Liora Schultz, MD

Abstract

The use of radiotherapy as bridging therapy to chimeric antigen receptor T-cell therapy (CAR-T) in pre-B acute lymphoblastic leukemia (B-ALL) has been minimally explored. Here, we present a boy with B-ALL who relapsed after allogeneic bone marrow transplant with disseminated disease, including significant symptomatic cardiovascular and gastrointestinal (GI) involvement. The cardiac and GI leukemic infiltrates were successfully treated with bridging radiation therapy (BRT) prior to CAR-T infusion. Using this approach, he successfully tolerated CAR-T with no evidence of disease or sequelae on 3-month follow-up. This is the first reported case of safe and effective delivery of cardiac BRT in B-ALL.

View details for DOI 10.1002/pbc.28870

View details for PubMedID 33355997

View details for DOI 10.1016/j.jaccao.2020.08.009

View details for Web of Science ID 000613114700018

Abstract

PURPOSE: Immunomonitoring of chimeric antigen receptor (CAR) T cells relies primarily on their quantification in the peripheral blood, which inadequately quantifies their biodistribution and activation status in the tissues. Non-invasive molecular imaging of CAR T cells by positron emission tomography (PET) is a promising approach with the ability to provide spatial, temporal and functional information. Reported strategies rely on the incorporation of reporter transgenes or ex vivo biolabeling, significantly limiting the application of CAR T cell molecular imaging. In the present study, we assessed the ability of antibody-based PET (immunoPET) to non-invasively visualize CAR T cells.EXPERIMENTAL DESIGN: After analyzing human CAR T cells in vitro and ex vivo from patient samples to identify candidate targets for immunoPET, we employed a syngeneic, orthotopic murine tumor model of lymphoma to assess the feasibility of in vivo tracking of CAR T cells by immunoPET using the 89Zr-DFO-anti-ICOS tracer we previously reported.RESULTS: Analysis of human CD19-CAR T cells during activation identified the Inducible T-cell COStimulator (ICOS) as a potential target for immunoPET. In a preclinical tumor model, 89Zr-DFO-ICOS mAb PET-CT imaging detected significantly higher signal in specific bone marrow-containing skeletal sites of CAR T cell treated mice compared with controls. Importantly, administration of ICOS-targeting antibodies at tracer doses did not interfere with CAR T cell persistence and function.CONCLUSIONS: This study highlights the potential of ICOS-immunoPET imaging for monitoring of CAR T cell therapy, a strategy readily applicable to both commercially available and investigational CAR T cells.

View details for DOI 10.1158/1078-0432.CCR-20-2770

View details for PubMedID 33087332

View details for DOI 10.1038/s41409-020-01081-0

View details for PubMedID 33070150

Abstract

BACKGROUND: Chimeric antigen receptor (CAR) therapy and hematopoietic stem cell transplantation (HSCT) are therapeutics for relapsed acute lymphocytic leukemia (ALL) that are increasingly being used in tandem. We identified a non-physiologic CD19+/CD3+ T-cell population in the leukapheresis product of a patient undergoing CAR T-cell manufacturing who previously received a haploidentical HSCT, followed by infusion of a genetically engineered T-cell addback product. We confirm and report the origin of these CD19+/CD3+ T cells that have not previously been described in context of CAR T-cell manufacturing. We additionally interrogate the fate of these CD19-expressing cells as they undergo transduction to express CD19-specific CARs.MAIN BODY: We describe the case of a preteen male with multiply relapsed B-ALL who was treated with sequential cellular therapies. He received an alphabeta T-cell depleted haploidentical HSCT followed by addback of donor-derived T cells genetically modified with a suicide gene for iCaspase9 and truncated CD19 for cell tracking (RivoCel). He relapsed 6months following HSCT and underwent leukapheresis and CAR T-cell manufacturing. During manufacturing, we identified an aberrant T-cell population dually expressing CD19 and CD3. We hypothesized that these cells were RivoCel cells and confirmed using flow cytometry and PCR that the identified cells were in fact RivoCel cells and were eliminated with iCaspase9 activation. We additionally tracked these cells through CD19-specific CAR transduction and notably did not detect T cells dually positive for CD19 and CD19-directed CARs. The most likely rationale for this is in vitro fratricide of the CD19+ 'artificial' T-cell population by the CD19-specific CAR+ T cells in culture.CONCLUSIONS: We report the identification of CD19+/CD3+ cells in an apheresis product undergoing CAR transduction derived from a patient previously treated with a haploidentical transplant followed by RivoCel addback. We aim to bring attention to this cell phenotype that may be recognized with greater frequency as CAR therapy and engineered alphabetahaplo-HSCT are increasingly coupled. We additionally suggest consideration towards using alternative markers to CD19 as a synthetic identifier for post-transplant addback products, as CD19-expression on effector T cells may complicate subsequent treatment using CD19-directed therapy.

