Chimeric antigen receptor (CAR) T cells targeting CD19 are a breakthrough treatment for relapsed, refractory B cell malignancies
. Despite impressive outcomes, relapse with CD19
disease remains a ...challenge. We address this limitation through a first-in-human trial of bispecific anti-CD20, anti-CD19 (LV20.19) CAR T cells for relapsed, refractory B cell malignancies. Adult patients with B cell non-Hodgkin lymphoma or chronic lymphocytic leukemia were treated on a phase 1 dose escalation and expansion trial (NCT03019055) to evaluate the safety of 4-1BB-CD3ζ LV20.19 CAR T cells and the feasibility of on-site manufacturing using the CliniMACS Prodigy system. CAR T cell doses ranged from 2.5 × 10
-2.5 × 10
cells per kg. Cell manufacturing was set at 14 d with the goal of infusing non-cryopreserved LV20.19 CAR T cells. The target dose of LV20.19 CAR T cells was met in all CAR-naive patients, and 22 patients received LV20.19 CAR T cells on protocol. In the absence of dose-limiting toxicity, a dose of 2.5 × 10
cells per kg was chosen for expansion. Grade 3-4 cytokine release syndrome occurred in one (5%) patient, and grade 3-4 neurotoxicity occurred in three (14%) patients. Eighteen (82%) patients achieved an overall response at day 28, 14 (64%) had a complete response, and 4 (18%) had a partial response. The overall response rate to the dose of 2.5 × 10
cells per kg with non-cryopreserved infusion (n = 12) was 100% (complete response, 92%; partial response, 8%). Notably, loss of the CD19 antigen was not seen in patients who relapsed or experienced treatment failure. In conclusion, on-site manufacturing and infusion of non-cryopreserved LV20.19 CAR T cells were feasible and therapeutically safe, showing low toxicity and high efficacy. Bispecific CARs may improve clinical responses by mitigating target antigen downregulation as a mechanism of relapse.
Abstract Background aims Multiple steps are required to produce chimeric antigen receptor (CAR)-T cells, involving subset enrichment or depletion, activation, gene transduction and expansion. Open ...processing steps that increase risk of contamination and production failure are required. This complex process requires skilled personnel and costly clean-room facilities and infrastructure. Simplified, reproducible CAR-T-cell manufacturing with reduced labor intensity within a closed-system is highly desirable for increased availability for patients. Methods The CliniMACS Prodigy with TCT process software and the TS520 tubing set that allows closed-system processing for cell enrichment, transduction, washing and expansion was used. We used MACS-CD4 and CD8-MicroBeads for enrichment, TransAct CD3/CD28 reagent for activation, lentiviral CD8 TM-41BB-CD3 ζ-cfrag vectors expressing scFv for CD19 or CD20/CD19 antigens for transduction, TexMACS medium-3%-HS-IL2 for culture and phosphate-buffered saline/ethylenediaminetetraacetic acid buffer for washing. Processing time was 13 days. Results Enrichment (N = 7) resulted in CD4/CD8 purity of 98 ± 4.0%, 55 ± 6% recovery and CD3+ T-cell purity of 89 ± 10%. Vectors at multiplicity of infection 5–10 resulted in transduction averaging 37%. An average 30-fold expansion of 108 CD4/CD8-enriched cells resulted in sufficient transduced T cells for clinical use. CAR-T cells were 82–100% CD3+ with a mix of CD4+ and CD8+ cells that primarily expressed an effector-memory or central-memory phenotype. Functional testing demonstrated recognition of B-cells and for the CAR-20/19 T cells, CD19 and CD20 single transfectants were recognized in cytotoxic T lymphocyte and interferon-γ production assays. Discussion The CliniMACS Prodigy device, tubing set TS520 and TCT software allow CAR-T cells to be manufactured in a closed system at the treatment site without need for clean-room facilities and related infrastructure.
T-cell depletion (TCD) reduces the incidence of graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT). However, concerns about relapse, graft rejection, and variability in ...technique have limited the widespread application of this approach.
