A Phase II Trial of Peri-Transplant Palifermin with Busulfan, Melphalan and Fludarabine Followed by T-Cell Depleted Hematopoietic Stem Cell Transplants in Patients with Advanced Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Evolved From MDS

Abstract Abstract 1935 Introduction: The success of allogeneic HSCT in the treatment of advanced MDS has been limited by high incidence of relapse and transplant-related mortality (TRM). The main complications contributing to TRM are graft-vs-host disease (GvHD) and infections. Although T cell depletion has successfully reduced the incidence of GvHD, slow immune reconstitution and high rate of infections have compromised its full potential. T cell reconstitution after transplant requires a functional thymic epithelium. Transplant conditioning regimens damage the thymus and impair the production de novo of T cells. Keratinocyte growth factor (KGF) has an important role in healing the epithelium after injury. Palifermin, a human recombinant form of KGF, decreases the incidence and duration of mucositis after total body irradiation and has been approved by the FDA for this purpose in autologous and allogeneic HSCT. In murine models, KGF given before allogeneic transplant has a protective effect on the thymus and accelerates T cell reconstitution. The aim of this study was to assess whether administration of palifermin peri-transplant decreases TRM and improves the overall and disease-free survival (OS and DFS). This study was designed to reduce one- year TRM from 30% and 35% to 10% in HLA matched and mismatched arms, respectively. Patients: Between 11/2009–05/2012, 42 patients (advanced MDS: 26 or AML evolved from MDS: 16) enrolled on this trial. At transplant, 23 were in CR1, 3 were in second refractory cytopenia phase, and 16 had limited disease (<5% circulating blasts and <9% marrow blasts). The median age was 57.5 years (1–65), with 22 males and 20 females. Conditioning consisted of busulfan (12 doses over three days of 0.8 mg/kg IV for patients > 4 years old or 1.0 mg/kg IV for patients < 4 years old), melphalan (70 mg/m2 IV × 2 days), fludarabine (25 mg/m2 IV × 5 days), and rabbit ATG pre-transplant (2 doses and 3 doses for HLA matched and mismatched recipients, respectively). Palifermin was given according to the approved dose for mucositis prevention: 60 mcg/kg/day IV for 3 consecutive days before the preparative regimen, and 3 doses post transplant (day 0, +24hours, +48hours). Donors were HLA matched (31; 13 related and 18 unrelated) or unrelated mismatched (11). G-CSF mobilized donor peripheral blood stem cells underwent CD34+ selection and depletion of T cells using CliniMACS immunomagnetic selection columns (Milteny Biotec). Results: All 42 patients engrafted, 1 patient developed secondary graft failure. The cumulative incidence of grade III-IV aGvHD at day +100 and 1 year were 4.8% and 10.5%, respectively. The latter increase was due to late-onset acute GvHD. Only 1 of 33 patients at risk developed moderate chronic GvHD. The 2-year OS and DFS were 77% and 65%, respectively, and similar in the two arms (HLA matched and mismatched). The CI of relapse at 1-year was 12 % (similar in the two arms). The 1-year TRM was 20%; 18.4% in the HLA matched group (accrual met) and 22% in the mismatched arm (accrual ongoing). Causes of death were: infections (N=5; 3 HLA matched, 2 HLA mismatched), regimen related toxicity (N=2, liver VOD) and relapse (N=1). The frequency of infections was similar to historical controls; at 3 months post transplant, 30% of patients developed active CMV, EBV, or adenovirus infections, at 6 months 16.6%, and at 12 months 7.1%. The 6-month CI of CMV viremia in CMV seropositive patients was 75% and the 6-month CI of EBV viremia was 31%. Immune reconstitution as measured by CD4 count was slow, similar to historical controls, with median absolute CD4 count at 3 months of 77 cells/μl and 200 cells/μl by 1 year posttransplant. Other parameters to assess safety of this regimen, namely duration of narcotics use and days on TPN to measure severity of mucositis were similar to historical controls (same preparative regimen without palifermin). Conclusion: In this ongoing phase II trial the addition of peri transplant palifermin to a chemotherapy only myeloablative conditioning regimen in recipients of TCD HSCT for advanced MDS decreased the TRM, although did not meet the primary objective of this study (reduction to 10%). Also, there was no reduction in the incidence of viral infections and no improvement in immune reconstitution. The reduction in TRM resulted from early detection of infection and improved treatment options. Disclosures: Perales: SOBI Biovitrum, pharma company: SOBI Biovitrum, pharma company Other. Goldberg:SOBI Biovitrum: Research Funding.

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UM171-Expanded Cord Blood Transplants Support Robust T-Cell Reconstitution with Low Rates of Severe Infections

Blood ◽

10.1182/blood-2020-139598 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 36-37

Author(s):

Maude Dumont-Lagacé ◽

Qi Li ◽

Mégane Tanguay ◽

Jalila Chagraoui ◽

Tibila Kientega ◽

...

