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The observation that T cells can recognize and specifically eliminate cancer cells has spurred interest in the development of efficient methods to generate large numbers of T cells with specificity for tumor antigens that can be harnessed for use in cancer therapy. Recent studies have demonstrated that during encounter with tumor antigen, the signals delivered to T cells by professional antigen-presenting cells can affect T-cell programming and their subsequent therapeutic efficacy. This has stimulated efforts to develop artificial antigen-presenting cells that allow optimal control over the signals provided to T cells. In this review, we will discuss the advantages and disadvantages of cellular and acellular artificial antigen-presenting cell systems and their use in T-cell adoptive immunotherapy for cancer. [ABSTRACT FROM AUTHOR]

Discusses research which evaluated the safety and anti-leukemic efficacy of adoptive T-cell therapy with CD8[sup +] cytotoxic T lymphocytes (CTL) clones specific for tissue-restricted minor histocompatibility (H) Ags, in patients with advanced myelodysplastic syndrome and acute leukemia who relapse after hematopoietic cell transplantation from an MHC-identical donor. Generation of the CTL clones; Observation on graft-versus-tumor effects.

Purpose: The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is expressed in hematopoietic and epithelial cancers but has limited expression on normal adult tissues. This phase I study evaluated the safety of targeting ROR1 with autologous T lymphocytes engineered to express a ROR1 chimeric antigen receptor (CAR). Secondary objectives evaluated the persistence, trafficking, and antitumor activity of CAR-T cells., Patients and Methods: Twenty-one patients with ROR1+ tumors received CAR-T cells at one of four dose levels: 3.3 × 105, 1 × 106, 3.3 × 106, and 1 × 107 cells/kg body weight, administered after lymphodepletion with cyclophosphamide/fludarabine or oxaliplatin/cyclophosphamide. Cohort A included patients with chronic lymphocytic leukemia (CLL, n = 3); cohort B included patients with triple-negative breast cancer (TNBC, n = 10) or non-small cell lung cancer (NSCLC, n = 8). A second infusion was administered to one patient in cohort A with residual CLL in the marrow and three patients in cohort B with stable disease after first infusion., Results: Treatment was well tolerated, apart from one dose-limiting toxicity at dose level 4 in a patient with advanced NSCLC. Two of the three (67%) patients with CLL showed robust CAR-T-cell expansion and a rapid antitumor response. In patients with NSCLC and TNBC, CAR-T cells expanded to variable levels and infiltrated tumors poorly and 1 of 18 patients (5.5%) achieved partial response by RECIST 1.1., Conclusions: ROR1 CAR-T cells were well tolerated in most patients. Antitumor activity was observed in CLL but was limited in TNBC and NSCLC. Immunogenicity of the CAR and lack of sustained tumor infiltration were identified as limitations. See related commentary by Kobold, p. 437., (©2024 The Authors; Published by the American Association for Cancer Research.)

CD19-directed chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy elicits high response rates but fails to induce durable responses in most adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). In a previous clinical trial (NCT01865617), we observed anti-CAR immune responses associated with impaired in vivo CAR T-cell expansion after second infusions. Because these CD8+ T-cell responses were predominantly directed at peptides derived from the murine single chain variable fragment (scFv) in the CAR, we conducted a clinical trial investigating the safety and efficacy of CD19 CAR T-cells engineered with a CAR incorporating a fully human scFv (JCAR021) in adults with R/R B-ALL (NCT03103971). Twenty-three patients received lymphodepletion chemotherapy and JCAR021 infusion. Nineteen patients developed CRS (any grade, 83%; grade 2, 61%) and 12 developed neurotoxicity (52%; grade ≥3, 35%). The overall response and CR/CRi rates were 82% and 64%, respectively. We observed MRD-negative marrow responses in 82% of those with marrow disease and extramedullary responses by PET-CT in 79% (CR, 50%) of those with measurable FDG-avid disease. The median duration of remission (DOR) was 10 months with a 4-year DOR probability of 29%. Four patients underwent allo-HCT while in CR/CRi after JCAR021. Durable remissions were observed in patients with low marrow disease burden. In contrast, the DOR was limited in those with high marrow burden, highlighting a remaining critical need to identify new strategies to prolong remissions. We observed similar outcomes in CAR-naïve adult B-ALL patients receiving CD19 CAR T-cells expressing a fully human or murine scFv-containing CAR., (Copyright © 2025 American Society of Hematology.)

Abstract: Chimeric antigen receptor (CAR) T cells and bispecific antibodies targeting B-cell maturation antigen (BCMA) have significantly advanced the treatment of relapsed and refractory multiple myeloma. Resistance to BCMA-targeting therapies, nonetheless, remains a significant challenge. BCMA shedding by γ-secretase is a known resistance mechanism, and preclinical studies suggest that inhibition may improve anti-BCMA therapy. Leveraging a phase 1 clinical trial of the γ-secretase inhibitor (GSI), crenigacestat, with anti-BCMA CAR T cells (FCARH143), we used single-nuclei RNA sequencing and assay for transposase-accessible chromatin sequencing to characterize the effects of GSI on the tumor microenvironment. The most significant impacts of GSI involved effects on monocytes, which are known to promote tumor growth. In addition to observing a reduction in the frequency of nonclassical monocytes, we also detected significant changes in gene expression, chromatin accessibility, and inferred cell-cell interactions after exposure to GSI. Although many genes with altered expression are associated with γ-secretase-dependent signaling, such as Notch, other pathways were affected, indicating GSI has far-reaching effects. Finally, we detected monoallelic deletion of the BCMA locus in some patients with prior exposure to anti-BCMA therapy, which significantly correlated with reduced progression-free survival (PFS; median PFS, 57 vs 861 days). GSIs are being explored in combination with the full spectrum of BCMA-targeting agents, and our results reveal widespread effects of GSI on both tumor and immune cell populations, providing insight into mechanisms for enhancing BCMA-directed therapies., (© 2025 American Society of Hematology. Published by Elsevier Inc. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production.  In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics., (© 2024. The Author(s).)

Abstract: Relapse is the leading cause of death after allogeneic hematopoietic stem cell transplantation (HCT) for leukemia. T cells engineered by gene transfer to express T cell receptors (TCR; TCR-T) specific for hematopoietic-restricted minor histocompatibility (H) antigens may provide a potent selective antileukemic effect post-HCT. We conducted a phase 1 clinical trial using a novel TCR-T product targeting the minor H antigen, HA-1, to treat or consolidate treatment of persistent or recurrent leukemia and myeloid neoplasms. The primary objective was to evaluate the feasibility and safety of administration of HA-1 TCR-T after HCT. CD8+ and CD4+ T cells expressing the HA-1 TCR and a CD8 coreceptor were successfully manufactured from HA-1-disparate HCT donors. One or more infusions of HA-1 TCR-T following lymphodepleting chemotherapy were administered to 9 HCT recipients who had developed disease recurrence after HCT. TCR-T cells expanded and persisted in vivo after adoptive transfer. No dose-limiting toxicities occurred. Although the study was not designed to assess efficacy, 4 patients achieved or maintained complete remissions following lymphodepletion and HA-1 TCR-T, with 1 patient still in remission at >2 years. Single-cell RNA sequencing of relapsing/progressive leukemia after TCR-T therapy identified upregulated molecules associated with T-cell dysfunction or cancer cell survival. HA-1 TCR-T therapy appears feasible and safe and shows preliminary signals of efficacy. This clinical trial was registered at ClinicalTrials.gov as #NCT03326921., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

