scholarly journals Product Characteristics and Multi-Arm Clinical Trial Design for TSC-100 and TSC-101, TCR-T Cells That Target Leukemia Following Hematopoietic Cell Transplantation

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3863-3863
Author(s):  
Shrikanta Chattopadhyay ◽  
Christopher Malcuit ◽  
Ryo Takeuchi ◽  
Emmett Hedblom ◽  
Warren Jaworowicz ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Trial Design ◽  
Hematopoietic Cell Transplantation ◽  
Clinical Trial Design ◽  
Phase 2 ◽  
Engineered T Cells ◽  
Relapse Rates

Abstract Background: While adoptive cell therapies such as CAR-T therapies have transformed the treatment of lymphoid malignancies by targeting lineage-specific antigens, they have yet to demonstrate safety and efficacy against myeloid malignancies. T cells expressing T cell Receptors (TCRs) for the HLA-A*02:01-restricted minor histocompatibility antigens HA-1 and HA-2 have been observed to clonally expand after hematopoietic cell transplantation (HCT) in donor-recipient pairs mismatched for these antigens. These expanded T cells clones are associated with significantly lower relapse rates (Marijt et al. Proc. Natl. Acad. Sci. 2003; Spierings et al. Biol. Blood Marrow Transplant. 2013) indicating a specific graft versus leukemia effect. Engineered T cells expressing an HA-1-targeting TCR have demonstrated safety and preliminary anti-leukemic activity in patients with relapsed leukemia after HCT (Krakow et al. ASH 2020). We have developed engineered TCR-T cell products, TSC-100 and TSC-101, that target HA-1 and HA-2 respectively for the treatment of leukemias after HCT and present their product characteristics and the clinical trial design here. Methods and Results: To minimize potential safety risks, process variability, and costs associated with lentiviruses, our proprietary T-Integrate manufacturing platform uses a transposon/ transposase system delivered into pan T cells. This enables the introduction of larger vectors with an increased number of functional elements. Our transposon vector encodes both the α and β chains of the TCR under a strong promoter. We find high levels of cell-surface TCR that suppresses endogenous TCRs, thereby minimizing non-specific alloreactivity and potential graft versus host disease (GvHD). In mixed lymphocyte reactions, we find undetectable to minimal alloreactivity of the engineered T cell product compared with non-engineered T cells. The vector also encodes the α and β chains of CD8 ensuring that both CD8+ and CD4+ T cells in the product acquire cytotoxicity and we demonstrate efficient killing of target cells by both T cell types. The vector includes a short peptide tag that is recognized by a GMP-grade antibody, enabling efficient purification of engineered T cells during manufacturing along with the ability to track these T cells in patients. The manufacturing process generates more than 10 billion cells with an estimated vein-to-vein time of ~3 weeks, including product release testing. We routinely find high product purity exceeding 90% engineered T cells, high cytotoxicity in vitro and vector copy numbers <5 copies/cell, ensuring low risks of oncogenicity. The planned clinical trial design is a multi-arm Phase 1/2 trial that includes a control arm for safety and early efficacy comparisons. Patients with AML, ALL and MDS planned for HCT are eligible. Since disease burden is lowest soon after HCT with lower risks of acquired resistance, TCR-T treatment will begin shortly after HCT to prevent disease relapse. Because relapse rates are far higher with reduced intensity conditioning (RIC), only RIC-eligible patients are included. To ensure that all patient-donor pairs are mismatched for the minor antigens, only patients eligible for haploidentical transplantation will be included which enables HLA mismatches. Assignment to treatment or control arms is determined by HLA type as well as the minor antigen status as determined by a PCR-based central lab assay. Since both HA-1 and HA-2 are presented on HLA-A*02:01, all patients with HLA-A*02:01 are eligible for TCR-T treatment. HA-1-positive patients are assigned to the TSC-100 treatment and HA-2 positive patients are assigned to the TSC-101 arm. Donors for these patients are required to be mismatched at either HLA-A*02:01 or the minor antigens. HLA-A*02:01 negative patients will be assigned to the control arm. Analysis of CIBMTR datasets found that this HLA-based 'biological randomization' did not affect outcomes. Dosing of TCR-T cells begins upon count recovery after RIC-HCT and up to three doses will be administered every 40 days if there is no high-grade toxicity. Early readouts of biological activity include monitoring for minimal residual disease and kinetics of donor chimerism. Recruitment begins in Q1 2022 and after the recommended Phase 2 dose has been identified, the study will transition to a Phase 2 study to assess relapse rates of TSC-100- and TSC-101-treated patients versus the control arm. Disclosures Macbeath: TScan Therapeutics: Current Employment, Current equity holder in publicly-traded company.

