[Show abstract][Hide abstract] ABSTRACT: Engineered T cell therapies have begun to demonstrate impressive clinical responses in patients with B cell malignancies. Despite this efficacy, many patients are unable to receive T cell therapy because of failure of in vitro expansion, a necessary component of cell manufacture and a predictor of in vivo activity. To evaluate the biology underlying these functional differences, we investigated T cell expansion potential and memory phenotype during chemotherapy in pediatric patientswith acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL).We found that patients with T cell populations enriched for early lineage cells expanded better in vitro and that patients with ALL had higher numbers of these cells with a corresponding enhancement in expansion as compared to cells from patients with NHL. We further demonstrated that early lineage cells were selectively depleted by cyclophosphamide and cytarabine chemotherapy and that culture with interleukin-7 (IL-7) and IL-15 enriched select early lineage cells and rescued T cell expansion capability. Thus, early lineage cells are essential to T cell fitness for expansion, and enrichment of this population either by timing of T cell collection or culture method can increase the number of patients eligible to receive highly active engineered cellular therapies.
Full-text · Article · Jun 2016 · Science translational medicine
[Show abstract][Hide abstract] ABSTRACT: Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Untreated hepatic VOD/SOS with multi-organ failure (MOF) is associated with >80% mortality. Defibrotide has shown promising efficacy treating hepatic VOD/SOS with MOF in phase 2 studies. This phase 3 study investigated the safety and efficacy of defibrotide in adult and pediatric patients with established hepatic VOD/SOS and advanced MOF. Patients (n=102) given 25 mg/kg/day defibrotide were compared with 32 historical controls identified out of 6867 medical charts of HSCT patients by a blinded independent medical review committee. Baseline characteristics between groups were well balanced. The primary objective was to compare survival at Day+100 post-HSCT; observed rates equaled 38.2% in the defibrotide group and 25.0% in the control group (estimated difference of 23.0%; 95.1% confidence interval [CI] 5.2%-40.8%; P=.0109, using a propensity-adjusted analysis based on 4 prognostic factors of survival). Observed Day+100 complete response (CR) rates equaled 25.5% for defibrotide and 12.5% in the controls (19.0% difference using similar methodology; 95.1% CI 3.5-34.6; P=.0160). Defibrotide was generally well-tolerated with manageable toxicity. Related adverse events included hemorrhage or hypotension; there was no difference in the incidence of common hemorrhagic adverse events (including pulmonary alveolar [11.8% and 15.6%] and gastrointestinal [7.8% and 9.4%]) between the defibrotide and control groups, respectively. Defibrotide was associated with significant improvement in Day+100 survival and CR rate. The historical-control methodology offers a novel, meaningful approach for phase 3 evaluation of orphan diseases associated with high mortality. This study is registered to www.clinicaltrials.gov as NCT00358501.
[Show abstract][Hide abstract] ABSTRACT: Patients with autoimmune multi-lineage cytopenias are often refractory to standard therapies requiring chronic immunosuppression with medications with limited efficacy and high toxicity. We present data on 30 patients treated on a multicenter prospective clinical trial using sirolimus as monotherapy. All children (N=12) with autoimmune lymphoproliferative syndrome (ALPS) achieved a durable complete response, including rapid improvement in autoimmune disease, lymphadenopathy, and splenomegaly within 1-3 months of starting sirolimus. Double negative T (DNT) cells were no longer detectable in most, yet other lymphocyte populations were spared, suggesting a targeted effect of sirolimus. We also treated 12 patients with multi-lineage cytopenias secondary to common variable immune deficiency (CVID), Evans syndrome (ES) or systemic lupus erythematosus (SLE), and most achieved a CR (N= 8), although the time to CR was often slower than was seen in ALPS. Six children with single lineage autoimmune cytopenias were treated and only two responded. Sirolimus was well tolerated with very few side effects. All of the responding patients have remained on therapy for over one year (median 2 years, range 1-4.5 years). In summary, sirolimus led to complete and durable responses in a majority of children with refractory multi-lineage autoimmune cytopenias. The responses seen in ALPS patients were profound suggesting that sirolimus should be considered as a first-line, steroid-sparing treatment for patients needing chronic therapy. The results in other multi-lineage autoimmune cytopenia cohorts were encouraging and sirolimus should be considered in children with SLE, ES, and CVID.
