Hyperleukocytosis in a neuroblastoma patient after treatment with natural killer T cells expressing a GD2-specific chimeric antigen receptor and IL15
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ABSTRACT: The ability of immune cells to expand numerically after infusion distinguishes adoptive immunotherapies from traditional drugs, providing unique therapeutic advantages as well as the potential for unmanageable toxicities. Here, we describe a case of lethal hyperleukocytosis in a patient with neuroblastoma treated on a phase 1 clinical trial (NCT03294954) with autologous natural killer T cells (NKTs) expressing a GD2-specific chimeric antigen receptor and cytokine IL15 (GD2-CAR.15). This patient was the first to be treated on dose level (DL) 5 and the first patient whose product was restimulated with K562-derived artificial antigen-presenting cells (aAPCs) instead of autologous peripheral blood mononuclear cells (PBMCs). Twelve previously treated patients on DLs 1 through 4 did not experience significant toxicity. Our root-cause analysis revealed no genetic alterations of known clinical significance and excluded the possibility of clonal expansion due to insertional retroviral mutagenesis. The use of aAPCs instead of PBMCs for CAR-NKT restimulation induced a hyperproliferative state associated with a distinct gene expression profile that likely contributed to an explosive lymphocyte expansion event and uncontrolled toxicity in the patient. These findings warrant the implementation of measures to control immune cell activation during manufacture of cell therapy products.
Project description:Vα24-invariant natural killer T cells (NKTs) have antitumor properties that can be enhanced by transgenic expression of tumor-specific receptors. Here, we report the results of the first-in-human clinical evaluation of autologous NKTs co-expressing a GD2-specific chimeric antigen receptor with interleukin (IL)15 (GD2-CAR.15) in 12 children with neuroblastoma (NB) treated on four dose levels (NCT03294954). Objectives included assessing safety, antitumor activity, and immune response. No dose-limiting toxicities occurred, and one patient had grade 2 cytokine release syndrome resolved by tocilizumab. The overall response rate was 25% (3/12) and disease control rate was 58% (7/12) including four patients with stable disease, two partial responses, and one complete response. CD62L+ NKT frequency in infused products correlated with CAR-NKT expansion in patients and was higher in responders than non-responders (71% vs 35.3%, p=0.002). Singe-cell RNA sequencing analysis identified B cell translocation gene 1 (BTG1) as one of the top upregulated genes in GD2-CAR.15-NKTs after in vitro serial tumor challenge. Genetic gain- and loss-of-function experiments revealed that BTG1 is a key driver of hyporesponsiveness in exhausted NKT and T cells. Crucially, NKTs co-expressing GD2-CAR.15 and BTG1-specific shRNA eradicated metastatic NB in mice. These results indicate that CAR-NKTs are safe, produce objective responses in NB patients, and that targeting BTG1 can enhance their therapeutic potency.
Project description:Vα24-invariant natural killer T cells (NKTs) have antitumor properties that can be enhanced by transgenic expression of tumor-specific receptors. Here, we report the results of the first-in-human clinical evaluation of autologous NKTs co-expressing a GD2-specific chimeric antigen receptor with interleukin (IL)15 (GD2-CAR.15) in 12 children with neuroblastoma (NB) treated on four dose levels (NCT03294954). Objectives included assessing safety, antitumor activity, and immune response. No dose-limiting toxicities occurred, and one patient had grade 2 cytokine release syndrome resolved by tocilizumab. The overall response rate was 25% (3/12) and disease control rate was 58% (7/12) including four patients with stable disease, two partial responses, and one complete response. CD62L+ NKT frequency in infused products correlated with CAR-NKT expansion in patients and was higher in responders than non-responders (71% vs 35.3%, p=0.002). Singe-cell RNA sequencing analysis identified B cell translocation gene 1 (BTG1) as one of the top upregulated genes in GD2-CAR.15-NKTs after in vitro serial tumor challenge. Genetic gain- and loss-of-function experiments revealed that BTG1 is a key driver of hyporesponsiveness in exhausted NKT and T cells. Crucially, NKTs co-expressing GD2-CAR.15 and BTG1-specific shRNA eradicated metastatic NB in mice. These results indicate that CAR-NKTs are safe, produce objective responses in NB patients, and that targeting BTG1 can enhance their therapeutic potency.
