ABSTRACT: Chimeric antigen receptor (CAR)-modified T-cells have become established as an effective treatment of haematological cancers. In the context of relapsed and refractory childhood pre-B cell acute lymphoblastic leukaemia (B ALL), CD19 targeting CAR T-cells often induce durable remissions. Previously, we generated a novel low-affinity CAR incorporating a CD19-specific single-chain variable fragment (scFV) called CAT, displaying a faster off-rate of interaction than the FMC63 CD19 binder used in prior clinical studies. Here, we systematically analysed CD19 CAR T-cells of ten children with relapsed or refractory B ALL enrolled in the CARPALL trial (NCT02443831). To characterize persisting CD19 CAR T-cells, we performed high throughput single-cell gene expression and T-cell receptor (TCR) sequencing of infusion products and serial blood and bone marrow samples up to five years post-infusion. We isolated CAR T-cells from peripheral blood or bone marrow by flow cytometry for CD3 and CAR expression, prior to single cell sequencing (Chromium 10X) platform.
Project description:<p>The adoptive transfer of autologous T cells genetically modified to express a CD19-specific, 4-1BB/CD3zeta-signaling chimeric antigen receptor (CAR; CTL019) has shown remarkable activity in patients with B acute lymphoblastic leukemia. Similar therapy can induce long-term remissions for relapsed/refractory chronic lymphocytic leukemia (CLL) patients, but in only a small subset of subjects. The determinants of response and resistance to CTL019 therapy of CLL are not fully understood. We employed next generation sequencing of RNA (RNA-seq) to identify predictive indicators of response to CTL019 treatment. We performed RNA-seq on leukapheresis and manufactured infusion product T cells from patients with heavily pre-treated and high-risk disease. To characterize potency, we also performed RNA-seq on the cellular infusion product after CAR-specific stimulation. Our findings indicate that durable remission in CLL is associated with gene expression signatures of early memory T cell differentiation (e.g., STAT3), while T cells from poorly- or non-responding patients exhibited elevated expression of key regulators of late memory as well as effector T cell differentiation, apoptosis, aerobic glycolysis, hypoxia and exhaustion. These gene expression signatures, along with additional immunological biomarkers, may be used to identify which patients are most likely to respond to cellular therapies and suggest manufacturing modifications that might potentiate the generation of maximally efficacious infusion products.</p>
Project description:Single cell full transcriptome sequencing of CD19 CAR T-cell infusion products used for standard of care treatment for relapsed/refractory large B-cell lymphoma.
Project description:<p>Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory (r/r) large B-cell lymphoma (LBCL) results in durable response in only a subset of patients. MYC overexpression in LBCL tumors is associated with poor response to treatment. We tested whether a MYC-driven polyamine signature, as a liquid biopsy, is predictive of response to anti-CD19 CAR-T therapy in patients with r/r LBCL. Elevated plasma acetylated polyamines were associated with non-durable response. Concordantly, increased expression of spermidine synthase, a key enzyme which regulates levels of acetylated spermidine, was prognostic for survival in r/r LBCL. A broad metabolite screen identified additional markers which resulted in a 6-marker panel (6MetP) consisting of acetylspermidine, diacetylspermidine and lysophospholipids which was validated in an independent set from another institution as predictive of non-durable response to CAR T therapy. A polyamine centric metabolomics liquid biopsy panel has predictive value for response to CAR-T therapy in r/r LBCL. </p>
Project description:Single cell hybrid-capture targeted sequencing of CD19 CAR T-cell infusion products used for standard of care treatment for relapsed/refractory large B-cell lymphoma.
Project description:Autologous anti-CD19 chimeric antigen receptor T-cell (CAR T) therapy is highly effective in relapsed/refractory large B-cell lymphoma (rrLBCL) but is associated with toxicities that delay recovery. While the biological mechanisms of cytokine release syndrome and neurotoxicity have been investigated, the pathophysiology is poorly understood for prolonged cytopenia, defined as grade ≥3 cytopenia lasting beyond 30 days after CAR T infusion. By performing single-cell RNA-sequencing analysis of bone marrow samples from healthy donors and rrLBCL patients with and without prolonged cytopenia, we identified a significantly increased frequency of clonally expanded CX3CR1hi cytotoxic T-cells, expressing high interferon (IFN)-γ and cytokine signaling gene sets, associated with prolonged cytopenia. In line with this, hematopoietic stem cells from these patients expressed IFN-γ response signatures. IFN-γ deregulates hematopoietic stem cell self-renewal and differentiation and can be targeted with thrombopoietin agonists or IFN-γ neutralizing antibodies, highlighting a potential mechanism-based approach for the treatment of CAR T-associated prolonged cytopenia.
Project description:Interventions: Group 1: Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) and patients with relapsed or refractory acute lymphocytic leukemia (ALL) who have been selected for treatment with CD19-targeting CAR-T cells will be recruited. Stool samples are collected at multiple timepoints (before lymphodepletion, before T-cell infusion, and after T-cell infusion).
Primary outcome(s): The main outcome is bacterial alpha diversity according to Simpson (AD) at the time of CAR-T cell therapy, which should be associated with survival within 24 months.
Study Design: Allocation: ; Masking: ; Control: ; Assignment: ; Study design purpose: treatment
Project description:Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B-cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in a patient remains largely unexplored. Single-cell RNA sequencing samples were collected at three phases: CAR-T products before infusion, CAR-T on day 8 after infusion, and CAR-T on day 15 after infusion. After obtaining the PBMCs for each phase, CAR-T and endogenous T cells were collected by fluorescence-activated cell sorting with anti-Mouse IgG Biotin, FITC Streptavidin, and anti-human CD3 APC.
Project description:Chimeric Antigen Receptor (CAR) T cell therapy was adopted as a clinical modality for patients with relapsed/refractory hematological malignancies. Despite the clinical efficacy of CAR-T cell therapy, a considerable fraction of patients still relapses during the first months following CAR-T cell infusion. The limited CAR-T cell efficiency is thought to relate to epigenetic mechanisms involved in T cell suppression and dysfunction. Here, screening of multiple epigenetic inhibitors revealed that targeting PRC2 consistently enhanced the cytotoxic/effector phenotype of CD8 T cells. Notably, PRC2 inhibition promoted the differentiation of GZMB+ effector memory 19BBζ CAR-T cells and enhanced their antitumor activity both in vitro and in vivo. Consistent with their long-lasting antitumor activity, PRC2-inhibited 19BBζ CAR-T cells did not exhibit any signs of dysfunctionality/exhaustion. Furthermore, TCR restimulation along with PRC2 inhibition of patient-derived anti-CD19 CAR-T cells also induced the development of GZMB+ effector memory cells and elicited potent antitumor responses against CD19+ Daudi cells. In line with this, the gene signature derived from in-house PRC2-inhibited 19BBζ CAR-T cells was enriched in tisagenlecleucel (tisa-cel) BBζ CAR-T cell therapy responders with large B-cell lymphoma. Collectively, our results demonstrated that targeting PRC2 may be a promising approach to enhance a functional effector program in CAR-T cells against hematological malignancies.
Project description:Markers predicting response and resistance to chimeric antigen receptor (CAR) T cells in relapsed/refractory multiple myeloma are currently missing. We subjected cells isolated from peripheral blood and bone marrow before and after the application of CAR T cells directed against B cell maturation antigen to single cell multi-omic analyses to identify markers associated with resistance and early relapse.