ABSTRACT: single cell RNASEQ files for Mullighan BiTE RNASEQ3 paper titled "Tumor intrinsic and extrinsic mechanisms of response and resistance to blinatumomab in relapsed/refractory acute lymphoblastic leukemia"
Project description:WXS files for Mullighan BiTE WXS paper titled "Tumor intrinsic and extrinsic mechanisms of response and resistance to blinatumomab in relapsed/refractory acute lymphoblastic leukemia"
Project description:RNAseq files for Mullighan BiTE RNASEQ1 paper titled "Tumor intrinsic and extrinsic mechanisms of response and resistance to blinatumomab in relapsed/refractory acute lymphoblastic leukemia"
Project description:WGS files for Mullighan BiTE WGS paper titled "Tumor intrinsic and extrinsic mechanisms of response and resistance to blinatumomab in relapsed/refractory acute lymphoblastic leukemia"
Project description:lowinput RNASEQ files for Mullighan BiTE RNASEQ2 paper titled "Tumor intrinsic and extrinsic mechanisms of response and resistance to blinatumomab in relapsed/refractory acute lymphoblastic leukemia"
Project description:Blinatumomab, a bispecific T-cell engager (BiTE) associated with improved survival in relapsed or refractory acute lymphoblastic leukemia (ALL), was recently approved for treatment of minimal residual disease (MRD). MRD is an important predictor of survival in ALL, and recent studies suggest that achievement of MRD-negativity with blinatumomab improves outcomes in patients with ALL. However, further research is needed to determine how to optimally incorporate blinatumomab, and other novel therapies, into current therapies for ALL.
Project description:Targeted therapy has been the forefront of cancer treatment. Cancer immunotherapy is the most recent focus. In addition, novel immunotherapeutics targeting B cell receptor signaling (e.g., ibrutinib), T cell receptor ( e.g., CART19), and NK cells (e.g., AFM13) are being developed. This review summarized the new development in blinatumomab (MT103/MEDI-538), a first-in-class bispecific T engager (BiTE) antibody against CD19/CD3 in patients with relapsed/refractory precursor B cell acute lymphoid leukemia.
Project description:Adults with relapsed/refractory B-acute lymphoblastic leukemia (ALL) have a complete remission (CR) rate of 20-45% and median overall survival of 3-9 months, depending on the duration of the first remission and number of lines of salvage therapy. Allogeneic hematopoietic stem cell transplantation (alloHSCT) is the only curative option for adult patients with relapsed/refractory ALL, and achievement of CR is a crucial step before alloHSCT. Blinatumomab is a bispecific T-cell engager (BiTE®) antibody construct with dual specificity for CD19 and CD3, simultaneously binding CD3-positive cytotoxic T cells and CD19-positive B cells, resulting in T-cell-mediated serial lysis of normal and malignant B cells. It recently gained accelerated approval by the US Food and Drug Administration (FDA) for the treatment of relapsed/refractory Philadelphia chromosome-negative ALL, based on a large phase II trial of 189 adults with relapsed/refractory B-ALL, which showed a CR/CRh (CR with partial hematologic recovery) of 43% after two cycles of treatment. Toxicities include cytokine-release syndrome (CRS) and neurologic events (encephalopathy, aphasia, and seizure). CRS can be alleviated by step-up dosing and dexamethasone, without affecting the cytotoxic effect of blinatumomab. The cause of neurologic toxicity is unclear but is also observed with other T-cell therapies and may relate to variable expression of CD19 within the brain. This review encompasses the preclinical rationale of using the BITE® class of compounds (blinatumomab being the only one that is FDA approved), with clinical data using blinatumomab in the relapsed/refractory setting (pediatrics and adults), the minimal residual disease setting (adults), as well as Philadelphia chromosome-positive ALL. The review also examines the main adverse events: their prevention, recognition, and management; possible mechanisms of resistance; causes of relapse. It also summarizes future trials evaluating the drug earlier in the treatment course to improve activity.
