Efficacy Of Donor Lymphocyte Infusion Research Articles

Analysis of Safety and Efficacy of Donor Lymphocyte Infusion in Prophylactic, Pre-Emptive and Treatment Strategies Post Allogeneic Stem Cell Transplant

Analysis of Safety and Efficacy of Donor Lymphocyte Infusion in Prophylactic, Pre-Emptive and Treatment Strategies Post Allogeneic Stem Cell Transplant

VLA-4 Agonist Enhances the Capacity of HSC Engraftment and Immune Reconstitution

Poor donor cell implantation and delayed hematopoietic reconstitution are important factors affecting the prognosis of patients after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). However, our understanding of the critical endogenous signals that reconstitute hematopoiesis in transplant patients remains limited，which is essential for achieving targeted interventions and preventing donor-recipient chimeric states after transplantation. Here, we revealed the reconstitution dynamics of human allogeneic hematopoietic stem and progenitor cells (HSPCs) and immune cell subpopulations in the post-transplantation mixed donor chimerism (MDC) to fully donor chimerism (FDC) state at single-cell resolution. The hematopoietic stem cell (HSC) implantation process involves extensive interactions with immune cells mainly through surface Kcnq5, Itga4 (encoding a subunit of VLA-4), Tfrc, CD44 receptor, and ligands for Rps19, B2m, etc. Further identification of VLA-4(integrin α4β1) as a potential regulatory target for HSC implantation by single-cell sequencing of a stable allogeneic bone marrow transplantation (Allo-BMT) MDC-FDC mouse model. Grafts Itgα4 and Itgβ1 deletion impair donor implantation and further diminish the efficacy of donor lymphocyte infusion (DLI) following Allo-BMT, rather than directly affecting DLI. Critically, we identified a VLA-4 agonist that promotes donor implantation in the mixed chimeric mouse model of Allo-BMT in a time-dependent manner, with the most pronounced promotion of early T cell implantation in particular. Moreover, it was found to enhance the self-renewal capacity of HSC and lymphoid reconstitution in competitive transplantation and human umbilical cord blood transplantation xenograft experiments. Fortunately, VLA-4 agonist does not exacerbate the acute graft-versus-host disease(aGVHD) process while maintaining the graft-versus-leukemia (GVL) effect. VLA-4 agonist not only upregulates of both Itgα4 and Itgβ1 expression, but also promotes the ERK/2 phosphorylation pathway, which affects HSC biological functions, and this process can be inhibited by ERK kinase inhibitors. These results provide insights into the regenerative process of transplanted HSPCs in human patients，and demonstrate a previously unknown positive regulation of HSC engraftment and immune reconstitution by VLA-4, and allow for a new and simple translational strategy to enhance HSC transplantation.