To design new CARs targeting hepatitis B virus (HBV), we isolated human monoclonal antibodies recognizing the HBV envelope proteins from single B cells of a patient with a resolved infection. HBV-specific memory B cells were isolated by incubating peripheral blood mononuclear cells with biotinylated hepatitis B surface antigen (HBsAg), followed by single-cell flow cytometry-based sorting of live, CD19 + IgG + HBsAg + cells. Amplification and sequencing of immunoglobulin genes from single memory B cells identified variable heavy and light chain sequences. Corresponding immunoglobulin chains were cloned into IgG1 expression vectors and expressed in mammalian cells. Two antibodies named 4D06 and 4D08 were found to be highly specific for HBsAg, recognized a conformational and a linear epitope, respectively, and showed broad reactivity and neutralization capacity against all major HBV genotypes. 4D06 and 4D08 variable chain fragments were cloned into a 2 nd generation CAR format with CD28 and CD3zeta intracellular signaling domains. The new CAR constructs displayed a high functional avidity when expressed on primary human T cells. CAR-grafted T cells proved to be polyfunctional regarding cytokine secretion and killed HBV-positive target cells. Interestingly, background activation of the 4D08-CAR recognizing a linear instead of a conformational epitope was consistently low. In a preclinical model of chronic HBV infection, murine T cells grafted with the 4D06 and the 4D08 CAR showed on target activity indicated by a transient increase in serum transaminases, and a lower number of HBV-positive hepatocytes in the mice treated. This study demonstrates an efficient and fast approach to identifying pathogen-specific monoclonal human antibodies from small donor cell numbers for the subsequent generation of new CARs., Competing Interests: UP is a co-founder, shareholder, and SCG Cell Therapy Pte Ltd board member. UP received personal fees from Abbott, Abbvie, Arbutus, Gilead, GSK, J&J, MSD, Roche, Sanofi, Sobi, and Vaccitech. SR was a founder, has served as an advisor, and has patents licensed to Juno Therapeutics; is a founder of and holds equity in Lyell Immunopharma; and has served on the advisory boards for Adaptive Biotechnologies and Nohla. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Schreiber, Dressler, Loffredo-Verde, Asen, Färber, Wang, Groll, Chakraborty, Kolbe, Kreer, Kosinska, Simon, Urban, Klein, Riddell and Protzer.)

The expression of a synthetic chimeric antigen receptor (CAR) to redirect antigen specificity of T cells is transforming the treatment of hematological malignancies and autoimmune diseases [1-7]. In cancer, durable efficacy is frequently limited by the escape of tumors that express low levels or lack the target antigen [8-12]. These clinical results emphasize the need for immune receptors that combine high sensitivity and multispecificity to improve outcomes. Current mono- and bispecific CARs do not faithfully recapitulate T cell receptor (TCR) function and require high antigen levels on tumor cells for recognition [13-17]. Here, we describe a novel synthetic chimeric TCR (ChTCR) that exhibits superior antigen sensitivity and is readily adapted for bispecific targeting. Bispecific ChTCRs mimic TCR structure, form classical immune synapses, and exhibit TCR-like proximal signaling. T cells expressing Bi-ChTCRs more effectively eliminated tumors with heterogeneous antigen expression in vivo compared to T cells expressing optimized bispecific CARs. The Bi-ChTCR architecture is resilient and can be designed to target multiple B cell lineage and multiple myeloma antigens. Our findings identify a broadly applicable approach for engineering T cells to target hematologic malignancies with heterogeneous antigen expression, thereby overcoming the most frequent mechanism of relapse after current CAR T therapies., Competing Interests: Competing Interests: S.S., G.B. and S.R.R. are inventors on a patent (FHCC: 21–126-WO-PCT | App No. PCT/US2023/066466| COMPOSITIONS AND METHODS FOR CELLULAR IMMUNOTHERAPY) filed by Fred Hutchinson Cancer Center and related to this work. S.R.R. was a founder, has served as an advisor, and has patents licensed to Juno Therapeuwcs; S.R.R is a founder of and holds equity in Lyell Immunopharma and has served on the advisory boards for Adapwve Biotechnologies, Outpace Bio and Nohla.

Chronic antigen stimulation is thought to generate dysfunctional CD8 T cells. Here, we identify a CD8 T cell subset in the bone marrow tumor microenvironment that, despite an apparent terminally exhausted phenotype (T PHEX ), expressed granzymes, perforin, and IFN-γ. Concurrent gene expression and DNA accessibility revealed that genes encoding these functional proteins correlated with BATF expression and motif accessibility. IFN-γ + T PHEX effectively killed myeloma with comparable efficacy to transitory effectors, and disease progression correlated with numerical deficits in IFN-γ + T PHEX . We also observed IFN-γ + T PHEX within CD19-targeted chimeric antigen receptor T cells, which killed CD19 + leukemia cells. An IFN-γ + T PHEX gene signature was recapitulated in T EX cells from human cancers, including myeloma and lymphoma. Here, we characterize a T EX subset in hematological malignancies that paradoxically retains function and is distinct from dysfunctional T EX found in chronic viral infections. Thus, IFN-γ + T PHEX represent a potential target for immunotherapy of blood cancers.