scholarly journals Reconstitution of T Cell Subsets Following Allogeneic Hematopoietic Cell Transplantation

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1974 ◽  
Author(s):  
Linde Dekker ◽  
Coco de Koning ◽  
Caroline Lindemans ◽  
Stefan Nierkens
Keyword(s):  
Overall Survival ◽  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Hematopoietic Cell Transplantation ◽  
Cell Subset ◽  
Γδ T Cells ◽  
Hematopoietic Cell ◽  
T Cell Subsets ◽  
T Cell Subset

Allogeneic (allo) hematopoietic cell transplantation (HCT) is the only curative treatment option for patients suffering from chemotherapy-refractory or relapsed hematological malignancies. The occurrence of morbidity and mortality after allo-HCT is still high. This is partly correlated with the immunological recovery of the T cell subsets, of which the dynamics and relations to complications are still poorly understood. Detailed information on T cell subset recovery is crucial to provide tools for better prediction and modulation of adverse events. Here, we review the current knowledge regarding CD4+ and CD8+ T cells, γδ T cells, iNKT cells, Treg cells, MAIT cells and naive and memory T cell reconstitution, as well as their relations to outcome, considering different cell sources and immunosuppressive therapies. We conclude that the T cell subsets reconstitute in different ways and are associated with distinct adverse and beneficial events; however, adequate reconstitution of all the subsets is associated with better overall survival. Although the exact mechanisms involved in the reconstitution of each T cell subset and their associations with allo-HCT outcome need to be further elucidated, the data and suggestions presented here point towards the development of individualized approaches to improve their reconstitution. This includes the modulation of immunotherapeutic interventions based on more detailed immune monitoring, aiming to improve overall survival changes.

scholarly journals Donor-Derived CD4+ T Cells and Human Herpesvirus 6B Detection After Allogeneic Hematopoietic Cell Transplantation

2020 ◽  
Author(s):  
Derek J Hanson ◽  
Hu Xie ◽  
Danielle M Zerr ◽  
Wendy M Leisenring ◽  
Keith R Jerome ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Cd4 T Cells ◽  
Hematopoietic Cell Transplantation ◽  
Mononuclear Cells ◽  
Human Herpesvirus ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Peripheral Blood Mononuclear

Abstract We sought to determine whether donor-derived human herpesvirus (HHV) 6B–specific CD4+ T-cell abundance is correlated with HHV-6B detection after allogeneic hematopoietic cell transplantation. We identified 33 patients who received HLA-matched, non–T-cell–depleted, myeloablative allogeneic hematopoietic cell transplantation and underwent weekly plasma polymerase chain reaction testing for HHV-6B for 100 days thereafter. We tested donor peripheral blood mononuclear cells for HHV-6B–specific CD4+ T cells. Patients with HHV-6B detection above the median peak viral load (200 copies/mL) received approximately 10-fold fewer donor-derived total or HHV-6B–specific CD4+ T cells than those with peak HHV-6B detection at ≤200 copies/mL or with no HHV-6B detection. These data suggest the importance of donor-derived immunity for controlling HHV-6B reactivation.

scholarly journals Pretransplant CSF-1 therapy expands recipient macrophages and ameliorates GVHD after allogeneic hematopoietic cell transplantation

2011 ◽  
Vol 208 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Daigo Hashimoto ◽  
Andrew Chow ◽  
Melanie Greter ◽  
Yvonne Saenger ◽  
Wing-Hong Kwan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Cell Expansion ◽  
Acute Gvhd ◽  
Hematopoietic Cell Transplantation ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Host Macrophage

Acute graft-versus-host disease (GVHD) results from the attack of host tissues by donor allogeneic T cells and is the most serious limitation of allogeneic hematopoietic cell transplantation (allo-HCT). Host antigen-presenting cells are thought to control the priming of alloreactive T cells and the induction of acute GVHD after allo-HCT. However, whereas the role of host DC in GVHD has been established, the contribution of host macrophages to GVHD has not been clearly addressed. We show that, in contrast to DC, reducing of the host macrophage pool in recipient mice increased donor T cell expansion and aggravated GVHD mortality after allo-HCT. We also show that host macrophages that persist after allo-HCT engulf donor allogeneic T cells and inhibit their proliferation. Conversely, administration of the cytokine CSF-1 before transplant expanded the host macrophage pool, reduced donor T cell expansion, and improved GVHD morbidity and mortality after allo-HCT. This study establishes the unexpected key role of host macrophages in inhibiting GVHD and identifies CSF-1 as a potential prophylactic therapy to limit acute GVHD after allo-HCT in the clinic.