ASXL1 Truncating Mutations Drive Leukemic Resistance to T Cell Attack

Restoration of graft-versus leukemia activity underlies the efficacy of donor lymphocyte infusion (DLI), a curative immunotherapy for leukemic relapse following allogeneic stem cell transplant (SCT). We found that while specific exhausted T cell subsets defined DLI response, no pattern of T cell dysfunction appeared in nonresponders (NRs) [PMID: 34758319]. We hypothesized that leukemic molecular pathways define DLI resistance (DLIr). We performed whole exome sequencing on bone marrow samples collected before and after DLI from 11 patients (pts) with relapsed chronic myeloid leukemia (CML) at Dana-Farber Cancer Institute. We used MuTect2 to discover somatic alterations using genomic DNA from recipient-derived mesenchymal stromal cells and donor peripheral blood cells as germline sources. The burden of nonsynonymous mutations and mutational spectra was similar between responders (Rs) and non-responders (NRs). Known non-Philadelphia (Ph) chromosome cancer drivers were found in 0/7 Rs and 4/4 NRs (RUNX1 (1/4), IKZF1 (2/4), and truncating exon 12 ASXL1 mutations (ASXL1 m) (3/4)). We profiled 6 more DLI-treated pts with relapsed CML from the MD Anderson Cancer Center with a targeted mutation panel that identified ASXL1 m in 4/5 NRs. Altogether, we found ASXL1 m in 78% (7/9) of NRs and 0% (0/10) of Rs (p=7e-4, two-sided Fisher's test), suggesting ASXL1 m as a driver of DLIr. To discover molecular pathways of DLIr, we interrogated unpublished non T-cell single cell (sc)RNA-seq data in our DLI cohort (8 R, 6 NR). Leukemic cells were identified for patients (n=8) with sex-mismatched SCT by male sex-defining genes, which correlated with Ph chromosomal positivity (Pearson correlation = 0.85). These cells were primarily confined to the myeloid population, so we performed a scRNA myeloid reclustering (138,152 cells) with Harmony batch correction and identified 5 populations enriched in R vs NR; 4 clusters in NR, and 1 monocyte cluster in R (p=0.039, 0.005, 0.038, 0.043, and 0.025, respectively). These NR clusters were enriched in progenitor cell identities, notably the LSC17 [PMID: 27926740] signature (p<2e-16). Interrogation of immune pathways in the LSC cluster showed downregulation of HLA-I and multiple antigen processing/presentation (APP) genes in NRs (p<2e-16), while HLA-II remained unchanged. Thus, ASXL1 m may mediate immune escape through suppression of HLA-I expression and antigen presentation. To directly test this hypothesis, we CRISPR corrected the endogenous ASXL1 m (Y591*) in a BCR-ABL-driven leukemic cell line (K562). This wildtype reversion (ASXL1 c) increased HLA-I expression at the RNA (RNA-seq; HLA-B/C, log2foldchange= -4.77, q=7e-42) and protein level (flow cytometry; 49.0% vs 1.62%, q=2e-4); here too, HLA-II expression remained unaffected by ASXL1 mutation status. Gene-set enrichment analysis also showed increased APP expression in ASXL1 c K562 (NES=-1.75, q=0.01). We then sought to identify whether correction of ASXL1m acted through known regulators of HLA-I. Treatment with IFNɣ or EPZ011989, an inhibitor of enhancer of zeste-homolog 2 (EZH2), resulted in greater HLA-I in K562 ASXL1 c (85.0% vs 50.2% and 89.5% vs 39.3%, respectively, q<0.001) suggesting that ASXL1 cacts orthogonally to IFNɣ or EZH2. ASXL1 c also mediated increased T-cell cytotoxicity towards K562 ASXL1 c vs ASXL1 m without (43% vs 16%, q=2e-4) and with IFNɣ pre-treatment (71% vs 34%, q=1e-6) at 10:1 target to effector ratios. Finally, to study other disease contexts, we examined published sc chromatin accessibility and scRNA-seq data from a chronic myelomonocytic leukemia cohort [PMID: 35301312] and an acute myeloid leukemia cohort [PMID:32649887], respectively. We found both chromatin and transcriptional states enriched in ASXL1m samples to have decreased accessibility and expression, respectively, of HLA-I and APP genes (p<2E-16). In summary, we integrated molecular analyses with immuno-functional studies to define a novel oncogenetic pathway of immune evasion. Specifically, we link DLIr to ASXL1 m that suppresses transcription of HLA-I and antigen presentation machinery in myeloid diseases; moreover, its correction restores anti-leukemic CD8+ T-cell cytotoxicity. Ongoing studies will examine additional clinical contexts and the epigenetic mechanisms by which ASXL1m regulates HLA-I expression.

Magnesium enhances the graft-versus-tumor effect of donor lymphocytic infusion on hematologic malignancies.

Donor lymphocyte infusion (DLI) cures relapsed hematologic malignancies after allogeneic hematopoietic stem cell transplantation through the graft-versus-tumor (GVT) effect. Although the important role of magnesium in enhancing immunity has been mentioned in studies, limited clinical data have explored how magnesium affects the efficacy of DLI. Besides, although laboratory data demonstrate that magnesium can enhance CD8+ T cells effector function, whether magnesium regulates the tumor killing effect of peripheral blood mononuclear cells (PBMCs) remains to be explored. Here, for the retrospective study, we collected clinical data of relapsed patients receiving DLI and explored the relationship between different serum magnesium levels and patient outcomes. For in vitro studies, we investigated the effect of magnesium on the cytotoxicity of DLI cells which were PBMCs and preliminarily explored the mechanism. Eighty-one patients were enrolled in this study. It was found that the high post-DLI magnesium level was significantly associated with a higher incidence of complete remission (CR) or partial remission (CR/PR) and a higher possibility of survival. The magnesium level after DLI was an independent risk factor of overall survival. In vitro studies proved that increased magnesium enhanced the cytotoxic function of PBMCs on hematologic malignancies. Besides, magnesium modulated LFA-1 headpiece opening. When blocking the integrin-ligand interaction between LFA-1 and ICAM-1, the regulation effect of magnesium on PBMCs was weakened. Therefore, it was possible that magnesium regulated PBMCs effector function by stimulating LFA-1. These results show that serum magnesium levels affect immunological responses mediated by donor lymphocytes in hematologic malignancies.

