Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has shown remarkable clinical efficacy in B-cell cancers. However, CAR T cells can induce substantial toxic effects, and the manufacture of ...the cells is complex. Natural killer (NK) cells that have been modified to express an anti-CD19 CAR have the potential to overcome these limitations.
In this phase 1 and 2 trial, we administered HLA-mismatched anti-CD19 CAR-NK cells derived from cord blood to 11 patients with relapsed or refractory CD19-positive cancers (non-Hodgkin's lymphoma or chronic lymphocytic leukemia CLL). NK cells were transduced with a retroviral vector expressing genes that encode anti-CD19 CAR, interleukin-15, and inducible caspase 9 as a safety switch. The cells were expanded ex vivo and administered in a single infusion at one of three doses (1×10
, 1×10
, or 1×10
CAR-NK cells per kilogram of body weight) after lymphodepleting chemotherapy.
The administration of CAR-NK cells was not associated with the development of cytokine release syndrome, neurotoxicity, or graft-versus-host disease, and there was no increase in the levels of inflammatory cytokines, including interleukin-6, over baseline. The maximum tolerated dose was not reached. Of the 11 patients who were treated, 8 (73%) had a response; of these patients, 7 (4 with lymphoma and 3 with CLL) had a complete remission, and 1 had remission of the Richter's transformation component but had persistent CLL. Responses were rapid and seen within 30 days after infusion at all dose levels. The infused CAR-NK cells expanded and persisted at low levels for at least 12 months.
Among 11 patients with relapsed or refractory CD19-positive cancers, a majority had a response to treatment with CAR-NK cells without the development of major toxic effects. (Funded by the M.D. Anderson Cancer Center CLL and Lymphoma Moonshot and the National Institutes of Health; ClinicalTrials.gov number, NCT03056339.).
Outcomes for patients with refractory diffuse large B cell lymphoma (DLBCL) are poor. In the multicenter ZUMA-1 phase 1 study, we evaluated KTE-C19, an autologous CD3ζ/CD28-based chimeric antigen ...receptor (CAR) T cell therapy, in patients with refractory DLBCL. Patients received low-dose conditioning chemotherapy with concurrent cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) for 3 days followed by KTE-C19 at a target dose of 2 × 106 CAR T cells/kg. The incidence of dose-limiting toxicity (DLT) was the primary endpoint. Seven patients were treated with KTE-C19 and one patient experienced a DLT of grade 4 cytokine release syndrome (CRS) and neurotoxicity. Grade ≥3 CRS and neurotoxicity were observed in 14% (n = 1/7) and 57% (n = 4/7) of patients, respectively. All other KTE-C19-related grade ≥3 events resolved within 1 month. The overall response rate was 71% (n = 5/7) and complete response (CR) rate was 57% (n = 4/7). Three patients have ongoing CR (all at 12+ months). CAR T cells demonstrated peak expansion within 2 weeks and continued to be detectable at 12+ months in patients with ongoing CR. This regimen of KTE-C19 was safe for further study in phase 2 and induced durable remissions in patients with refractory DLBCL.
In a multicenter phase 1 study, Locke, Neelapu, et al. report tolerability and safety of KTE-C19, a CD19 chimeric antigen receptor technology, in patients with chemorefractory DLBCL. More importantly, KTE-C19 could provide durable clinical benefit in this difficult-to-treat patient population, demonstrating broad clinical applicability of KTE-C19.
The Programmed Death-1 (PD-1) immune checkpoint pathway may be usurped by tumors, including diffuse large B-cell lymphoma (DLBCL), to evade immune surveillance. The reconstituting immune landscape ...after autologous hematopoietic stem-cell transplantation (AHSCT) may be particularly favorable for breaking immune tolerance through PD-1 blockade.
We conducted an international phase II study of pidilizumab, an anti-PD-1 monoclonal antibody, in patients with DLBCL undergoing AHSCT, with correlative studies of lymphocyte subsets. Patients received three doses of pidilizumab beginning 1 to 3 months after AHSCT.
Sixty-six eligible patients were treated. Toxicity was mild. At 16 months after the first treatment, progression-free survival (PFS) was 0.72 (90% CI, 0.60 to 0.82), meeting the primary end point. Among the 24 high-risk patients who remained positive on positron emission tomography after salvage chemotherapy, the 16-month PFS was 0.70 (90% CI, 0.51 to 0.82). Among the 35 patients with measurable disease after AHSCT, the overall response rate after pidilizumab treatment was 51%. Treatment was associated with increases in circulating lymphocyte subsets including PD-L1E-bearing lymphocytes, suggesting an on-target in vivo effect of pidilizumab.
This is the first demonstration of clinical activity of PD-1 blockade in DLBCL. Given these results, PD-1 blockade after AHSCT using pidilizumab may represent a promising therapeutic strategy in this disease.
Autologous T cells expressing a CD19-specific chimeric antigen receptor (CD19.CAR) are active against B-cell malignancies, but it is unknown whether allogeneic CD19.CAR T cells are safe or effective. ...After allogeneic hematopoietic stem cell transplantation (HSCT), infused donor-derived virus-specific T cells (VSTs) expand in vivo, persist long term, and display antiviral activity without inducing graft-vs-host disease; therefore, we determined whether donor VSTs, engineered to express CD19.CAR, retained the characteristics of nonmanipulated allogeneic VSTs while gaining antitumor activity. We treated 8 patients with allogeneic (donor-derived) CD19.CAR-VSTs 3 months to 13 years after HSCT. There were no infusion-related toxicities. VSTs persisted for a median of 8 weeks in blood and up to 9 weeks at disease sites. Objective antitumor activity was evident in 2 of 6 patients with relapsed disease during the period of CD19.CAR-VST persistence, whereas 2 patients who received cells while in remission remain disease free. In 2 of 3 patients with viral reactivation, donor CD19.CAR-VSTs expanded concomitantly with VSTs. Hence CD19.CAR-VSTs display antitumor activity and, because their number may be increased in the presence of viral stimuli, earlier treatment post-HSCT (when lymphodepletion is greater and the incidence of viral infection is higher) or planned vaccination with viral antigens may enhance disease control. This study is registered at clinicaltrials.gov as #NCT00840853.
