth factor type 1 receptor DNA/mRNA (IGF-1R AS ODN), in adults with newly diagnosed GBM (NCT02507583). Methods: Tumor cells collected during resection were treated ex vivo with IGF-1R AS ODN, encapsulated in biodiffusion chambers with IGF-1R AS ODN, irradiated, then implanted in an abdominal acceptor site on the first post-operative day. Four vaccine exposures were evaluated: lowest (10 chambers implanted for 24 hours); lower (10 / 48 hours); higher (20 / 24 hours); and highest (20 / 48 hours). Standard of care (SOC; ie, radiotherapy and temozolomide) was initiated after 4-6 weeks. Randomization was halted after patient 23 and subsequent patients received the highest exposure. Evaluation of safety and tumor responses were the primary and secondary objectives, respectively. Exploratory objectives included assessment of progression-free survival (PFS) and overall survival (OS). The SOC comparator group was an antecedent cohort of 35 newly diagnosed, GBM patients treated at the same center. Results: Thirty-three patients were enrolled between September 1, 2015 and March 1, 2018. Six, 5, 5, and 17 patients received the lowest, lower, higher, and highest exposures. Median (range) follow-up was 13 (4-39) months. As of the January 1, 2019 cutoff, no vaccine-related adverse events were observed. Seventeen of 33 (51.5%) remained progression-free, 12 of whom are alive and functioning well. The autologous cell vaccine significantly prolonged PFS and OS vs. SOC (Table). Survival advantages were conferred by the highest exposure to the autologous cell vaccine and good T cell function prior to surgery. Conclusions: This vaccine was well-tolerated and prolonged PFS and OS when compared with SOC alone. Table.Survival outcomes in patients receiving vaccine vs. SOC aloneTreatment group2 yr OS estimateMedian OS (mo)p-value v. SOC for OS1 yr PFS estimateMedian PFS estimatep-value v. SOC for PFSVaccine highest dose (N=17)34%21.9.04141%10.4.031Vaccine all (ITT, N=33)31%17.3.01642%9.8.018SOC (n=35)14%12.128%6.9 Citation Format: David W. Andrews, Samantha Garcia, Kevin D. Judy, Larry A. Harshyne, Sanjana Govindarajan, Lawrence Kenyon, Kiran Talekar, Adam Flanders, Kofi-Buaku Atsina, Lyndon Kim, Nina L. Martinez, Wenyin Shi, Maria Werner-Wasik, Mikhail Prosniak, Mark T. Curtis, Rhonda Kean, Emily Bongiorno, Sami Sauma, Kara Pigott, Charles B. Scott, D Craig Hooper. Results of a Phase Ib trial of an autologous cell vaccine for newly diagnosed glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT038.

Autologous tumor cells/bacillus Calmette-Guérin/formalin-based novel breast cancer vaccine induces an immune antitumor response.

Autologous cancer cell vaccines represent a multivalent patient-specific treatment. Studies have demonstrated that these immunotherapies should be combined with immunomodulators to improve results. We tested in breast cancer the antitumor effects of a 200 µg autologous tumor cells homogenate combined with 0.0625 mg of bacillus Calmette-Guérin (BCG), and 0.02% formalin. We used a 4T1 murine model of BALB/c receiving four weekly injections of either this vaccine or control treatments. The control treatments were either Phosphate Buffer Saline, BCG treated with formalin, or the tumor cells homogenate plus BCG alone. We found that mice treated with the vaccine had the lowest tumor growth rate and mitosis percentage. The vaccinated group also showed a marked increase in infiltration of antitumor cells (natural killer, CD8+ T and CD4+ Th1 cells), as well as a decrease of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). Additionally, we also observed a possible activation of the immune memory response as indicated by plasma cell tumor infiltration. Our results demonstrate that our proposed breast cancer vaccine induces a potent antitumor effect in 4T1 tumor-bearing mice. Its effectiveness, low cost and simple preparation method, makes it a promising treatment candidate for personalized breast cancer immunotherapy.

Induction of immunogenic cell death of cancer cell by using chemical detergent treatment and its activation of immune system

Allogenic whole cancer cell vaccines have been proposed for cancer immunotherapy. Immunogenic cell death (ICD) is one of programed cell death and the ICD induced cells show high immunogenicity and can activate immune system effectively. So, ICD induced cancer cell is expected as an autologous cell vaccine. As ICD induction method, chemical and physical methods have been proposed. Among them, high hydrostatic pressure (HHP) treatment can induce ICD of cancer cell. The HHP‐ICD induced cancer cells show higher immune activation than other methods. However, the ICD induction efficiency is still low. Therefore, in order to develop simple and effective ICD induction method, we investigated ICD induction method by using various detergents, such as SDS, Triton X‐100 and Tween 20. HeLa cells were treated with detergents at various concentrations. For the Tween 20 treated HeLa cell, the calreticulin and HMGB1 translocations were confirmed by confocal laser microscopic observation (Fig. 1). This result indicates that immunogenic cell death of HeLa cells was induced by the detergent treatment. For SDS and Triton X‐100, although the cell death was induced, the calreticulin and HMGB1 translocations were not confirmed. The ICD induced HeLa cells were effectively phagocytosed by macrophage‐like cells and the effective secretion of TNF‐alpha from the macrophage‐like cells also confirmed by ELIZA assay (Fig. 2). From these results, it was suggested that the ICD inducted cancer cells by using Tween 20 could activate immune system.Support or Funding InformationJSPS Grant‐in‐Aid for Scientific Research (B)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Inmunoterapia en melanoma: vacunas de células dendríticas

