Results of 2 parallel phase 2 trials of transplantation of unrelated umbilical cord blood (UCB) or bone marrow (BM) from HLA-haploidentical relatives provided equipoise for direct comparison of these ...donor sources. Between June 2012 and June 2018, 368 patients aged 18 to 70 years with chemotherapy-sensitive lymphoma or acute leukemia in remission were randomly assigned to undergo UCB (n = 186) or haploidentical (n = 182) transplant. Reduced-intensity conditioning comprised total-body irradiation with cyclophosphamide and fludarabine for both donor types. Graft-versus-host disease prophylaxis for UCB transplantation was cyclosporine and mycophenolate mofetil (MMF) and for haploidentical transplantation, posttransplant cyclophosphamide, tacrolimus, and MMF. The primary end point was 2-year progression-free survival (PFS). Treatment groups had similar age, sex, self-reported ethnic origin, performance status, disease, and disease status at randomization. Two-year PFS was 35% (95% confidence interval CI, 28% to 42%) compared with 41% (95% CI, 34% to 48%) after UCB and haploidentical transplants, respectively (P = .41). Prespecified analysis of secondary end points recorded higher 2-year nonrelapse mortality after UCB, 18% (95% CI, 13% to 24%), compared with haploidentical transplantation, 11% (95% CI, 6% to 16%), P = .04. This led to lower 2-year overall survival (OS) after UCB compared with haploidentical transplantation, 46% (95% CI, 38-53) and 57% (95% CI 49% to 64%), respectively (P = .04). The trial did not demonstrate a statistically significant difference in the primary end point, 2-year PFS, between the donor sources. Although both donor sources extend access to reduced-intensity transplantation, analyses of secondary end points, including OS, favor haploidentical BM donors. This trial was registered at www.clinicaltrials.gov as #NCT01597778.
In patients undergoing allogeneic hematopoietic stem-cell transplantation (HSCT), a calcineurin inhibitor plus methotrexate has been a standard prophylaxis against graft-versus-host disease (GVHD). A ...phase 2 study indicated the potential superiority of a post-transplantation regimen of cyclophosphamide, tacrolimus, and mycophenolate mofetil.
In a phase 3 trial, we randomly assigned adults with hematologic cancers in a 1:1 ratio to receive cyclophosphamide-tacrolimus-mycophenolate mofetil (experimental prophylaxis) or tacrolimus-methotrexate (standard prophylaxis). The patients underwent HSCT from an HLA-matched related donor or a matched or 7/8 mismatched (i.e., mismatched at only one of the
,
,
, and
loci) unrelated donor, after reduced-intensity conditioning. The primary end point was GVHD-free, relapse-free survival at 1 year, assessed in a time-to-event analysis, with events defined as grade III or IV acute GVHD, chronic GVHD warranting systemic immunosuppression, disease relapse or progression, and death from any cause.
In a multivariate Cox regression analysis, GVHD-free, relapse-free survival was significantly more common among the 214 patients in the experimental-prophylaxis group than among the 217 patients in the standard-prophylaxis group (hazard ratio for grade III or IV acute GVHD, chronic GVHD, disease relapse or progression, or death, 0.64; 95% confidence interval CI, 0.49 to 0.83; P = 0.001). At 1 year, the adjusted GVHD-free, relapse-free survival was 52.7% (95% CI, 45.8 to 59.2) with experimental prophylaxis and 34.9% (95% CI, 28.6 to 41.3) with standard prophylaxis. Patients in the experimental-prophylaxis group appeared to have less severe acute or chronic GVHD and a higher incidence of immunosuppression-free survival at 1 year. Overall and disease-free survival, relapse, transplantation-related death, and engraftment did not differ substantially between the groups.
