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Purpose: To study the biology and identify markers of severe cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) in children after chimeric antigen receptor T-cell (CAR T) treatment. Experimental Design: We used comprehensive proteomic profiling to measure over 1,400 serum proteins at multiple serial timepoints in a cohort of patients with B-cell acute lymphoblastic leukemia treated with the CD19-targeted CAR T CTL019 on two clinical trials. Results: We identified fms-like tyrosine kinase 3 (FLT3) and mast cell immunoglobulin-like receptor 1 (MILR1) as preinfusion predictive biomarkers of severe CRS. We demonstrated that CRS is an IFNγ-driven process with a protein signature overlapping with hemophagocytic lymphohistiocytosis (HLH). We identified IL18 as a potentially targetable cytokine associated with the development of ICANS. Conclusions: We identified preinfusion biomarkers that can be used to predict severe CRS with a sensitivity, specificity, and accuracy superior to the current gold standard of disease burden. We demonstrated the fundamental role of the IFNγ pathway in driving CRS, suggesting CRS and carHLH are overlapping rather than distinct phenomena, an observation with important treatment implications. We identified IL18 as a possible targetable cytokine in ICANS, providing rationale for IL18 blocking therapies to be translated into clinical trials in ICANS.

The success of chimeric antigen receptor (CAR)–mediated immunotherapy in acute lymphoblastic leukemia (ALL) highlights the potential of T-cell therapies with directed cytotoxicity against specific tumor antigens. The efficacy of CAR T-cell therapy depends on the engraftment and persistence of T cells following adoptive transfer. Most protocols for T-cell engineering routinely expand T cells ex vivo for 9 to 14 days. Because the potential for engraftment and persistence is related to the state of T-cell differentiation, we hypothesized that reducing the duration of ex vivo culture would limit differentiation and enhance the efficacy of CAR T-cell therapy. We demonstrated that T cells with a CAR-targeting CD19 (CART19) exhibited less differentiation and enhanced effector function in vitro when harvested from cultures at earlier (day 3 or 5) compared with later (day 9) timepoints. We then compared the therapeutic potential of early versus late harvested CART19 in a murine xenograft model of ALL and showed that the antileukemic activity inversely correlated with ex vivo culture time: day 3 harvested cells showed robust tumor control despite using a 6-fold lower dose of CART19, whereas day 9 cells failed to control leukemia at limited cell doses. We also demonstrated the feasibility of an abbreviated culture in a large-scale current good manufacturing practice–compliant process. Limiting the interval between T-cell isolation and CAR treatment is critical for patients with rapidly progressing disease. Generating CAR T cells in less time also improves potency, which is central to the effectiveness of these therapies. Cancer Immunol Res; 6(9); 1100–9. ©2018 AACR.

Fig. S1. CARTmeso cell manufacturing and treatment schedules. Fig. S2. Detection of human anti-chimeric antibody responses in patients post-CARTmeso cell infusion. Fig. S3. Serum cytokines and chemokines in PDA patient 21211-101. Fig. S4. CARTmeso cytolytic activity against allogeneic and autologous pancreatic cancer cell lines Table S1. Patient demographics. Table S2. Treatment-related adverse events. Table S3. Protoarray analysis of serum samples from mesothelioma patient 17510-105 Table S4. Protoarray analysis of serum samples from pancreatic cancer patient 21211-101

Supplemental Information and Legends

S3. Serial quantification of serum IL6 from a patient with prolonged subjectove myalgia post IT injection of mRNA c-Met CAR T cells.

S1. Clinical trial schema. S2. Representative immunohistochemistry (IHC). S3. Histology and IHC of tumor tissue pre and post intratumoral injection of RNA CAR T c- Met from one patient. S4. Histology and IHC of tumor tissue pre and post intratumoral injection with lidocaine (1 mL) and RNA CAR T c-Met (1 mL) from another patient. S5. Characterization of CD68+ tumor infiltrated immune cells using multiplex IHC analyses as described (1) in pre and post IT injection of RNA CAR T c-Met tumor tissue sections from two patients.