The interaction of the tumor necrosis factor receptor (TNFR) family member CD27 on naive CD8 + T (Tn) cells with homotrimeric CD70 on antigen-presenting cells (APCs) is necessary for T cell memory fate determination. Here, we examined CD27 signaling during Tn cell activation and differentiation. In conjunction with T cell receptor (TCR) stimulation, ligation of CD27 by a synthetic trimeric CD70 ligand triggered CD27 internalization and degradation, suggesting active regulation of this signaling axis. Internalized CD27 recruited the signaling adaptor TRAF2 and the phosphatase SHP-1, thereby modulating TCR and CD28 signals. CD27-mediated modulation of TCR signals promoted transcription factor circuits that induced memory rather than effector associated gene programs, which are induced by CD28 costimulation. CD27-costimulated chimeric antigen receptor (CAR)-engineered T cells exhibited improved tumor control compared with CD28-costimulated CAR-T cells. Thus, CD27 signaling during Tn cell activation promotes memory properties with relevance to T cell immunotherapy., Competing Interests: Declaration of interests C.A.J.-R., C.E.C., and S.R.R. are inventors on a patent (“engineered trimeric CD70 proteins and uses thereof”; WO2021072127A3) filed by Fred Hutchinson Cancer Center and licensed by Lyell Immunopharma. S.R.R. was a founder, has served as an advisor, and has patents licensed to Juno Therapeutics; S.R.R is a founder of and holds equity in Lyell Immunopharma and has served on the advisory boards for Adaptive Biotechnologies and Nohla., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The paucity of tumor-specific targets for chimeric antigen receptor (CAR) T-cell therapy of solid tumors necessitates careful preclinical evaluation of the therapeutic window for candidate antigens. Human epidermal growth factor receptor 2 (HER2) is an attractive candidate for CAR T-cell therapy in humans but has the potential for eliciting on-target off-tumor toxicity. We developed an immunocompetent tumor model of CAR T-cell therapy targeting murine HER2 (mHER2) and examined the effect of CAR affinity, T-cell dose, and lymphodepletion on safety and efficacy., Methods: Antibodies specific for mHER2 were generated, screened for affinity and specificity, tested for immunohistochemical staining of HER2 on normal tissues, and used for HER2-targeted CAR design. CAR candidates were evaluated for T-cell surface expression and the ability to induce T-cell proliferation, cytokine production, and cytotoxicity when transduced T cells were co-cultured with mHER2+ tumor cells in vitro. Safety and efficacy of various HER2 CARs was evaluated in two tumor models and normal non-tumor-bearing mice., Results: Mice express HER2 in the same epithelial tissues as humans, rendering these tissues vulnerable to recognition by systemically administered HER2 CAR T cells. CAR T cells designed with single-chain variable fragment (scFvs) that have high-affinity for HER2 infiltrated and caused toxicity to normal HER2-positive tissues but exhibited poor infiltration into tumors and antitumor activity. In contrast, CAR T cells designed with an scFv with low-affinity for HER2 infiltrated HER2-positive tumors and controlled tumor growth without toxicity. Toxicity mediated by high-affinity CAR T cells was independent of tumor burden and correlated with proliferation of CAR T cells post infusion., Conclusions: Our findings illustrate the disadvantage of high-affinity CARs for targets such as HER2 that are expressed on normal tissues. The use of low-affinity HER2 CARs can safely regress tumors identifying a potential path for therapy of solid tumors that exhibit high levels of HER2., Competing Interests: Competing interests: SRR was a founder, has served as an advisor, and has patents licensed to Juno Therapeutics; is a founder of and holds equity in Lyell Immunopharma; and has served on the advisory boards for Adaptive Biotechnologies, Nohla and Ervaccine. The other authors have declared that no conflict of interest exists., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: More than half of the patients treated with CD19-targeted chimeric antigen receptor (CAR) T-cell immunotherapy for large B-cell lymphoma (LBCL) do not achieve durable remission, which may be partly due to PD-1/PD-L1-associated CAR T-cell dysfunction. We report data from a phase 1 clinical trial (NCT02706405), in which adults with LBCL were treated with autologous CD19 CAR T cells (JCAR014) combined with escalating doses of the anti-PD-L1 monoclonal antibody, durvalumab, starting either before or after CAR T-cell infusion. The addition of durvalumab to JCAR014 was safe and not associated with increased autoimmune or immune effector cell-associated toxicities. Patients who started durvalumab before JCAR014 infusion had later onset and shorter duration of cytokine release syndrome and inferior efficacy, which was associated with slower accumulation of CAR T cells and lower concentrations of inflammatory cytokines in the blood. Initiation of durvalumab before JCAR014 infusion resulted in an early increase in soluble PD-L1 (sPD-L1) levels that coincided with the timing of maximal CAR T-cell accumulation in the blood. In vitro, sPD-L1 induced dose-dependent suppression of CAR T-cell effector function, which could contribute to inferior efficacy observed in patients who received durvalumab before JCAR014. Despite the lack of efficacy improvement and similar CAR T-cell kinetics early after infusion, ongoing durvalumab therapy after JCAR014 was associated with re-expansion of CAR T cells in the blood, late regression of CD19+ and CD19- tumors, and enhanced duration of response. Our results indicate that the timing of initiation of PD-L1 blockade is a key variable that affects outcomes after CD19 CAR T-cell immunotherapy for adults with LBCL., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Adoptive immunotherapy based on chimeric antigen receptor (CAR)-engineered T cells has exhibited impressive clinical efficacy in treating B-cell malignancies. However, the potency of CAR-T cells carriethe potential for significant on-target/off-tumor toxicities when target antigens are shared with healthy cells, necessitating the development of complementary safety measures. In this context, there is a need to selectively eliminate therapeutically administered CAR-T cells, especially to revert long-term CAR-T cell-related side effects. To address this, we have developed an effective cellular-based safety mechanism to specifically target and eliminate the transferred CAR-T cells. As proof-of-principle, we have designed a secondary CAR ( anti -CAR CAR) capable of recognizing a short peptide sequence (Strep-tag II) incorporated into the hinge domain of an anti -CD19 CAR. In in vitro experiments, these anti -CAR CAR-T cells have demonstrated antigen-specific cytokine release and cytotoxicity when co-cultured with anti -CD19 CAR-T cells. Moreover, in both immunocompromised and immunocompetent mice, we observed the successful depletion of anti -CD19 CAR-T cells when administered concurrently with anti -CAR CAR-T cells. We have also demonstrated the efficacy of this safeguard mechanism in a clinically relevant animal model of B-cell aplasia induced by CD19 CAR treatment, where this side effect was reversed upon anti -CAR CAR-T cells infusion. Notably, efficient B-cell recovery occurred even in the absence of any pre-conditioning regimens prior anti -CAR CAR-T cells transfer, thus enhancing its practical applicability. In summary, we developed a robust cellular safeguard system for selective in vivo elimination of engineered T cells, offering a promising solution to address CAR-T cell-related on-target/off-tumor toxicities., Competing Interests: DB is co-founder of STAGE Cell Therapeutics GmbH now Juno Therapeutics, a Bristol-Myers Squibb Company and T Cell Factory B.V. now Kite/a Gilead Company. DB has a consulting contract with and receives sponsored research support from Juno Therapeutics/BMS. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Svec, Dötsch, Warmuth, Trebo, Fräßle, Riddell, Jäger, D’Ippolito and Busch.)

The period between "successful" treatment of localized breast cancer and the onset of distant metastasis can last many years, representing an unexploited window to eradicate disseminated disease and prevent metastases. We find that the source of recurrence-disseminated tumor cells (DTCs) -evade endogenous immunity directed against tumor neoantigens. Although DTCs downregulate major histocompatibility complex I, this does not preclude recognition by conventional T cells. Instead, the scarcity of interactions between two relatively rare populations-DTCs and endogenous antigen-specific T cells-underlies DTC persistence. This scarcity is overcome by any one of three immunotherapies that increase the number of tumor-specific T cells: T cell-based vaccination, or adoptive transfer of T cell receptor or chimeric antigen receptor T cells. Each approach achieves robust DTC elimination, motivating discovery of MHC-restricted and -unrestricted DTC antigens that can be targeted with T cell-based immunotherapies to eliminate the reservoir of metastasis-initiating cells in patients., Competing Interests: Declaration of interests S.R.R. is a co-founder of Lyell Immunopharma, has research funding from Lyell Immunopharma, and holds equity in Lyell Immunopharma. S.R.R. has patents in the field of cellular therapy unrelated to this work licensed to Juno Therapeutics/Bristol Myers Squibb and Lyell Immunopharma. M.H.L. has served as a consultant for Scribe Biosciences, Inc. S.S. has received research funding from Lyell Immunopharma, has a patent licensed by Lyell Immunopharma, holds equity and has served as a consultant for Lyell Immunopharma outside the submitted work. J.R.V. has intellectual property unrelated to this work licensed to Lyell Immunopharma and has received research grant support form Lyell Immunopharma and Bristol Myers Squibb., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Importance: Metastatic soft tissue sarcomas (STSs) have limited systemic therapy options, and immunomodulation has not yet meaningfully improved outcomes. Intratumoral (IT) injection of the toll-like receptor 4 (TLR4) agonist glycopyranosyl lipid A in stable-emulsion formulation (GLA-SE) has been studied as immunotherapy in other contexts., Objective: To evaluate the safety, efficacy, and immunomodulatory effects of IT GLA-SE with concurrent radiotherapy in patients with metastatic STS with injectable lesions., Design, Setting, and Participants: This phase 1 nonrandomized controlled trial of patients with STS was performed at a single academic sarcoma specialty center from November 17, 2014, to March 16, 2016. Data analysis was performed from August 2016 to September 2022., Interventions: Two doses of IT GLA-SE (5 μg and 10 μg for 8 weekly doses) were tested for safety in combination with concurrent radiotherapy of the injected lesion., Main Outcomes and Measures: Primary end points were safety and tolerability. Secondary and exploratory end points included local response rates as well as measurement of antitumor immunity with immunohistochemistry and T-cell receptor (TCR) sequencing of tumor-infiltrating and circulating lymphocytes., Results: Twelve patients (median [range] age, 65 [34-78] years; 8 [67%] female) were treated across the 2 dose cohorts. Intratumoral GLA-SE was well tolerated, with only 1 patient (8%) experiencing a grade 2 adverse event. All patients achieved local control of the injected lesion after 8 doses, with 1 patient having complete regression (mean regression, -25%; range, -100% to 4%). In patients with durable local response, there were detectable increases in tumor-infiltrating lymphocytes. In 1 patient (target lesion -39% at 259 days of follow-up), TCR sequencing revealed expansion of preexisting and de novo clonotypes, with convergence of numerous rearrangements coding for the same binding sequence (suggestive of clonal convergence to antitumor targets). Single-cell sequencing identified these same expanded TCR clones in peripheral blood after treatment; these T cells had markedly enhanced Tbet expression, suggesting TH1 phenotype., Conclusions and Relevance: In this nonrandomized controlled trial, IT GLA-SE with concurrent radiotherapy was well tolerated and provided more durable local control than radiotherapy alone. Patients with durable local response demonstrated enhanced IT T-cell clonal expansion, with matched expansion of these clonotypes in the circulation. Additional studies evaluating synergism of IT GLA-SE and radiotherapy with systemic immune modulation are warranted., Trial Registration: ClinicalTrials.gov Identifier: NCT02180698.