Outcomes of 44 patients receiving HLA-identical sibling TCD grafts using a uniform technique for CD34(+) selection as the sole form of immune suppression were compared with outcomes of 84 patients receiving T-replete grafts and pharmacologic immune suppression therapy (IST).
Groups were similar, except for fewer men (36% with TCD v 56% with IST) and more frequent use of radiation-containing regimens (100% with TCD v 50% with IST) in the CD34-selected TCD cohort. The proportion of patients with neutrophil engraftment at day 28 was similar (96% with IST and 100% with TCD grafts). The 100-day rates of grade 2 to 4 acute GVHD were 39% and 23% with IST and TCD grafts, respectively (P = .07). Corresponding 2-year rates of chronic GVHD were lower with TCD grafts than IST (19% v 50%, respectively; P < .001). There were no differences in rates of graft rejection, leukemia relapse, treatment-related mortality, and disease-free and overall survival rates. At 1 year, 54% and 12% of patients were still on immunosuppression in the IST and TCD cohorts, respectively. TCD was associated with a higher GVHD-free survival at 2 years compared with IST (41% v 19%, respectively; P = .006).
These results suggest that TCD via CD34 selection might lower long-term morbidity as a result of chronic GVHD without negatively impacting relapse rates in patients with acute myeloid leukemia. Additional prospective studies should be undertaken to definitively address the role of TCD in HCT.
Inhibitory killer immunoglobulin (Ig)-like receptors (KIRs) recognize HLA-C and -B epitopes on target cells, thereby regulating natural killer (NK) cell activity. In 178 patients receiving ...T-cell-depleted HLA-identical sibling transplants for acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), or myelodysplastic syndrome (MDS), analysis of donor KIR genotype with HLA genotype demonstrated that 62.9% of the patients lacked an HLA ligand for donor-inhibitory KIR. Lack of HLA ligand for donor-inhibitory KIR (missing KIR ligand) had no effect on disease-free survival (DFS), overall survival (OS), or relapse in patients receiving transplants for CML and ALL. In patients with AML and MDS, however, there was a significant missing KIR ligand effect on DFS (P = .014; hazard ratio HR, 0.53; 95% confidence interval 95% CI, 0.28-0.88) and OS (P = .03; HR, 0.53; 95% CI, 0.3-0.93). Incidence of relapse was also lower in patients with AML and MDS who lacked the HLA ligand for donor-inhibitory KIR (P = .04; HR, 0.41; 95% CI, 0.18-0.97). AML and MDS patients lacking 2 HLA ligands for donor-inhibitory KIR had the highest DFS (P = .002) and OS (P = .003). There was no significant contribution of donor-activating KIR to transplantation outcome in these patients. These data indicate that the absence of class I ligand in the recipient for donor-inhibitory KIR can be a prognostic factor for transplantation outcome in HLA-identical sibling transplantation and that the lack of HLA-C or -B ligands for donor-inhibitory KIR can contribute to improved outcomes for patients with AML and MDS. (Blood. 2005;105:4878-4884)
Background
Donor lymphocyte infusion (DLI) is often used to treat leukemic relapse after hematopoietic cell transplantation (HCT). However, the relationship between outcomes and distinct DLI ...cellular composition has not been previously reported. Additionally, there are limited published data on efficacy in pediatrics. We evaluated whether DLI cellular content and development of graft‐versus‐host disease (GVHD) impacted disease and influenced overall survival (OS) in children receiving DLI for recurrent leukemia.
Methods
We performed an Institutional Review Board–approved, retrospective study investigating all consecutive DLIs given to patients at the Children's Hospital of Wisconsin between 1980 and 2018. Analyses were conducted using Mann–Whitney, Fisher exact, and chi‐square tests.