Chimeric antigen receptors (CAR) are synthetic molecules that provide new specificities to T cells. Although successful in treatment of hematologic malignancies, CAR T cells are ineffective for solid tumors to date. We found that the cell-surface molecule c-Met was expressed in ∼50% of breast tumors, prompting the construction of a CAR T cell specific for c-Met, which halted tumor growth in immune-incompetent mice with tumor xenografts. We then evaluated the safety and feasibility of treating metastatic breast cancer with intratumoral administration of mRNA-transfected c-Met-CAR T cells in a phase 0 clinical trial (NCT01837602). Introducing the CAR construct via mRNA ensured safety by limiting the nontumor cell effects (on-target/off-tumor) of targeting c-Met. Patients with metastatic breast cancer with accessible cutaneous or lymph node metastases received a single intratumoral injection of 3 × 107 or 3 × 108 cells. CAR T mRNA was detectable in peripheral blood and in the injected tumor tissues after intratumoral injection in 2 and 4 patients, respectively. mRNA c-Met-CAR T cell injections were well tolerated, as none of the patients had study drug–related adverse effects greater than grade 1. Tumors treated with intratumoral injected mRNA c-Met-CAR T cells were excised and analyzed by immunohistochemistry, revealing extensive tumor necrosis at the injection site, cellular debris, loss of c-Met immunoreactivity, all surrounded by macrophages at the leading edges and within necrotic zones. We conclude that intratumoral injections of mRNA c-Met-CAR T cells are well tolerated and evoke an inflammatory response within tumors. Cancer Immunol Res; 5(12); 1152–61. ©2017 AACR.

Off-target toxicity due to the expression of target antigens in normal tissue represents a major obstacle to the use of chimeric antigen receptor (CAR)-engineered T cells for treatment of solid malignancies. To circumvent this issue, we established a clinical platform for engineering T cells with transient CAR expression by using in vitro transcribed mRNA encoding a CAR that includes both the CD3-ζ and 4-1BB costimulatory domains. We present two case reports from ongoing trials indicating that adoptive transfer of mRNA CAR T cells that target mesothelin (CARTmeso cells) is feasible and safe without overt evidence of off-tumor on-target toxicity against normal tissues. CARTmeso cells persisted transiently within the peripheral blood after intravenous administration and migrated to primary and metastatic tumor sites. Clinical and laboratory evidence of antitumor activity was shown in both patients, and the CARTmeso cells elicited an antitumor immune response revealed by the development of novel antiself antibodies. These data show the potential of using mRNA-engineered T cells to evaluate, in a controlled manner, potential off-tumor on-target toxicities and show that short-lived CAR T cells can induce epitope spreading and mediate antitumor activity in patients with advanced cancer. Thus, these findings support the development of mRNA CAR-based strategies for carcinoma and other solid tumors. Cancer Immunol Res; 2(2); 112–20. ©2013 AACR.

Supplementary methods, statistical methods, results, tables, and figures. Supplementary Table 1. CRS grading system. Supplementary Table 2. Samples collected and time points on the trials. Supplementary Table 3. HLH diagnostic criteria. Supplementary Table 4. Timing of severe CRS relative to CRS onset and time from infusion. Supplementary Table 5. Patient demographics and baseline characteristics. Supplementary Table 6. Co-morbid infections. Supplementary Table 7. Median (range) for baseline cytokine values comparing normal subjects and total study population, children on the trials, and adults on the trials. Supplementary Table 8. Median (range) baseline cytokine values comparing baseline disease burden. Supplementary Table 9. Median (range) one-month peak cytokine values in children and adults comparing CRS grades (0-3 vs 4-5). Supplementary Table 10. Time points of target cytokine assessment listed as day since CTL019 infusion, with the acceptable windows provided by the study protocols. Supplementary Table 11. Median (range) day 1-3 peak cytokine values for those with severe (grade 4-5) and without severe (grade 0-3) CRS for total study population, and split into adults and children. Supplementary Table 12. Summary of all predictive models generated by discovery cohort and validated. Supplementary Table 13. Clinical details on the validation cohort. Supplementary Table 14. Therapies used for CRS. Supplementary Table 15. Tocilizumab use by grade and age, as well as, clinical effects of tocilizumab on CRS. Supplementary Table 16. Lee CRS grading scale. Supplementary Table 17. Davila CRS grading scale. Supplementary Table 18. Reclassification of CRS severity by dividing grade 3 into 3a and 3b. Supplementary Table 19. Summary of top predictive models with alternate determination of CRS severity. Supplementary Figure 1. CRP and ferritin are poor early predictors of severe CRS. Supplementary Figure 2. Early increases in IFNγ and sgp130 after CTL019 infusion are associated with development of severe CRS. Supplementary Figure 3. Severity of CRS correlates moderately with CAR T cell expansion but early expansion of CAR T cells does not predict CRS severity. Supplementary Figure 4. Cytokine profiles predict CRS. Supplementary Figure 5. Alternate CRS prediction models.