Low incidence and morbidity of Epstein-Barr virus reactivation following donor lymphocyte infusions.

Low incidence and morbidity of Epstein-Barr virus reactivation following donor lymphocyte infusions.

A Multicenter Phase 2 Clinical Trial of 10-Day Decitabine, Dose-Escalated Donor Lymphocyte Infusion, and Ruxolitinib for Relapsed Acute Myeloid Leukemia and Myelodysplastic Syndromes after Allogeneic Hematopoietic Cell Transplantation

Post-transplantation relapse of acute myeloid leukemia and myelodysplastic syndromes has a poor prognosis. Donor lymphocyte infusion (DLI) is one treatment approach. However, efficacy is limited, and toxicity, mostly in the form of acute graft-versus-host disease (GVHD), is frequent. We tested a novel approach using 10-day decitabine, dose-escalated DLI, and ruxolitinib in a multicenter phase 2 trial aimed at increasing the efficacy of DLI and reducing its toxicity. Up to four 28-day cycles were administered. The primary endpoint was 6-month overall survival (OS). Of the 14 patients who started cycle 1, 13 received 1 DLI, 6 received 2 DLIs, and 1 received 3 4 DLIs. A preplanned interim analysis after enrolling 14 patients suggested futility, and the trial was closed to accrual. The final analysis showed a 6-month OS of 36% (95% confidence interval [CI], 18 to 72), a 1-year progression-free survival of 7% (95% CI, 1% to 47%), a 6-month cumulative incidence of grade II-IV acute GVHD of 57% (95% CI, 26% to 80%), and a 1-year nonrelapse mortality of 14% (95% CI, 2% to 38%). The combined modality treatment studied in this trial was ineffective and did not reduce DLI toxicity.

152 - Efficacy of Donor Lymphocyte Infusions in Achieving Disease Control Among Myeloid Malignancy Patients Treated with an Allogeneic Hematopoietic Stem Cell Transplantation

152 - Efficacy of Donor Lymphocyte Infusions in Achieving Disease Control Among Myeloid Malignancy Patients Treated with an Allogeneic Hematopoietic Stem Cell Transplantation

RETRACTED: The impact of second-donor lymphocyte infusion on secondary graft failure after allogeneic hematopoietic stem cell transplantation through activation of Foxp3 and regulatory T cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Editor of Cytotherapy has retracted this article. The article duplicates significant parts of a paper that had already appeared in Transplantation and Cellular Therapy, Volume 28, Issue 3, 2022, Pages 152.e1-152.e7, https://doi.org/10.1016/j.jtct.2021.12.017 In accordance with Committee on Publication Ethics (COPE) and Elsevier's policies, the authors have been contacted. After considering the author's response, the decision has been made to retract the paper. Redundant publications overweigh the relative importance of published findings and distort the academic record of the authors. One of the conditions of submission of a paper for publication is therefore that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents a misuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Optimization of Donor Lymphocyte Infusion for AML Relapse After Allo-HCT in the Era of New Drugs and Cell Engineering.

Donor lymphocyte infusion (DLI) is a key strategy for the treatment of AML relapse after allogeneic hematopoietic cell transplantation (allo-HCT) and has been used for either prophylactic, pre-emptive, or therapeutic purposes. However, the prognosis of these patients remains dismal even after DLI infusion (2-year overall survival, ~25%), and the efficacy is achieved at the cost of toxicities such as graft-versus-host (GVH) disease. Attempts to optimize DLI efficacy and safety, such as dose/timing modification and the use of cytoreduction, before DLI have been performed previously. Recently, a great number of novel targeted and immunomodulatory agents have emerged. Some of them, such as hypomethylating agents, FLT3 and Bcl-2 inhibitors, have been used in combination with DLI, aiming to enhance the graft-versus-leukemia effect. Moreover, manipulation of the DLI graft through cell selection (e.g., donor NK cells) or cell engineering (donor CAR-T cells) has shown potentially superior anti-tumor effects but less GVH effect than conventional DLI in clinical trials. This review summarizes the recent advances on the use of DLI for the prophylaxis/treatment of AML relapse and discusses future strategies which may further improve the treatment efficacy.