Project description:Despite remarkable progress in B cell malignancies, T cells expressing chimeric antigen receptors (CARs) remain ineffective in solid tumors in part because T cells do not traffic effectively to or survive in tumor tissues. We engineered Vα24-invariant natural killer T cells (NKTs), which intrinsically home to tumor sites, to co-express a GD2-specific CAR with interleukin (IL)15 and evaluated their therapeutic efficacy in children with relapsed/resistant neuroblastoma (NB)(NCT03294954). The first three patients received a single infusion of 3x10e6 autologous CAR-NKTs per square meter of body surface area and tolerated the treatment well. CAR-NKTs expanded in vivo, localized to the tumor, and in one patient induced a near-complete regression of bone metastatic lesions.
Project description:Vα24-invariant natural killer T cells (NKTs) possess innate antitumor properties that can be exploited for cancer immunotherapy. We have shown that the CD62L+ central memory-like subset drives NKT in vivo anti-tumor activity, but molecular mediators of NKT central memory differentiation remain unknown. Here, we demonstrate that CD62L+ NKTs express Wnt/β-catenin transcription factor LEF1 and maintain active Wnt/β-catenin signaling. CRISPR/Cas9-mediated LEF1 knockout reduced CD62L+ frequency after antigenic stimulation, while Wnt/β-catenin activator Wnt3a ligand increased CD62L+ frequency. LEF1 overexpression promoted NKT expansion and limited exhaustion following serial tumor challenge and was sufficient to induce a central memory-like transcriptional program in NKTs. In mice, NKTs expressing a GD2-specific chimeric antigen receptor (CAR) with LEF1 demonstrated superior control of neuroblastoma xenograft tumors compared to CAR-NKTs. These results identify LEF1 as a transcriptional activator of the NKT central memory program and advance development of NKT cell-based immunotherapy.
Project description:Diffuse intrinsic pontine glioma (DIPG) and other H3K27M-mutated diffuse midline gliomas (DMGs) are universally lethal central nervous system (CNS) tumors that occur most commonly in children and young adults1. Average life expectancy is ten months from diagnosis, and 5-year survival is less than 1%2. Palliative radiotherapy is the only established treatment3, and neither cytotoxic nor targeted pharmacological approaches have demonstrated anti-tumor responses or improved prognosis to date3,4. We previously discovered that the disialoganglioside GD2 is highly and uniformly expressed on H3K27M+ DMG cells and demonstrated that intravenously (IV) administered GD2.4-1BB.z chimeric antigen receptor (CAR) T-cells eradicated established DMGs in patient-derived orthotopic murine models5, thereby providing the rationale for a first-in-human/first-in-child Phase 1 clinical trial (NCT04196413). Because CAR T-cell-induced inflammation and edema of the brainstem can result in obstructive hydrocephalus, increased intracranial pressure, and dangerous tissue shifts, a number of neurocritical care precautions were incorporated in the clinical trial design and management plan. Here we present the clinical experience from the first four patients with H3K27M+ DMG treated with GD2-CAR T-cells at dose level 1 (DL1; 1e6 GD2-CAR T-cells/kg administered IV). Patients who exhibited clinical benefit were eligible for subsequent administrations of GD2-CAR T-cells. Given preclinical evidence for increased CAR T-cell potency6, and the potential for diminished immunogenicity with locoregional administration, second doses were administered intracerebroventricularly (ICV) through an Ommaya catheter to three patients. As predicted from preclinical models, toxicity was largely related to the neuroanatomical location of the tumors and was reversible with intensive supportive care. Although GD2 is expressed at low levels in normal neural tissue, no evidence of on-target, off-tumor toxicity was observed. Three of four patients exhibited clinical and radiographic improvement, underscoring the promise of this approach for H3K27M+ DMG therapy. Correlative studies of serum and CSF revealed marked proinflammatory cytokine production following GD2 CAR T cell administration and single cell transcriptomic analysis of 65,598 single cells from CAR T cell products and patient CSF has begun to reveal differences that correlate with the heterogeneity between subjects and routes of administration.
Project description:The purpose of the experiment was to compare the transcriptional profile of T-cells expressing a GD2-CAR construct or a GD2-CAR.C7R construct (where the GD2-CAR and the C7R construct are co-expressed), after the T-cells had been exposed to two serial tumor cell co-cultures. C7R is an engineered IL-7 receptor that has been rendered constitutively active. The sample replicates were generated using peripheral blood mononuclear cells (PBMCs) obtained from healthy human donors.