Among patients undergoing allogeneic HLA-matched HSCT with reduced-intensity conditioning, GVHD-free, relapse-free survival at 1 year was significantly more common among those who received cyclophosphamide-tacrolimus-mycophenolate mofetil than among those who received tacrolimus-methotrexate. (Funded by the National Heart, Lung, and Blood Institute and others; BMT CTN 1703 ClinicalTrials.gov number, NCT03959241.).
Despite impressive progress, more than 50% of patients treated with CD19-targeting chimeric antigen receptor T cells (CAR19) experience progressive disease. Ten of 16 patients with large B cell ...lymphoma (LBCL) with progressive disease after CAR19 treatment had absent or low CD19. Lower surface CD19 density pretreatment was associated with progressive disease. To prevent relapse with CD19
or CD19
disease, we tested a bispecific CAR targeting CD19 and/or CD22 (CD19-22.BB.z-CAR) in a phase I clinical trial ( NCT03233854 ) of adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL) and LBCL. The primary end points were manufacturing feasibility and safety with a secondary efficacy end point. Primary end points were met; 97% of products met protocol-specified dose and no dose-limiting toxicities occurred during dose escalation. In B-ALL (n = 17), 100% of patients responded with 88% minimal residual disease-negative complete remission (CR); in LBCL (n = 21), 62% of patients responded with 29% CR. Relapses were CD19
in 50% (5 out of 10) of patients with B-ALL and 29% (4 out of 14) of patients with LBCL but were not associated with CD22
disease. CD19/22-CAR products demonstrated reduced cytokine production when stimulated with CD22 versus CD19. Our results further implicate antigen loss as a major cause of CAR T cell resistance, highlight the challenge of engineering multi-specific CAR T cells with equivalent potency across targets and identify cytokine production as an important quality indicator for CAR T cell potency.
Bacterial bloodstream infections are a major cause of morbidity and mortality among patients undergoing hematopoietic cell transplantation (HCT). Although previous research has demonstrated that ...pathogens may translocate from the gut microbiome into the bloodstream to cause infections, the mechanisms by which HCT patients acquire pathogens in their microbiome have not yet been described. Here, we use linked-read and short-read metagenomic sequencing to analyze 401 stool samples collected from 149 adults undergoing HCT and hospitalized in the same unit over three years, many of whom were roommates. We use metagenomic assembly and strain-specific comparison methods to search for high-identity bacterial strains, which may indicate transmission between the gut microbiomes of patients. Overall, the microbiomes of patients who share time and space in the hospital do not converge in taxonomic composition. However, we do observe six pairs of patients who harbor identical or nearly identical strains of the pathogen Enterococcus faecium, or the gut commensals Akkermansia muciniphila and Hungatella hathewayi. These shared strains may result from direct transmission between patients who shared a room and bathroom, acquisition from a common hospital source, or transmission from an unsampled intermediate. We also identify multiple patients with identical strains of species commonly found in commercial probiotics, including Lactobacillus rhamnosus and Streptococcus thermophilus. In summary, our findings indicate that sharing of identical pathogens between the gut microbiomes of multiple patients is a rare phenomenon. Furthermore, the observed potential transmission of commensal, immunomodulatory microbes suggests that exposure to other humans may contribute to microbiome reassembly post-HCT.