High response rates have been reported after CD19-targeted chimeric antigen receptor-modified (CD19 CAR) T-cell therapy for relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), yet the factors associated with duration of response in this setting are poorly characterized. We analyzed long-term outcomes in 47 patients with R/R CLL and/or Richter transformation treated on our phase 1/2 clinical trial of CD19 CAR T-cell therapy with an updated median follow-up of 79.6 months. Median progression-free survival (PFS) was 8.9 months, and the 6-year PFS was 17.8%. Maximum standardized uptake value (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.07-1.23; P < .001) and bulky disease (≥5 cm; HR, 2.12; 95% CI, 1.06-4.26; P = .034) before lymphodepletion were associated with shorter PFS. Day +28 complete response by positron emission tomography-computed tomography (HR, 0.13; 95% CI, 0.04-0.40; P < .001), day +28 measurable residual disease (MRD) negativity by multiparameter flow cytometry (HR, 0.08; 95% CI, 0.03-0.22; P < .001), day +28 MRD negativity by next-generation sequencing (HR, 0.21; 95% CI, 0.08-0.51; P < .001), higher peak CD8+ CAR T-cell expansion (HR, 0.49; 95% CI; 0.36-0.68; P < .001), higher peak CD4+ CAR T-cell expansion (HR, 0.47; 95% CI; 0.33-0.69; P < .001), and longer CAR T-cell persistence (HR, 0.56; 95% CI, 0.44-0.72; P < .001) were associated with longer PFS. The 6-year duration of response and overall survival were 26.4% and 31.2%, respectively. CD19 CAR T-cell therapy achieved durable responses with curative potential in a subset of patients with R/R CLL. This trial was registered at www.clinicaltrials.gov as #NCT01865617., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: γ-Secretase inhibitors (GSIs) increase B cell maturation antigen (BCMA) density on malignant plasma cells and enhance antitumour activity of BCMA chimeric antigen receptor (CAR) T cells in preclinical models. We aimed to evaluate the safety and identify the recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat (LY3039478) for individuals with relapsed or refractory multiple myeloma., Methods: We conducted a phase 1, first-in-human trial combining crenigacestat with BCMA CAR T-cells at a single cancer centre in Seattle, WA, USA. We included individuals aged 21 years or older with relapsed or refractory multiple myeloma, previous autologous stem-cell transplant or persistent disease after more than four cycles of induction therapy, and Eastern Cooperative Oncology Group performance status of 0-2, regardless of previous BCMA-targeted therapy. To assess the effect of the GSI on BCMA surface density on bone marrow plasma cells, participants received GSI during a pretreatment run-in, consisting of three doses administered 48 h apart. BCMA CAR T cells were infused at doses of 50 × 10 6 CAR T cells, 150 × 10 6 CAR T cells, 300 × 10 6 CAR T cells, and 450 × 10 6 CAR T cells (total cell dose), in combination with the 25 mg crenigacestat dosed three times a week for up to nine doses. The primary endpoints were the safety and recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat, an oral GSI. This study is registered with ClinicalTrials.gov, NCT03502577, and has met accrual goals., Findings: 19 participants were enrolled between June 1, 2018, and March 1, 2021, and one participant did not proceed with BCMA CAR T-cell infusion. 18 participants (eight [44%] men and ten [56%] women) with multiple myeloma received treatment between July 11, 2018, and April 14, 2021, with a median follow up of 36 months (95% CI 26 to not reached). The most common non-haematological adverse events of grade 3 or higher were hypophosphataemia in 14 (78%) participants, fatigue in 11 (61%), hypocalcaemia in nine (50%), and hypertension in seven (39%). Two deaths reported outside of the 28-day adverse event collection window were related to treatment. Participants were treated at doses up to 450 × 10 6 CAR + cells, and the recommended phase 2 dose was not reached., Interpretations: Combining a GSI with BCMA CAR T cells appears to be well tolerated, and crenigacestat increases target antigen density. Deep responses were observed among heavily pretreated participants with multiple myeloma who had previously received BCMA-targeted therapy and those who were naive to previous BCMA-targeted therapy. Further study of GSIs given with BCMA-targeted therapeutics is warranted in clinical trials., Funding: Juno Therapeutics-a Bristol Myers Squibb company and the National Institutes of Health., Competing Interests: Declaration of interest AJC receives research funding from Juno Therapeutics—a Bristol Myers Squibb company, Nektar, Janssen, Abbvie, Harpoon, Sanofi, Adaptive Biotechologies, and Celgene; is a consultant for Adaptive Biotechnologies, Bristol Myers Squibb, and Abbvie; and receives payment for presentations from Curio Science, DAVA Oncology, and MJH Life Sciences. XS receives research funding from Juno Therapeutics—a Bristol Myers Squibb company. MJP is a consultant for SpringWorks Therapeutics, owns stock or has stock options in Lyell Immunopharma, and is currently employed by CellPoint. CJT receives research funding from Bristol Myers Squibb; has right to receive payments from royalties for inventions licensed to third parties, including Bristol Myers Squibb; is a consultant for Caribou, Myeloid Therapeutics, Precision Biosciences, Arsenal Bio, Century Therapeutics, Allogene, Legend Bio, Nektar, Syncopation Life Sciences, Sobi, Expert Connect, Decheng Capital, Asher Bio, Genentech, and Amgen; has received payment for presentations from St Judes, Malaysian Society for Hematology, Japan Society for Transplantation and Cell Therapy, and Bristol Myers Squibb; and has stock or stock options in Caribou, Myeloid Therapeutics, Precision Biosciences, Arsenal bio, and Eureka Therapeutics. BGT receives research funding from Bristol Myers Squibb; royalties from Mustang Bio; has patents with Mustang Bio; participates on a data safety monitoring board with Mustang Bio and Proteios Technology; and has stock or stock options with Proteios Technology. ENL has research funding from GSK, Celgene, Amgen, Genentech, Beigene, and Seattle Genetics and has received payment for presentations from Curio Science, Janssen, and Pharmacyclics. SAT has stock or stock options in Bristol Myers Squibb and is a current employee of Juno Therapeutics—a Bristol Myers Squibb company. BW has research funding from Amgen, Novartis, Kite, Beam, Wugen, and Biosight and receives payment for lectures from Amgen. MS receives research funding from Mustang Bio, Bristol Myers Squibb, Pharmacyclics, Genentech, Abbvie, TG Therapeutics, BeiGene, AstraZeneca, Genmab, Morphosys, Incyte, and Vincerx; is a consultant for AbbVie, Genentech, AstraZeneca, Pharmacyclices, BeiGene, Bristol Myers Squibb, Morphosys, Incyte, Kite, Eli Lilly, Genmab, Mustang Bio, Regeneron, ADC therapeutics, Fate Therapeutics, Nurix, and MEI Pharma; and receives payment for presentations from AbbVie, Genentech, AstraZeneca, Pharmacyclics, BeiGene, Bristol Myers Squibb, Morphosys, Incyte, Kite, Eli Lilly, Genmab, Mustang Bio, Regeneron, ADC therapeutics, Fate Therapeutics, Nurix, and MEI Pharma. JG receives research funding from Sobi, Juno Therapeutics— a Bristol Myers Squibb company, Celgene—a Bristol Myers Squibb company, and Angiocrine Bioscience; is a consultant for Sobi, Legend Biotech, Janssen, Kite Pharma, and MorphoSys;, and is on an advisory board for Century Therapeutics. DGM receives research funding from Kite Pharma, Juno Therapeutics—a Bristol Myers Squibb company, Celgene, Legend Biotech, and Bristol Myers Squibb; is a consultant for A2 Biotherapeutics, Navan Technologies, Chimeric Therapeutics, Genentech, Bristol Myers Squibb, ImmmPACT Bio, and Gilead Sciences; has rights to royalties for patents licensed to Juno Therapeutics—a Bristol Myers Squibb company; serves as an advisory board member for Bristol Myers Squibb, Caribou Biosciences, Celgene, Genentech, Incyte, Janssen, Juno Therapeutics—a Bristol Myers Squibb company, Mustang Bio, Morphosys, Kite, Lilly, Novartis, and Umoja; and has stocks or stock options in A2 Biotherapeutics and Navan Technologies. SRR has research funding from the National Institutes of Health, Leukemia and Lymphoma Society, Juno Therapeutics—a Bristol Myers Squibb company, Lyelle Immunopharma, and Outpace Biosciences; has rights to royalties from Juno Therapeutics—a Bristol Myers Squibb company, Lyell Immunopharma, Deverra Therapeutics; is a consultant from Lyell Immunopharma and Adaptive Biotechnologies; has patents from Juno Therapeutics—a Bristol Myers Squibb company and Lyell Immunopharma; serves on a board of directors for Ozette Technologies; and has stocks or stock options from Lyell Immunopharma and Adaptive Biotechnologies. DJG held the sponsor-investigator investigational new drug application from the US Food and Drug Administration for this study; has obtained grants or contracts through Fred Hutchinson Cancer Center with Juno Therapeutics—a Bristol Myers Squibb company, Seattle Genetics, Janssen Biotech, SpringWorks Therapeutics, Cellectar Biosciences, The Allen Institute for Immunology, The Leukemia and Lymphoma Society, and the National Institutes of Health; is in consulting agreements with Ensoma; has served on an advisory board for GSK, Janssen Biotech, Legend Biotech, and Celgene; and has two US provisional patent applications (62/582,270 and 62/582,308) through Fred Hutchinson Cancer Center and Juno Therapeutics—a Bristol Myers Squibb company. BDS, DGC, TG, JV, VQW, AGC, and FM declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Therapy with CD19-directed chimeric antigen receptor (CAR) T cells has transformed the treatment of advanced B-cell malignancies. However, loss of or low antigen expression can enable tumor escape and limit the duration of responses achieved with CAR T-cell therapy. Engineering bispecific CAR T cells that target 2 tumor antigens could overcome antigen-negative escape. We found that CD79a and b, which are heterodimeric components of the B-cell receptor, were expressed on 84.3% of lymphoma cases using immunohistochemistry, and 87.3% of CD79ab-positive tumors also coexpressed CD19. We generated 3 bispecific permutations: tandem, bicistronic, and pooled products of CD79a-CD19 or CD79b-CD19 CAR T cells and showed that bispecific CAR T cells prevented the outgrowth of antigen-negative cells in a CD19-loss lymphoma xenograft model. However, tandem and bicistronic CAR T cells were less effective than monospecific CD19 or CD79a CAR T cells for the treatment of tumors that only expressed CD19 or CD79, respectively. When compared with monospecific CAR T cells, T cells expressing a tandem CAR exhibited reduced binding of each target antigen, and T cells expressing a bicistronic CAR vector exhibited reduced phosphorylation of downstream CAR signaling molecules. Our study showed that despite added specificity, tandem and bicistronic CAR T cells exhibit different defects that impair recognition of tumor cells expressing a single antigen. Our data provide support for targeting multiple B-cell antigens to improve efficacy and identify areas for improvement in bispecific receptor designs., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Chimeric antigen receptor (CAR)-modified T-cell therapies targeting CD19 represent a new treatment option for patients with relapsed/refractory (R/R) B-cell malignancies. However, CAR T-cell therapy fails to elicit durable responses in a significant fraction of patients. Limited in vivo proliferation and survival of infused CAR T cells are key causes of failure. In a phase 1/2 clinical trial of CD19 CAR T cells for B-cell malignancies (#NCT01865617), low serum interleukin 15 (IL-15) concentration after CAR T-cell infusion was associated with inferior CAR T-cell kinetics. IL-15 supports T-cell proliferation and survival, and therefore, supplementation with IL-15 may enhance CAR T-cell therapy. However, the clinical use of native IL-15 is challenging because of its unfavorable pharmacokinetic (PK) and toxicity. NKTR-255 is a polymer-conjugated IL-15 that engages the entire IL-15 receptor complex (IL-15Rα/IL-2Rβγ) and exhibits reduced clearance, providing sustained pharmacodynamic (PD) responses. We investigated the PK and immune cell PDs in nonhuman primates treated with NKTR-255 and found that NKTR-255 enhanced the in vivo proliferation of T cells and natural killer cells. In vitro, NKTR-255 induced dose-dependent proliferation and accumulation of human CD19 CAR T cells, especially at low target cell abundance. In vivo studies in lymphoma-bearing immunodeficient mice demonstrated enhanced antitumor efficacy of human CD19 CAR T cells. In contrast to mice treated with CAR T cells alone, those that received CAR T cells and NKTR-255 had markedly higher CAR T-cell counts in the blood and marrow that were sustained after tumor clearance, without evidence of persistent proliferation or ongoing activation/exhaustion as assessed by Ki-67 and inhibitory receptor coexpression. These data support an ongoing phase 1 clinical trial of combined therapy with CD19 CAR T cells and NKTR-255 for R/R B-cell malignancies., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

