4th Vaccination Research Articles

COVID-19 mRNA booster vaccine induces transient CD8+ T effector cell responses while conserving the memory pool for subsequent reactivation

Immunization with two mRNA vaccine doses elicits robust spike-specific CD8+ T cell responses, but reports of waning immunity after COVID-19 vaccination prompt the introduction of booster vaccination campaigns. However, the effect of mRNA booster vaccination on the spike-specific CD8+ T cell response remains unclear. Here we show that spike-specific CD8+ T cells are activated and expanded in all analyzed individuals receiving the 3rd and 4th mRNA vaccine shots. This CD8+ T cell boost response is followed by a contraction phase and lasts only for about 30-60 days. The spike-specific CD8+ T memory stem cell pool is not affected by the 3rd vaccination. Both 4th vaccination and breakthrough infections with Delta and Omicron rapidly reactivate CD8+ T memory cells. In contrast, neutralizing antibody responses display little boost effect towards Omicron. Thus, COVID-19 mRNA booster vaccination elicits a transient T effector cell response while long-term spike-specific CD8+ T cell immunity is conserved to mount robust memory recall targeting emerging variants of concern.

Randomized phase II trial of a first-in-human cancer cell lysate vaccine in patients with thoracic malignancies.

BackgroundAlthough most malignancies express cancer-testis antigens (CTA), immune responses to these proteins are limited in thoracic oncology patients. This trial was undertaken to examine if a cancer cell lysate vaccine could induce immunity to CTA, and to ascertain if metronomic cyclophosphamide and celecoxib enhances vaccine-induced immune responses.MethodsEleven patients with primary thoracic malignancies and 10 patients with extrathoracic neoplasms metastatic to the chest rendered NED by conventional therapies were randomized to receive H1299 lung cancer cell lysates (10 mg protein/vaccine) with Iscomatrix™ adjuvant via deep intradermal injection q 4 weeks ×6 with or without daily oral metronomic cyclophosphamide/celecoxib. The primary endpoint was serologic response to purified CTA assessed 1 month after the 6th vaccination. Secondary endpoints included assessment of the effects of cyclophosphamide and celecoxib on frequency and magnitude of vaccine-induced immune responses to CTA. Exploratory endpoints included evaluation of the effects of the vaccine regimens on peripheral immune subsets. Standard of care imaging studies were obtained at baseline and 1 month after the 3rd and 6th vaccinations.ResultsAll patients exhibited local and systemic inflammatory responses lasting 72–96 hours following vaccinations. There were no dose limiting treatment related toxicities. Fourteen patients (67%) completed all six vaccinations. Eight of 14 patients (57%) exhibited serologic responses to NY-ESO-1. One patient developed antibodies to GAGE7; several patients exhibited reactivity to XAGE and MAGE-C2. Vaccine therapy decreased the percent of Tregs (P=0.0068), PD-1 expression on Tregs (P=0.0027), PD-L1 expression on CD14+ monocytes (P=0.0089), PD-L1 expression on classical monocytes (P=0.016), and PD-L1 expression on intermediate monocytes (P=0.0031). Cyclophosphamide/celecoxib did not appear to increase immune responses or enhance vaccine-induced alterations in peripheral immune subsets.ConclusionsH1299 lysate vaccines with Iscomatrix™ induce immune responses to CTA and modulate peripheral immune subsets in a manner that may enhance antitumor immunity in patients with thoracic malignancies.

Human Endogenous Retroviruses (HERVs) and Mammalian Apparent LTRs Retrotransposons (MaLRs) Are Dynamically Modulated in Different Stages of Immunity.

Simple SummaryHuman Endogenous retroviruses (HERVs) and Mammalian Apparent LTRs Retrotransposons (MaLRs) are remnants of ancient retroviral infections that make up about 8% of the human genome. HERV and MaLR expression is regulated in immunity, and, in particular, is known for their up-regulation after innate immune activation. In this work, we analyzed the differential expression of HERVs and MaLRs in different stages of immunity, triggered by the administration of an inactivated vaccine.Human Endogenous retroviruses (HERVs) and Mammalian Apparent LTRs Retrotransposons (MaLRs) are remnants of ancient retroviral infections that represent a large fraction of our genome. The HERV and MaLR transcriptional activity is regulated in developmental stages, adult tissues, and pathological conditions. In this work, we used a bioinformatics approach based on RNA-sequencing (RNA-seq) to study the expression and modulation of HERVs and MaLR in a scenario of activation of the immune response. We analyzed transcriptome data from subjects before and after the administration of an inactivated vaccine against the Hantaan orthohantavirus, the causative agent of Korean hemorrhagic fever, to investigate the HERV and MaLR expression and differential expression in response to the administration of the vaccine. Specifically, we described the HERV transcriptome in PBMCs and identified HERV and MaLR loci differentially expressed after the 2nd, 3rd, and 4th inactivated vaccine administrations. We found that the expression of 545 HERV and MaLR elements increased in response to the vaccine and that the activation of several individual HERV and MaLR loci is specific for each vaccine administration and correlated to different genes and immune-related pathways.

Local immune responses to VAA DNA vaccine against Listonella anguillarum in flounder (Paralichthys olivaceus)

The efficacy of DNA vaccine is associated closely with the expression of the antigen and the intensity of local immune responses. In our previous study, a recombinant DNA plasmid expressing the VAA protein (pVAA) of Listonella anguillarum has been proved to have a good protection against the infection of L. anguillarum. In the present study, the local immune responses eliciting by immunizing flounder with intramuscular (I.M.) injection of pVAA was investigated at the cellular and genetic level, the muscle at the injection site at 7th post vaccination day was sampled and analyzed by hematoxylin-eosin (H&E) staining, immunohistochemistry (IHC), flow cytometry (FCM), RNA sequencing (RNA-Seq)-based transcriptomics and RT-qPCR. Then variations on the specific antibodies in serum at 1st–6th post vaccination week and the relative percent survival rate (RPS) at following 14 days after challenge were measured. The H&E results showed that inflammatory cells and immune cells significantly increased at the injection site. The IHC using monoclonal antibody against T cell markers revealed that both CD4-1+ and CD4-2+ T lymphocytes were recruited to the injection site and FCM results showed that the proportion of CD4-1+ cells in pVAA immunized group was 28.6 %, in the control group was 8.7 %, and that of CD4-2+ cells in two groups was 21.2 % and 8.5 %, respectively. These results indicating that the proportion of CD4+ cells in the immune group was significantly increased compared with the control group. Moreover, there were 2551 genes differently expressed in pVAA immunized group, KEGG analysis showed the genes involved in the signal transduction and immune system, and surface markers for B-cells genes, T-cells and antigen presenting cells (APCs) genes were highly upregulated, suggesting the activation of the systemic immune responses. Antibody specific anti-L. anguillarum or anti-rVAA antibodies were significantly induced at 2nd post-immunization week, that reached a peak at 4–5th week. RPS in pVAA group was 53.85±3.64 %. In conclusion, pVAA induced effective local immune responses and then the systematic response. This probably is the main contribution of pVAA to effective protection against L. anguillarum.