[Show abstract][Hide abstract] ABSTRACT: Patients with multiply relapsed or refractory chronic lymphocytic leukemia (CLL) have a poor prognosis. Chimeric antigen receptor (CAR)-modified T cells targeting CD19 have the potential to improve on the low complete response rates with conventional therapies by inducing sustained remissions in patients with refractory B cell malignancies. We previously reported preliminary results on three patients with refractory CLL. We report the mature results from our initial trial using CAR-modified T cells to treat 14 patients with relapsed and refractory CLL. Autologous T cells transduced with a CD19-directed CAR (CTL019) lentiviral vector were infused into patients with relapsed/refractory CLL at doses of 0.14 × 10(8) to 11 × 10(8) CTL019 cells (median, 1.6 × 10(8) cells). Patients were monitored for toxicity, response, expansion, and persistence of circulating CTL019 T cells. The overall response rate in these heavily pretreated CLL patients was 8 of 14 (57%), with 4 complete remissions (CR) and 4 partial remissions (PR). The in vivo expansion of the CAR T cells correlated with clinical responses, and the CAR T cells persisted and remained functional beyond 4 years in the first two patients achieving CR. No patient in CR has relapsed. All responding patients developed B cell aplasia and experienced cytokine release syndrome, coincident with T cell proliferation. Minimal residual disease was not detectable in patients who achieved CR, suggesting that disease eradication may be possible in some patients with advanced CLL.
No preview · Article · Sep 2015 · Science translational medicine
[Show abstract][Hide abstract] ABSTRACT: The cancer-testis antigen NY-ESO-1 is expressed by many solid tumors and has limited expression by mature somatic tissues, making it a highly attractive target for tumor immunotherapy. Targeting NY-ESO-1 using engineered T cells has demonstrated clinical efficacy in the treatment of some adult tumors. Neuroblastoma is a significant cause of cancer mortality in children, and is a tumor type shown to be responsive to immunotherapies. We evaluated a large panel of primarily resected neuroblastoma samples and demonstrated that 23% express NY-ESO-1. After confirming antigen-specific activity of T cells genetically engineered to express an NY-ESO-1 directed high-affinity transgenic T cell receptor in vitro, we performed xenograft mouse studies assessing the efficacy of NY-ESO-1-targeted T cells in both localized and disseminated models of neuroblastoma. Disease responses were monitored by tumor volume measurement and in vivo bioluminescence. After delivery of NY-ESO-1 transgenic TCR T cells, we observed significant delay of tumor progression in mice bearing localized and disseminated neuroblastoma, as well as enhanced animal survival. These data demonstrate that NY-ESO-1 is an antigen target in neuroblastoma and that targeted T cells represent a potential therapeutic option for patients with neuroblastoma.
[Show abstract][Hide abstract] ABSTRACT: We previously showed that minimal residual disease (MRD) detection pre-hematopoietic cell transplant (HCT) and acute GvHD (aGvHD) independently predicted risk of relapse in pediatric ALL. In this study we further define risk by assessing timing of relapse and the effects of leukemia risk category and post-HCT MRD. By multivariate analysis, pre-HCT MRD <0.1% and aGvHD by day +55 were associated with decreased relapse and improved event-free survival (EFS). Intermediate leukemia risk status predicted decreased relapse, and improved EFS and overall survival (OS). Patients with pre-HCT MRD ⩾0.1% who did not develop aGvHD compared with those with MRD <0.1% who did develop aGvHD had much worse survival (2 years EFS 18% vs 71%; P=0.001, 2 years OS 46 vs 74%; P=0.04). Patients with pre-HCT MRD <0.1% who did not experience aGvHD had higher rates of relapse than those who did develop aGvHD (40% vs 13%; P= 0.008). Post-HCT MRD led to a substantial increase in relapse risk (HR=4.5, P<0.01). Patients at high risk of relapse can be defined after transplant using leukemia risk category, presence of MRD pre or post HCT, and occurrence of aGvHD. An optimal window to initiate intervention to prevent relapse occurs between day +55 and +200 after HCT.Bone Marrow Transplantation advance online publication, 11 May 2015; doi:10.1038/bmt.2015.103.
No preview · Article · May 2015 · Bone marrow transplantation