Immune Reconstitution after Haploidentical Hematopoietic Cell Transplantation: Impact of Reduced Intensity Conditioning and CD3/CD19-Depleted Grafts

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1175-1175
Author(s):  
Birgit Federmann ◽  
Matthias Haegele ◽  
Christoph Faul ◽  
Wichard Vogel ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cell Transplantation ◽  
Immune Reconstitution ◽  
Hematopoietic Cell Transplantation ◽  
Nk Cell ◽  
Reduced Intensity Conditioning ◽  
Haploidentical Hematopoietic Cell Transplantation ◽  
Reduced Intensity

Abstract Haploidentical hematopoietic cell transplantation (HHCT) using CD3/CD19 depleted grafts may lead to faster engraftment and immune reconstitution since grafts contain also graft-facilitating-cells, CD34− progenitors, NK cells, and dendritic cells. Reduced intensity conditioning may also have a positive impact on immune reconstitution following HHCT. 26 adults received CD3/CD19 depleted HHCT after RIC (150–200 mg/m2 fludarabine, 10mg/kg thiothepa, 120 mg/m2 melphalan and 5mg/day OKT-3 (day −5 to +14)) at our institution between 2005–2008. We prospectively evaluated engraftment and immune reconstitution. B-, NK-, T- and T-cell subsets (CD3/8, CD4/8, CD4/45RA/RO), TCR-Vβ repertoire and NK-cell receptors (NKP30, NKP44, NKP46, NKG2D, CD158a/b/e, CD85j, NKG2A, CD161) were analyzed by FACS. Grafts contained 8.8×106 CD34+ (range, 4.3–18.0 ×106), 2.9×104 CD3+ (range, 1.2–9.2×104) and 3.6×107 CD56+ (range, 0.02–23.0 ×107) cells/kg. Engraftment was rapid with a median time to >500 granulocytes/μl of 11 days (range, 9–15) and a median time to >20 000 platelets/μl of 11 days (range, 8–23). Full chimerism was reached on day 14 (median; range, 6–26). NK-cell engraftment was rapid, reaching normal values on day 20 (median of 247 CD16+CD56+CD3− cells/μl (range, 1–886)) with NK cells comprising up to 70% of lymphocytes. B-cell reconstitution was delayed with 81 (range, 0–280) and 335 (range, 11–452) CD19+20+ cells/μl on days 150 and 400, respectively. T-cell reconstitution was impaired with 49 (range, 0–586) and 364 (range, 35–536) CD3+ cells/μl on day 60 and day 150, respectively. We observed an increase of CD3+CD8+ cells in contrast to CD3+CD4+ cells early after HHCT with a median of 24 (range, 0–399) vs 16 (range, 0–257) and 159 (range, 1–402) vs 96 (range, 18–289) cells/μl on day 50 and day 200, respectively. CD4+CD45RA+ T cells increased slowly while CD4+CD45RO+ T cells reconstituted faster with a median of 61 CD4+CD45RO+ cells/μl (range, 0–310) vs 24 CD4+CD45RA+ (range, 0 to 152) on day 100. Within the CD4+CD25+ regulatory T cells there was a slow regeneration with median of 14 CD4+CD25+ cells/μl (range, 0–96) on day 100 and 28 CD4+CD25+ cells/μl (range, 19–160) on day 200. CD14+CD45+ monocytes did not reach normal values within the time of observation with 7 CD14+CD45+ cells/μl (range, 0–21) on day 120 and 7 CD14+CD45+ cells (range, 2–381) on day 400. TCR-Vβ repertoire and NK-cell receptor reconstitution was analyzed so far in 7 and 8 patients, respectively. We found a skewed T-cell repertoire with oligoclonal T-cell expansions to day 100 and normalization after day 200. An increased natural cytotoxicity receptor (NKP30, NKP44, NKP46) and NKG2A, but decreased NKG2D and KIR-expression was observed on NK-cells until day 100. In conclusion, T- and B-cell reconstitution is delayed after HHCT using CD3/CD19 depleted grafts and RIC. However, T-cell reconstitution is faster compared to data published with CD34 selected grafts and myeloablative conditioning. A fast NK-cell reconstitution early after HHCT was observed. Thus a combination of reduced intensity conditioning with CD3/CD19 depleted grafts appears to accelerate the immune recovery after haploidentical stem cell transplantation.