Abstract P3-09-15: A phase 1b study of PVX-410 (PVX) vaccine plus durvalumab (DUR) as adjuvant therapy in HLA-A2+ early stage triple negative breast cancer (eTNBC) to assess safety and immune response

Abstract Background: eTNBC remains at high risk for recurrence despite modern (neo)adjuvant chemotherapy. Immunotherapy with checkpoint inhibition is active in early and metastatic TNBC, and vaccines may further induce host immune response. PVX-410 (PVX, OncoPep) is a novel tetra-peptide vaccine with 3 of the 4 antigens (XBP1 [2 splice variants] and CD138) commonly overexpressed in TNBC. Here we present results from a phase1b study evaluating safety, tolerability and immune response of PVX and durvalumab (DUR) as adjuvant therapy in eTNBC. Methods: Eligibility for this phase 1b multi-center, single arm study included: HLA-A2+ female patients (pts) with TNBC and tumor size at least 1 cm or node positive; treatment with at least 4 cycles of adjuvant or neoadjuvant chemotherapy; completion of all planned therapy 1-6 months prior to study entry. Pts with local-regional recurrence without evidence of distant metastases treated with curative were also eligible. Pts received 6 doses of 800ug PVX (subcutaneously) emulsified in Montanide and co-administered with Hiltonol (IM) every 2 weeks, and 2 doses of 1500mg DUR (IV) concurrent with the 4th and 6th vaccine treatments. The study included a 6 pt run-in to assess for dose limiting toxicity (DLT), followed by a 14 pt expansion. Blood samples were collected for immune response assessment via flow cytometry at week 0 (Baseline) and at weeks 6, 10, 14, and 24 post-treatment. The primary objective was safety and tolerability. The key secondary objective was PVX specific immune response assessment defined at week 14 as a 2-fold or greater change over baseline in the proportion of CD3+CD8+ T cells that expressed IFNγ and the proportion of CD3+CD8+ T cells positive for PVX tetramers following an in vitro stimulation of PBMC with PVX peptides and a flow cytometric determination. Other immune response assessments included the proportion of CD3+CD8+ T cells expressing TNFα, IL-2, and CD137 following the in vitro peptide stimulation. Results: Among 22 pts enrolled, median age was 48 yrs (range 34-68) and anatomical stage at diagnosis was: Stage 1 = 1 (4.5%), Stage 2 = 14 (64%), and Stage 3 = 7 (32%). Among 20 pts evaluable for week 14 immune response, all planned PVX doses were given, and 1 DUR dose was held due to toxicity (tox). No DLTs were observed in the 6 pt run-in. The most common adverse events (all grades) include: injection site reaction (96%), flu-like symptoms, fatigue (41% each), arthralgia, pruritis (36% each), ALT elevation (32%), myalgia (27%), pain, diarrhea, AST and amylase elevation (23% each). One pt had grade 3 diarrhea and 1 pt had grade 3 hyponatremia, AST and ALT elevation. There were no grade 4 or 5 events. Immune response assessment for the first 12 pts are available at the time of abstract submission. Comparing baseline to week 14, 10 of 12 patients demonstrated a PVX specific immune response (as defined above). Immune response persisted in all patient samples tested at 6 months. Additionally, most pts tested to date had increases over baseline in the proportions of CD3+CD8+ T cells that expressed TNFα, IL-2, and CD137 following the in vitro stimulation with PVX peptides. Final immune response assessment in all 20 evaluable patients will be updated for presentation. At the time of data cut off (4/29/19), with a median follow up of 15.4 months, 4 of 22 (18%) pts had a local (1) or metastatic (3) recurrence and 2 (9%) have died. Conclusions: PVX plus DUR is safe and tolerable in pts with eTNBC with no new unexpected toxicities identified. Immune response data demonstrate that PVX induces antigen-specific T cell expansion and activation in these pts as observed by increases in PVX tetramer, IFNγ, TNFα, IL-2 and CD137 positive T cells. These immune responses to PVX persisted for up to 6 months in most patients, indicating a prolonged immune response. Citation Format: Steven J Isakoff, Sylvia Adams, Hatem H Soliman, Nadine Tung, William T Barry, Jiani Hu, Lorenzo Trippa, Rachel Deering, Joanne Parker, Hannah Park, Elena F Brachtel, Leif W Ellisen, Mariano Severgnini, Doris Peterkin, Sara M Tolaney. A phase 1b study of PVX-410 (PVX) vaccine plus durvalumab (DUR) as adjuvant therapy in HLA-A2+ early stage triple negative breast cancer (eTNBC) to assess safety and immune response [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-09-15.

Outcome of Repeated Vaccination to Hepatitis B Virus in Patients Failing to Respond to Vaccination Following Allogeneic Hematopoietic Stem Cell Transplantation (HSCT): If at First You Don't Succeed, Try Try Again