Results
Thirty patients ≤20 years old with hematologic malignancies (myeloid AML/MDS/CML/JMML, n = 23; lymphoid ALL, n = 7) received DLI to treat post‐transplant relapse. We found no significant difference in OS or development of GVHD based on CD3, CD4, CD8, CD56, or CD19 DLI cellular composition. With a median follow‐up of 0.69 (range, 0.04–16.61) years, OS at five years was 32% ± 9%. The lymphoid group had a five‐year survival rate at 71% ± 17% compared with the myeloid group at 22% ± 9%, although not statistically significant (P = 0.11). The development of GVHD did not affect OS (P = 0.62).
Conclusion
Here, we report a single‐center, long‐term experience of pediatric DLIs. Surprisingly, many children with ALL were able to achieve durable remissions. Although cellular composition did not have a significant effect on GVHD or OS in our small study, engineering DLI products to maximize specific effector cell populations could be one strategy to improve efficacy.
Abstract Background aims Removing DMSO post-thaw results in: reduced infusion reactions, improved recovery and stability of viable CD34+ cells. Validated methods use 5%–8.3% Dextran 40 with 2.5%–4.2% ...HSA for this purpose. Recent shortages of clinical grade Dextran require identification of suitable alternatives. Methods PBPC were used to compare a standard 2X wash medium of 5 parts 10% Dextran 40 in saline (DEX) with 1 part 25% HSA (8.3% DEX/ 4.2% HSA) with Hydroxyethyl Starch (HES)-based solutions. Cells in replicate bags were diluted with an equal volume of wash solution, equilibrated 5 minutes, the bag filled with wash medium, pelleted and the supernatant expressed. Bags were restored to the frozen volume in wash medium and tested by single platform flow cytometry and CFU. Total viability, viable TNC, MNC, and CD34+ cell recovery, and CD34+ cell viability were compared immediately post-thaw and after 90 minutes. Results 5.2% HES/4.2% HSA did not differ from our standard in CD34 recovery or viability. Due to concerns that high concentrations of HES could affect renal function we tested 0.6% HES/2.5% HSA resulting in significantly poorer CD34 recovery and viability. Results improved using 2.4% HES/4.2% HSA and when 0.6% HES/4.2%HSA was used no significant differences were seen. CFU assays confirmed no differences between the standard dextran arm and HES at 2.4% or 0.6% so long as HSA was at 4.2%. Conclusions We conclude that HES from 0.6% to 5.2% with 4.2% HSA is a suitable substitute for Dextran 40 as a reconstitution/washing medium for PBPC products.
We conducted a phase 2 study in which patients undergoing allogeneic hematopoietic stem cell transplantation received tocilizumab in addition to standard immune suppression with tacrolimus and ...methotrexate for graft-
-host disease prophylaxis. Thirty-five patients were enrolled between January 2015 and June 2016. The median age of the cohort was 66 (range: 22-76). All patients received busulfan-based conditioning, and were transplanted with human leukocyte antigen-matched related or matched unrelated bone marrow or peripheral stem cell grafts. The cumulative incidences of grades II-IV and III-IV acute graft-
-host disease were 14% (95% CI 5-30) and 3% (95% CI 0-11) at day 100, and 17% (95% CI 7-31) and 6% (95% CI 1-16) at day 180, respectively. Notably, there were no cases of graft-
-host disease of the lower gastrointestinal tract within the first 100 days. A comparison to 130 matched controls who only received tacrolimus and methotrexate demonstrated a lower cumulative incidence of grades II-IV acute graft-
-host disease (17%
45%,
=0.003) and a significant increase in grades II-IV acute graft-
-host disease-free survival at six months (69%
42%,
=0.001) with tocilizumab, tacrolimus and methotrexate, which was the primary endpoint of the study. Immune reconstitution was preserved in patients treated with tocilizumab, tacrolimus and methotrexate, as T-cell and B-cell subsets recovered to near normal levels by 6-12 months post-transplantation. We conclude that tocilizumab has promising activity in preventing acute graft-
-host disease, particularly in the lower gastrointestinal tract, and warrants examination in a randomized setting.