View details for DOI 10.1136/jitc-2020-001073

View details for PubMedID 32929049

View details for DOI 10.1002/pbc.28411

View details for Web of Science ID 000549825100001

View details for DOI 10.1002/pbc.28411

View details for PubMedID 32779834

Abstract

Immunomonitoring of chimeric antigen receptor (CAR) T cells relies primarily on their quantification in the peripheral blood, which inadequately quantifies their biodistribution and activation status in the tissues. Noninvasive molecular imaging of CAR T cells by PET is a promising approach with the ability to provide spatial, temporal, and functional information. Reported strategies rely on the incorporation of reporter transgenes or ex vivo biolabeling, significantly limiting the application of CAR T-cell molecular imaging. In this study, we assessed the ability of antibody-based PET (immunoPET) to noninvasively visualize CAR T cells.After analyzing human CAR T cells in vitro and ex vivo from patient samples to identify candidate targets for immunoPET, we employed a syngeneic, orthotopic murine tumor model of lymphoma to assess the feasibility of in vivo tracking of CAR T cells by immunoPET using the 89Zr-DFO-anti-ICOS tracer, which we have previously reported.Analysis of human CD19-CAR T cells during activation identified the Inducible T-cell COStimulator (ICOS) as a potential target for immunoPET. In a preclinical tumor model, 89Zr-DFO-ICOS mAb PET-CT imaging detected significantly higher signal in specific bone marrow-containing skeletal sites of CAR T-cell-treated mice compared with controls. Importantly, administration of ICOS-targeting antibodies at tracer doses did not interfere with CAR T-cell persistence and function.This study highlights the potential of ICOS-immunoPET imaging for monitoring of CAR T-cell therapy, a strategy readily applicable to both commercially available and investigational CAR T cells.See related commentary by Volpe et al., p. 911.

View details for DOI 10.1158/1078-0432.CCR-20-2770

View details for PubMedCentralID PMC7887027

Abstract

Chimeric Antigen Receptor (CAR) T cell therapy targeting CD19 has introduced a paradigmatic shift in our treatment approach for advanced B cell malignancies. A major advance has been in the field of pediatric B-ALL where complete responses have been achieved across clinical trials with rates of 65-90% in the relapsed/refractory setting. These striking early response rates led to FDA approval of Tisagenlecleucel, CD19-specific CAR T cells, in August 2017. With broadened access and available longitudinal follow up, it is imperative to study the true durability of CAR-mediated responses and establish long-term relapse free and survival outcomes following CAR therapy. Phase I and II clinical trials have reported event-free survival rates of 50% at 1 year following CD19-CAR infusion in children and young adults with B-ALL. Here, we review some of the major challenges accounting for the discrepancy between early response rates and long term outcomes. In specific, relapse with CD19+ or CD19- disease has emerged as a major challenge following CD19-CAR T cell therapy. Related, is the issue of CAR persistence which has been shown to correlate with long-term outcomes. We highlight select efforts to optimize clinical strategies and CAR design to promote enhanced persistence. To date, we do not have robust predictors of response durability and relapse following CAR therapy. The ability to identify patients at risk of relapse in an a priori manner may introduce an interventional window to consolidate CAR-mediated remissions and enhance response durability. This review highlights the need to bridge the gap between the remarkable early complete responses achieved with CD19-CAR T cell therapy and the long-term survival outcomes.