Keyword(s):

T Cells ◽

Stem Cell ◽

T Cell ◽

Cord Blood ◽

Immune Reconstitution ◽

Post Transplant ◽

T Cell Reconstitution ◽

Significant Difference ◽

Severe Infections ◽

Related Mortality

Introduction Rapid T cell reconstitution following hematopoietic stem cell transplantation is essential for protection against infections and has been associated with lower incidence of chronic graft-vs-host disease (cGVHD), relapse and transplant-related mortality (TRM). While cord blood (CB) transplants are associated with lower rates of cGVHD and relapse, their low stem cell content results in slower immune reconstitution and higher risk of graft failure, severe infections and TRM. Recently, results of a Phase I/II trial revealed that single UM171-expanded CB transplant allowed the use of smaller CB units without compromising engraftment. We now report on T cell reconstitution and immune function in patients transplanted with UM171-expanded CB grafts. Methods We performed a retrospective analysis of 20 patients treated with UM171-expanded CB and compared it to a contemporary cohort of 12 patients treated in the same institution who received unmanipulated CB transplant with similar conditioning regimens. Of note, no patient received ATG as part of the conditioning in either cohort. We used flow cytometry and TCR sequencing to evaluate T cell reconstitution, and virus-specific ELISpot assays to evaluate T cell function in the first year post-transplantation. We also categorized infectious events as per definitions of infection severity in the BMT CTN Technical MOP Version 3.0 and report the mean cumulative count of infectious events for each cohort. Results While median T cell dose in graft was at least 2-3x lower for the cohort of patients treated with UM171-expanded CB due to the selection of smaller cords and to cell loss occurring during CD34 selection process, numbers and phenotype of T cells at 3, 6 and 12 months post-transplant were similar in patients treated with UM171-expanded or unmanipulated CB transplant. TCR sequencing analyses revealed that UM171 patients had greater T cell diversity and higher numbers of T cell clonotypes at 12 months post-transplant compared to patients who received unmanipulated CB. Younger UM171 patients (i.e. <40 years old) also showed a more pronounced increase in naïve T cells and recent thymic emigrants (RTE) between 3- and 12-months post-transplant compared to age-matched unmanipulated CB patients, suggesting that UM171-expansion improves thymopoiesis at least in the young patients. This also correlated with the demonstration that UM171 expands common lymphoid progenitors in vitro. ELISpot assays revealed that UM171 patients showed early virus-specific T cell reactivity, at 2- and 3-months post-transplant. Most importantly, UM171 patients had a 2-fold lower frequency of severe (i.e. grade 2-3) infections at 1 year post-transplant, even though time to engraftment of 500 neutrophils was similar between the two cohorts (17 and 20 days for the UM171-expanded and unmanipulated CB cohorts respectively, p=0.94). Conclusion Our data show that the relative T-cell paucity of the UM171 graft is rapidly compensated after transplant with no significant difference observed between the two cohorts in terms of numbers and phenotypes of T cells at 3, 6 or 12 months post-transplant. Although it is difficult to dissect the relative contribution of homeostatic expansion and de novo thymopoiesis, recipients of UM171 grafts had a greater TCR diversity at one year, which was more evident among patients younger than 40 years of age. The prompt immune reconstitution observed in UM171 patients translated into a low rate of severe (grade 2-3) infections and no infection-related mortality. These results support rapid and functional T cell reconstitution following UM171 expanded CB transplantation, which likely contributes to the absence of moderate/severe cGVHD, infection-related mortality and late TRM observed in this cohort. Figure legend: Mean cumulative counts of infectious events in patients transplanted with UM171-expanded (blue) or unmanipulated (red) CB. Mean cumulative counts are shown for all infectious events (A), bacterial (B) and viral (C) infections. Events were categorized by type and severity as per BMT CTN guidelines (Appendix 4A). Infectious events of grade 1-3 are shown in pale colors, while more severe events (grade 2-3) are shown in dark colors. Censored patients (including those who relapsed) are indicated with white circles. Figure 1 Disclosures Dumont-Lagacé: ExCellThera: Current Employment. Busque:Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria. Sauvageau:ExCellThera: Current equity holder in private company, Other: CEO, Patents & Royalties. Cohen:ExCellThera: Consultancy, Other: principal investigator of an ongoing UM171 clinical trial.

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A Randomized Phase II Trial of Idiotype Vaccination and Adoptive Autologous T-Cell Transfer in Multiple Myeloma patients

Blood ◽

10.1182/blood.2020008493 ◽

2021 ◽

Author(s):

Muzaffar H Qazilbash ◽

Neeraj Y Saini ◽

Cha Soung-chul ◽

Zhe Wang ◽

Edward Stadtmauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase Ii ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Phase Ii Trial ◽

Ex Vivo ◽

Vaccine Strategy ◽

Randomized Phase Ii

We hypothesized that combining adoptively transferred autologous T cells with a cancer vaccine strategy would enhance therapeutic efficacy by adding anti-myeloma idiotype-keyhole limpet hemocyanin (Id-KLH) vaccine to vaccine-specific co-stimulated T cells. In this randomized, phase II trial, eligible patients received either the control (KLH only) or Id-KLH vaccine, an auto-transplant, vaccine-specific co-stimulated T-cells expanded ex-vivo, and two booster doses of the assigned vaccine. In 36 patients (20 in KLH, 16 in Id-KLH) enrolled, no dose-limiting toxicity was seen in either arm. At last evaluation, 6 (30%) and 8 (50%) had achieved complete remission in KLH-only and Id-KLH, respectively (p=0.22) and no difference in 3-year progression-free survival was observed (59% and 56%, respectively; p=0.32). In a 594 Nanostring nCounter gene panel analyzed for immune reconstitution (IR), compared with KLH-only patients, there was a greater change in IR genes in T-cells in Id-KLH patients relative to baseline. Specifically, upregulation of genes associated with activation, induction of effector function, and generation of memory CD8+ T cells after Id-KLH, but not after KLH control vaccination, was observed. Similarly, responding patients across both arms were associated with upregulation of genes associated with T-cell activation. At baseline, all patients had greater expression of CD8+ T-cell exhaustion markers. These changes were associated with functional Id-specific immune responses in a subset of Id-KLH patients analyzed. In conclusion, in this combination immunotherapy approach, we observed a significantly more robust IR in CD4+ and CD8+ T cells in the Id-KLH arm, supporting further investigation of vaccine and adoptive immunotherapy strategies.