The therapeutic potential of recombinant cytokines has been limited by the severe side effects of systemic administration. We describe a strategy to reduce the dose-limiting toxicities of monomeric cytokines by designing two components that require colocalization for activity and that can be independently targeted to restrict activity to cells expressing two surface markers. We demonstrate the approach with a previously designed mimetic of cytokines interleukin-2 and interleukin-15-Neoleukin-2/15 (Neo-2/15)-both for trans-activating immune cells surrounding targeted tumor cells and for cis-activating directly targeted immune cells. In trans-activation mode, tumor antigen targeting of the two components enhanced antitumor activity and attenuated toxicity compared with systemic treatment in syngeneic mouse melanoma models. In cis-activation mode, immune cell targeting of the two components selectively expanded CD8 +  T cells in a syngeneic mouse melanoma model and promoted chimeric antigen receptor T cell activation in a lymphoma xenograft model, enhancing antitumor efficacy in both cases., (© 2022. The Author(s).)

Therapies with genetically modified T cells that express chimeric antigen receptors (CARs) specific for CD19 or B cell maturation antigen (BCMA) are approved to treat certain B cell malignancies. However, translating these successes into treatments for patients with solid tumours presents various challenges, including the risk of clinically serious on-target, off-tumour toxicity (OTOT) owing to CAR T cell-mediated cytotoxicity against non-malignant tissues expressing the target antigen. Indeed, severe OTOT has been observed in various CAR T cell clinical trials involving patients with solid tumours, highlighting the importance of establishing strategies to predict, mitigate and control the onset of this effect. In this Review, we summarize current clinical evidence of OTOT with CAR T cells in the treatment of solid tumours and discuss the utility of preclinical mouse models in predicting clinical OTOT. We then describe novel strategies being developed to improve the specificity of CAR T cells in solid tumours, particularly the role of affinity tuning of target binders, logic circuits and synthetic biology. Furthermore, we highlight control strategies that can be used to mitigate clinical OTOT following cell infusion such as regulating or eliminating CAR T cell activity, exogenous control of CAR expression, and local administration of CAR T cells., (© 2022. Springer Nature Limited.)