Efficacy of Donor Lymphocyte Infusion in CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplant for Myeloid and Lymphoid Malignancies: A Single Center Experience

Introduction Donor lymphocyte infusion (DLI) has been used to prevent or treat relapse after allogeneic hematopoietic stem cell transplantation (alloHCT) since the 1990s. Retrospective series have reported variable efficacy (CML up to 60%, ALL 0% in some series) with rates of DLI-associated graft-versus host disease (GVHD) of 40-60%. DLI's ability to potentiate graft versus leukemia effects and GVHD are thought to be primarily T Cell mediated, and T cell chimerism, repertoire, and exhaustion may have important influence on outcomes.The use of ex-vivo T cell depleted CD34 selected alloHCT has been shown to provide similar survival to unmodified grafts but with lower acute and chronic GVHD, and is now being studied in a randomized trial exploring calcineurin inhibitor free GVHD prevention regimens (BMT CTN 1301). There is however limited data on DLI in this context. Here we describe safety and efficacy outcomes of DLI in recipients of CD34 selected alloHCT.Methods This retrospective study included all CD34 selected alloHCT recipients at our center who received DLI from January 2005 to January 2016 for treatment or prevention of relapse. We excluded patients with multiple myeloma as these results have been reported elsewhere. Primary outcomes were maintenance or achievement of disease remission, and change in whole bone marrow and peripheral T Cell chimerism over time. A loess smoothed curve was used to visually display changes in chimerism over time and to provide time point chimerism estimates.Results 58 patients received DLI for frank relapse (n=20), minimal residual disease (MRD, n=11), or for relapse prevention in the context of mixed marrow or peripheral blood chimerism (n=27). AML (40%) and MDS (29%) were the most common diagnoses, and most patients (74%) had intermediate disease risk index (Table 1). All patients received peripheral blood stem cell grafts and myeloablative conditioning. Median DLI dose was 0.5 x 106 CD3 cells/kg (0.01-10.0) with 86% of patients receiving doses between 0.1 and 1.0 x 106 CD3 cells/kg. DLI was most often given once (67%), with some patients having 2 (21%) or > 2 treatments (12%). Of the 20 patients who received DLI for frank relapse, 3 (15%) achieved remission, and of the 11 patients who received DLI for minimal residual disease, 8 (73%) achieved remission. Of the 27 patients with mixed chimerism treated with preventive DLI, remission was maintained in 22 (81%). Achieving or maintaining remission was not independently associated with underlying diagnosis, use of adjunctive hypomethylating agents or stem cell boost, or DLI dose or frequency in this cohort. DLI resulted in an average whole bone marrow donor chimerism increase after DLI, regardless of DLI indication (9% at 90 days; Fig 1). T Cell donor chimerism also increased after DLI, with a more pronounced increase in patients treated for relapse (50%) than those treated for relapse prevention (12%; Fig 1). Prior to DLI, rates of grade II-IV and III-IV acute GVHD were 10 and 3% respectively, and no patients had moderate or severe chronic GVHD. All GVHD had resolved prior to DLI administration. After DLI we observed 2 episodes (3%) of late acute grade II-IV GVHD (both grade III skin), and 4 episodes (7%) of moderate-severe chronic GVHD with median onset of 99 and 80 days post DLI, respectively (range 44-401).Conclusions DLI given after CD34+ selected alloHCT was associated with GVHD rates that were substantially lower than reported in other DLI contexts. Disease response to DLI was higher in MRD positive patients than for those with frank relapse (15 vs 73%), suggesting that regular MRD assessment and prompt DLI administration may be an effective relapse prevention strategy in MRD positive patients. The low relapse rate observed in patients with mixed chimerism receiving preventive DLI (19%) was not substantially different than historical relapse rates observed in CD34+ selected patients at our institution, so does not yet provide a convincing signal to explore DLI for relapse prevention in the absence of MRD. In summary, DLI given after T Cell depleted alloHCT was associated with low rates of GVHD and may be an effective strategy to prevent frank relapse in MRD positive patients after alloHCT. Acknowledging the inherent limitations of our small sample size, our observations suggest broader exploration of this safe and potentially effective strategy is warranted. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Targeting non-engrafting IL-2 activated intentionally mismatched donor lymphocytes with monoclonal or bispecific antibodies for treatment of otherwise incurable cancer.

