Elizabeth Veloso

Restoration of immunity in lymphopenic individuals with cancer by vaccination and adoptive T-cell transfer

Immunodeficiency is a barrier to successful vaccination in individuals with cancer and chronic infection. We performed a randomized phase 1/2 study in lymphopenic individuals after high-dose chemotherapy and autologous hematopoietic stem cell transplantation for myeloma. Combination immunotherapy consisting of a single early post-transplant infusion of in vivo vaccine-primed and ex vivo costimulated autologous T cells followed by post-transplant booster immunizations improved the severe immunodeficiency associated with high-dose chemotherapy and led to the induction of clinically relevant immunity in adults within a month after transplantation. Immune assays showed accelerated restoration of CD4 T-cell numbers and function. Early T-cell infusions also resulted in significantly improved T-cell proliferation in response to antigens that were not contained in the vaccine, as assessed by responses to staphylococcal enterotoxin B and cytomegalovirus antigens (P < 0.05). In the setting of lymphopenia, combined vaccine therapy and adoptive T-cell transfer fosters the development of enhanced memory T-cell responses.

Combination immunotherapy using adoptive T-cell transfer and tumor antigen vaccination on the basis of hTERT and survivin after ASCT for myeloma

In a phase 1/2 two-arm trial, 54 patients with myeloma received autografts followed by ex vivo anti-CD3/anti-CD28 costimulated autologous T cells at day 2 after transplantation. Study patients positive for human leukocyte antigen A2 (arm A, n = 28) also received pneumococcal conjugate vaccine immunizations before and after transplantation and a multipeptide tumor antigen vaccine derived from the human telomerase reverse transcriptase and the antiapoptotic protein survivin. Patients negative for human leukocyte antigen A2 (arm B, n = 26) received the pneumococcal conjugate vaccine only. Patients exhibited robust T-cell recoveries by day 14 with supraphysiologic T-cell counts accompanied by a sustained reduction in regulatory T cells. The median event-free survival (EFS) for all patients is 20 months (95% confidence interval, 14.6-24.7 months); the projected 3-year overall survival is 83%. A subset of patients in arm A (36%) developed immune responses to the tumor antigen vaccine by tetramer assays, but this cohort did not exhibit better EFS. Higher posttransplantation CD4(+) T-cell counts and a lower percentage of FOXP3(+) T cells were associated with improved EFS. Patients exhibited accelerated polyclonal immunoglobulin recovery compared with patients without T-cell transfers. Adoptive transfer of tumor antigen vaccine-primed and costimulated T cells leads to augmented and accelerated cellular and humoral immune reconstitution, including antitumor immunity, after autologous stem cell transplantation for myeloma. This study was registered at www.clinicaltrials.gov as NCT00499577.

Telomerase-Specific T-Cell Immunity in Breast Cancer: Effect of Vaccination on Tumor Immunosurveillance

The human telomerase reverse transcriptase (hTERT) is nearly universally overexpressed in human cancer, contributes critically to oncogenesis, and is recognized by cytotoxic T cells that lyse tumors. CD8+ T cells specific for hTERT naturally occur in certain populations of cancer patients in remission, but it remains poorly understood whether such T cells could contribute to tumor immunosurveillance. To address this issue, we induced hTERT-specific T cells in vivo via peptide vaccination in 19 patients with metastatic breast cancer who otherwise had no measurable T-cell responses to hTERT at baseline. Tumor-infiltrating lymphocytes (TIL) were evident after, but not before vaccination, with 4% to 13% of postvaccine CD8+ TIL specific for the immunizing hTERT peptide. Induction of TIL manifested clinically with tumor site pain and pruritus and pathologically with alterations in the tumor microenvironment, featuring histiocytic accumulation and widespread tumor necrosis. hTERT-specific CD8+ T cells were also evident after vaccination in the peripheral blood of patients and exhibited effector functions in vitro including proliferation, IFN-gamma production, and tumor lysis. An exploratory landmark analysis revealed that median overall survival was significantly longer in those patients who achieved an immune response to hTERT peptide compared with patients who did not. Immune response to a control cytomegalovirus peptide in the vaccine did not correlate with survival. These results suggest that hTERT-specific T cells could contribute to the immunosurveillance of breast cancer and suggest novel opportunities for both therapeutic and prophylactic vaccine strategies for cancer.