Increased apoptosis of peripheral blood T cells following allogeneic hematopoietic cell transplantation

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3832-3839 ◽  
Author(s):  
Ming-Tseh Lin ◽  
Li-Hui Tseng ◽  
Haydar Frangoul ◽  
Ted Gooley ◽  
Ji Pei ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Cell Apoptosis ◽  
Hematopoietic Cell Transplantation ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Cd4 T Cell ◽  
Spontaneous Apoptosis ◽  
T Cell Apoptosis

Lymphopenia and immune deficiency are significant problems following allogeneic hematopoietic cell transplantation (HCT). It is largely assumed that delayed immune reconstruction is due to a profound decrease in thymus-dependent lymphopoiesis, especially in older patients, but apoptosis is also known to play a significant role in lymphocyte homeostasis. Peripheral T cells from patients who received HCT were studied for evidence of increased cell death. Spontaneous apoptosis was measured in CD3+ T cells following a 24-hour incubation using 7-amino-actinomycin D in conjunction with the dual staining of cell surface antigens. Apoptosis was significantly greater among CD3+ T cells taken from patients 19-23 days after transplantation (30.4% ± 12.5%,P < .05), and 1 year after transplantation (9.7% ± 2.8%, P < .05) compared with healthy controls (4.0% ± 1.5%). Increased apoptosis occurred preferentially in HLA (human leukocyte antigen)-DR positive cells and in both CD3+/CD4+ and CD3+/CD8+ T-cell subsets, while CD56+/CD3− natural killer cells were relatively resistant to apoptosis. The extent of CD4+T-cell apoptosis was greater in patients with grade II-IV acute graft-versus-host disease (GVHD) (33.9% ± 11.3%) compared with grade 0-I GVHD (14.6 ± 6.5%, P < .05). T-cell apoptosis was also greater in patients who received transplantations from HLA-mismatched donors (39.5% ± 10.4%,P < .05) or HLA-matched unrelated donors (32.1% ± 11.4%, P < .05) compared with patients who received transplantations from HLA-identical siblings (19.6% ± 6.7%). The intensity of apoptosis among CD4+ T cells was significantly correlated with a lower CD4+ T-cell count. Together, these observations suggest that activation of T cells in vivo, presumably by alloantigens, predisposes the cells to spontaneous apoptosis, and this phenomenon is associated with lymphopenia. Activation-induced T-cell apoptosis may contribute to delayed immune reconstitution following HCT.

scholarly journals Method of Mobilization: Implication on Cell Subsets in the Graft and Immune Reconstitution Post Autologous Hematopoietic Cell Transplantation (AHCT)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1132-1132
Author(s):  
Melhem M. Solh ◽  
Rathmann Kristin ◽  
Sauvi chang-Fong ◽  
Jeremiah Oyer ◽  
Wesam B. Ahmed ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Peripheral Blood ◽  
Immune Reconstitution ◽  
Hematopoietic Cell Transplantation ◽  
Hematopoietic Cell ◽  
P Value ◽  
Autologous Hematopoietic Cell Transplantation ◽  
Graft Composition