Abstract Background aims Methods for processing products used for hematopoietic progenitor cell (HPC) transplantation must ensure their safety and efficacy. Personnel training and ongoing competency ...assessment is critical to this goal. Here we present results from a global survey of methods used by a diverse array of cell processing facilities for the initial training and ongoing competency assessment of key personnel. Methods The Alliance for Harmonisation of Cellular Therapy Accreditation (AHCTA) created a survey to identify facility type, location, activity, personnel, and methods used for training and competency. A survey link was disseminated through organizations represented in AHCTA to processing facilities worldwide. Responses were tabulated and analyzed as a percentage of total responses and as a percentage of response by region group. Results Most facilities were based at academic medical centers or hospitals. Facilities with a broad range of activity, product sources and processing procedures were represented. Facilities reported using a combination of training and competency methods. However, some methods predominated. Cellular sources for training differed for training versus competency and also differed based on frequency of procedures performed. Most facilities had responsibilities for procedures in addition to processing for which training and competency methods differed. Although regional variation was observed, training and competency requirements were generally consistent. Conclusions Survey data showed the use of a variety of training and competency methods but some methods predominated, suggesting their utility. These results could help new and established facilities in making decisions for their own training and competency programs.
Background
As hematopoietic stem cell transplantation expands globally, identification of the key elements that make up high‐quality training programs will become more important to optimizing ...collection practices and quality of the products collected.
Study Design and Methods
Multiple‐choice and open questions to identify training practices of those collecting hematopoietic progenitor cell–apheresis HPC(A) and –cord blood HPC(CB) products were distributed via an electronic survey tool worldwide. Data were collected on facility demographics, job descriptions, and the content of training programs including general practices, staff assessment, retraining, and unique program features.
Results
Respondents from more than 50 countries predominantly associating with facilities in North America and Europe represented transplant centers or transfusion services also performing collections. For the majority of staff performing HPC(A) collections (50%), initial training required as many procedures as necessary be done until competency was achieved. Competency was evaluated by direct observation comparing performance to written procedures or protocol steps (47%), combination of written assessment and observation (45%), evaluation of product quality (40%), and written assessment alone (12%). Staff retraining was customized on a case‐by‐case basis (42%). Similar criteria were placed on HPC(CB) training, with an emphasis on product quality measured by sterility, CD34+ cell collection efficiency, hematocrit, volume, and mononuclear cell count.
Conclusion
Observation, practice, evaluation, and retraining until competency is achieved marked the training programs. Success was based on the ability of staff to execute procedures ultimately measured in product quality. Identified features may assist facilities in further developing and strengthening their own training programs.
Many of the 51 serotypes of adenovirus have been associated with clinically relevant infection. Adenovirus can disseminate rapidly in patients with a compromised immune system, such as that which ...occurs secondary to haematopoietic progenitor-cell transplantation. The higher rate of infection in recipients of T cell-depleted grafts and in those undergoing T cell-targeted treatment during graft versus host disease demonstrates the importance of a T-cell response in preventing disseminated infection. Studies have shown that the memory response to adenovirus is directed primarily to the hexon protein and is dominated by CD4+ T cells, probably due to the ability of the virus to block its presentation on HLA class I antigens. We have developed an approach to expand adenovirus-specific T cells using a pool of overlapping pentadecapeptides derived from selected conserved regions of hexon. We characterized responses to identify the peptides that are recognized, the responding T-cell subsets and their HLA restriction. Of eight lines that were characterized extensively, seven included both CD4+ and CD8+ T cells and each recognized between two and eight unique peptide sequences. By focusing the response on the conserved sequences of hexon, the cell lines are likely to recognize most of the serotypes responsible for clinically relevant disease. The 15 aa peptides used to prime the responses are more likely than whole virus or longer peptides to expand the less frequent CD8+ memory subset. Lines prepared by using our method may be more effective in adoptive immunotherapy protocols designed to prevent or treat disseminated adenovirus infections in high-risk patients.
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