Project description:Blinatumomab, a bispecific antibody that directs CD3+ T cells to CD19+ tumor cells, shows variable efficacy in B-progenitor acute lymphoblastic leukemia (B-ALL). To determine tumor-intrinsic and -extrinsic determinants of response, we studied 44 adults with relapsed or refractory B-ALL (including 2 minimal residual disease positive) treated with blinatumomab using bulk tumor and single-cell sequencing. The overall response rate in patients with hematological disease was 55%, with a high response rate in those with CRLF2-rearranged Philadelphia chromosome-like ALL (12 [75%] of 16). Pretreatment samples of responders exhibited a tumor-intrinsic transcriptomic signature of heightened immune response. Multiple mechanisms resulted in loss of CD19 expression, including CD19 mutations, CD19-mutant allele-specific expression, low CD19 RNA expression, and mutations in CD19 signaling complex member CD81. Patients with low hypodiploid ALL were prone to CD19- relapse resulting from aneuploidy-mediated loss of the nonmutated CD19 allele. Increased expression of a CD19 isoform with intraexonic splicing of exon 2, CD19 ex2part, at baseline or during therapy was associated with treatment failure. These analyses demonstrate both tumor-intrinsic and -extrinsic factors influence blinatumomab response. We show that CD19 mutations are commonly detected in CD19- relapse during blinatumomab treatment. Identification of the CD19 ex2part splice variant represents a new biomarker predictive of blinatumomab therapy failure.
Project description:The B cell surface antigen CD19 is a target for treating B cell malignancies, such as B cell precursor acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma. The BiTE® immuno-oncology platform includes blinatumomab, which is approved for relapsed/refractory B cell precursor acute lymphoblastic leukemia and B cell precursor acute lymphoblastic leukemia with minimal residual disease. Blinatumomab is also being evaluated in combination with other agents (tyrosine kinase inhibitors, checkpoint inhibitors, and chemotherapy) in various treatment settings, including frontline protocols. An extended half-life BiTE molecule is also under investigation. Patients receiving blinatumomab may experience cytokine release syndrome and neurotoxicity; however, these events may be less frequent and severe than in patients receiving other CD19-targeted immunotherapies, such as chimeric antigen receptor T cell therapy. We review BiTE technology for treating malignancies that express CD19, analyzing the benefits and limitations of this bispecific T cell engager platform from clinical experience with blinatumomab.
Project description:Few patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) achieve prolonged disease-free survival. Blinatumomab, a bispecific T-cell engaging antibody construct, transiently links CD3-positive T cells to CD19-positive B cells. This phase 2 study evaluated stepwise (9-28-112 ?g/d with weekly dose increases; n = 23) or flat (112 ?g/d; n = 2) dosing of blinatumomab by continuous infusion, with dexamethasone prophylaxis, in patients with relapsed/refractory DLBCL. Patients received a median of 3 prior lines of therapy. Median time since last regimen was 1.5 months. Seventeen patients ended treatment in cycle 1 (induction), 7 in cycle 2 (consolidation), and 1 in retreatment. Among 21 evaluable patients, the overall response rate after 1 blinatumomab cycle was 43%, including complete responses (CRs) in 19%. Three patients had late CR in follow-up without other treatment. The most common adverse events with stepwise dosing were tremor (48%), pyrexia (44%), fatigue (26%), and edema (26%). Grade 3 neurologic events with stepwise dosing were encephalopathy and aphasia (each 9%) and tremor, speech disorder, dizziness, somnolence, and disorientation (each 4%). Of 5 (22%) patients who discontinued stepwise dosing because of adverse events, 4 (17%) had neurologic events. Most neurologic events resolved. The flat-dose cohort was stopped because of grade 3 neurologic events in both patients. Blinatumomab monotherapy appears effective in patients with relapsed/refractory DLBCL, a heavily pretreated patient population with a high unmet medical need. Further studies need to define the optimal approach to achieve the target dose without early dropout. The study was registered at www.clinicaltrials.gov as #NCT01741792.