Adoptive transfer of T cells expressing chimeric antigen receptors (CAR-T) effectively treats refractory hematologic malignancies in a subset of patients but can be limited by poor T-cell expansion and persistence in vivo. Less differentiated T-cell states correlate with the capacity of CAR-T to proliferate and mediate antitumor responses, and interventions that limit tumor-specific T-cell differentiation during ex vivo manufacturing enhance efficacy. NOTCH signaling is involved in fate decisions across diverse cell lineages and in memory CD8+ T cells was reported to upregulate the transcription factor FOXM1, attenuate differentiation, and enhance proliferation and antitumor efficacy in vivo. Here, we used a cell-free culture system to provide an agonistic NOTCH1 signal during naïve CD4+ T-cell activation and CAR-T production and studied the effects on differentiation, transcription factor expression, cytokine production, and responses to tumor. NOTCH1 agonism efficiently induced a stem cell memory phenotype in CAR-T derived from naïve but not memory CD4+ T cells and upregulated expression of AhR and c-MAF, driving heightened production of interleukin-22, interleukin-10, and granzyme B. NOTCH1-agonized CD4+ CAR-T demonstrated enhanced antigen responsiveness and proliferated to strikingly higher frequencies in mice bearing human lymphoma xenografts. NOTCH1-agonized CD4+ CAR-T also provided superior help to cotransferred CD8+ CAR-T, driving improved expansion and curative antitumor responses in vivo at low CAR-T doses. Our data expand the mechanisms by which NOTCH can shape CD4+ T-cell behavior and demonstrate that activating NOTCH1 signaling during genetic modification ex vivo is a potential strategy for enhancing the function of T cells engineered with tumor-targeting receptors., (© 2022 by The American Society of Hematology.)

The CBFA2T3-GLIS2 (C/G) fusion is a product of a cryptic translocation primarily seen in infants and early childhood and is associated with dismal outcome. Here, we demonstrate that the expression of the C/G oncogenic fusion protein promotes the transformation of human cord blood hematopoietic stem and progenitor cells (CB HSPCs) in an endothelial cell coculture system that recapitulates the transcriptome, morphology, and immunophenotype of C/G acute myeloid leukemia (AML) and induces highly aggressive leukemia in xenograft models. Interrogating the transcriptome of C/G-CB cells and primary C/G AML identified a library of C/G-fusion-specific genes that are potential targets for therapy. We developed chimeric antigen receptor (CAR) T cells directed against one of the targets, folate receptor α (FOLR1), and demonstrated their preclinical efficacy against C/G AML using in vitro and xenograft models. FOLR1 is also expressed in renal and pulmonary epithelium, raising concerns for toxicity that must be addressed for the clinical application of this therapy. Our findings underscore the role of the endothelial niche in promoting leukemic transformation of C/G-transduced CB HSPCs. Furthermore, this work has broad implications for studies of leukemogenesis applicable to a variety of oncogenic fusion-driven pediatric leukemias, providing a robust and tractable model system to characterize the molecular mechanisms of leukemogenesis and identify biomarkers for disease diagnosis and targets for therapy.

Activation of a conditional safety switch has the potential to reverse serious toxicities arising from the administration of engineered cellular therapies, including chimeric antigen receptor (CAR) T cells. The functionally inert, non-immunogenic cell surface marker derived from human epidermal growth factor receptor (EGFRt) is a promising safety switch that has been used in multiple clinical constructs and can be targeted by cetuximab, a clinically available monoclonal antibody. However, this approach requires high and persistent cell surface expression of EGFRt to ensure that antibody-mediated depletion of engineered cells is rapid and complete. Here we show that incorporating a short juxtamembrane sequence into the EGFRt polypeptide enhances its expression on the surface of T cells and their susceptibility to antibody-dependent cellular cytotoxicity (ADCC). Incorporating this optimized variant (EGFRopt) into bicistronic and tricistronic CAR designs results in more rapid in vivo elimination of CAR T cells and robust termination of their effector activity compared to EGFRt. These studies establish EGFRopt as a superior safety switch for the development of next-generation cell-based therapeutics., Competing Interests: SR is a co-founder of Lyell Immunopharma, Inc. and has received grant funding from Lyell Immunopharma,Inc. SR was a cofounder Juno Therapeutics, a Bristol Myers Squibb company and has served as a scientific advisor to Juno Therapeutics and Adaptive Biotechnologies. SP is an employee of Lyell Immunopharma, Inc. ML is a co-founder of Lyell Immunopharma, Inc., and Outpace Bio. HM andML are listed as inventors on patent applications related to this work.HM, LT, andMLare employees of Outpace Bio, a licensee of patent rights owned by Lyell Immunopharma, Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Shabaneh, Moffett, Stull, Derezes, Tait, Park, Riddell and Lajoie.)

Fn14 is a cell surface receptor with key functions in tissue homeostasis and injury but is also linked to chronic diseases. Despite its physiological and medical importance, the regulation of Fn14 signaling and turnover is only partly understood. Here, we demonstrate that Fn14 is cleaved within its transmembrane domain by the protease γ-secretase, resulting in secretion of the soluble Fn14 ectodomain (sFn14). Inhibition of γ-secretase in tumor cells reduced sFn14 secretion, increased full-length Fn14 at the cell surface, and enhanced TWEAK ligand-stimulated Fn14 signaling through the NFκB pathway, which led to enhanced release of the cytokine tumor necrosis factor. γ-Secretase-dependent sFn14 release was also detected ex vivo in primary tumor cells from glioblastoma patients, in mouse and human plasma and was strongly reduced in blood from human cancer patients dosed with a γ-secretase inhibitor prior to chimeric antigen receptor (CAR)-T-cell treatment. Taken together, our study demonstrates a novel function for γ-secretase in attenuating TWEAK/Fn14 signaling and suggests the use of sFn14 as an easily measurable pharmacodynamic biomarker to monitor γ-secretase activity in vivo., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)

Immune checkpoint blockade is effective in treating many human cancers. In this issue of Cell, Luoma et al. show that tissue-resident memory T cells in head and neck cancers rapidly respond to immune checkpoint blockade, and they identify specific CD8 + T cells in pretreatment blood that predict pathologic tumor regression., Competing Interests: Declaration of interests S.R.R. is a founder and shareholder of Lyell Immunopharma and serves as an advisor to Lyell Immunopharma and Adaptive Biotechnologies. J.R.V. and S.R.R. have received research funding and have intellectual property licensed to Lyell Immunopharma. J.R.V. and S.R.R. have received research support from Bristol Myers Squibb., (Copyright © 2022 Elsevier Inc. All rights reserved.)

One obstacle for human solid tumor immunotherapy research is the lack of clinically relevant animal models. In this study, we sought to establish a chimeric antigen receptor (CAR) T-cell treatment model for naturally occurring canine sarcomas as a model for human CAR T-cell therapy. Canine CARs specific for B7-H3 were constructed using a single-chain variable fragment derived from the human B7-H3-specific antibody MGA271, which we confirmed to be cross-reactive with canine B7-H3. After refining activation, transduction, and expansion methods, we confirmed target killing in a tumor spheroid three-dimensional assay. We designed a B7-H3 canine CAR T-cell and achieved consistently high levels of transduction efficacy, expansion, and in vitro tumor killing. Safety of the CAR T cells were confirmed in two purposely bred healthy canine subjects following lymphodepletion by cyclophosphamide and fludarabine. Immune response, clinical parameters, and manifestation were closely monitored after treatments and were shown to resemble that of humans. No severe adverse events were observed. In summary, we demonstrated that similar to human cancers, B7-H3 can serve as a target for canine solid tumors. We successfully generated highly functional canine B7-H3-specific CAR T-cell products using a production protocol that closely models human CAR T-cell production procedure. The treatment regimen that we designed was confirmed to be safe in vivo. Our research provides a promising direction to establish in vitro and in vivo models for immunotherapy for canine and human solid tumor treatment., (©2022 The Authors; Published by the American Association for Cancer Research.)

Chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA-CARTx) is an emerging treatment for relapsed or refractory multiple myeloma (R/R MM). Here we characterize the epidemiology of infections, risk factors for infection, and pathogen-specific humoral immunity in patients receiving BCMA-CARTx for R/R MM. We performed a retrospective cohort study in 32 adults with R/R MM enrolled in 2 single-institution phase 1 clinical trials of BCMA-CARTx administered after lymphodepleting chemotherapy alone (n = 22) or with a gamma secretase inhibitor (GSI). We tested serum before and up to approximately 180 days after BCMA-CARTx for measles-specific IgG and for any viral-specific IgG using a systematic viral epitope scanning assay to describe the kinetics of total and pathogen-specific IgG levels pre- and post-BCMA-CARTx. We identified microbiologically documented infections to determine infection incidence and used Poisson regression to explore risk factors for infections within 180 days after BCMA-CARTx. Most individuals developed severe neutropenia, lymphopenia, and hypogammaglobulinemia after BCMA-CARTx. Grade ≥3 cytokine release syndrome (CRS; Lee criteria) occurred in 16% of the participants; 50% of the participants received corticosteroids and/or tocilizumab. Before BCMA-CARTx, 28 of 32 participants (88%) had an IgG <400 mg/dL, and only 5 of 27 (19%) had seropositive measles antibody titers. After BCMA-CARTx, all participants had an IgG <400 mg/dL and declining measles antibody titers; of the 5 individuals with baseline seropositive levels, 2 remained above the seroprotective threshold post-treatment. Participants with IgG MM (n = 13) had significantly fewer antibodies to a panel of viral antigens compared with participants with non-IgG MM (n = 6), both before and after BCMA-CARTx. In the first 180 days after BCMA-CARTx, 17 participants (53%) developed a total of 23 infections, of which 13 (57%) were mild-to-moderate viral infections. Serious infections were more frequent in the first 28 days post-treatment. Infections appeared to be more common in individuals with higher-grade CRS. Individuals with R/R MM have substantial deficits in humoral immunity. These data demonstrate the importance of plasma cells in maintaining long-lived pathogen-specific antibodies and suggest that BCMA-CARTx recipients need ongoing surveillance for late-onset infections. Most infections were mild-moderate severity viral infections. The incidence of early infection appears to be lower than has been reported after CD19-directed CARTx for B cell neoplasms, possibly due to differences in patient and disease characteristics and regimen-related toxicities., (Copyright © 2022 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

CAR T cells are remarkably effective in hematologic malignancies, but tumor cells expressing low antigen levels can escape elimination. In Nature Medicine, Mansilla-Soto et al. design new chimeric receptors that link the variable regions of antibodies directly to T cell receptor chains and recognize tumor cells with improved antigen sensitivity., Competing Interests: Declaration of interests S.R.R. is a founder of Juno Therapeutics, now Juno/Bristol Myers Squibb, and a founder of and advisor to Lyell Immunopharma. S.R.R. has patents related to the field of chimeric antigen receptor-modified T cells and their use in immunotherapy., (Copyright © 2022 Elsevier Inc. All rights reserved.)

CD4 + T cells that recognize tumor antigens are required for immune checkpoint inhibitor efficacy in murine models, but their contributions in human cancer are unclear. We used single-cell RNA sequencing and T cell receptor sequences to identify signatures and functional correlates of tumor-specific CD4 + T cells infiltrating human melanoma. Conventional CD4 + T cells that recognize tumor neoantigens express CXCL13 and are subdivided into clusters expressing memory and T follicular helper markers, and those expressing cytolytic markers, inhibitory receptors, and IFN-γ. The frequency of CXCL13 + CD4 + T cells in the tumor correlated with the transcriptional states of CD8 + T cells and macrophages, maturation of B cells, and patient survival. Similar correlations were observed in a breast cancer cohort. These results identify phenotypes and functional correlates of tumor-specific CD4 + T cells in melanoma and suggest the possibility of using such cells to modify the tumor microenvironment., Competing Interests: Declaration of interests S.R.R. is a co-founder of Lyell Immunopharma. J.R.V and S.R.R. have received grant funding and have intellectual property licensed to Lyell Immunopharma. J.R.V. and A.M.H. have received research support from Bristol Myers Squibb. R.G. has received consulting income from Illumina and declares ownership in Ozette Technologies, Modulus Therapeutics, and minor stock ownerships in 10X Genomics., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Graft-versus-host disease (GVHD) causes morbidity and mortality following allogeneic hematopoietic cell transplantation. Naive T cells (T N ) cause severe GVHD in murine models. We evaluated chronic GVHD (cGVHD) and other outcomes in three phase II clinical trials of T N -depletion of peripheral blood stem-cell (PBSC) grafts., Methods: One hundred thirty-eight patients with acute leukemia received T N -depleted PBSC from HLA-matched related or unrelated donors following conditioning with high- or intermediate-dose total-body irradiation and chemotherapy. GVHD prophylaxis was with tacrolimus, with or without methotrexate or mycophenolate mofetil. Subjects received CD34-selected PBSC and a defined dose of memory T cells depleted of T N . Median follow-up was 4 years. The primary outcome of the analysis of cumulative data from the three trials was cGVHD., Results: cGVHD was very infrequent and mild (3-year cumulative incidence total, 7% [95% CI, 2 to 11]; moderate, 1% [95% CI, 0 to 2]; severe, 0%). Grade III and IV acute GVHD (aGVHD) occurred in 4% (95% CI, 1 to 8) and 0%, respectively. The cumulative incidence of grade II aGVHD, which was mostly stage 1 upper gastrointestinal GVHD, was 71% (95% CI, 64 to 79). Recipients of matched related donor and matched unrelated donor grafts had similar rates of grade III aGVHD (5% [95% CI, 0 to 9] and 4% [95% CI, 0 to 9]) and cGVHD (7% [95% CI, 2 to 13] and 6% [95% CI, 0 to 12]). Overall survival, cGVHD-free, relapse-free survival, relapse, and nonrelapse mortality were, respectively, 77% (95% CI, 71 to 85), 68% (95% CI, 61 to 76), 23% (95% CI, 16 to 30), and 8% (95% CI, 3 to 13) at 3 years., Conclusion: Depletion of T N from PBSC allografts results in very low incidences of severe acute and any cGVHD, without apparent excess risks of relapse or nonrelapse mortality, distinguishing this novel graft engineering strategy from other hematopoietic cell transplantation approaches., Competing Interests: Marie BleakleyStock and Other Ownership Interests: HighPass BioConsulting or Advisory Role: HighPass Bio, Orca BioResearch Funding: HighPass BioPatents, Royalties, Other Intellectual Property: TCRs specific for minor histocompatibility antigen HA-1 and uses thereof US20190211076A1 and international. Patent issued January 21, 2020. US10,538,574. Inventor on patent. Held by Fred Hutchinson Cancer Research CenterOther Relationship: Miltenyi Biotec Alison SehgalSpeakers' Bureau: OncLiveResearch Funding: Kite/Gilead, Juno Therapeutics Melinda A. BiernackiEmployment: Outpace Bio (I), Lyell Immunopharma (I)Stock and Other Ownership Interests: Lyell Immunopharma (I), Outpace Bio (I)Patents, Royalties, Other Intellectual Property: My partner receives royalties from a patent held by the Fred Hutchinson Cancer Research Center pertaining to nanomaterials for mRNA delivery. There is no relationship between the research in the current publication and the technology in the patent (I) Elizabeth F. KrakowResearch Funding: HighPass Bio (Inst) Ann DahlbergResearch Funding: Jazz Pharmaceuticals, Atara Biotherapeutics Paul J. MartinStock and Other Ownership Interests: Procter & GambleHonoraria: Janssen/Pharmacyclics, TherakosConsulting or Advisory Role: Pfizer, Mesoblast, Rigel, Talaris, MalinckrodtResearch Funding: AltruBio (Inst) Paul A. CarpenterHonoraria: Johnson and Johnson CorporationConsulting or Advisory Role: Janssen Scientific AffairsResearch Funding: Pharmacyclics, Janssen, Incyte Mary E. FlowersHonoraria: Astellas Pharma, MallinckrodtResearch Funding: Pharmacyclics, Incyte Theodore A. GooleyConsulting or Advisory Role: Kiadis Pharma, Pharmacyclics, Regimmune Brent L. WoodHonoraria: Amgen, Seattle Genetics, AbbVie, Janssen, Amgen, Astellas Pharma, Roche Diagnostics, Beckman CoulterConsulting or Advisory Role: SysmexResearch Funding: Amgen (Inst), Seattle Genetics (Inst), Pfizer (Inst), Juno Therapeutics (Inst), BiolineRx (Inst), Biosight (Inst), Stemline Therapeutics (Inst), Janssen Oncology (Inst), Novartis, Kite, a Gilead Company (Inst), Macrogenics (Inst)Travel, Accommodations, Expenses: Amgen Stanley R. RiddellEmployment: Lyell ImmunopharmaLeadership: Lyell ImmunopharmaStock and Other Ownership Interests: Lyell Immunopharma (Inst), Adaptive BiotechnologiesConsulting or Advisory Role: Lyell ImmunopharmaResearch Funding: Lyell ImmunopharmaPatents, Royalties, Other Intellectual Property: Patents, licensing fees, and royalties from Bristol Myers Squibb, Lyell, and Deverra. Patents, licensing fees, and royalties from Bristol Myers Squibb, Lyell, and Deverra (Inst) Warren D. ShlomchikEmployment: Bluesphere BioStock and Other Ownership Interests: Bluesphere BioConsulting or Advisory Role: Bluesphere BioResearch Funding: Bluesphere BioPatents, Royalties, Other Intellectual Property: T-cell receptorsNo other potential conflicts of interest were reported.