Background: Recipient immunity is compromised after HSCT, obligating patients (pts) to take prophylactic antimicrobial and antiviral agents and to be reimmunized to viral and bacterial pathogens. Hepatitis B virus (HBV) infection is a major public health problem, with about 30% of the world population having serological evidence of current or past HBV infection. HBV vaccination post-HSCT is imperative in these pts, as most lose protective HBV surface antibodies (anti-HBs) following conditioning, placing them at high risk for HBV reactivation. Guidelines recommend delaying vaccination (including HBV) for 6-12 months following transplantation to allow for cellular and humoral immune recovery. Even with delaying vaccination, immunosuppression, graft-versus-host disease (GVHD), and delayed immune reconstitution hinder the effectiveness of vaccines. The efficacy of HBV vaccination is not well defined in pts on immunosuppressive therapy (IST) and/or in those with GVHD. Further, little data exists on the efficacy of HBV revaccination in pts failing to respond to the 1st vaccination series. We studied factors impacting the success of vaccination in pts undergoing one to four HBV vaccination series after HSCT. Methods: This single-center, retrospective study evaluated the effectiveness of HBV vaccine in HSCT pts by assessing protective antibody generation after vaccination. Fifty-two pts (25 female, 27 male) who received at least one 3-dose HBV vaccination series post-HSCT and who had evaluable post-vaccine anti-HBs titers were included in the analysis. Pts with negative or indeterminate anti-HBs titers following the first vaccine series were eligible to receive one or more additional series of HBV vaccinations. All pts were treated with cyclophosphamide and fludarabine based conditioning (± anti-thymocyte globulin) and received GVHD prophylaxis with either cyclosporine/tacrolimus with or without mycophenolate mofetil. The vaccine response rate over a series of vaccinations was estimated by Kaplan-Meier methods. The development of response after the first vaccination was correlated with patient baseline and post-HSCT factors including pretransplant HBV titers, vaccination time post-transplant, use of rituximab and IST and absolute lymphocyte count (ALC), CD4, and CD8 cell counts and history of acute or chronic GVHD. Results: The studied cohort included 52 HSCT pts with a median age of 22 years (range 7-62) and a variety of diagnoses (38 aplastic anemia, 6 myelodysplastic syndrome and 8 hematological malignancies). Thirty-five pts underwent HSCT from an HLA-matched donor and 17 pts received a combined haploidentical and umbilical cord blood transplant. The median time to first HBV vaccination was 12 months (8-37) post-HSCT. Following the 1st vaccination series; 19, 4 and 2 pts received a 2nd, 3rd and 4th vaccination series. The estimated cumulative anti-HBs response rates were 51.9%, 82.3%, 91.1% and 100% for the four vaccination series, respectively (Figure). A logistic regression analysis revealed: a) Pts who achieved a response after the initial vaccination series had higher CD4 counts compared to those who failed to mount a response (median CD4 count 450 vs. 300/μL, P= 0.024, Figure); b) Pts without a history of acute GVHD (n=23) were significantly more likely to respond to the 1st vaccination series compared to those with acute GVHD (n=29) (response: 69.6% vs 37.9%, P= 0.029). Other factors included in this analysis were not found to be correlated with the anti-HBs response after the initial vaccination series. Conclusions: Multiple rounds of HBV vaccination may be required before a protective antibody response is achieved. After the first vaccination series, only 51.9% of pts achieved a response, with lower pre-vaccination CD4 counts and a prior history of acute GVHD being negatively associated with vaccine success. Remarkably, with continued vaccination attempts (up to four vaccination series), all evaluable pts ultimately developed a protective anti-HBs response. Figure Disclosures Shalabi: GlaxoSmithKline: Other: Spouse is employed by GSK Pharma.

Co-Administration of HIV Env Protein with DNA and/or NYVAC Vaccines in Humans Results in Earlier and Potent Generation of Anti-Env Antibody Responses

Background: The immunization regimens evaluated to date in the development of HIV vaccines have included purified Env protein vaccines as a part of the boosting components of the vaccination regimen. In the present study, we tested the hypothesis that the co-administration of Env protein with either DNA or NYVAC vector vaccines during the priming results in early generation of antibody responses to the Env V1/V2 region that are important markers for effective protection against infection. This study evaluated a multicomponent HIV vaccine including as immunogens either DNA or NYVAC vectors alone or in combination with Env protein, followed by a co-delivered NYVAC/protein boost. Methods: Ninety-six HIV-1 uninfected subjects were randomized in this double-blind placebo-controlled phase 1b human clinical trial to receive 2x NYVAC followed by 2x NYVAC+AIDSVAX® B/E (n = 20); 4x NYVAC+AIDSVAX® B/E (n = 20); 2x DNA followed by 2x NYVAC+AIDSVAX® B/E (n = 20); 2x DNA+AIDSVAX® B/E followed by 2x NYVAC+AIDSVAX® B/E (n = 20); or placebo (n = 16). Immune response measures included cross-clade and epitopespecific binding antibodies, neutralizing antibodies (nAb), and antibody dependent cell-mediated cytotoxicity (ADCC). Findings: IgG response rates were 74-95% at 2 weeks post 4th vaccination across study groups. Early administration of the gp120 protein was associated with a markedly earlier and higher AUC for gp120 binding, anti-V1V2, neutralizing antibody, and with better antibody response coverage over a period of 18 months than the regimens delaying the gp120 protein until the 6 month vaccination Interpretation: Co-administration of AIDSVAX® B/E gp120 protein components with DNA and/or NYVAC vectors during priming results in early and potent induction of Env V1/V2 IgG binding antibody responses, markers associated with reduced risk of infection in a previous efficacy trial. This immunization approach should be considered for induction of preventative antibodies in future HIV vaccine efficacy trials. Trial Registration: ClinicalTrials.gov: NCT01799954. Funding Statement: UM1 AI068614, UM1 AI068635, UM1 AI068618 and UM1 AI069481. Declaration of Interests: The authors have declared that no conflict of interest exists. Ethics Approval Statement: The study protocol was approved by the institutional ethics committee of the Centre Hospitalier Universitaire Vaudois (CHUV) (Lausanne, Switzerland) and by Swissmedic, the Swiss Agency for Therapeutic Products (Bern, Switzerland). All study participants provided written informed consent prior to participation.

A phase 1b study of safety and immune response to PVX-410 vaccine alone and in combination with durvalumab (MEDI4736) in HLA-A2+ patients following adjuvant therapy for stage 2/3 triple negative breast cancer.

TPS1126 Background: Stage 2-3 triple negative breast cancer (TNBC) remains at high risk for recurrence despite modern adjuvant therapy. An important role for the immune system in TNBC has recently emerged. Tumor infiltrating lymphocytes (TILs) are correlated with improved prognosis and several PD-1/PD-L1 checkpoint inhibitors, including Durvalumab (DUR), demonstrated activity in metastatic TNBC. Vaccines are a promising approach to further enhance the immune response in many cancers including TNBC. PVX-410 (PVX) is a novel tetra-peptide vaccine against XBP1 (2 splice variants), CD138 and CS1 that was safe and induced immune responses in a phase 1b study in smoldering myeloma. XBP1 and CD138 are also over-expressed in TNBC. Methods: This Phase 1b multi-center, single arm study will enroll 20 HLA-A2+ female patients (pts) following completion of all adjuvant therapy for stage 2-3 TNBC. Pts will receive 6 doses of 800ug PVX (emulsified in Montanide (SC) and co-administered with Hiltonol (IM)) at 2-week intervals, and 2 doses of DUR 1500mg IV at the 4th and 6th vaccine visits. Eligible pts must be between 1-6 months from completing adjuvant therapy, have no prior autoimmune disease, and have residual disease if neoadjuvant therapy was used. The primary objective is to determine the safety and tolerability of the combination, and the key secondary objective is to determine the immune response to PVX + DUR. If ≤1 pt in the first 6 has a protocol defined dose limiting toxicity within 4 weeks after the first DUR dose, accrual will continue to 20 pts. Immune response will be assessed at baseline, pre-dose 4 PVX/dose 1 DUR, and 4 weeks after completing protocol therapy. Paired data in 20 pts provides 90% power to see a shift of 0.75 standardized units from baseline to 4 weeks post treatment with the signed rank test. Immune response will be determined by a FACs based assay of antigen specific CD3+CD8+ T lymphocyte response and IFN-γ production (intracellular staining) in patient PBMCs. Additional correlative studies, including T-cell PD-1 and tissue PD-L1, XBP1, and CD138, are planned. Currently 4 pts are enrolled. Clinical trial information: NCT02826434.