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Impact of Different T Cell Depletion Protocols on Immune Reconstitution Following Allogeneic Hematopoietic Stem Cell Transplantation

Blood ◽

10.1182/blood-2020-139208 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 43-44

Author(s):

Amandine Pradier ◽

Adrien Petitpas ◽

Anne-Claire Mamez ◽

Federica Giannotti ◽

Sarah Morin ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Reconstitution ◽

Cell Depletion ◽

Unrelated Donor ◽

T Cell Depletion ◽

Hematopoietic Stem ◽

Post Transplant ◽

The Impact

Introduction Allogeneic hematopoietic stem cell transplantation (HSCT) is a well-established therapeutic modality for a variety of hematological malignancies and congenital disorders. One of the major complications of the procedure is graft-versus-host-disease (GVHD) initiated by T cells co-administered with the graft. Removal of donor T cells from the graft is a widely employed and effective strategy to prevent GVHD, although its impact on post-transplant immune reconstitution might significantly affect anti-tumor and anti-infectious responses. Several approaches of T cell depletion (TCD) exist, including in vivo depletion using anti-thymocyte globulin (ATG) and/or post-transplant cyclophosphamide (PTCy) as well as in vitro manipulation of the graft. In this work, we analyzed the impact of different T cell depletion strategies on immune reconstitution after allogeneic HSCT. Methods We retrospectively analysed data from 168 patients transplanted between 2015 and 2019 at Geneva University Hospitals. In our center, several methods for TCD are being used, alone or in combination: 1) In vivo T cell depletion using ATG (ATG-Thymoglobulin 7.5 mg/kg or ATG-Fresenius 25 mg/kg); 2) in vitro partial T cell depletion (pTCD) of the graft obtained through in vitro incubation with alemtuzumab (Campath [Genzyme Corporation, Cambridge, MA]), washed before infusion and administered at day 0, followed on day +1 by an add-back of unmanipulated grafts containing about 100 × 106/kg donor T cells. The procedure is followed by donor lymphocyte infusions at incremental doses starting with 1 × 106 CD3/kg at 3 months to all patients who had received pTCD grafts with RIC in the absence of GVHD; 3) post-transplant cyclophosphamide (PTCy; 50 mg/kg) on days 3 and 4 post-HSCT. Absolute counts of CD3, CD4, CD8, CD19 and NK cells measured by flow cytometry during the first year after allogeneic HSCT were analyzed. Measures obtained from patients with mixed donor chimerism or after therapeutic DLI were excluded from the analysis. Cell numbers during time were compared using mixed-effects linear models depending on the TCD. Multivariable analysis was performed taking into account the impact of clinical factors differing between patients groups (patient's age, donor type and conditioning). Results ATG was administered to 77 (46%) patients, 15 (9%) patients received a pTCD graft and 26 (15%) patients received a combination of both ATG and pTCD graft. 24 (14%) patients were treated with PTCy and 26 (15%) patients received a T replete graft. 60% of patients had a reduced intensity conditioning (RIC). 48 (29%) patients received grafts from a sibling identical donor, 94 (56%) from a matched unrelated donor, 13 (8%) from mismatched unrelated donor and 13 (8%) received haploidentical grafts. TCD protocols had no significant impact on CD3 or CD8 T cell reconstitution during the first year post-HSCT (Figure 1). Conversely, CD4 T cells recovery was affected by the ATG/pTCD combination (coefficient ± SE: -67±28, p=0.019) when compared to the T cell replete group (Figure 1). Analysis of data censored for acute or chronic GVHD requiring treatment or relapse revealed a delay of CD4 T cell reconstitution in the ATG and/or pTCD treated groups on (ATG:-79±27, p=0.004; pTCD:-100±43, p=0.022; ATG/pTCD:-110±33, p<0.001). Interestingly, pTCD alone or in combination with ATG resulted in a better reconstitution of NK cells compared to T replete group (pTCD: 152±45, p<0.001; ATG/pTCD: 94±36, p=0.009; Figure 1). A similar effect of pTCD was also observed for B cells (pTCD: 170±48, p<.001; ATG/pTCD: 127±38, p<.001). The effect of pTCD on NK was confirmed when data were censored for GVHD and relapse (pTCD: 132±60, p=0.028; ATG/pTCD: 106±47, p=0.023) while only ATG/pTCD retained a significant impact on B cells (102±49, p=0.037). The use of PTCy did not affect T, NK or B cell reconstitution when compared to the T cell replete group. Conclusion Our results indicate that all TCD protocols with the only exception of PTCy are associated with a delayed recovery of CD4 T cells whereas pTCD of the graft, alone or in combination with ATG, significantly improves NK and B cell reconstitution. Figure 1 Disclosures No relevant conflicts of interest to declare.