e15033 Background: Cure of certain resistant cancers by donor lymphocyte infusion (DLI) following allogeneic stem cell transplantation (SCT) suggests that alloreactive lymphocytes can eliminate otherwise resistant cancer. First patient with resistant relapse following supra-lethal chemoradiotherapy treated with DLI is alive & well > 34 years; > 400 patients with hematological malignancies confirmed DLI efficacy for prevention & treatment of relapse. Using murine leukemia (BCL1) & metastatic breast cancer (4T1), IL-2 activated mismatched lymphocytes with no prior SCT eliminated otherwise lethal minimal residual disease (MRD). Using anti-EpCAM x anti-CD3 bispecific antibody (BSA) lethal melanoma was eliminated, also resulted in long-lasting immunity against lethal tumor challenge. Graft-vs-host disease (GVHD) was prevented by consistent rejection of mismatched lymphocytes. Accordingly, our goal was to develop effective immunotherapy of cancer using non-engrafting intentionally mismatched Allogeneic Targeted Activated Cancer Killer cells (ATACK) using relevant monoclonal antibodies (MoAb) or BSA. Methods: Patients with multiple myeloma & lymphoma and advanced solid tumors were treated with haploidentical or unrelated donor lymphocytes pre-activated 5 days with IL-2, following non-myeloablative conditioning with endoxan or fludarabine and IL-2 injection x5 days for in vivo lymphocyte activation. ATACK with no MoAb was investigated in 40 patients with different cancers. Safety of ATACK with MoAb was investigated in 16 patients with resistant NHL, metastatic breast, lung & colorectal cancer, using commercial MoAbs against CD20, Her-2, EGFR or VEGF, respectively, or using anti-EpCAM BSA. Results: Protocols were well-tolerated with mild transient toxicity following ATACK and BSA. No patient developed GVHD. Disease-free survival > 15 years was documented in 2/2 patient with multiple myeloma and 2/2 patients with lymphoma. Longterm progression-free survival was observed in 5/31 evaluable patients with advanced metastatic solid tumors treated with no MoAbs. Minor toxicity in targeted ATACK recipients was manageable in outpatient clinic. Conclusions: Intentionally mismatched IL-2 activated killer cells guided by MoAbs or BSA represents a promissing approach for treatment, possibly even cure, of cancer patients with MRD while avoiding GVHD.

Efficacy and Toxicity of Donor Lymphocyte Infusions in the Management of Mixed Donor-Recipient Chimerism Following Allogeneic Stem Cell Transplantation for Lymphoid Malignancies:- a Study of the LWP-EBMT

Efficacy and Toxicity of Donor Lymphocyte Infusions in the Management of Mixed Donor-Recipient Chimerism Following Allogeneic Stem Cell Transplantation for Lymphoid Malignancies:- a Study of the LWP-EBMT

Donor Lymphocyte Infusions for the Treatment of Relapsed Non-Hodgkin Lymphoma Following Allogeneic Stem Cell Transplantation: A LWP-EBMT Study