Abstract 2366: Pilot study of DNA microseeding to activate immune rejection of canine melanoma

Abstract Background: Canine malignant melanoma provides a model to study DNA vaccine delivery systems. A xenogeneic human tyrosinase (huTYR) DNA vaccine delivered by Biojector2000 received United States Department of Agriculture licensure when it appeared to prolong survival of dogs with melanoma compared to historical, stage-matched controls and to stimulate immune responses in some dogs. The current study evaluates toxicity, transgene expression, and antibody responses to huTYR in companion dogs with spontaneously developing melanoma following delivery of huTYR DNA to the skin via a modified tattoo device, a method termed DNA microseeding. Methods: Five companion dogs with melanoma were scheduled to receive huTYR DNA at two sites (Site A and Site B) on the inner thigh by DNA microseeding every 2 weeks for 4 administrations at a range of huTYR DNA doses; 2 dogs (50 μg [Site A] and 100 μg [Site B]); 2 dogs (200 μg [Site A] and 400 μg [Site B]); and 1 dog (83 μg [Site A] and 83 μg commercial huTYR plasmid [Site B]). Vaccine site biopsies were obtained to determine transgene expression 24 hours after the 1st and 3rd vaccination time-points, and 48 hours after the 2nd and 4th vaccination time-points. Blood samples were obtained at baseline and 2 weeks after the 2nd, 3rd, and 4th vaccinations to quantify TYR-specific antibodies via indirect ELISA. Results: No toxicity, beyond local site irritation, related to the vaccine administration was observed. The 3 dogs with known disease at study entry received 3, 1 and 4 treatments before discontinuation of treatment due to progressive disease. The 2 dogs without evidence of disease at study entry received all 4 planned treatments and remained without evidence for recurrence after treatment for the duration of the study (6 weeks). Only rare huTYR+ cells with macrophage-like morphology were observed in some vaccine site biopsies. A significant increase in anti-huTYR IgG was detected at Day 57 compared to pre-treatment in 2 of the 4 evaluable dogs (p = 0.03 Wilcoxon Mann Whitney), and these were the 2 dogs without evidence of disease at study entry. Baseline anti-huTYR IgG levels were also greater compared to IgG levels against an irrelevant control antigen. Conclusions: While microseeding of huTYR plasmid DNA resulted in only rare transgene expression at DNA doses up to 400 μg, humoral responses against huTYR were substantially boosted in 2 of 4 evaluable dogs. Additional testing is needed to determine if DNA microseeding enhances huTYR DNA vaccine immunogenicity compared to Biojector delivery. Citation Format: Cindy L. Zuleger, Chulhi Kang, Erik A. Ranheim, Ilene Kurzman, Michael D. Macklin, Michael A. Newton, David M. Vail, Jedd D. Wolchok, Elof Eriksson, Mark R. Albertini. Pilot study of DNA microseeding to activate immune rejection of canine melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2366.

MRNA-transfected dendritic cell vaccine in combination with metronomic cyclophosphamide as treatment for patients with advanced malignant melanoma

ABSTRACTIntroduction: Vaccination with dendritic cells (DCs) has generally not fulfilled its promise in cancer immunotherapy due to ineffective translation of immune responses into clinical responses. A proposed reason for this is intrinsic immune regulatory mechanisms, such as regulatory T cells (Tregs). A metronomic regimen of cyclophosphamide (mCy) has been shown to selectively deplete Tregs. To test this in a clinical setting, we conducted a phase I trial to evaluate the feasibility and safety of vaccination with DCs transfected with mRNA in combination with mCy in patients with metastatic malignant melanoma (MM). In addition, clinical and immunological effect of the treatment was evaluated.Experimental design: Twenty-two patients were enrolled and treated with six cycles of cyclophosphamide 50 mg orally bi-daily for a week every second week (day 1–7). During the six cycles patients received at least 5 × 106 autologous DCs administered by intradermal (i.d.) injection in the week without chemotherapy. Patients were evaluated 12 and 27 weeks and every 3rd mo thereafter with CT scans according to RECIST 1.0. Blood samples for immune monitoring were collected at baseline, at the time of 4th and 6th vaccines. Immune monitoring consisted of IFNγ ELISpot assay, proliferation assay, and flow cytometry for enumeration of immune cell subsets.Results: Toxicity was manageable. Eighteen patients were evaluable after six cycles. Of these, nine patients had progressive disease as best response and nine patients achieved stable disease. In three patients minor tumor regression was observed. By IFNγ ELISpot and proliferation assay immune responses were seen in 6/17 and 4/17 patients, respectively; however, no correlation with clinical response was found. The percentage of Tregs was unchanged during treatment.Conclusion: Treatment with autologous DCs transfected with mRNA in combination with mCy was feasible and safe. Importantly, mCy did not alter the percentage of Tregs in our patient cohort. There was an indication of clinical benefit; however, more knowledge is needed in order for DCs to be exploited as a therapeutic option.

Phase I/II Clinical Trial of CpG-Activated Whole Cell Vaccine in Mantle Cell Lymphoma (MCL): Results in Safety and Efficacy from Planned Interim Analysis