Rapid Immune Recovery and Graft-versus-Host Disease ^ like Engraftment Syndrome following Adoptive Transfer of Costimulated Autologous T Cells

Purpose: Previously, we showed that adoptive transfer of in vivo vaccine-primed and ex vivo (anti-CD3/anti-CD28) costimulated autologous T cells (ex-T) at day +12 after transplant increased CD4 and CD8 T-cell counts at day +42 and augmented vaccine-specific immune responses in patients with myeloma. Here, we investigated the safety and kinetics of T-cell recovery after infusing ex-T at day +2 after transplant. Experimental Design: In this phase I/II two-arm clinical trial, 50 patients with myeloma received autografts after high-dose melphalan followed by infusions of ex-T at day +2 after transplant. Patients also received pretransplant and posttransplant immunizations using a pneumococcal conjugate vaccine only (arm B; n = 24) or the pneumococcal conjugate vaccine plus an HLA-A2–restricted multipeptide vaccine for HLA-A2+ patients (arm A; n = 26). Results: The mean number of T cells infused was 4.26 × 1010 (range, 1.59-5.0). At day 14 after transplant, the median CD3, CD4, and CD8 counts were 4,198, 1,545, and 2,858 cells/μL, respectively. Interleukin (IL)-6 and IL-15 levels increased early after transplant and IL-15 levels correlated significantly to day 14 T-cell counts. Robust vaccine-specific B- and T-cell responses were generated. T-cell infusions were well tolerated with no effect on hematopoietic recovery. Eight patients (16%) developed a T-cell “engraftment syndrome” characterized by diarrhea and fever that was clinically and histopathologically indistinguishable from grade 1 to 3 acute graft-versus-host disease (GVHD) of the gastrointestinal tract (seven patients) and/or grade 1 to 2 cutaneous GVHD (four patients). Conclusions: Adoptive T-cell transfers achieve robust T-cell recovery early after transplant and induce moderate-to-severe autologous GVHD in a subset of patients.

Antiviral effects of autologous CD4 T cells genetically modified with a conditionally replicating lentiviral vector expressing long antisense to HIV.

We report the safety and tolerability of 87 infusions of lentiviral vector–modified autologous CD4 T cells (VRX496-T; trade name, Lexgenleucel-T) in 17 HIV patients with well-controlled viremia. Antiviral effects were studied during analytic treatment interruption in a subset of 13 patients. VRX496-T was associated with a decrease in viral load set points in 6 of 8 subjects (P = .08). In addition, A → G transitions were enriched in HIV sequences after infusion, which is consistent with a model in which transduced CD4 T cells exert antisense-mediated genetic pressure on HIV during infection. Engraftment of vector-modified CD4 T cells was measured in gut-associated lymphoid tissue and was correlated with engraftment in blood. The engraftment half-life in the blood was approximately 5 weeks, with stable persistence in some patients for up to 5 years. Conditional replication of VRX496 was detected periodically through 1 year after infusion. No evidence of clonal selection of lentiviral vector–transduced T cells or integration enrichment near oncogenes was detected. This is the first demonstration that gene-modified cells can exert genetic pressure on HIV. We conclude that gene-modified T cells have the potential to decrease the fitness of HIV-1 and conditionally replicative lentiviral vectors have a promising safety profile in T cells.

Transfer of influenza vaccine–primed costimulated autologous T cells after stem cell transplantation for multiple myeloma leads to reconstitution of influenza immunity: results of a randomized clinical trial

Severe immune deficiency follows autologous stem cell transplantation for multiple myeloma and is associated with significant infectious morbidity. This study was designed to evaluate the utility of a pretransplantation vaccine and infusion of a primed autologous T-cell product in stimulating specific immunity to influenza. Twenty-one patients with multiple myeloma were enrolled from 2007 to 2009. Patients were randomly assigned to receive an influenza-primed autologous T-cell product or a nonspecifically primed autologous T-cell product. The study endpoint was the development of hemagglutination inhibition titers to the strain-specific serotypes in the influenza vaccine. Enzyme-linked immunospot assays were performed to confirm the development of influenza-specific B-cell and T-cell immunity. Patients who received the influenza-primed autologous T-cell product were significantly more likely to seroconvert in response to the influenza vaccine (P = .001). Seroconversion was accompanied by a significant B-cell response. No differences were observed in the global quantitative recovery of T-cell and B-cell subsets or in global T-cell and B-cell function. The provision of a primed autologous T-cell product significantly improved subsequent influenza vaccine responses. This trial was registered at www.clinicaltrials.gov as #NCT00499577.