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New Developments in Allotransplant Immunology

Hematology ◽

10.1182/asheducation-2003.1.350 ◽

2003 ◽

Vol 2003 (1) ◽

pp. 350-371 ◽

Cited By ~ 39

Author(s):

A. John Barrett ◽

Katayoun Rezvani ◽

Scott Solomon ◽

Anne M. Dickinson ◽

Xiao N. Wang ◽

...

Keyword(s):

T Cells ◽

Stem Cell ◽

T Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Immune Reconstitution ◽

Cytokine Gene ◽

Post Transplant ◽

Cytokine Milieu ◽

Cytokine Gene Polymorphisms

Abstract After allogeneic stem cell transplantation, the establishment of the donor’s immune system in an antigenically distinct recipient confers a therapeutic graft-versus-malignancy effect, but also causes graft-versus-host disease (GVHD) and protracted immune dysfunction. In the last decade, a molecular-level description of alloimmune interactions and the process of immune recovery leading to tolerance has emerged. Here, new developments in understanding alloresponses, genetic factors that modify them, and strategies to control immune reconstitution are described. In Section I, Dr. John Barrett and colleagues describe the cellular and molecular basis of the alloresponse and the mechanisms underlying the three major outcomes of engraftment, GVHD and the graft-versus-leukemia (GVL) effect. Increasing knowledge of leukemia-restricted antigens suggests ways to separate GVHD and GVL. Recent findings highlight a central role of hematopoietic-derived antigen-presenting cells in the initiation of GVHD and distinct properties of natural killer (NK) cell alloreactivity in engraftment and GVL that are of therapeutic importance. Finally, a detailed map of cellular immune recovery post-transplant is emerging which highlights the importance of post-thymic lymphocytes in determining outcome in the critical first few months following stem cell transplantation. Factors that modify immune reconstitution include immunosuppression, GVHD, the cytokine milieu and poorly-defined homeostatic mechanisms which encourage irregular T cell expansions driven by immunodominant T cell–antigen interactions. In Section II, Prof. Anne Dickinson and colleagues describe genetic polymorphisms outside the human leukocyte antigen (HLA) system that determine the nature of immune reconstitution after allogeneic stem cell transplantation (SCT) and thereby affect transplant outcomethrough GVHD, GVL, and transplant-related mortality. Polymorphisms in cytokine gene promotors and other less characterized genes affect the cytokine milieu of the recipient and the immune reactivity of the donor. Some cytokine gene polymorphisms are significantly associated with transplant outcome. Other non-HLA genes strongly affecting alloresponses code for minor histocompatibility antigens (mHA). Differences between donor and recipient mHA cause GVHD or GVL reactions or graft rejection. Both cytokine gene polymorphisms (CGP) and mHA differences resulting on donor-recipient incompatibilities can be jointly assessed in the skin explant assay as a functional way to select the most suitable donor or the best transplant approach for the recipient. In Section III, Dr. Nelson Chao describes non-pharmaceutical techniques to control immune reconstitution post-transplant. T cells stimulated by host alloantigens can be distinguished from resting T cells by the expression of a variety of activation markers (IL-2 receptor, FAS, CD69, CD71) and by an increased photosensitivity to rhodamine dyes. These differences form the basis for eliminating GVHD-reactive T cells in vitro while conserving GVL and anti-viral immunity. Other attempts to control immune reactions post-transplant include the insertion of suicide genes into the transplanted T cells for effective termination of GVHD reactions, the removal of CD62 ligand expressing cells, and the modulation of T cell reactivity by favoring Th2, Tc2 lymphocyte subset expansion. These technologies could eliminate GVHD while preserving T cell responses to leukemia and reactivating viruses.

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Keratinocyte growth factor augments immune reconstitution after autologous hematopoietic progenitor cell transplantation in rhesus macaques.

Blood ◽

10.1182/blood-2006-12-065623 ◽

2007 ◽

Vol 110 (1) ◽

pp. 441-449 ◽

Cited By ~ 75

Author(s):

Ruth Seggewiss ◽

Karin Loré ◽

F. Javier Guenaga ◽

Stefania Pittaluga ◽

Joseph Mattapallil ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Growth Factor ◽

Immune Reconstitution ◽

Progenitor Cell ◽

Rhesus Macaques ◽

Keratinocyte Growth Factor ◽

Hematopoietic Progenitor Cell ◽

Thymic Epithelial Cells ◽

T Cell Reconstitution

Opportunistic infections contribute to morbidity and mortality after peripheral blood progenitor cell (PBPC) transplantation and are related to a deficient T-cell compartment. Accelerated T-cell reconstitution may therefore be clinically beneficent. Keratinocyte growth factor (KGF) has been shown to protect thymic epithelial cells in mice. Here, we evaluated immune reconstitution after autologous CD34+ PBPC transplantation in rhesus macaques conditioned with myeloablative total body irradiation in the absence or presence of single pretotal body irradiation or repeated peritransplant KGF administration. All KGF-treated animals exhibited a well-preserved thymic architecture 12 months after graft. In contrast, thymic atrophy was observed in the majority of animals in the control group. The KGF-treated animals showed higher frequencies of naive T cells in lymph nodes after transplantation compared with the control animals. The animals given repeated doses of KGF showed the highest levels of T-cell receptor excision circles (TRECs) and the lowest frequencies of Ki67+ T cells, which suggest increased thymic-dependent reconstitution in these animals. Of note, the humoral response to a T-cell–dependent neo-antigen was significantly higher in the KGF-treated animals compared with the control animals. Thus, our findings suggest that KGF may be a useful adjuvant therapy to augment T-cell reconstitution after human PBPC transplantation.