IntroductionMCL has a poor prognosis. In eligible patients, intensifying frontline, CHOP-like regimens (e.g., cytarabine) as well as high-dose chemotherapy and autologous stem cell transplant (HDT/ASCT) consolidation in first remission have improved progression free survival (PFS) but less so, overall (OS). Preclinical animal models show benefits of adding tumor-specific T-cells to ASCT. CpG (PF-3512676) is a toll-like receptor 9 (TLR9) agonist and an effective vaccine adjuvant that induces costimulatory molecule expression on both antigen-presenting and MCL cells. This phase I/II clinical trial (NCT00490529) adds autologous T-cell transfer, harvested from patients after vaccination with CpG-activated autologous MCL cells - a maneuver termed immunotransplant. This is a planned interim analysis for safety and efficacy triggered by the first 20 patients reaching 1 year post ASCT.MethodsPrior to therapy, subjects' tumor cells are collected by biopsy or apheresis and patient-specific vaccine is created by incubating fresh tumor cells with CpG (3 mcg/mL PF-3512676, 72-hr culture), then irradiated and cryopreserved. Patients receive induction chemoimmunotherapy of physician's choice. Patients achieving at least partial response (PR) then receive 3 subcutaneous autologous tumor vaccinations (1 x 108 cells/dose) mixed with CpG (18 mg) every 4-7 days. Primed T-cells (≥ 1 x 1010 CD3 cells) were collected by apheresis 2-4 weeks following vaccine 3 and a rituximab (375 mg/m2) B-cell purge. After standard HDT/ASCT (conditioning = BCNU, cyclophosphamide, etoposide), primed T-cells and a 4th vaccination are given on day+1. A 5th CpG-MCL vaccination followed 3 months post ASCT. The primary endpoint of this study is freedom from minimal residual disease (MRD) at 1 year post ASCT, measured by presence of patient-specific, malignant B-cell VDJ sequence in peripheral blood (ClonoSeq™, analyzed at a sensitivity of ≥ 1 clone/10,000 leukocytes) -an endpoint previously shown to be highly prognostic. Secondary endpoints include PFS, OS, and immune response to vaccine. 59, transplant-eligible, MCL patients are targeted for accrual in this 2-stage design.ResultsIn this interim analysis of 24 patients accrued, 20 have surpassed 1 year post ASCT. All patients had Stage IV disease. Median values included (range): follow-up 43.5 months (11.5-60.1), age 60 years (47-70), and MIPI score 5.9 (5.1-7.8). Vaccine was made from biopsy alone (n=12), apheresis alone (n=9), or both (n=1). Frontline therapy included R-CHOP (n=7), R-hyperCVAD (n=14), alternating R-CHOP/R-DHAP (n=2), and R-EPOCH (n=1). 19 patients achieved complete response while another 3 had PR. All responding patients were vaccinated, able to yield sufficient T-cells for adoptive transfer, and proceeded through standard HDT/ASCT. At 1-year post ASCT, freedom from MRD was 90.5% (n=21). 2 patients did not reach 1-year post ASCT. One died from an ASCT complication (metapneumovirus) while the other relapsed 6 months following ASCT (included in MRD analysis). The most common toxicity due to CpG-MCL vaccine was erythematous rash at injection site (90.9%, n=20, each grade 1). No serious adverse events were seen related to vaccines or adoptive T-cell transfer. All patients had successful hematopoietic recovery, but two were delayed and received backup stem cell infusions with eventual recovery. Though median PFS and OS have not been reached, 3-year PFS and OS at interim analysis are 54.5% and 63.6%, respectively (intention to treat). In this data set, higher expression of co-stimulatory molecules (such as CD40, CD80, and CD86) on a subject's MCL in response to CpG was associated with freedom from MRD (p =0.02). Post-ASCT, higher peripheral T-cell granzyme and perforin response to ex vivo re-challenge with autologous MCL cells was also associated with freedom from MRD (p =0.01).ConclusionsThe addition of CpG-activated, whole MCL vaccination and autologous, adoptive T-cell transfer to standard therapy appears both feasible and safe. At interim analysis, the 1-year freedom from MRD surpasses rates previously reported in other studies and warrants further investigation. To date, 46 patients have either completed and/or are continuing to undergo study treatment and the study remains open to accrual for patients newly diagnosed with MCL. DisclosuresMiklos:Pharmacyclics: Research Funding. Rezvani:Pharmacyclics: Research Funding. Faham:Adaptive Biotechnologies: Employment. Levy:Immune Design: Research Funding; Dynavax: Research Funding.

Detection and Tracking of NY-ESO-1-Specific CD8+ T Cells by High-Throughput T Cell Receptor β (TCRB) Gene Rearrangements Sequencing in a Peptide-Vaccinated Patient

Comprehensive immunological evaluation is crucial for monitoring patients undergoing antigen-specific cancer immunotherapy. The identification and quantification of T cell responses is most important for the further development of such therapies. Using well-characterized clinical samples from a high responder patient (TK-f01) in an NY-ESO-1f peptide vaccine study, we performed high-throughput T cell receptor β-chain (TCRB) gene next generation sequencing (NGS) to monitor the frequency of NY-ESO-1-specific CD8+ T cells. We compared these results with those of conventional immunological assays, such as IFN-γ capture, tetramer binding and limiting dilution clonality assays. We sequenced human TCRB complementarity-determining region 3 (CDR3) rearrangements of two NY-ESO-1f-specific CD8+ T cell clones, 6-8L and 2F6, as well as PBMCs over the course of peptide vaccination. Clone 6-8L possessed the TCRB CDR3 gene TCRBV11-03*01 and BJ02-01*01 with amino acid sequence CASSLRGNEQFF, whereas 2F6 possessed TCRBV05-08*01 and BJ02-04*01 (CASSLVGTNIQYF). Using these two sequences as models, we evaluated the frequency of NY-ESO-1-specific CD8+ T cells in PBMCs ex vivo. The 6-8L CDR3 sequence was the second most frequent in PBMC and was present at high frequency (0.7133%) even prior to vaccination, and sustained over the course of vaccination. Despite a marked expansion of NY-ESO-1-specific CD8+ T cells detected from the first through 6th vaccination by tetramer staining and IFN-γ capture assays, as evaluated by CDR3 sequencing the frequency did not increase with increasing rounds of peptide vaccination. By clonal analysis using 12 day in vitro stimulation, the frequency of B*52:01-restricted NY-ESO-1f peptide-specific CD8+ T cells in PBMCs was estimated as only 0.0023%, far below the 0.7133% by NGS sequencing. Thus, assays requiring in vitro stimulation might be underestimating the frequency of clones with lower proliferation potential. High-throughput TCRB sequencing using NGS can potentially better estimate the actual frequency of antigen-specific T cells and thus provide more accurate patient monitoring.

MP2-20 FEASIBILITY STUDY OF PERSONALIZED PEPTIDE VACCINATION FOR PLATINUM-BASED CHEMOTHERAPY RESISTANT METASTATIC UPPER TRACT UROTHELIAL CARCINOMA PATIENTS