This is a narrative review that shows accessible information to the scientific community about melanoma and immunotherapy. Dendritic cells have the ability to participate in innate and adaptive immunity, but are not unfamiliar to the immune evasion of tumors. Knowing the biology and role has led to generate in vitro several prospects of autologous cell vaccines against diverse types of cancer in humans and animal models. However, given the low efficiency they have shown, we must implement strategies to enhance their natural capacity either through the coexpression of key molecules to activate or reactivate the immune system, in combination with biosimilars or chemotherapeutic drugs. The action of natural products as alternative or adjuvant immunostimulant should not be ruled out. All types of immunotherapy should measure the impact of myeloid suppressor cells, which can attack the immune system and help tumor progression, respectively. This can reduce the activity of cellular vaccines and/or their combinations, that could be the difference between success or not of the immunotherapy. Although for melanoma there exist biosimilars approved by the Food and Drug Administration (FDA), not all have the expected success. Therefore it is necessary to evaluate other strategies including cellular vaccines loaded with tumor antigenic peptides expressed exclusively or antigens from tumor extracts and their respective adjuvants.

An adjuvanted whole cell vaccine as post-remission immunotherapy for acute leukemia

Many acute leukemia patients treated with chemotherapy are at high risk of relapse without allogeneic stem cell transplantation, an immunotherapy that is limited by significant toxicity and donor availability. We propose that post-remission vaccination with a simple autologous whole cell vaccine adjuvanted with α-galactosylceramide may be effective to prevent relapse of acute leukemia.

In vitro-activated tumor-bearing host T cells and the effectiveness of tumor vaccine immunotherapy

BACKGROUND AND OBJECTIVEVaccination during periods of lymphopenia may facilitate immune responses to weak self-antigens and enhance antitumor immunity. The objective of this study was to determine the effectiveness of tumor vaccine immunotherapy combined with immune reconstruction using tumor-bearing host immune cells in lymphopenia, and to investigate the role of tumor-bearing host T cells activated in vitro during immunotherapy.DESIGN AND SETTINGAnimal study conducted in the First Affiliated Hospital of Xi’an Jiaotong University from January 2009 to January 2010.PATIENTS AND METHODSLymphopenia was induced by cyclophosphamide. A reconstituted immune system with different syngeneic lymphocytes was employed, including lymphocytes from naïve rats (unsensitized group), tumor-bearing rats (tumor-bearing group), and tumor-bearing rats activated in vitro (activated group). All rats were immunized with granulocyte-macrophage colony-stimulating factor (GM-CSF)-modified NuTu-19 ovarian cancer (GM-CSF/NuTu-19) cells. Tumor vaccine-draining lymph nodes (TVDLNs) were harvested, and then stimulated to induce effector T cells (TE). TE were then adoptively transferred to rats bearing a 3-day pre-established abdominal tumor (NuTu-19), and the survival rate was calculated.RESULTSCompared with the unsensitized group, the levels of interleukin-2 (IL-2) were significantly lower in the tumor-bearing group, whereas that of IL-4 were significantly higher (P<.05). The number of CD4+ T cells secreting interferon-γ and the specific cytotoxicity of CD8+ cytotoxic T lymphocytes were significantly lower (P<.05). The survival was significantly higher in the activated group compared with the other groups.CONCLUSIONSLymphocytes from tumor-bearing rats activated in vitro can effectively reverse the immunosuppressive effects of tumor-bearing hosts.