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HSV-TK Engineered Donor Lymphocytes Add-Backs Reduce Late Mortality and Improve Survival of High Risk Acute Leukemia after Haplo-HSCT: Results of a Phase II Multicenter Trial.

Blood ◽

10.1182/blood.v106.11.439.439 ◽

2005 ◽

Vol 106 (11) ◽

pp. 439-439 ◽

Cited By ~ 2

Author(s):

F. Ciceri ◽

C. Bonini ◽

M.T. Lupo Stanghellini ◽

A. Bondanza ◽

Z. Magnani ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Median Time ◽

Phase Ii ◽

Immune Reconstitution ◽

Multicenter Trial ◽

T Cell Repertoire ◽

Cell Repertoire ◽

Late Mortality ◽

Donor Lymphocytes

Abstract The outcome of haplo-SCT is limited by delayed immune reconstitution resulting in a high rate of late mortality and relapse. Here, we report results of a phase II multicenter trial (MM TK007) of early add-backs of donor lymphocytes genetically engineered to express the herpes simplex thymidine kinase (TK) suicide gene after haplo-SCT in inducing immune reconstitution and selective control of GvHD by ganciclovir. Twentysix advanced age pts (median age 51, 17–63) were transplanted for high risk leukemia; disease status at SCT was CR1 (8), CR2 (7), refractory (11). A median of 12.2x106/kg (7.3–16.8) CD34+ selected (Clinimacs) and 1x104/kg (0.8–1.4) CD3+ cells were infused after a myeloablative conditioning. 24/26 pts engrafted with a median time of 14 d (8–21) for ANC >1.0x109/l and 13 d (11–24) for plt >50x109/l. No immune reconstitution and no GvHD were observed in absence of TK-add-back. Sixteen pts received TK-DLI at a median dose of 107/kg with 1st infusion at d +42 and 13 pts obtained CD3+ >100/mcl at a median time of 91 d (61–127) from SCT and 24 d (14–42) from TK-DLI. Transduced cells were documented ex vivo in all pts and represented a median of 48% (10–90) of CD3+ cells. Five pts developed acute GvHD, (grade I to IV) that was always completely abrogated by ganciclovir. In patients in CR at time of SCT who were alive at d +42 and received add-backs of Tk cells, OS rate was 46% at 800 days (intention-to-treat analysis: 38% OS at 800 days post-SCT). Of significance, the cumulative incidence of TRM and relapse showed a 40% probability of mortality with a median time of death of 90 days and last event at day +166. This figure indicate that TK cell add-backs abolish late mortality after CD34+ SCT in adults. In patients in relapse at time of HSCT, a median OS of 201 days was obtained in ITT, with a significant advantage on expected survival without transplantation (60 d) and superior results as compared to haplo EBMT registry (80 d). The 2-year estimation of events of this multicenter phase II study confirm that TK-DLI is an effective tool for promoting immune reconstitution and protecting pts from late infectious mortality after haplo-SCT. We believe that these results are due to the rapid development of a wide T cell repertoire obtained by TK cell infusions. Immunological follow-up showed Th1/Tc1 effector memory T cells, with a wide TCR repertoire in the first 3 months after SCT in all patients. High frequencies of T cells specific for CMV (median: 35 and 93 spots/105 cells with CMV-infected donor and host fibroblasts) and EBV (median: 58 and 41 spots/105 cells with donor and host EBV-LCL) were detected by gIFN ELISpot at time of immunereconstitution, and correlated with complete control of viral infections. Normalization of the T cell repertoire was documented by spectratype, immune-phenotype for naïve and memory T cell subsets and gIFN ELIspot 6 months after treatment. A phase III randomized multicentric study will start in 2006.

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Donor DC Subsets Polarize Donor T-Cell Immune Responses in Allogeneic BMT.

Blood ◽

10.1182/blood.v106.11.573.573 ◽

2005 ◽

Vol 106 (11) ◽

pp. 573-573

Author(s):

Jian-Ming Li ◽

Cynthia Giver ◽

Doug McMillan ◽

Wayne Harris ◽

David L. Jaye ◽

...

Keyword(s):