You have accessJournal of UrologyBladder Cancer: Upper Tract TCC I1 Apr 2015MP2-20 FEASIBILITY STUDY OF PERSONALIZED PEPTIDE VACCINATION FOR PLATINUM-BASED CHEMOTHERAPY RESISTANT METASTATIC UPPER TRACT UROTHELIAL CARCINOMA PATIENTS Shigetaka Suekane, Masanori Noguchi, Kousuke Ueda, Tsukasa Igawa, Tetsuro Sasada, and Kyogo Itoh Shigetaka SuekaneShigetaka Suekane More articles by this author , Masanori NoguchiMasanori Noguchi More articles by this author , Kousuke UedaKousuke Ueda More articles by this author , Tsukasa IgawaTsukasa Igawa More articles by this author , Tetsuro SasadaTetsuro Sasada More articles by this author , and Kyogo ItohKyogo Itoh More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.143AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The prognosis of metastatic upper tract urothelial carcinoma ( UTUC ) patients who failed platinum-based chemotherapy remains very poor. We conducted a feasibility study of personalized peptide vaccine ( PPV ) for platinum-based chemotherapy resistant metastatic UTUC patients to explore cancer vaccine as a new treatment modality. METHODS A total of 34 UTUC patients were enrolled to this study, who were platinum-based chemotherapy resistant metastatic 21 pelvic cancer and 13 ureter cancer. A maximum of four HLA-matched peptides showing higher antigen-specific immunoglobulin G ( IgG ) responses were selected based on measurement of IgG against different cytotoxic T lymphocyte ( CTL ) epitope peptides followed by subcutaneous vaccination. This study protocol was approved by the institutional ethical review boards of Kurume University, and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all patients before entering this clinical trial. RESULTS There were no vaccine-related severe adverse events of PPV in all patients. Median overall survival ( OS ) time from the first PPV was 13.0 months in platinum-based chemotherapy resistant metastatic UTUC patients. Increased the anti-peptide IgG titer were revealed seventeen patients ( 50.0% ) of thirty-four patients at post 6th vaccination, and sixteen patients ( 100% ) of sixteen patients at post 12th vaccination. Seventeen patients with 12th more PPV showed significantly longer survival than 17 patients with less than 12th PPV (hazard ratio [HR], 4.775, P=0.0015). Peptide-specific immune response at 12th PPV in platinum-based chemotherapy resistant metastatic UTUC patients was favorable biomarker for OS ( P=0.0002 ), regardless of the response at 6th PPV. CONCLUSIONS PPV as a new treatment modality in patients with platinum-based chemotherapy resistant metastatic UTUC is active and well tolerated, improving survival with immune responses. Further large-scale, randomized trials are needed to confirm these results. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e18 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shigetaka Suekane More articles by this author Masanori Noguchi More articles by this author Kousuke Ueda More articles by this author Tsukasa Igawa More articles by this author Tetsuro Sasada More articles by this author Kyogo Itoh More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Abstract 2892: Vaccination with a therapeutic cancer vaccine containing prostate specific antigen and the biological adjuvants IL-2 and GM-CSF results in reduced serum PSA in prostate cancer patients

Abstract In 1997 we initiated a phase I/II clinical trial of a therapeutic prostate cancer vaccine. We have enrolled 12 biopsy confirmed prostate cancer patients in this study and 11 finished the initial course of 6 intradermal vaccinations containing prostate specific antigen (50 μg) and biological adjuvants (IL-2, 20,000 units, and GM-CSF, 16.7 μg) at 0, 1, 2, 6, 10 and 14 weeks. During this study the prostate cancer patients received no other concurrent therapy (surgery, hormone, radiation, radioactive seeds, chemotherapy). One of the 12 patient's PSA rose from 7.6 to 13.7 after the fourth vaccination and he (patient #8) withdrew from the study to seek other therapy. In the remaining 11 prostate cancer patients serum PSA concentrations were determined before initiating vaccination and 3-4 weeks after the 6th vaccination. There was a decrease in the PSA levels in 8 of 12 of the prostate cancer patients after 6 vaccinations. One of the patients (patient #3), whose PSA had dropped from 6.8 to 6.4 and had previously received radiotherapy (the only patient previously treated), elected to withdraw from the study and underwent radical prostatectomy. Nine of the original 12 patients have received monthly 3 intradermal IL-2 injections (11 million units) alternated with 3 further vaccinations for the 6 months following the initial vaccinations, and 8 patients have been followed from 18 to 92 months. The mean PSA values for the 8 patients still being followed without additional therapy were 5.8 initially, decreasing to 4.1 after 6 vaccines, 3.7 after 12 vaccines and is 4.7 after a mean follow-up of 49 months (median follow-up of 45.5 months). These promising results have led to the creation of the U.S. Navy Cancer Vaccine Program with a Phase I clinical trial at the Veterans Administration Medical Center San Diego/UCSD Medical School. Citation Format: Jonathan F. Head, Robert L. Elliott. Vaccination with a therapeutic cancer vaccine containing prostate specific antigen and the biological adjuvants IL-2 and GM-CSF results in reduced serum PSA in prostate cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2892. doi:10.1158/1538-7445.AM2014-2892

A phase II trial evaluating the clinical and immunologic response of HLA-A2+ non-small cell lung cancer patients vaccinated with an hTERT cryptic peptide

ObjectivesThe immunological and clinical responses of patients with NSCLC treated, in the context of an expanded action program, with the cryptic hTERT-targeting Vx-001 vaccine are presented. Materials and methodsForty-six HLA-A*0201-positive patients with advanced NSCLC and residual (n=27) or progressive (n=19) disease following front-line treatment received two subcutaneous injections of the optimized TERT572Y peptide followed by four injections of the native TERT572 peptide, every 3 weeks. Peptide-specific immune responses were monitored by enzyme-linked immunosorbent spot assay at baseline, and after the 2nd and the 6th vaccinations. Thirty-eight HLA-A*0201-positive matched patients were used as historical controls. ResultsTwenty-three patients (50%) completed the vaccination protocol and 87% received at least two administrations. Twelve patients (26%) without disease progression after the 6th vaccination received boost vaccinations. Three (7%) patients achieved a partial response and 13 (28%) disease stabilization. The disease control rate was significantly higher in patients with non-squamous histology compared to those with squamous-cell histology [n=14 (45%) versus n=2 (13%); p=0.03]. The median progression-free survival (PFS) and overall survival (OS) was 3.8 (range, 0.7–99.4) and 19.8 months (range, 0.7–99.4), respectively. Patients who developed immune response had a numerically higher PFS compared to those who failed to mount any (6.7 versus 2.7 months; p=0.090). However, the median OS for the immune-responders was significantly prolonged compared to non-responders (40.0 versus 9.2 months, respectively; p=0.02). Toxicity was <grade 2. ConclusionVx-001 vaccine is well tolerated and induced a TERT-specific immunological response, which was significantly correlated with improved clinical outcome.