Table S1 and Figures S1 -S8

PDF file - 435K, Representative flow cytometry plots

B cell maturation was defined by flow cytometry

PDF file - 1065KB, Supplemental Data for Figure 4.

Supplementary Figure from Comprehensive Serum Proteome Profiling of Cytokine Release Syndrome and Immune Effector Cell–Associated Neurotoxicity Syndrome Patients with B-Cell ALL Receiving CAR T19

Detailed flow cytometric analysis of expanded cells from children and adults

Supplementary Figure S2 - PDF file 84K, Phenotype of DCs following lysate-pulsing (i.e. HOCl-L, UVB-L or FTL), and activation with LPS and IFN-gamma. Unpulsed, mature (mDC) or immature DCs (iDC) served as controls. Data was presented as mean plus-minus SEM

Supplementary Materials, Methods, Figures and Table legends - PDF file 87K, Supplementary file giving details of supplementary materials and methods, figure legends and table legends

sTable 1 shows radiation characteristics of Group A, B, and C. sTable 2 shows characteristics of CART-BCMA cells during manufacturing and at peak expansion in vivo in Group A, B, and C. sTable 3 shows details of radiation received after CART-BCMA therapy. sFigure 1 shows soluble BCMA serum levels before cyclophosphamide lymphodepletion on Day -3. sFigure 2 shows that prior radiation exposure is not associated with the level of CART-BCMA cells in vivo at peak expansion. sFigure 3 shows radiation was not associated with the level of persistent CART-BCMA cells in peripheral blood at Day 28. sFigure 4 shows level of CART-BCMA cells at peak expansion and Day 28 correlated with clinical response, and within responders, receipt of prior radiation was not associated with differences in CART=BCMA levels.

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Purpose: Previously, we showed that adoptive transfer of in vivo vaccine-primed and ex vivo (anti-CD3/anti-CD28) costimulated autologous T cells (ex-T) at day +12 after transplant increased CD4 and CD8 T-cell counts at day +42 and augmented vaccine-specific immune responses in patients with myeloma. Here, we investigated the safety and kinetics of T-cell recovery after infusing ex-T at day +2 after transplant.Experimental Design: In this phase I/II two-arm clinical trial, 50 patients with myeloma received autografts after high-dose melphalan followed by infusions of ex-T at day +2 after transplant. Patients also received pretransplant and posttransplant immunizations using a pneumococcal conjugate vaccine only (arm B; n = 24) or the pneumococcal conjugate vaccine plus an HLA-A2–restricted multipeptide vaccine for HLA-A2+ patients (arm A; n = 26).Results: The mean number of T cells infused was 4.26 × 1010 (range, 1.59-5.0). At day 14 after transplant, the median CD3, CD4, and CD8 counts were 4,198, 1,545, and 2,858 cells/μL, respectively. Interleukin (IL)-6 and IL-15 levels increased early after transplant and IL-15 levels correlated significantly to day 14 T-cell counts. Robust vaccine-specific B- and T-cell responses were generated. T-cell infusions were well tolerated with no effect on hematopoietic recovery. Eight patients (16%) developed a T-cell “engraftment syndrome” characterized by diarrhea and fever that was clinically and histopathologically indistinguishable from grade 1 to 3 acute graft-versus-host disease (GVHD) of the gastrointestinal tract (seven patients) and/or grade 1 to 2 cutaneous GVHD (four patients).Conclusions: Adoptive T-cell transfers achieve robust T-cell recovery early after transplant and induce moderate-to-severe autologous GVHD in a subset of patients.