Stem Cells ◽

T Cells ◽

T Cell ◽

Immune Responses ◽

Peripheral Blood ◽

Immune Reconstitution ◽

Hematopoietic Cell ◽

Post Transplant ◽

Donor T Cells ◽

Ifn Γ

Abstract Introduction: Impaired or inappropriate immune reconstitution after allogeneic bone marrow transplantation (BMT) can lead to infection, graft-versus-host disease (GvHD) and leukemia relapse. We have previously reported that BM contains two populations of dendritic cell (DC) subsets, CD11b+ DC and CD11b− DC, and that CD11b depleted donor BM promoted increased donor T-cell chimerism and increased graft-versus-leukemia (GvL) activity in C57BL/6 → B10BR transplants [BBMT, 2004, 10: 540]. To explore the mechanism by which CD11b-depletion improved allo-reactivity, we performed allogeneic hematopoietic cell transplants using defined populations of donor stem cells, DCs, and T-cells in a MHC mis-matched BMT model. Methods: We transplanted FACS purified populations of 50,000 GFP+ CD11b- DC or CD11b+ DC in combination with 5,000 FACS purified Lin- Sca-1+ c-kit+ hematopoietic stem cells (HSC) and 300,000 or 1,000,000 congenic spleen T-cells from C57BL/6 donors into C57BL/6[H-2Kb], B10BR[H-2Kk] and PL/J[H-2Ku] recipients. Proliferation of CFSE stained donor T-cells was measured at 72 hours post-transplant. FACS cytometric bead array and intracellular cytokine staining measured serum and intracellular cytokines in donor T-cells. Results: The initial proliferation and Ki-67 expression of CFSE labeled donor T-cells in allogeneic recipients were much higher than in syngeneic recipients (homeostatic proliferation). Confocal microscopy showed co-localization of donor DC subsets with donor T-cells in the recipient spleens at 3 and 10 days post-transplant. In the allogeneic transplant settings, donor T-cells co-transplanted with CD11b- DC showed increased IFN-γ synthesis at 3 and 10 days post-transplant compared to donor T-cells co-transplanted with HSC plus CD11b+ DC or HSC alone. Increased proliferation of donor T-cells led to increased donor T-cell chimerism at day 10, 30, 60, and day105 post-transplant among recipients of CD11b- DC compared to recipients of HSC alone or HSC plus CD11b+ DC (Figure 1). Transplantation of spleen T-cells and CD11b- DC did not increase GvHD, but was associated with full donor chimerism. In contrast, transplantation of allogeneic CD11b+ DC led to persistence and expansion of residual host T-cells (Figure 2), increased numbers of donor CD4+CD25++Foxp3+ T-cells, and higher serum level of IL-10 supporting early post-transplant expansion of donor T regulatory cells (Treg). Conclusions: Donor CD11b- DC promoted immune reconstitution by polarizing donor T-cells to Th1 immune responses associated with increased IFN-γ synthesis and donor T-cell proliferation, while donor CD11b+ DC suppressed immune reconstitution by inhibiting donor T-cell allogeneic immune responses. These data support a novel paradigm for the regulation of post-transplant immunity and suggest clinical methods to test the hypothesis that manipulation of the DC content of a hematopoietic cell allograft regulates post transplant immunity in the clinical setting. Figure 1. Donor Spleen Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(+)DC and spleen T-cells] Figure 1. Donor Spleen Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(+)DC and spleen T-cells] Figure 2. Host Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(-)DC and spleen T-cells] Figure 2. Host Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(-)DC and spleen T-cells]

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Flagellin, a TLR5 Agonist, Reduces GvHD in Allogeneic HSCT Recipients While Enhancing Anti-Viral Immunity: A Novel Therapeutic Approach

Blood ◽

10.1182/blood.v118.21.144.144 ◽

2011 ◽

Vol 118 (21) ◽

pp. 144-144

Author(s):

Mohammad S Hossain ◽

David L Jaye ◽

Brian P Pollack ◽

Alton B Farr ◽

John Roback ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Cd8 T Cells ◽

Viral Immunity ◽

Hematopoietic Stem ◽

Allogeneic Hsct ◽

Post Transplant ◽

Radiation Chimeras ◽

Donor T Cells

Abstract Abstract 144 In MHC-mismatched allogeneic hematopoietic stem cell transplantation (allo-HSCT), host antigen specific donor T cells mediate acute and chronic graft-versus-host disease (GvHD). Based upon the radio-protective effects of flagellin, a TLR5 agonist protein (∼50 kDa) extracted from bacterial flagella, we reasoned that flagellin might modulate donor T cells immune responses toward host antigens, reduce GvHD, and improve immune responses to CMV infection in experimental models of allogeneic HSCT. Two 50mg/mouse i.p doses of highly purified flagellin were administered 3 hrs before irradiation and 24 hrs after allo-HSCT in H-2b ^ CB6F1 and H-2k ^ B6 models. GvHD scores were obtained with weekly clinical examination and with histological scoring of intestine, colon, liver and skin at necropsy. Flagellin treatment successfully protected allo-HSCT recipients from acute and chronic GvHDs after transplantation of 5×106 splenocytes and 5×106 T cell depleted (TCD) BM, and significantly increased survival compared to PBS-treated control recipients. Reduced acute GvHD was associated with significant reduction of a) early post-transplant proliferation of donor CD4+ and CD8+ T cells measured by Ki67 and CFSE staining, b) fewer CD62L+, CD69+, CD25+, ICOS-1+ and PD-1+ donor CD4+ and CD8+ T cells compared with the PBS-treated control recipients. Decreased numbers of activated and proliferating donor T cells were associated with significantly reduced pro-inflammatory serum IFN-g, TNF-a, and IL-6 on days 4–10 post transplant in flagellin-treated recipients compared with the PBS-treated recipients. Interestingly, both flagellin-treated recipients and PBS-treated recipients had over 99% donor T cell chimerism at 2 months post transplant. Moreover, MCMV infection on 100+ days post-transplant flagellin-treated mice significantly enhanced anti-viral immunity, including more donor MCMV-peptide-tetramer+ CD8+ T cells in the blood (p<0.05), and less MCMV in the liver on day 10 post infection (p<0.02) compared with the PBS-treated control recipients. Overall immune reconstitution after flagellin-treatment was robust and associated with larger numbers of CD4+CD25+foxp3+ regulatory T cells in the thymus. To further define the role of flagellin-TLR5 agonistic interactions in the reduction of GvHD, we next generated B6 ^ TLR5 KO (KO) and KOB^6 radiation chimeras by transplanting 10 × 106 BM cells from wild-type (WT) B6 or TLR5 KO donors into the congenic CD45.1+ B6 or KO recipients conditioned with 11Gy (5.5Gyx2) TBI. The radiation chimeras were irradiated again with 9.0Gy (4.5Gy × 2) on 60 days after the first transplant and transplanted with 3 × 106 splenocytes and 5 × 106 TCD BM from H-2K congenic donors. Two 50mg doses of flagellin were administered 3 hrs before irradiation and 24 hrs after HSCT. All flagellin-treated B6 ^ B6 radiation chimeras survived with only 12% weight-loss by 80 days post transplant compared with 50% survival among recipients of flagellin-treated B6 ^ KO and 40% survival among KO ^ B6 radiation chimeras. All flagellin-treated KO^ KO and PBS-treated radiation chimeras died within 65 days post transplant. These data suggested that interaction of flagellin with the TLR5 expressing host gut epithelium and donor hematopoietic cells are both required for the maximum protective effect of this TLR5 agonist on GvHD in allogeneic HSCT recipients. Together our data demonstrate that peritransplant administration of flagellin effectively controls acute and chronic GvHD while preserving enhanced post-transplant donor anti-opportunistic immunity. Since flagellin has been found to be safe for use in humans as vaccine adjuvant in a number of clinical trials, the clinical use of flagellin in the setting of allogeneic HSCT is of interest. Disclosures: No relevant conflicts of interest to declare.