Omidubicel is an ex vivo expanded hematopoietic progenitor cell and nonexpanded myeloid and lymphoid cell product derived from a single umbilical cord blood unit. We report results of a phase 3 trial ...to evaluate the efficacy of omidubicel compared with standard umbilical cord blood transplantation (UCBT). Between January 2017 and January 2020, 125 patients age 13 to 65 years with hematologic malignancies were randomly assigned to omidubicel vs standard UCBT. Patients received myeloablative conditioning and prophylaxis with a calcineurin inhibitor and mycophenolate mofetil for graft-versus-host disease (GVHD). The primary end point was time to neutrophil engraftment. The treatment arms were well balanced and racially diverse. Median time to neutrophil engraftment was 12 days (95% confidence interval CI, 10-14 days) for the omidubicel arm and 22 days (95% CI, 19-25 days) for the control arm (P < .001). The cumulative incidence of neutrophil engraftment was 96% for patients receiving omidubicel and 89% for patients receiving control transplants. The omidubicel arm had faster platelet recovery (55% vs 35% recovery by 42 days; P = .028), had a lower incidence of first grade 2 to 3 bacterial or invasive fungal infection (37% vs 57%; P = .027), and spent more time out of hospital during the first 100 days after transplant (median, 61 vs 48 days; P = .005) than controls. Differences in GVHD and survival between the 2 arms were not statistically significant. Transplantation with omidubicel results in faster hematopoietic recovery and reduces early transplant-related complications compared with standard UCBT. The results suggest that omidubicel may be considered as a new standard of care for adult patients eligible for UCBT. The trial was registered at www.clinicaltrials.gov as #NCT02730299.
Rituximab resistance Rezvani, Andrew R; Maloney, David G
Best practice & research. Clinical haematology,
06/2011, Letnik:
24, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Rituximab has become a ubiquitous component of treatment regimens for follicular non-Hodgkin lymphoma. Despite widespread clinical use, the mechanisms by which tumor cells resist rituximab-mediated ...destruction remain unclear. Rituximab relies in part on immune effector mechanisms for its antitumor effect, and thus resistance may be mediated not only by intrinsic tumor-cell alterations but also by the host immunological environment. In this article, we explore the mechanisms of action of rituximab, the incidence of rituximab resistance, and potential mechanisms of resistance. Finally, we discuss novel approaches to modulate the antibody, the tumor cell, and the host immunologic environment to overcome rituximab resistance. Further research into the mechanisms of rituximab resistance will be essential to improving the efficacy of anti-CD20 therapy in NHL, and may also pay dividends in the optimization of monoclonal antibody therapy across a wide range of diseases.
We evaluated 917 adult lymphoma patients who received haploidentical (n = 185) or HLA-matched unrelated donor (URD) transplantation either with (n = 241) or without antithymocyte globulin (ATG; n = ...491) following reduced-intensity conditioning regimens. Haploidentical recipients received posttransplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis, whereas URD recipients received calcineurin inhibitor-based prophylaxis. Median follow-up of survivors was 3 years. The 100-day cumulative incidence of grade III-IV acute GVHD on univariate analysis was 8%, 12%, and 17% in the haploidentical, URD without ATG, and URD with ATG groups, respectively (P = .44). Corresponding 1-year rates of chronic GVHD on univariate analysis were 13%, 51%, and 33%, respectively (P < .001). On multivariate analysis, grade III-IV acute GVHD was higher in URD without ATG (P = .001), as well as URD with ATG (P = .01), relative to haploidentical transplants. Similarly, relative to haploidentical transplants, risk of chronic GVHD was higher in URD without ATG and URD with ATG (P < .0001). Cumulative incidence of relapse/progression at 3 years was 36%, 28%, and 36% in the haploidentical, URD without ATG, and URD with ATG groups, respectively (P = .07). Corresponding 3-year overall survival (OS) was 60%, 62%, and 50% in the 3 groups, respectively, with multivariate analysis showing no survival difference between URD without ATG (P = .21) or URD with ATG (P = .16), relative to haploidentical transplants. Multivariate analysis showed no difference between the 3 groups in terms of nonrelapse mortality (NRM), relapse/progression, and progression-free survival (PFS). These data suggest that reduced-intensity conditioning haploidentical transplantation with posttransplant cyclophosphamide does not compromise early survival outcomes compared with matched URD transplantation, and is associated with significantly reduced risk of chronic GVHD.
•Risk of grade III-IV acute and chronic GVHD is significantly lower with haploidentical compared with URD transplantation.•Relapse risk, NRM, PFS, and OS was similar in haploidentical transplants compared with unrelated donor transplants.
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