Augmentation of anti-HLA-E antibodies with concomitant HLA-Ia reactivity in IFNγ-treated autologous melanoma cell vaccine recipients

HLA-E expressed on the surface of melanoma cells and shed into circulation are known to inhibit killing of tumor cells by binding to CD94/NKGA2 receptors on cytotoxic T- and NKT cells. Interferon (IFN)-γ is known to promote HLA-E over-expression on the cell surface and shedding. The shed HLA-E heavy chain may expose cryptic epitopes to elicit antibodies (Abs). The anti-HLA-E Abs may bind to shed HLA-E or to the tumor cell surface to block its interaction with CTL/NKT cells. This is the basis for a melanoma cell vaccine that will generate anti-HLA-E Abs. The objective of this study was to characterize the antibody response and characterize the cross-reactivity of the antibodies produced in melanoma patients immunized with autologous melanoma cells treated with IFNγ. Anti-HLA-E murine mAbs and serum anti-HLA-E Abs in healthy individuals were known to react with HLA-Ia alleles, which is attributed to the presence of peptide sequences shared between HLA-E and HLA-Ia. Therefore, pre- and post-immune (weeks 4 and 24) serum Abs reacting to both HLA-E and HLA-Ia alleles were measured by multiplex Luminex®-based immunoassay. To ascertain whether the reactivity of the serum Abs to HLA-Ia was due to anti-HLA-E Abs, the shared-peptides were used to inhibit anti-HLA-E and HLA-Ia reactivities. The level of anti-HLA-E IgG in sera has increased post-immunization from its pre-immune level. Concomitantly, the HLA-Ia reactivity of the sera was also augmented. The reactivity of both anti-HLA-E Abs and HLA-Ia were inhibited by the shared-peptides. The HLA-Ia reactivity of the anti-HLA-E Abs in patients’ sera is similar to the HLA-Ia reactivity of the anti-HLA-E mAbs and anti-HLA-E Abs in normal sera. The results establish the immunogenicity of HLA-E and also ascertain that the HLA-Ia reactivity of the anti-HLA-E Abs is due to shared-peptide epitopes.

Tumor-derived interleukin-10 as a prognostic factor in stage III patients undergoing adjuvant treatment with an autologous melanoma cell vaccine.

Interleukin-10 (IL-10) downregulates T-cell-mediated immune responses. We studied the association between IL-10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients undergoing adjuvant treatment with a vaccine prepared from the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP). Forty-four patients with cutaneous melanoma (29 stage III and 15 stage IV) were prospectively evaluated. Tumor cells were extracted from metastatic deposits for production of DNP-modified autologous melanoma cell vaccine. Small aliquots of the melanoma cell suspensions were separated prior to vaccine processing and cultured overnight for IL-10 production. Based on a blind assessment of the distribution of IL-10 levels in the culture supernatants, a cutoff of 200pg/ml was used to define high versus low IL-10 producers. Cox regression model was used for multivariate analysis. Overall survival was calculated using the Kaplan-Meier method, and survival curves were compared with the log-rank test. Out of 44 patients, 29 were low and 15 were high IL-10 producers. The median OS was significantly worse for high compared with low IL-10 producers (10.5months vs. 42months; P=0.022). In stage III patients, the multivariate hazard ratio for high versus low IL-10 producers was 2.92 (95% CI, 1.04-8.20; P=0.041). The corresponding hazard ratio in stage IV patients was 0.92 (95% CI, 1.04-8.20; P=0.888). High IL-10 production in the tumor microenvironment could be a determinant of clinical outcomes in stage III melanoma patients receiving autologous melanoma cell vaccine.

Interleukin-10 as a prognostic factor in patients treated with autologous melanoma cell vaccine.

8588 Background: Interleukin-10 (IL-10) downregulates the T cell-mediated immune response. We studied the association between IL10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients who were treated with cancer vaccine consisting of the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP). It was assumed that production of IL-10 in tumor cell suspensions reflect the degree of IL-10 in tumor microenvironment. Methods: Tumor cells were extracted from metastatic tissues and cryopreserved until vaccine production. Small fraction of melanoma cell suspensions were separated prior to vaccine production and cultured overnight for the production of IL-10 in the culture supernatants. After inactivation with radiation and modification with DNP, autologous melanoma cells were injected to patients as a cancer vaccine. The final vaccine products did not produce IL-10. Forty four patients including 29 stage III and 15 stage IV disease were evaluated. The cut-off of 200 pg/mL was used to differentiate high versus low IL-10 producers based on scattergram. Cox regression model was used for multivariate analysis. Overall survival was calculated using Kaplan and Meier method and survival curves were compared with log-rank tests. Results: Out of 44 patients, 29 were low and 15 were high IL-10 producers. The overall survival (OS) was significantly longer for low versus high IL-10 producers (median OS 42 vs. 10.5 months, p = 0.02). In stage III patients, median OS for low and high IL-10 producers was 84 months and 9.7 months respectively (p = 0.07). In stage IV patients, the corresponding values were 13.7 months and 10.5 months (0.62). In multivariate analysis, the hazard ratios for stage III and stage IV patients were 2.92 (1.04-8.20) and 0.92 (0.28-3.00). Conclusions: Our study suggests that high IL-10 production in tumor cells is associated with worse prognosis in stage III melanoma patients receiving autologous vaccine. It has been shown that delayed-type hypersensitivity to autologous tumor cells is associated with longer OS. By downregulating the T cell mediated immune response, IL-10 in tumor microenvironment may decrease the effectiveness of the vaccine. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration AVAX