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Addition of Clofarabine to TLI/ATG Conditioning: Impact on Immune Reconstitution and Clinical Outcomes,

Blood ◽

10.1182/blood.v118.21.4066.4066 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4066-4066

Author(s):

Brett Glotzbecker ◽

Heidi Mills ◽

Jacalyn Rosenblatt ◽

Robin Joyce ◽

James Levine ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Median Time ◽

Cd8 T Cells ◽

Fold Increase ◽

Disease Relapse ◽

Platelet Recovery ◽

Post Transplant ◽

T Cell Reconstitution

Abstract Abstract 4066 The fundamental challenge in designing an effective conditioning regimen for allogeneic transplantation involves the prevention of disease relapse while minimizing the risk for Graft versus Host Disease (GVHD). Treatment with total lymphocyte irradiation (TLI) and anti-thymocyte globulin (ATG) has been shown to minimize the risk of GVHD through the biasing of the T cell reconstitution towards an inhibitory phenotype. However, disease relapse remains a significant concern. Clofarabine is a second generation nucleoside analog with potent cytoreductive capacity and demonstrates efficacy in hematological malignancies. In this study, we examined the combination of clofarabine, TLI and ATG with respect to T cell reconstitution, risk for GVHD and transplant outcome. Sequential cohorts of 5 patients were treated with TLI and ATG alone or in conjunction with 20 mg/m2, 30 mg/m2 or 40 mg/m2 of clofarabine for 5 days. Cyclosporine and mycophenolate mofetil were administered as GVHD prophylaxis. Twenty patients have been enrolled (5 AML/MDS, 2 ALL, 6 lymphoma, 2 CLL, 5 myeloma) and received HLA matched peripheral blood stem cells collected from related (N=11) and unrelated donors (N=9). Of 19 evaluable patients, 15 are alive with a median follow up of 665 days. Day 30 and 100 mortality was 0% for TLI and ATG and 0% and 10% for those receiving clofarabine. The maximum tolerated dose (MTD) of clofarabine was 30 mg/m2 as 2 patients experienced treatment related mortality at the 40 mg/m2 dose level. Grade 5 infections and multiorgan failure occurred in both patients. All patients demonstrated engraftment with mean bone marrow donor chimerism of 92.5% at Day 30. The first cohort's ANC did not drop below 500 cells/uL, while median time to neutrophil engraftment in the patients who received clofarabine was 9 days. The median time to platelet recovery was 11 and 12 days for patients receiving TLI and ATG alone or with clofarabine, respectively (p=0.39). T cell reconstitution studies demonstrated a significant decrease in CD4+ cells to (<200 cells/uL) persisting for more than 6 months and a more than a two fold increase in circulating CD56+ NK cells. No significant decrease in CD8 T cells in the early post-transplant period was seen in either group. The mean percentage of regulatory T cells (CD4+/25+/FoxP3+) rose in the early post-transplant period following TLI and ATG (5.5 to 14.2% from baseline to day 30; p=0.015), but not in those receiving clofarabine (8.1 to 6%; p=0.15). Assessment of T cell polarization at these time points demonstrated a two fold increase in CD8+ T cells expressing IL-4 at Day 30 in patients receiving TLI and ATG alone (p=0.04); but not following clofarabine containing conditioning. Consistent with these findings, the incidence of grade II-IV GVHD was 0% and 42% in those receiving TLI and ATG alone or in conjunction with clofarabine, respectively. cGVHD was seen in 20% and 42% of patients, respectively. In contrast, disease progression was seen in 60% of patients receiving TLI and ATG alone as compared to 27% receiving clofarabine, TLI, and ATG. In summary, the addition of clofarabine to TLI and ATG conditioning resulted in a decrease in circulating regulatory T cells, decreased CD8+ T cell expression of IL-4, and was associated with an increased risk of GVHD and a potential for a decrease in the risk of relapse. Disclosures: Chen: Genzyme: Membership on an entity's Board of Directors or advisory committees. Avigan:Genzyme: Research Funding.