View details for DOI 10.3389/fimmu.2020.01985

View details for PubMedID 32849662

Abstract

The prognosis for patients with large B-cell lymphoma (LBCL) progressing after treatment with chimeric antigen receptor (CAR) T-cell therapy targeting CD19 (CAR19) is poor. We report on the first three consecutive patients with autologous CAR19-refractory LBCL treated with a single infusion of autologous 1106 CAR+ T-cells/kg targeting CD22 (CAR22) as part of a phase I dose escalation study. CAR22 therapy was relatively well tolerated, without any observed non-hematologic adverse events higher than grade 2. Following infusion, all three patients achieved complete remission, with all responses ongoing at the time of last follow up (mean 7.8 months, range 6-9.3). Circulating CAR22 cells demonstrated robust expansion (peak range 85.4-350 cells/L), and persisted beyond three months in all patients with continued radiographic responses and corresponding decreases in circulating tumor DNA (ctDNA) beyond six months post-infusion. Further accrual at a higher dose level in this phase 1 dose-escalation study is ongoing and will explore the role of this therapy in patients who have failed prior CAR T-cell therapies. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT04088890).

View details for DOI 10.1182/blood.2020009432

View details for PubMedID 33512414

View details for Web of Science ID 000538564000033

Abstract

Successes in CAR T cell translation have propelled their commercial launch, but expanding the impact of cancer immunotherapies remains challenging.

View details for PubMedID 30814337

Abstract

Somatic mutations in cancer are a potential source of cancer specific neoantigens. Acute myeloid leukemia (AML) has common recurrent mutations shared between patients in addition to private mutations specific to individuals. We hypothesized that neoantigens derived from recurrent shared mutations would be attractive targets for future immunotherapeutic approaches. Here we sought to study the HLA Class I and II immunopeptidome of thirteen primary AML tumor samples and two AML cell lines (OCI-AML3 and MV4-11) using mass spectrometry to evaluate for endogenous mutation-bearing HLA ligands from common shared AML mutations. We identified two endogenous, mutation-bearing HLA Class I ligands from nucleophosmin (NPM1). The ligands, AVEEVSLRK from two patient samples and C(cys)LAVEEVSL from OCI-AML3, are predicted to bind the common HLA haplotypes, HLA-A*03:01 and HLA-A*02:01 respectively. Since NPM1 is mutated in approximately one-third of patients with AML, the finding of endogenous HLA ligands from mutated NPM1 supports future studies evaluating immunotherapeutic approaches against this shared target, for this subset of patients with AML.

View details for DOI 10.1371/journal.pone.0219547

View details for PubMedID 31291378

Abstract

Immunotherapies have been successfully developed for the treatment of B-cell acute lymphoblastic leukemia (B-ALL) with FDA approval of blinatumomab, inotuzumab, and tisagenlecleucel for relapsed or refractory patients. These agents target either CD19 or CD22, which are both expressed on the surface of the leukemic blasts in the majority of patients. The use of these agents has greatly transformed the landscape of available treatment, and it has provided curative therapy in some patients. As the field has matured, we are learning that for most patients, the currently available immunotherapies are not curative. Leukemic resistance to both CD19 and CD22 pressure has been described and is a major component of developed resistance to these therapies. Patients with B-ALL have developed CD19- or CD22-negative B-ALL, and in more rare cases, they have undergone lineage switch to acute myeloid leukemia. Current efforts are focusing on overcoming antigen escape, either by forced antigen expression or by dual-targeting therapies. A functional immune system is also required for maximal benefit of immunotherapy, particularly with chimeric antigen receptor (CAR) T-cell therapies. Data are now being produced that may allow for the prospective identification of patients whose immune deficits may be identified up front and predict failure. Preclinical work is focusing on additional engineering of CAR T cells to overcome these inherent immune deficits. Last, with improved knowledge of which patients are likely to benefit from immunotherapy as definitive treatment, those patients who are predicted to develop resistance may be prospectively recommended to undergo a consolidative hematopoietic cell transplant to lessen the recurrence risk.