Supplementary Table S1 - PDF file 191K, Cytokine and chemokine productions from DCs of ovarian cancer subjects that were loaded with HOCl-oxidized autologous whole tumor lysate and matured with LPS and IFN-gamma

Purpose: Chemokines are implicated in T-cell trafficking. We mapped the chemokine landscape in advanced stage ovarian cancer and characterized the expression of cognate receptors in autologous dendritic cell (DC)–vaccine primed T cells in the context of cell-based immunotherapy.Experimental Design: The expression of all known human chemokines in patients with primary ovarian cancer was analyzed on two independent microarray datasets and validated on tissue microarray. Peripheral blood T cells from five HLA-A2 patients with recurrent ovarian cancer, who previously received autologous tumor DC vaccine, underwent CD3/CD28 costimulation and expansion ex vivo. Tumor-specific T cells were identified by HER2/neu pentamer staining and were evaluated for the expression and functionality of chemokine receptors important for homing to ovarian cancer.Results: The chemokine landscape of ovarian cancer is heterogeneous with high expression of known lymphocyte-recruiting chemokines (CCL2, CCL4, and CCL5) in tumors with intraepithelial T cells, whereas CXCL10, CXCL12, and CXCL16 are expressed quasi-universally, including in tumors lacking tumor-infiltrating T cells. DC-vaccine primed T cells were found to express the cognate receptors for the above chemokines. Ex vivo CD3/CD28 costimulation and expansion of vaccine-primed Tcells upregulated CXCR3 and CXCR4, and enhanced their migration toward universally expressed chemokines in ovarian cancer.Conclusions: DC-primed tumor-specific T cells are armed with the appropriate receptors to migrate toward universal ovarian cancer chemokines, and these receptors are further upregulated by ex vivo CD3/CD28 costimulation, which render T cells more fit for migrating toward these chemokines. Clin Cancer Res; 21(12); 2840–50. ©2015 AACR.

Supplementary Materials and Methods, Supplementary Figure Legend, Supplementary Table 1. Supplementary Table 1: Cell line origin and characteristics

Purpose: Whole tumor lysates are promising antigen sources for dendritic cell (DC) therapy as they contain many relevant immunogenic epitopes to help prevent tumor escape. Two common methods of tumor lysate preparations are freeze-thaw processing and UVB irradiation to induce necrosis and apoptosis, respectively. Hypochlorous acid (HOCl) oxidation is a new method for inducing primary necrosis and enhancing the immunogenicity of tumor cells.Experimental Design: We compared the ability of DCs to engulf three different tumor lysate preparations, produce T-helper 1 (TH1)-priming cytokines and chemokines, stimulate mixed leukocyte reactions (MLR), and finally elicit T-cell responses capable of controlling tumor growth in vivo.Results: We showed that DCs engulfed HOCl-oxidized lysate most efficiently stimulated robust MLRs, and elicited strong tumor-specific IFN-γ secretions in autologous T cells. These DCs produced the highest levels of TH1-priming cytokines and chemokines, including interleukin (IL)-12. Mice vaccinated with HOCl-oxidized ID8-ova lysate–pulsed DCs developed T-cell responses that effectively controlled tumor growth. Safety, immunogenicity of autologous DCs pulsed with HOCl-oxidized autologous tumor lysate (OCDC vaccine), clinical efficacy, and progression-free survival (PFS) were evaluated in a pilot study of five subjects with recurrent ovarian cancer. OCDC vaccination produced few grade 1 toxicities and elicited potent T-cell responses against known ovarian tumor antigens. Circulating regulatory T cells and serum IL-10 were also reduced. Two subjects experienced durable PFS of 24 months or more after OCDC.Conclusions: This is the first study showing the potential efficacy of a DC vaccine pulsed with HOCl-oxidized tumor lysate, a novel approach in preparing DC vaccine that is potentially applicable to many cancers. Clin Cancer Res; 19(17); 4801–15. ©2013 AACR.