Feasibility study of personalized peptide vaccination for recurrent ovarian cancer patients

Context: To develop a personalized peptide vaccine (PPV) for recurrent ovarian cancer patients and evaluate its efficacy from the point of view of overall survival (OS), Phase II study of PPV was performed.Patients and methods: Forty-two patients, 17 with platinum-sensitive and 25 with platinum-resistant recurrent ovarian cancer, were enrolled in this study and received a maximum of four peptides based on HLA-A types and IgG responses to the peptides in pre-vaccination plasma.Results: Expression of 13 of the 15 parental tumor-associated antigens encoding the vaccine peptides, with the two prostate-related antigens being the exceptions, was confirmed in the ovarian cancer tissues. No vaccine-related systemic severe adverse events were observed in any patients. Boosting of cytotoxic T lymphocytes or IgG responses specific for the peptides used for vaccination was observed in 18 or 13 of 42 cases at 6th vaccination, and 19 or 29 of 30 cases at 12th vaccination, respectively. The median survival time (MST) values of the platinum-sensitive- and platinum-resistant recurrent cases were 39.3 and 16.2 months, respectively. The MST of PPV monotherapy or PPV in combination with any chemotherapy during the 1st to 12th vaccination of platinum-sensitive cases was 39.3 or 32.2 months, and that of platinum-resistant cases was 16.8 or 16.1 months, respectively. Importantly, lymphocyte frequency and epitope spreading were significantly prognostic of OS.Discussion and conclusion: Because of the safety and possible prolongation of OS, a clinical trial of PPV without chemotherapy during the 1st to 12th vaccination in recurrent ovarian cancer patients is merited.

Abstract P5-01-05: Personalized peptide vaccines in combination with conventional chemo- or endocrine therapy for metastatic breast cancer: A single-arm phase II study

Abstract Background: Immunotherapy using multiple personalized peptide vaccines (PPV) has been reported to be effective for boosting anticancer immunity in patients (pts) with advanced prostate cancer and glioblastoma. The PPVs binding HLA-A2, A24, A3 family and A26 molecules were selected from 31 candidate peptides derived from various tumor associated antigens. Currently, we performed a phase II trial to evaluate the benefit of the PPVs in combination with conventional chemo-or endocrine therapy for pretreated metastatic breast cancer (MBC). Methods: Seventy-one pretreated pts had histologically confirmed measurable MBC and their HLA A molecules matched each of HLA-A2, A24, A26 and A3 family. Pre-vaccination plasma was measured for their IgG levels reactive to each of 31 peptides followed by administration subcutaneously of the four peptides at maximum showing higher levels of IgG in order with schedule of every 1-2 week. The concurrent conventional chemotherapy or endocrine therapy was available for the combination of PPVs. The primary endpoint was anti-tumor immunologic effect and safety, and the secondary endpoints were clinical responses and survival. Levels of IgG reactive to each of the 31 peptides in the pre- and post-treatment plasma at every 6 times of vaccination were measured using LUMNEX system. The CTL responses were simultaneously evaluated using ELISPOT method. Clinical response was evaluated by RECIST criteria. Results: Between May 2009 and December 2012, a total of 71 pts (Luminal-Her2- cases: 39; Her2+cases: 18; Triple negative(TN) cases:14) were enrolled in this study. The median duration of follow-up was 20.7 months. Concurrent chemotherapies (capecitabine, gemcitabine, eribulin, vinorelbine etc.) and endocrine therapies (aromatase inhibitor, toremifen or fulvestrant) were administered to 36 and 24 pts, respectively. Trastuzumab, Laptinib or Bevacizumab was simultaneously used for 13 pts. After 6th vaccination, the IgG reaction and CTL response were identified in 53 of 71 (74.6%) pts and 33 of 63 (52.3%) pts. There were no significant differences between TN cases and the other cases of MBC with regard to immunological humoral and/or cellular responses. No vaccine-related severe adverse events were observed. Clinical response rate of assessable 61 pts was 14.8% (CR 3, PR 6, SD 24, PD 28). The median PFS and OS were 7.6 m and 20.7 m, respectively. In contrast, the PFS and OS of luminal type, Her2 type or TN type were 12, 4.6 or 8.3 m and 24, 15 or 12 m. Conclusions: The phase II PPVs study for MBC demonstrated the promising response and safety, and further studies are essential to identify the clinical benefits of this novel therapy. Clinical trial information: UMIN000001482. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-01-05.

Abstract P4-13-04: Autologous dendritic cells vaccines combined with neoadjuvant chemotherapy increase total pCR in stages II-III non-overexpressing HER2 breast cancer patients and induce phenotypic changes in peripheral blood

Abstract Background Based on the synergistic effect between immuno- and chemotherapy (CT), we have elaborated an autologous vaccine with dendritic cells loaded with patients´ own tumor antigens (lysate), and we have already demonstrated that the addition of the vaccines to a standard neoadjuvant CT schedule has increased total pCR (breast+ axilla) in stages II-III non-overexpressing HER2 breast cancer patients (Santisteban M, SABCS 2012). Both cohorts, the control (C) and the vaccinated (V) were well balanced related to demographic characteristics. Toxicity has been similar in both the C and the V cohorts. Moreover, we have analyzed the phenotypic changes in peripheral blood induced by the vaccine and its correlation with pathologic responses. Indeed, we have studied if the amount of lysate used to load the dendritic cells or the total dendritic cell numbers received by the patients in the first five doses (before surgery) is correlated with pCR Methods Twenty-eight patients with stage II-III HER2 negative breast cancer have started on sequential neoadjuvant CT based on dose dense antracyclines (E 100mg/m2 and C 600 mgr/m2) x4 cycles plus GM-CSF followed by taxanes (DOC 75-100 mgr/m2) x4 cycles plus vaccination. The C historic cohort was composed of thirty patients who received the same treatment except for the absence of the vaccines. Vaccine calendar was started after the 4th EC and alternated with DOC and as maintenance up to a maximum of a 2 year-period. The first 5 vaccines were administered before breast surgery. Changes in different lymphocytes populations were measured in peripheral blood of patients at different points by flow cytometry (absolute cell counts). To date, twenty-one patients have both determinations of lymphocyte subpopulations before the 1st and the 6th vaccine. Paired samples t-tests and Fisher exact were used Results pCR was superior in the V cohort (24% versus 3.3%, p = 0.04). Lymphocyte subpopulations were measured in peripheral blood (cells/uL) and a stimulation of the immune system was found after the 5 vaccines schedule at the time of surgery as follows: NK (p&amp;lt;0.001), T cytotoxic CD8 (p = 0.018), T helper CD4 (p = 0.04), CD19 (p = 0.001), HLADRCD8 (p = 0.007), CD16CD8 (p = 0.003), HLADRCD4 (p&amp;lt;0.001), CD16CD4 (p = 0.008) and T regulators lymphocytes (p = 0.004). We did not find any differences among CD57CD8 (p = 0.17), CD56CD8 (p = 0.11), CD57CD4 (p = 0.45) and CD56CD4 (p = 0.65). We neither see correlation among the amount of lysate to load dendritic cells and the tpCR (p = 0.09) nor the amount of dendritic cells (summatory of 5 vaccines) administered intradermally and the pCR (p = 0.59) Conclusions Immunotherapy added to standard neoadjuvant CT could improve total pCR in stage II-III non-overexpressing HER2 breast cancer patients. After 5 doses of vaccination plus chemotherapy, we can observe phenotypic changes in peripheral blood: some immune system subpopulations increased statistically after the treatment in vaccinated patients. Neither the amount of lysate nor the number of dendritic cells used in the five first vaccines significantly correlated with the pRC. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-13-04.