IntroductionRelapse of non-Hodgkin lymphoma (NHL) following allogeneic stem cell transplantation (alloSCT) is a common occurrence associated with a poor outcome with limited treatment options. Donor lymphocyte infusions (DLI) are commonly employed in this setting in an attempt to exploit the allogeneic graft versus lymphoma (GVL) effect to induce remissions. There is however a paucity of data describing the efficacy of DLIs in inducing remissions in NHL subtypes and the risk of subsequently developing graft versus host disease (GVHD). We report here the largest series of patients with NHL receiving DLI for relapse after alloSCT.MethodsPatients relapsing after an alloSCT for NHL and receiving DLI were identified on the EBMT database. Centres were invited to contribute additional data. 118 patients [follicular lymphoma (FL) n=28, diffuse large B cell lymphoma (DLBCL) n=28, T cell lymphoma (TCL) n=52 and mantle cell lymphoma (MCL) n=10] from 39 centres who received DLI as the only treatment for relapse were identified. Patients receiving DLI in combination with other therapy were excluded from this analysis. The median age at alloSCT was 50 (range 18-73) years. There were 81 male and 37 female patients who underwent an alloSCT with reduced intensity (RIC) (n=90) or myeloablative conditioning (MAC) (n=28) at a median of 2.4 (range 0.3-26.3) years from diagnosis. Allogeneic cells were provided from matched sibling (n=63), unrelated (n=47) or mismatched family (n=8) donors and 85 patients received either ATG/ALG or CAMPATH as part of GVHD prophylaxis. The median time from alloSCT to relapse was 3.8 months (range 18 days-67 months).ResultsPatients received a median of 1 (range 1-19) DLI at a median starting dose of 1.5 x106 CD3/kg (range 0.01-120x106 CD3/kg) at a median of 152 days (range 18-2136) post alloSCT. The median last dose of DLI was 10x106/kg (range 0.1-180x106/kg) given at a median of 353 days (range 41-2725) post alloSCT. The median time from relapse to the first DLI was 35 days (range 0-168). Acute GVHD and chronic GVHD prior to DLI was reported in 29% and 14% of patients, respectively. Of 93 evaluable patients 47 (51%) patients achieved a complete remission, 10 (11%) a partial remission, 13 (14%) stable disease and 23 (25%) had progressive disease following DLI. The median duration of response was 36 months (range 1-168). When analysed according to histology the overall response rate (ORR) (CR+PR) for FL was 84% (CR 68%), DLBCL 41% (32% CR), TCL 54% (46% CR) and MCL 86% (CR 71%). The median duration of responses for FL, DLBCL, TCL and MCL were 30 (range 2-150), 38 (4-76), 37 (range 1-168) and 50 months (13-116) respectively. With a median follow up of 77 months after the 1st DLI 36 (31%) patients remain in complete remission, 29 (25%) without any further therapy. 37 (35%) went on to receive additional antilymphoma therapy after the DLI. Of 17 patients with FL achieving a CR post DLI 12 (71%) remain in remission without further therapy at a median of 78 (9-158) months after DLI. Of 18 patients with TCL that achieved a CR with DLI, 15 (83%) remain in remission without further therapy at a median of 95 (range 42-161) months after DLI. Following the DLI 43 (36%) patients developed aGVHD (6 grade I, 13 grade II, 11 grade III, 9 grade IV, 4 grade unknown) and 33 (28%) developed cGVHD (11 limited, 20 extensive, 2 unknown). Following the first DLI the cumulative incidence of relapse was 31% (CI 22-41) at 4 years and of NRM 28% (CI 20-37). The 4-year PFS after 1st DLI was 39% (CI 30-50) and the OS, 44% (CI 35-54).ConclusionsDLI induce significant rates of disease response in patients with NHL relapsing after alloSCT providing clear proof of principle of the allogeneic GVL effect. The rates of response are most impressive in FL and MCL. The majority of patients with TCL and FL that achieve a CR post DLI remain in remission with long term follow up. Acute and chronic GVHD is a significant complication of DLI. DisclosuresRobinson:Sandoz: Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau. Chalandon:Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel costs. Beelen:Medac: Consultancy, Other: Travel Support. Finke:Neovii: Consultancy, Honoraria, Other: travel grants, Research Funding; Medac: Consultancy, Honoraria, Other: travel grants, Research Funding; Riemser: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Other: travel grants, Research Funding. Tischer:Jazz Pharmaceuticals: Other: Jazz Advisory Board. Corradini:Amgen: Honoraria, Other: Advisory Board & Lecturer; Novartis: Honoraria, Other: Advisory Board & Lecturer; Abbvie: Honoraria, Other: Advisory Board & Lecturer; Sandoz: Other: Advisory Board; Sanofi: Honoraria, Other: Advisory Board & Lecturer; Gilead: Honoraria, Other: Advisory Board & Lecturer; Takeda: Honoraria, Other: Advisory Board & Lecturer; Roche: Honoraria, Other: Advisory Board & Lecturer; Janssen: Honoraria, Other: Lecturer; Celgene: Honoraria, Other: Advisory Board & Lecturer.

Donor lymphocyte infusions in adolescents and young adults for control of advanced pediatric sarcoma.