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Lineage–Specific Chimerism and Incidence of Graft-Failure Following T-Cell Replete Haploidentical Transplantation Using Post-Transplant Cyclophosphamide in Eighty-Nine Consecutive Patients From a Single-Center.

Blood ◽

10.1182/blood.v120.21.3030.3030 ◽

2012 ◽

Vol 120 (21) ◽

pp. 3030-3030

Author(s):

Amaani Hussain ◽

Connie A. Sizemore ◽

Xu Zhang ◽

Melissa Sanacore ◽

Stacey Brown ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Graft Failure ◽

Myeloid Cells ◽

Time Points ◽

Post Transplant ◽

Haploidentical Transplantation ◽

Cell Engraftment ◽

Preparative Regimen ◽

Spontaneous Improvement

Abstract Abstract 3030 T-cell replete HLA-haploidentical transplantation using post-transplant cyclophosphamide for prevention of GVHD and graft rejection (Haplo-PTCy) has recently emerged as a valid form of alternative-donor transplantation for patients who lack traditional matched-siblings (MSD) or matched-unrelated donors (MUD). We have demonstrated that patients undergoing Haplo-PTCy can have equivalent rates overall and disease-free survival and equivalent or lower cumulative incidences of GVHD and non-relapse mortality to patients transplanted contemporaneously from MSD and MUD at the same center (Bashey et al ASH 2011 abstract #833). In this study we assessed lineage-specific chimerism, together with incidence and outcome of graft-failure in 89 consecutive first Haplo-PTCy performed for hematologic malignancy in our center between Oct 2005 and Jun 2012. Patient characteristics: M 48, F 41; median age 48 (20–74); Diagnosis AML 28, ALL 16, CLL 11, NHL 9, HL 8, CML 8, MDS 7, MPS 2; median number of matched HLA loci were 5/10 (range 5/10 to 8/10); Median CD34+ and CD3+ cell dose infused were 4.01 × 106/kg (0.84–6.27) and 5.35 × 107/kg (1.4–53.82) respectively. Fifty-eight patients received a marrow graft and 31 received G-CSF mobilized PBSC. The preparative regimen was RIC/NST in 59 (fludarabine 30 mg/m2/d d -6 to -2, TBI 200cGy d-1, cyclophosphamide 14.5 mg/kg/d d-6 & -5, and 50 mg/kg/d d+3 & +4) and myeloablative in 30 (regimen A- fludarabine 30 mg/m2/d d -6 to -2, busulfan 110–130 mg/m2/d d-7 to -4, cyclophosphamide 14.5 mg/kg/d d-3 & -2, and 50 mg/kg/g d+3 & +4 [20 patients] and regimen B- fludarabine 30 mg/m2/d d -7 to -5, TBI 1200 cGy given in 8 fractions between days-4 to -1 and cyclophosphamide 50 mg/kg/d d +3 & +4 [10 patients]). The presence of pre-transplant anti-donor HLA antibodies were assessed using a solid phase assay (Panel Reactive Antibody, PRA, Clinimmune, CO) and by anti-donor cross-matching by flow cytometry (Clinimmune). All donors were selected to provide a negative cross-match using recipient serum and donor T-cells prior to transplant. Engraftment was determined using standard CIBMTR criteria. Lineage-specific chimerism was determined using PCR for short tandem repeats on peripheral blood mononuclear cells separated by CD3 and CD33 expression using immunomagnetic beads on d 30,60,90 and 180 following transplant. Median time to ANC > 500/mm3 was 16d (12–27d) and platelets > 20,000/mm3 was 26d (0–26d). Median T-cell (CD3) and myeloid (CD33) donor chimerisms were 100%, at all time-points assessed from d30–180 (Fig 1). All 30 patients who received a myeloablative Haplo-PTCy had full engraftment of T-cells and myeloid cells starting d +30. However six of 59 patients undergoing RIC/NST Haplo-PTCy had primary failure of T-cell engraftment -median CD3 chimerism (range) for these patients on d 30 and 60 were 0% (0–6%) and 0% (0–14%). Median CD33+ cell chimerism for the same patients on d 30 and 60 respectively were 86% (0–100%) and 45% (0–100%). Four of these patients underwent a second Haplo-PTCy, a median of 105d (range 8–123d) following the first transplant using a different haploidentical donor and the same preparative regimen. In each case the second Haplo-PTCy was successful (CD3+ donor chimerism 100% by d 30–60 in all cases). One patient who was too unwell for second Haplo-PTCy had spontaneous improvement in CD3 chimerism (6–14% d 30–90 improving to 100% d 180) and one patient died of progressive malignancy before a second Haplo-PTCy could be performed. These data demonstrate that full donor chimerism of T-cells and myeloid cells is usual following Haplo-PTCy from the earliest time-points assessed. Engraftment failure was not seen in any patient using the myeloablative regimens described above. Approximately 10% of patients conditioned with the RIC/NST regimen failed to undergo initial T-cell engraftment. However, re-transplantation was successful in all cases when attempted. Late spontaneous improvement of CD3 chimerism is also possible in patients with low level mixed chimerism early post-transplant. Fig 1. Fig 1. Disclosures: No relevant conflicts of interest to declare.

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