Induction Of In Vivo Oligoclonal T Cell Expansion and Specific In Vitro T Cell Responses Following K562/GM-CSF Vaccination Of MDS Patients

BackgroundMyelodysplatic syndromes (MDS) are a heterogeneous group of clonal hematopoietic stem cell malignancies, characterized by the ineffective hematopoiesis, and risk of progression to acute myeloid leukemia. Allogeneic stem cell transplant (SCT) remains the only potentially curative therapy, but toxicities limit its application in older adults. Vaccination strategies have been developed to modulate the immune system, ideally with less toxicity. We present results from a pilot study of single agent K562/GM-CSF whole cell vaccination in MDS patients (pts). MethodsPoor-risk or transfusion-dependent MDS pts (n=5) were enrolled and received K562/GM-CSF whole cell vaccine (1 X 108 cells) every 3 weeks for 4 cycles followed by a booster vaccination 8 weeks later. Eligible pts could receive supportive care only for the 2 months preceding study entry, have no history of SCT, and not be on immunosuppressants. Blood, bone marrow, and skin biopsies were taken prior to vaccination, day 4 following first vaccine, and at 4 weeks after the booster vaccination. Diversity of the T cell compartment was assessed in the blood, marrow and skin using the TCRExpress Quantitative Analysis Kit (Biomed Immunotech, Tampa FL). Fragment length analysis was performed by the DNA Analysis Facility. In vitro stimulation studies for proliferation and cytokine production were performed using peripheral blood monocytes (PBMCs) for the pt with the best clinical response (>4 years). Proliferation of banked PBMCs, collected prior to every vaccination and stimulated with the vaccine, was assessed using 3H-Thymidine. The cytokines generated were measured using a multiplexed bead based immunoassay (Human 17-plex bioplex pro-panel) (Biorad, Hercules CA). ResultsAll pts tolerated the vaccinations well with localized skin reactions being common. Clinically, 2 pts normalized their blood counts and became transfusion independent following the immunotherapy. One responding pt (CMML) remained stable without need for medical intervention for 4 yrs and only recently showed progression. T cell spectratyping indicated oligocolonal populations of T cells in post-vaccination skin, blood and marrow samples. T cells infiltrating the skin were tracked to the marrow. Interestingly, the best clinical responder demonstrated the most restricted skewed repertoire with a significant number of oligoclonal T cells tracking from skin to marrow (n=5). The marrow also had infiltrates of oligoclonal T cells not detected in the post-vaccination skin. Further, this skewed repertoire was absent when the pt relapsed. Proliferation assays measuring this pt's T cell cytokine production in response to the vaccine cells in vitro, showed increased levels of IL-2, IL-13 and IL-5 that were suppressed or not produced by the time of the 4th vaccination. Inversely, IL-6, IL-10, IL-17, IL-1beta, MIP-1beta and TNF alpha levels increased throughout. The expected proliferative “boost” was seen with the initiation of the booster vaccine series at the time of progression, and co-culture of the pt's lymphocytes with the vaccine cells suppressed the ability of the vaccine cells to produce GM-CSF in vitro. The ability to suppress GM-CSF production decreased during therapy and the pt's lymphocytes had no effect on GM-CSF production by the vaccine at the end of the immunotherapy. ConclusionsAll pts showed T cell skewing by spectratyping analysis, suggesting that each had a change in T cell proliferation patterns in response to the vaccine. One pt had a significant clinical response and the most specific T cell response by spectratyping to the original vaccine, followed by the absence of these cells in the marrow at the time of progression. This suggests that an immune response may have stabilized his disease and progression was associated with loss of this T cell population. Proliferation studies suggest that the lymphocytes recognized the vaccine. Lastly, GM-CSF levels produced by the vaccine were decreased during the vaccination cycles suggesting that the pt's lymphocytes and/or tumor had a suppressive effect on the vaccine cells. It is unclear if the GM-CSF suppression was essential, detrimental, or unrelated to the pt's clinical response. Further study of the T cells patterns in these pts may elucidate details of the immune response that are integral to clinical responses. Disclosures:No relevant conflicts of interest to declare.

New Wisdom to Defy an Old Enemy: Summary from a scientific symposium at the 4th Influenza Vaccines for the World (IVW) 2012 Congress, 11 October, Valencia, Spain

Both seasonal and pandemic influenza cause considerable morbidity and mortality globally. In addition, the ongoing threat of new, unpredictable influenza pandemics from emerging variant strains cannot be underestimated. Recently bioCSL (previously known as CSL Biotherapies) sponsored a symposium ‘New Wisdom to Defy an Old Enemy’ at the 4th Influenza Vaccines for the World Congress in Valencia, Spain. This symposium brought together a renowned faculty of experts to discuss lessons from past experience, novel influenza vaccine developments, and new methods to increase vaccine acceptance and coverage.Specific topics reviewed and discussed included new vaccine development efforts focused on improving efficacy via alternative administration routes, dose modifications, improved adjuvants, and the use of master donor viruses. Improved safety was also discussed, particularly the new finding of an excess of febrile reactions isolated to children who received the 2010 Southern Hemisphere (SH) trivalent inactivated influenza vaccine (TIV). Significant work has been done to both identify the cause and minimize the risk of febrile reactions in children.Other novel prophylactic and therapeutic advances were discussed including immunotherapy. Standard IVIg and hIVIg have been used in ferret studies and human case reports with promising results. New adjuvants, such as ISCOMATRIX™ adjuvant, were noted to provide single-dose, prolonged protection with seasonal vaccine after lethal H5N1 virus challenge in a ferret model of human influenza disease. The data suggest that adjuvanted seasonal influenza vaccines may provide broader protection than unadjuvanted vaccines. The use of an antigen-formulated vaccine to induce broad protection between pandemics that could bridge the gap between pandemic declaration and the production of a homologous vaccine was also discussed.Finally, despite the availability of effective vaccines, most current efforts to increase influenza vaccine coverage rates to higher levels (i.e., above 70–80%) have been ineffective in highly developed countries where the vaccine is used, hindered by the public's skepticism towards vaccines in general. New educational and social media methods to increase vaccine acceptance and coverage were discussed. While the first priority should be the development of improved influenza vaccines, a particular focus on the aging global population is critical. It is also important to draw lessons from other academic disciplines that can help to inform vaccine education programs, policy, and communication. By tailoring communications and patient education using an understanding of cognitive bias and the model of preferred cognitive styles, the likelihood of effecting desirable health decisions can be maximized, leading to improved vaccine coverage and control of influenza and other vaccine-preventable diseases.