•Allogeneic CD19-CAR VSTs are well tolerated by patients with relapsed B-cell malignancies post-HSCT.•At periods of CD19-CAR VST persistence, these cells demonstrate antitumor activity.
This study investigated the efficacy and safety of azacitidine maintenance in the posttransplant setting based on the encouraging phase 1/2 reports for azacitidine maintenance in patients with acute ...myeloid leukemia/myelodysplastic syndrome (AML/MDS). Between 2009 and 2017, a total of 187 patients aged 18 to 75 years were entered into a randomized controlled study of posttransplant azacitidine if they were in complete remission. Patients randomized to the treatment arm (n = 93) were scheduled to receive azacitidine, given as 32 mg/m2 per day subcutaneously for 5 days every 28 days for 12 cycles. The control arm (n = 94) had no intervention. Eighty-seven of the 93 patients started azacitidine maintenance. The median number of cycles received was 4; a total of 29 patients relapsed on study, and 23 patients withdrew from the study due to toxicity, patient's preference, or logistical reasons. Median relapse-free survival (RFS) was 2.07 years in the azacitidine group vs 1.28 years in the control group (P = .43). There was also no significant difference for overall survival, with a median of 2.52 years vs 2.56 years in the azacitidine and control groups (P = .85), respectively. Multivariate Cox regression analysis revealed no improvement in RFS or overall survival with the use of azacitidine as maintenance compared with the control group (hazard ratios of 0.73 95% confidence interval, 0.49-1.1; P = .14 and 0.84 95% confidence interval, 0.55-1.29; P = .43). This randomized trial with azacitidine maintenance showed that a prospective trial in the posttransplant setting was feasible and safe but challenging. Although RFS was comparable between the 2 arms, we believe the strategy of maintenance therapy merits further study with a goal to reduce the risk of relapse in patients with AML/MDS. This trial was registered at www.clinicaltrials.gov as #NCT00887068.
•In this phase 3, open-label, randomized trial, azacitidine maintenance did not improve RFS after transplant in high-risk AML/MDS.•We believe that posttransplant maintenance strategy merits further study to decrease the risk of relapse in AML/MDS patients.
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Steroids remain the initial therapy for acute graft-vs.-host disease (AGVHD). Strategies to improve response and minimize steroid exposure are needed. We report results of a randomized, adaptive, ...Bayesian-designed, phase II trial of prednisone with or without extracorporeal photopheresis (ECP) as an initial therapy for patients with newly diagnosed AGVHD. The primary endpoint was success at day 56 defined as: alive, in remission, achieving AGVHD response without additional therapy, and on <1 mg/kg at day 28 and <0.5 mg/kg on day 56 of steroids. Eighty-one patients were randomized to the ECP arm (n = 51) or steroids alone (n = 30). Median age was 54 years (range: 17-75); 90% had grade II AGVHD and 10% had grades III and IV AGVHD, with skin (85%), upper (22%)/lower (22%) gastrointestinal, and liver (10%) involvement. The ECP arm had a higher probability of success (0.815) and exceeded the predefined threshold for determining the investigational arm promising. ECP was potentially more beneficial than steroids-alone in skin-only AGVHD (response rate: 72% vs. 57%, respectively) than for visceral-organ AGVHD (47% vs. 43%, respectively). The addition of ECP to steroids may result in higher GVHD response as initial therapy for AGVHD, especially for patients with skin-only involvement.
Cord blood (CB) offers a number of advantages over other sources of hematopoietic stem cells, including a lower rate of chronic graft-versus-host disease (cGVHD) in the presence of increased HLA ...disparity. Recent research in experimental models of autoimmunity and in patients with autoimmune or alloimmune disorders has identified a functional group of interleukin-10 (IL-10)-producing regulatory B cells (Bregs) that negatively regulate T-cell immune responses. At present, however, there is no consensus on the phenotypic signature of Bregs, and their prevalence and functional characteristics in CB remain unclear. Here, we demonstrate that CB contains an abundance of B cells with immunoregulatory function. Bregs were identified in both the naive and transitional B-cell compartments and suppressed T-cell proliferation and effector function through IL-10 production as well as cell-to-cell contact involving CTLA-4. We further show that the suppressive capacity of CB-derived Bregs can be potentiated through CD40L signaling, suggesting that inflammatory environments may induce their function. Finally, there was robust recovery of IL-10–producing Bregs in patients after CB transplantation, to higher frequencies and absolute numbers than seen in the peripheral blood of healthy donors or in patients before transplant. The reconstituting Bregs showed strong in vitro suppressive activity against allogeneic CD4+ T cells, but were deficient in patients with cGVHD. Together, these findings identify a rich source of Bregs and suggest a protective role for CB-derived Bregs against cGVHD development in CB recipients. This advance could propel the development of Breg-based strategies to prevent or ameliorate this posttransplant complication.
•Cord blood is a rich source of B cells with immunoregulatory function.•IL-10–producing B cells may protect against cGVHD after cord blood transplantation.
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