BackgroundAllogeneic stem cell transplantation (allo-SCT) and donor lymphocyte infusions (DLI) may induce a graft-versus-tumor effect in pediatric sarcoma patients. Here, we describe general feasibility, toxicity and efficacy of DLI after allo-SCT.Results4 of 8 patients responded. ES#4 had stable disease (SD) for 9 months after DLI and RMS#4 partial response for 8 months with combined hyperthermia/chemotherapy. In ES#4, DLI led to SD for 6 months and reverted residual disease before allo-SCT into complete remission. After DLI, ES#4 and RMS#4 developed acute GvHD (°III–°IV), ES#4 also developed chronic GvHD. 5 patients including ES#4 lived longer than expected. Median survival after allo-SCT was 2.3 years, post-relapse survival (PRS) was 13 months. Off note, HLA-mismatched DLI were associated with a trend towards increased survival after allo-SCT and increased PRS compared to HLA-matched DLI (23 versus 3 months).Materials and MethodsWe studied eight adolescents and young adults (AYAs) with advanced Ewing sarcoma (ES#1-4) and rhabdomyosarcoma (RMS#1-4) who received DLI. Escalating doses ranged from 2.5 × 104 to 1 × 108 CD3+ cells/kg body weight. AYAs were evaluated for response to DLI, graft-versus-host disease (GvHD) and survival.ConclusionsDLI after allo-SCT may control advanced pediatric sarcoma in AYAs with controllable toxicity.

437 - Efficacy of Donor Lymphocyte Infusion in CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplant for Myeloid and Lymphoid Malignancies: A Single Center Experience

437 - Efficacy of Donor Lymphocyte Infusion in CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplant for Myeloid and Lymphoid Malignancies: A Single Center Experience

Efficacy Of Donor Lymphocyte Infusion For Mixed Donor Chimerism Post Hematopoietic Stem Cell Transplantation

Efficacy Of Donor Lymphocyte Infusion For Mixed Donor Chimerism Post Hematopoietic Stem Cell Transplantation

Donor Lymphocyte Infusions Used to Treat Mixed-Chimeric and High-Risk Patient Populations in the Relapsed and Nonrelapsed Settings after Allogeneic Transplantation for Hematologic Malignancies Are Associated with High Five-Year Survival if Persistent Full Donor Chimerism Is Obtained or Maintained

Mixed chimerism (MC), a persistent or increasing number of host cells after allogeneic hematopoietic stem cell transplantation (HSCT), is a predictor of disease relapse. Donor lymphocyte infusions (DLI) have the potential to enhance the graft-versus-malignancy (GVM) effect, reducing the risk of relapse in patients with MC. Hence, in addition to utilizing DLI in the relapsed setting, there is a motivation to pursue pre-emptive DLI for patients in complete remissions after HSCT. To assess the safety and efficacy of DLI, records of 86 patients who received DLI between 2003 and 2015 at a single institution were studied retrospectively. Patients who received DLI included 50 patients with relapsed/residual (RR) disease, 29 patients with emerging MC without detectable disease, and 7 patients in an “other” cohort who had neither RR disease nor emerging MC after HSCT. DLI were administered using a dose-escalation protocol. After DLI, 93% of MC patients converted to full donor chimerism (FDC). Nonrelapsed patients (MC and other) reported high overall survival (OS) at 1 and 5 years (83% at 1 year, 70% at 5 years for MC; 86% at 1 year, 69% at 5 years for other) and was statistically superior to 5-year OS for RR patients (nonrelapsed 69% versus RR 28%; P = .00032). Improved survival correlated with successful conversion to FDC after DLI for RR and MC cohorts: 71% 2-year OS for patients converted to FDC versus 13% for patients who failed to achieve FDC (P < .0001). DLI for nonrelapsed patients was associated with a superior 5-year progression-free survival (PFS) of 71% compared with 18% 5-year PFS in the RR group (P < .0001). Relapse/progressive disease was the most frequent cause of death (41%). Seven MC (24%), 2 other (29%), and 39 RR patients (78%) relapsed or did not respond after DLI. Overall, 6 patients (7%) died of graft-versus-host disease after DLI. Our results demonstrate a successful dose-escalation approach for nonrelapsed patients that correlated with high survival and a high rate of achieving FDC in MC and RR populations. DLI remain a viable option to boost the GVM effect in the relapsed setting and may pre-emptively protect against relapse in MC populations after HSCT.