Adoptive cell therapy with T cells engineered with customized receptors that redirect antigen specificity to cancer cells has emerged as an effective therapeutic approach for many malignancies. Toxicity due to on target or off target effects, antigen heterogeneity on cancer cells, and acquired T cell dysfunction have been identified as barriers that can hinder successful therapy. This review will discuss recent advances in T cell engineering that have enabled the application of logic gates in T cells that can mimic the integration of natural signaling pathways and act in a cell intrinsic or extrinsic fashion to precisely target tumor cells and regulate effector functions, potentially overcoming these barriers to effective therapy., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Chimeric antigen receptor (CAR)-modified T cell therapy is effective in treating lymphomas, leukemias, and multiple myeloma in which the tumor cells express high amounts of target antigen. However, achieving durable remission for these hematological malignancies and extending CAR T cell therapy to patients with solid tumors will require receptors that can recognize and eliminate tumor cells with a low density of target antigen. Although CARs were designed to mimic T cell receptor (TCR) signaling, TCRs are at least 100-fold more sensitive to antigen. To design a CAR with improved antigen sensitivity, we directly compared TCR and CAR signaling in primary human T cells. Global phosphoproteomic analysis revealed that key T cell signaling proteins-such as CD3δ, CD3ε, and CD3γ, which comprise a portion of the T cell co-receptor, as well as the TCR adaptor protein LAT-were either not phosphorylated or were only weakly phosphorylated by CAR stimulation. Modifying a commonplace 4-1BB/CD3ζ CAR sequence to better engage CD3ε and LAT using embedded CD3ε or GRB2 domains resulted in enhanced T cell activation in vitro in settings of a low density of antigen, and improved efficacy in in vivo models of lymphoma, leukemia, and breast cancer. These CARs represent examples of alterations in receptor design that were guided by in-depth interrogation of T cell signaling., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Therapeutic vaccines that augment T cell responses to tumor antigens have been limited by poor potency in clinical trials. In contrast, the transfer of T cells modified with foreign transgenes frequently induces potent endogenous T cell responses to epitopes in the transgene product, and these responses are undesirable, because they lead to rejection of the transferred T cells. We sought to harness gene-modified T cells as a vaccine platform and developed cancer vaccines composed of autologous T cells modified with tumor antigens and additional adjuvant signals (Tvax). T cells expressing model antigens and a broad range of tumor neoantigens induced robust and durable T cell responses through cross-presentation of antigens by host DCs. Providing Tvax with signals such as CD80, CD137L, IFN-β, IL-12, GM-CSF, and FLT3L enhanced T cell priming. Coexpression of IL-12 and GM-CSF induced the strongest CD4+ and CD8+ T cell responses through complimentary effects on the recruitment and activation of DCs, mediated by autocrine IL-12 receptor signaling in the Tvax. Therapeutic vaccination with Tvax and adjuvants showed antitumor activity in subcutaneous and metastatic preclinical mouse models. Human T cells modified with neoantigens readily activated specific T cells derived from patients, providing a path for clinical translation of this therapeutic platform in cancer.

Background: Synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are ideal solid tumors for the development of adoptive cellular therapy (ACT) targeting NY-ESO-1, as a high frequency of tumors homogeneously express this cancer-testes antigen. Data from early phase clinical trials have shown antitumor activity after the adoptive transfer of NY-ESO-1-specific T cells. In these studies, persistence of NY-ESO-1 specific T cells is highly correlated with response to ACT, but patients often continue to have detectable transferred cells in their peripheral blood following progression., Method: We performed a phase I clinical trial evaluating the safety of NY-ESO-1-specific endogenous T cells (ETC) following cyclophosphamide conditioning. Peripheral blood mononuclear cells (PBMCs) from treated patients were evaluated by flow cytometry and gene expression analysis as well as through ex vivo culture assays with and without IL-15., Results: Four patients were treated in a cohort using ETC targeting NY-ESO-1 following cyclophosphamide conditioning. Treatment was well tolerated without significant toxicity, but all patients ultimately had disease progression. In two of four patients, we obtained post-treatment tumor tissue and in both, NY-ESO-1 antigen was retained despite clear detectable persisting NY-ESO-1-specific T cells in the peripheral blood. Despite a memory phenotype, these persisting cells lacked markers of proliferation or activation. However, in ex vivo culture assays, they could be induced to proliferate and kill tumor using IL-15. These results were also seen in PBMCs from two patients who received gene-engineered T-cell receptor-based products at other centers., Conclusions: ETC targeting NY-ESO-1 with single-agent cyclophosphamide alone conditioning was well tolerated in patients with SS and those with MRCL. IL-15 can induce proliferation and activity in persisting NY-ESO-1-specific T cells even in patients with disease progression following ACT. These results support future work evaluating whether IL-15 could be incorporated into ACT trials post-infusion or at the time of progression., Competing Interests: Competing interests: SMP receives research funding from Merck, EMD Serono, Incyte, Presage, Janssen, Oncosec and Juno. He has consulting, honoraria and advisory activity with GlaxoSmith Kline, Daiichi Sankyo and Blueprint Medicine. SRR has received equity, consulting fees and research funding from Juno Therapeutics/a BMS company and Lyell Immunopharma. He has received consulting fees and equity from Adaptive Biotechnologies.VGP receives research funding from Merck, AstraZeneca, and Ipsen. He has had consulting, honoraria and advisory activity with Merck, GlaxoSmithKline, Imvax, and Takeda. VGP receives research funding from Merck, AstraZeneca, and Ipsen. He has had consulting, honoraria and advisory activity with Merck, GlaxoSmithKline, Imvax, and Takeda.GlaxoSmithKline, Imvax, and Takeda., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)