Abstract 4575: Correlates of clinical response following autologous stem cell transplant and adoptive immunotherapy with engineered T cells expressing an affinity-enhanced T cell receptor in patients with mutliple myeloma.

Background: Adoptive immunotherapy for cancer has been limited by lack of antigen specificity, low levels of target expression, and failure to break self-tolerance. We are conducting an early phase clinical trial (NCT01352286) attempting to overcome these barriers using T cells engineered with an HLA-A0201 restricted, affinity-enhanced TCR that recognizes an epitope expressed by the NY-ESO-1 and LAGE-1 cancer testis antigens; these cells are infused in the setting of profound lymphodepletion that accompanies high-dose chemotherapy with autologous stem cell transplant (aSCT) for patients with high risk or relapsed multiple myeloma (MM). Methods: Inclusion criteria include: 1) eligibility for aSCT, 2) PS of 0-2, 3) high risk MM or relapse after prior therapy, 4) HLA-A0201 positive, and 5) NY-ESO-1 and/or LAGE-1 positive tumor by PCR. CD25 depleted T cells are activated and expanded using anti-CD3/28 antibody conjugated microbeads, and genetically modified with a lentiviral vector. T cells are administered four days after high dose melphalan and two days following auto-SCT. Patients are evaluated for MM responses in accordance with the IMWG criteria at 6 weeks, and 3 and 6 months. At 3 months, patients with adequate marrow function start lenalidomide maintenance. Blood and marrow are monitored for persistence of engineered cells by qPCR and by surface expression of the NY-ESO-1 / LAGE-1 TCR using dextramerTM reagents. NY-ESO-1 and LAGE-1 antigen expression in marrow was assessed by qRT-PCR at baseline and post infusion. Results: As of November 2012, 21 patients have been enrolled, 15 have been infused; 4 were taken off study prior to infusion due to disease progression. An average of 2.7 x 109 engineered T cells were administered per patient (range 8.3 x 108-4.2 x 109), and the average transduction efficiency was 33% (range 30%-45%). More than 50% (8/15) of patients have high risk chromosomal abnormalities, and 3 (20%) have received prior aSCT. At 3 months post aSCT, 73% of patients were in a very good partial response (VGPR) or better. Gastrointestinal toxicity resulting from autologous GVHD (aGVHD) occurred in a subset of patients at a higher rate than reported following aSCT alone or aSCT and T cell infusion, and was resolved in all cases. Infused T cells typically showed peak expansion in blood at day 14, followed by durable persistence in blood and marrow at 6-12 months in all but one patient. Disease progression is typically accompanied by very low levels or loss of engineered T cell persistence or loss of target antigen on tumor. Conclusions: We report for the first time that possible correlates of clinical response in this study include persistence of engineered T cells and loss of antigen, suggesting specific activity of the infused cells. Infusions are well tolerated with a possible risk of manageable aGVHD. Citation Format: Aaron P. Rapoport, Edward A. Stadtmauer, Dan T. Vogl, Brendan Weiss, Gwendolyn K. Binder-Scholl, Dominic P. Smethurst, Jeffrey Finkelstein, Irina Kulikovskaya, Minnal Gupta, Erica Suppa, Tatiana Mikheeva, Joanna E. Brewer, Alan D. Bennett, Andrew B. Gerry, Nick J. Pumphrey, Helen K. Tayton-Martin, Lilliam Ribeiro, Elizabeth Veloso, Zhaohui Zheng, Ashraf Z. Bados, Saul Yanovich, Gorgun Akpek, Karen Dengel, Naseem Kerr, Sunita Philip, Kelly-Marie Betts, Sandra Westphal, Bruce L. Levine, Bent K. Jakobsen, Carl H. June, Michael Kalos. Correlates of clinical response following autologous stem cell transplant and adoptive immunotherapy with engineered T cells expressing an affinity-enhanced T cell receptor in patients with mutliple myeloma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4575. doi:10.1158/1538-7445.AM2013-4575