View details for DOI 10.1182/hematology.2019000018

View details for PubMedID 31808880

Abstract

Invitro cancer cultures, including three-dimensional organoids, typically contain exclusively neoplastic epithelium but require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of primary tumor epithelia with endogenous, syngeneic tumor-infiltrating lymphocytes (TILs) as a cohesive unit has been particularly elusive. Here, an air-liquid interface (ALI) method propagated patient-derived organoids (PDOs) from >100 human biopsies or mouse tumors in syngeneic immunocompetent hosts as tumor epithelia with native embedded immune cells (T, B, NK, macrophages). Robust droplet-based, single-cell simultaneous determination of gene expression and immune repertoire indicated that PDO TILs accurately preserved the original tumor Tcell receptor (TCR) spectrum. Crucially, human and murine PDOs successfully modeled immune checkpoint blockade (ICB) with anti-PD-1- and/or anti-PD-L1 expanding and activating tumor antigen-specific TILs and eliciting tumor cytotoxicity. Organoid-based propagation of primary tumor epithelium en bloc with endogenous immune stroma should enable immuno-oncology investigations within the TME and facilitate personalized immunotherapy testing.

View details for PubMedID 30550791

View details for DOI 10.1182/blood-2018-99-117445

View details for Web of Science ID 000454837602274

Abstract

Immunopeptidomes promise novel surface markers as ideal immunotherapy targets, but their characterization by mass spectrometry (MS) remains challenging. Until recently, cell numbers exceeding 109were needed to survey thousands of HLA ligands. Such limited analytical sensitivity has historically constrained the types of clinical specimens that can be evaluated to cell cultures or bulk tissues. Measuring immunopeptidomes from purified cell subpopulations would be preferable for many applications, particularly those evaluating rare, primary hematopoietic cell lineages. Here, we test the feasibility of immunopeptidome profiling from limited numbers of primary purified human regulatory T cells (TReg), conventional T cells (Tconv) and activated T cells. The combined T-cell immunopeptide dataset reported here contains 13,804 unique HLA ligands derived from 5,049 proteins. Of these, more than 700 HLA ligands were derived from 82 proteins that we exclusively identified from TReg-enriched cells. This study 1) demonstrates that primary, lineage-enriched T cell supbopulations recovered from single donors are compatible with immunopeptidome analysis; 2) presents new TReg-biased ligand candidates; and 3) supports immunopeptidome surveys value for revealing T cell biology that may not be apparent from expression data alone. Taken together, these findings open up new avenues for targeting TRegand abrogating their suppressive functions to treat cancer. This article is protected by copyright. All rights reserved.

View details for DOI 10.1002/pmic.201700410

View details for PubMedID 29493099

Abstract

Building upon preclinical advances, we are uncovering immunotherapy strategies that are translating into improved outcomes in tumor subsets. Advanced pediatric solid tumors carry poor prognoses and resultant robust efforts to apply immunotherapy advances to pediatric solid tumors are in progress. Here, we discuss recent developments in the field using mAb and mAb-based therapies including checkpoint blockade and chimeric antigen receptors (CARs).The pediatric solid tumor mAb experience targeting the diganglioside, GD2, for patients with neuroblastoma has been the most compelling to date. GD2 and alternative antigen-specific mAbs are now being incorporated into antibody-drug conjugates, bispecific antibodies and CARs for treatment of solid tumors. CARs in pediatric solid tumors have not yet achieved comparative responses to the hematologic CAR experience; however, novel strategies such as bispecific targeting, intratumoral administration and improved understanding of T-cell biology may yield enhanced CAR-efficacy. Therapeutic effect using single-agent checkpoint blocking antibodies in pediatric solid tumors also remains limited to date. Combinatorial strategies continue to hold promise and the clinical effect in tumor subsets with high antigenic burden is being explored.Pediatric immunotherapy remains at early stages of translation, yet we anticipate that with advanced technology, we will achieve widespread, efficacious use of immunotherapy for pediatric solid tumors.

View details for DOI 10.1097/MOP.0000000000000564

View details for PubMedID 29189429

Abstract

Tumor immunotherapy has had demonstrable efficacy in patients with cancer. The most promising results have been with T-cell-based therapies. These include adoptive cell transfer of tumor-infiltrating lymphocytes, genetically engineered T cells, and immune checkpoint inhibitor antibodies. In this review, we describe the different T-cell-based strategies currently in clinical trials and put their applications, present and future, into perspective.

View details for DOI 10.1158/2326-6066.CIR-15-0190

View details for PubMedID 26438444