CTLA4-CD28 chimera gene modification of T cells enhances the therapeutic efficacy of donor lymphocyte infusion for hematological malignancy

Donor lymphocyte infusion (DLI) followed by hematopoietic stem cell transplantation has served as an effective prevention/treatment modality against the relapse of some hematologic tumors, such as chronic myeloid leukemia (CML). However, the therapeutic efficacies of DLI for other types of leukemia, including acute lymphocytic leukemia (ALL), have been limited thus far. Therefore, we examined whether increasing the reactivity of donor T cells by gene modification could enhance the therapeutic efficacy of DLI in a murine model of ALL. When a CTLA4-CD28 chimera gene (CTC28) in which the intracellular signaling domain of CTLA4 was replaced with the CD28 signaling domain was introduced into CD4 and CD8 T cells in DLI, the graft-versus-tumor (GVT) effect was significantly increased. This effect was correlated with an increased expansion of donor CD8 T cells in vivo, and the depletion of CD8 T cells abolished this effect. The CD8 T cell expansion and the enhanced GVT effect were dependent on the transduction of both CD4 and CD8 T cells with CTC28, which emphasizes the role of dual modification in this therapeutic effect. The CTC28-transduced T cells that expanded in vivo also exhibited enhanced functionality. Although the potentiation of the GVT effect mediated by the CTC28 gene modification of T cells was accompanied by an increase of graft-versus-host disease (GVHD), the GVHD was not lethal and was mitigated by treatment with IL-10 gene-modified third-party mesenchymal stem cells. Thus, the combined genetic modification of CD4 and CD8 donor T cells with CTC28 could be a promising strategy for enhancing the therapeutic efficacy of DLI.

Preventing relapse after haematopoietic stem cell transplantation for acute leukaemia: the role of post-transplantation minimal residual disease (MRD) monitoring and MRD-directed intervention.

Relapse is the main cause of treatment failure after allogeneic haematopoietic stem cell transplantation (allo-HSCT) for acute leukaemia (AL). Post-transplantation minimal residual disease (MRD) monitoring enables risk stratification and identifies AL patients at higher risk of relapse. MRD assessment primarily involves the determination of leukaemia-associated immunophenotypic patterns using multiparameter flow cytometry, and the polymerase chain reaction (PCR)-based evaluation of expression levels of leukaemia-related genes (specific reciprocal gene rearrangements and other mutation types). In addition, next generation sequencing and digital PCR may further enrich current MRD detection. Several MRD-directed interventions have demonstrated the ability to reduce the risk of relapse with acceptable treatment-related toxicities. Donor lymphocyte infusion (DLI) is the most important intervention for MRD-positive patients, while several modified strategies, such as granulocyte colony-stimulating factor-mobilized peripheral blood cells followed by short term immune suppression and escalating dose regimen, further improve the safety and efficacy of DLI. Interferon therapy, targeted drugs, and hypomethylating agents have also been introduced for MRD-directed interventions. Referring to the issues of whether and who would benefit from pre-emptive intervention according to MRD, in this review, we summarized this rapidly evolving area of MRD monitoring and MRD-directed interventions in AL patients after allo-HSCT.

Comparison of outcomes after donor lymphocyte infusion with or without prior chemotherapy for minimal residual disease in acute leukemia/myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation.

The efficacy of donor lymphocyte infusion (DLI) without chemotherapy was investigated and compared with that of chemotherapy prior to DLI (Chemo-DLI) in patients who were minimal residual disease (MRD)-positive after allogeneic hematopoietic stem cell transplantation (HSCT). We enrolled 115 consecutive patients who received either DLI (n=20) or Chemo-DLI (n=95) during the same period. For each DLI recipient, three recipients matched for age at the HSCT, underlying diseases, and the year of the HSCT were randomly selected from the Chemo-DLI cohort (n=60). The 2-year cumulative incidence of severe acute graft-versus-host disease (GVHD) and chronic GVHD was comparable between the groups. Fifteen (75.0%) and 47 (78.3%) patients in the DLI and Chemo-DLI groups turned MRD-negative, respectively. The 2-year cumulative incidences of relapse and non-relapse mortality after intervention were 30.7 versus 39.6% (P=0.582) and 10.3 versus 6.0% (P=0.508) in the DLI and Chemo-DLI groups, respectively. The 2-year probabilities of disease-free, overall, and GVHD-free/relapse-free survival after preemptive intervention were 58.9 versus 54.3% (P=0.862), 69.3 versus 78.1% (P=0.361), and 44.4 versus 35.1% (P=0.489) in the DLI and Chemo-DLI groups, respectively. In multivariate analysis, the intervention method did not significantly influence the clinical outcomes. In summary, preemptive DLI alone may be effective for patients who are MRD-positive and may be a potential alternative for patients who refuse or are unable to receive Chemo-DLI after HSCT.