Project description:Chimeric antigen receptor-T (CAR-T) therapy remains to be investigated in T-cell malignancies. CD7 is an ideal target for T-cell malignancies but is also expressed on normal T cells, which may cause CAR-T cell fratricide. Donor-derived anti-CD7 CAR-T cells using endoplasmic reticulum retention have shown efficacy in patients with T-cell acute lymphoblastic leukemia (ALL). Here we launched a phase I trial to explore differences between autologous and allogeneic anti-CD7 CAR-T therapies in T-cell ALL and lymphoma. Ten patients were treated and 5 received autologous CAR-T therapies. No dose-limiting toxicity or neurotoxicity was observed. Grade 1-2 cytokine release syndrome occurred in 7 patients, and grade 3 in 1 patient. Grade 1-2 graft-versus-host diseases were observed in 2 patients. Seven patients had bone marrow infiltration, and 100% of them achieved complete remission with negative minimal residual disease within one month. Two-fifths of patients achieved extramedullary or extranodular remission. The median follow-up was 6 (range, 2.7- 14) months and bridging transplantation was not administrated. Patients treated with allogeneic CAR-T cells had higher remission rate, less recurrence and more durable CAR-T survival than those receiving autologous products. Allogeneic CAR-T cells appeared to be a better option for patients with T-cell malignancies.
Project description:Natural killer T cells (NKTs) are a promising platform for cancer immunotherapy, but few genes involved in regulation of NKT therapeutic activity have been identified. To discover regulators of NKT functional fitness, we developed a CRISPR/Cas9-based mutagenesis screen that employs a guide (g)RNA library targeting 1,118 immune-related genes. Unmodified NKTs and NKTs expressing a GD2-specific chimeric antigen receptor (CAR.NKTs) were transduced with the gRNA library and exposed to CD1d+/GD2- leukemia or CD1d-/GD2+ neuroblastoma cells, respectively, over six challenge cycles in vitro. Quantification of gRNA abundance revealed enrichment of PRDM1-specific gRNAs in both NKTs and CAR.NKTs, a result that was validated through targeted PRDM1 knockout. Transcriptional, phenotypic, and functional analyses demonstrated that CAR.NKTs with PRDM1 knockout undergo central memory-like differentiation and resist exhaustion while downregulating granzyme B and mediating reduced cytotoxicity in vitro and moderate antitumor activity in an in vivo xenogeneic neuroblastoma model. In contrast, shRNA-mediated knockdown of PRDM1 expression preserved CAR.NKT effector function while promoting central memory differentiation, resulting in CAR.NKTs with potent in vivo antitumor activity. Thus, we identified PRDM1 as a regulator of NKT memory differentiation and effector function that can be exploited to improve the efficacy of next-generation NKT-based cancer immunotherapy.
Project description:Purpose: To compare cell states between CD19-28z and GD2-28z human CAR T cells on day 10 of cell culture. Methods: Human T cells were activated and lentivirally transduced with CD19-28z or GD2-28z CAR constructs and maintained in culture for 10 days, and then delivered to the Stanford Functional Genomics Facility for 3' single-cell RNA-sequencing on the 10X Genomics platform. Results: Comparison of transcription factor profiles by single cell RNA-seq analysis of CD8+ T cells expressing CD19-28z vs. GD2-28z CAR confirmed that the bZIP family members JUN, JUNB, JUND, and ATF4 were among the most differentially expressed and broadly connected in exhausted GD2-28z CAR T cells. Conclusions: This study provides insights into cell states that could explain the underlying differences between highly functional CD19-28z CAR T cells and exhaustion-prone GD2-28z CAR T cells on day 10 in culture.
Project description:CAR-T cell therapy against MM currently shows promising results, but usually with serious toxicities. CAR-NK cells may exert less toxicity when redirected against resistant myeloma cells. CARs can be designed through the use of receptors, such as NKG2D, which recognizes a wide range of ligands to provide broad target specificity. Here, we test this approach by analyzing the anti-tumor activity of activated and expanded NK cells (NKAE) and CD45RA- T cells from MM patients that were engineered to express an NKG2D-based CAR. NKAE cells were cultured with irradiated Clone9.mbIL21 cells. Then, cells were transduced with an NKG2D-4-1BB-CD3z-CAR. CAR-NKAE cells exhibited no evidence of genetic abnormalities. Although memory T cells were more stably transduced, CAR-NKAE cells exhibited greater in vitro cytotoxicity against MM cells, while showing minimal activity against healthy cells. In vivo, CAR-NKAE cells mediated highly efficient abrogation of MM growth, and two of the treated mice remained disease-free. Overall, these results demonstrate that it is feasible to modify autologous NKAE cells from MM patients to safely express a NKG2D-CAR. Additionally, autologous CAR-NKAE cells display enhanced anti-myeloma activity demonstrating that they could be an effective strategy against MM supporting the development of NKG2D-CAR NK cell therapy for MM.