Abstract Method of Mobilization: Implication on Cell Subsets in The Graft and Immune Reconstitution post Autologous Hematopoietic Cell Transplantation (AHCT) The optimal mobilization method for either myeloma or lymphoma patients undergoing AHCT is still debatable and strategies for graft collection vary between different institutions. Plerixafor, a CXCR4 antagonist is used for peripheral blood stem cell mobilization in multiple myeloma and non-Hodgkins lymphoma patients requiring AHCT. The effect of plerixafor on graft composition has scarce data that are based mostly on cryopreserved samples. Moreover; the effect of plerixafor on immune reconstitution and hematologic recovery post AHCT has not been well evaluated. The goal of our study was to compare graft composition, hematologic and immune reconstitution recovery among patients mobilized with plerixafor plus G-CSF to those mobilized with G-CSF alone. Methods: 49 patients eligible for AHCT were enrolled on a single arm prospective trial at a single transplant center. All patients were mobilized with G-CSF 10µg/kg/day for 4 consecutive days. A peripheral blood CD34 level of <20/µl on day 4 was used as a cutoff to use plerixafor 0.24mg/kg in addition to G-CSf on 9pm of the fourth day. Peripheral blood collection was started on day 5 and was continued till the target dose is achieved or a minimum CD 34+ cell dose of >2x106 cells/Kg was obtained after 3 collection days. Samples from the freshly collected graft and patients' peripheral blood on days +30 and +60 were analyzed by flow cytometry (BD FACSCanto II) . A single platform assay was used (Beckman-Coulter Stem kit) via a ISHAGE protocol. The antibody cocktail contained the following pre-conjugated monoclonal antibodies: CD56-PE (Miltenyi Biotech, Auburn, CA), CD3-APC, CD16-FITC, (Beckman Coulter, Brea, CA), CD19-PE-CY7 (BD Biosciences, San Jose, CA). Data were acquired using BD FACSCanto II (BD Biosciences) and analyzed with the FACSDiva software (BD Biosciences) to quantify CD3+ T cells, CD3+ CD56+ NK-like T cells, CD56+ CD16+ and CD56+ CD16- NK cells as well as CD19+ B cells. Results: 49 patients with a median age of 58 years (range 21-75) were mobilized with either G-CSF alone (N=16) or plerixafor +G-CSF (G+P)(N=33).The median number of collection days was 1.42 and 1.81 (p=0.2) and the median collected CD34+ dose was 8.28x106/kg and 5.24x106 /kg (p=022) in the G+P and G-CSF alone groups respectively. Both groups had similar times to neutrophil and platelet engraftment. The graft analysis showed a white blood count of 309x109/l and 262x109/l (p=0.38), median percentage of CD34+ cells of 0.75% and 0.73% (p=0.81), percentage of CD3+ T cells of 25.6% and 22% (p=0.6) in the G+P and G-CSF alone groups resepectively. Both groups had similar proportions of CD3+, CD4+,CD8+, NK, NKT and iNKT cells in the mobilized grafts. Peripheral blood samples at day +30 and day +60 were analyzed for T cell markers and hematologic recovery (table 1). There was no significant difference between absolute lymphocyte counts, NK cell counts, T cells and absolute neutrophil count. Conclusion: Plerixafor when combined with G-CSF helps in achieving mobilization goals in patients predicted to be poor mobilizers based on peripheral CD34 levels. The addition of plerixafor doesn't not seem to affect T cell composition of the graft and yields similar hematologic and immune recovery when compared to mobilization with G-CSF alone. Table 1: Immune Reconstitution at Day 30 and Day 60 post Autologous Transplantation Treatment Group G-CSF (N=16) Plerixafor + G-CSF (N=33) P-value G-CSF (N=16) Plerixafor + G-CSF (N=33) P-value Day 30 Day 60 WBC 5.08 5.41 0.873 4.94 5.38 0.654 HGB 10.86 11.19 0.353 11.22 11.17 0.757 HCT 32.35 33.66 0.321 33.36 33.53 0.565 PLT 119.88 161.42 0.068 166.94 173.73 0.949 Abs Lymph 1.09 1.44 0.296 1.41 1.50 0.974 % NK 26.14 30.38 0.277 11.53 20.09 0.095 Abs NK 0.31 0.35 0.186 0.17 0.21 0.470 % T cell 67 60 0.183 76.15 67.39 0.340 Abs T cell 0.72 0.96 0.717 1.35 .82 0.095 NKT%* 5.28 3.33 8.25 3.38 B cell % 2.38 1.52 0.922 2.63 5.58 0.424 Abs. Neut count 2.99 2.64 0.488 2.85 3.01 0.848 Disclosures No relevant conflicts of interest to declare.

scholarly journals Therapeutic Vaccination of Hematopoietic Cell Transplantation Recipients Improves Protective CD8 T-Cell Immunotherapy of Cytomegalovirus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Kerstin M. Gergely ◽  
Jürgen Podlech ◽  
Sara Becker ◽  
Kirsten Freitag ◽  
Steffi Krauter ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Mhc Class I ◽  
Hematopoietic Cell Transplantation ◽  
Hematopoietic Cell ◽  
Class I ◽  
Therapeutic Vaccination ◽  
Cell Immunotherapy ◽  
T Cell Immunotherapy

Reactivation of latent cytomegalovirus (CMV) endangers the therapeutic success of hematopoietic cell transplantation (HCT) in tumor patients due to cytopathogenic virus spread that leads to organ manifestations of CMV disease, to interstitial pneumonia in particular. In cases of virus variants that are refractory to standard antiviral pharmacotherapy, immunotherapy by adoptive cell transfer (ACT) of virus-specific CD8+ T cells is the last resort to bridge the “protection gap” between hematoablative conditioning for HCT and endogenous reconstitution of antiviral immunity. We have used the well-established mouse model of CD8+ T-cell immunotherapy by ACT in a setting of experimental HCT and murine CMV (mCMV) infection to pursue the concept of improving the efficacy of ACT by therapeutic vaccination (TherVac) post-HCT. TherVac aims at restimulation and expansion of limited numbers of transferred antiviral CD8+ T cells within the recipient. Syngeneic HCT was performed with C57BL/6 mice as donors and recipients. Recipients were infected with recombinant mCMV (mCMV-SIINFEKL) that expresses antigenic peptide SIINFEKL presented to CD8+ T cells by the MHC class-I molecule Kb. ACT was performed with transgenic OT-I CD8+ T cells expressing a T-cell receptor specific for SIINFEKL-Kb. Recombinant human CMV dense bodies (DB-SIINFEKL), engineered to contain SIINFEKL within tegument protein pUL83/pp65, served for vaccination. DBs were chosen as they represent non-infectious, enveloped, and thus fusion-competent subviral particles capable of activating dendritic cells and delivering antigens directly into the cytosol for processing and presentation in the MHC class-I pathway. One set of our experiments documents the power of vaccination with DBs in protecting the immunocompetent host against a challenge infection. A further set of experiments revealed a significant improvement of antiviral control in HCT recipients by combining ACT with TherVac. In both settings, the benefit from vaccination with DBs proved to be strictly epitope-specific. The capacity to protect was lost when DBs included the peptide sequence SIINFEKA lacking immunogenicity and antigenicity due to C-terminal residue point mutation L8A, which prevents efficient proteasomal peptide processing and binding to Kb. Our preclinical research data thus provide an argument for using pre-emptive TherVac to enhance antiviral protection by ACT in HCT recipients with diagnosed CMV reactivation.

A randomized phase II clinical trial of enzalutamide in combination with the therapeutic cancer vaccine, PSA tricom, in metastatic, castration resistant prostate cancer.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. TPS5104-TPS5104
Author(s):  
Nishith K. Singh ◽  
Joseph W. Kim ◽  
Christopher Ryan Heery ◽  
William L. Dahut ◽  
Anna Couvillon ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Cancer Vaccine ◽  
Phase Iii ◽  
Cytotoxic T Cell ◽  
Phase 2 ◽  
Therapeutic Cancer Vaccine ◽  
Randomized Phase 2

TPS5104 Background: There is a strong rationale to combine therapeutic cancer vaccines with hormonal abrogation in prostate cancer. Androgen abrogation augments T-cell trafficking to prostate, decreases immune tolerance, increases production of naïve thymic T-cells, enhances cytotoxic T-cell repertoire. PSA TRICOM (PROSTVAC) is a therapeutic, viral-vector based, off-the-shelf, cancer vaccine of PSA & 3 co-stimulatory molecules in phase III testing. This was developed at the NCI in collaboration with Bavarian Nordic Immunotherapeutics. It has demonstrated safety and survival benefit in a randomized phase 2 trial of metastatic castrate resistant prostate cancer (mCRPC). Enzalutamide is a modern androgen receptor inhibitor (ARI) approved for the treatment of mCRPC. Data from the clinical trials with these therapies suggest good individual tolerability without any overlapping toxicities. Analysis of previous trials suggests that vaccines may enhance clinical outcomes with ARI. These data form the scientific basis for a combination approach of a cancer vaccine with ARI to control tumor progression in mCRPC. Methods: A randomized, phase 2, open-label clinical trial at the NCI will enroll 72 chemo-naïve, minimally symptomatic patients with mCRPC. They will be randomized (1:1) to enzalutamide (160 mg daily) alone, or enzalutamide with PSA TRICOM for treatment until radiographic progression. PSA-TRICOM will be administered in a core phase (with day 1, 15 and 29 then 4 additional monthly boosts) followed by continued boosts every 3 months. The primary end point will evaluate time to progression in each arm with secondary endpoints including overall survival and systemic immune responses (lymphocyte subsets, regulatory T-cells, regulatory T-cell function, cytokines, naïve thymic emigrants). If a therapeutic cancer vaccine can enhance the clinical efficacy of a hormonal agent such as enzalutamide, it may help define a new role for vaccines as an adjuvant to standard therapies. We will also evaluate this combination in a second trial in non-metastatic, castration-sensitive patients where this combination may yield its greatest clinical impact.

Sign in / Sign up

Export Citation Format

Share Document