PDF file - 54KB, Adverse Events Table.

PDF file - 198KB, MAGE-A3 Trojan Peptide Vaccine Reactogenicity.

PDF file - 40KB, ELISA Antibody Responses for the PCV (Prevnar-13(registered trademark)).

Purpose:B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor (CAR) T cells (CART-BCMA) are a promising treatment for relapsed/refractory multiple myeloma (r/rMM). We evaluated the safety and feasibility of bridging radiation (RT) in subjects treated on a phase I trial of CART-BCMA.Experimental Design:Twenty-five r/rMM subjects were treated in three cohorts with two doses of CART-BCMA cells ± cyclophosphamide. We retrospectively analyzed toxicity, response, and CART manufacturing data based on RT receipt.Results:Thirteen subjects received no RT 18–35). Group C had qualitatively lower rates of grade 4 (G4) hematologic toxicities (25%) versus A (61.5%) and B (62.5%). G3–4 neurotoxicity occurred in 7.7%, 25%, and 25% in Group A, B, and C, respectively. G3–4 cytokine release syndrome was observed in 38.5%, 25%, and 25% in Group A, B, and C, respectively. Partial response or better was observed in 54%, 38%, and 50% of Group A, B, and C, respectively. RT administered P = 0.002) and P = 0.069) before apheresis was associated with lower in vitro proliferation during manufacturing; however, in vivo CART-BCMA expansion appeared similar across groups.Conclusions:Bridging-RT appeared safe and feasible with CART-BCMA therapy in our r/rMM patients, though larger future studies are needed to draw definitive conclusions.

Supplementary Figure 1. Flow cytometry analysis of vaccine-primed and CD3/CD28 costimulated T cells after chemokine-induced migration.

Supplementary Data

Purpose: Metastatic breast cancer (MBC) response to allogeneic lymphocytes requires donor T-cell engraftment and is limited by graft-versus-host disease (GVHD). In mice, type-II–polarized T cells promote engraftment and modulate GVHD, whereas type-I–polarized T cells mediate more potent graft-versus-tumor (GVT) effects. This phase I translational study evaluated adoptive transfer of ex vivo costimulated type-I/type-II (T1/T2) donor T cells with T-cell–depleted (TCD) allogeneic stem cell transplantation (AlloSCT) for MBC.Experimental Design: Patients had received anthracycline, taxane, and antibody therapies, and been treated for metastatic disease and a human leukocyte antigen (HLA)-identical–sibling donor. Donor lymphocytes were costimulated ex vivo with anti-CD3/anti-CD28 antibody–coated magnetic beads in interleukin (IL)-2/IL-4–supplemented media. Patients received reduced intensity conditioning, donor stem cells and T1/T2 cells, and monitoring for toxicity, engraftment, GVHD, and tumor response; results were compared with historical controls, identically treated except for T1/T2 product infusions.Results: Mixed type-I/type-II CD4+ T cells predominated in T1/T2 products. Nine patients received T1/T2 cells at dose level 1 (5 × 106 cells/kg). T-cell donor chimerism reached 100% by a median of 28 days. Seven (78%) developed acute GVHD. At day +28, five patients had partial responses (56%) and none had MBC progression; thereafter, two patients had continued responses. Donor T-cell engraftment and tumor responses appeared faster than in historical controls, but GVHD rates were similar and responders progressed early, often following treatment of acute GVHD.Conclusion: Allogeneic T1/T2 cells were safely infused with TCD-AlloSCT, appeared to promote donor engraftment, and may have contributed to transient early tumor responses. Clin Cancer Res; 17(21); 6878–87. ©2011 AACR.

Supplementary Data from Rapid Immune Recovery and Graft-versus-Host Disease–like Engraftment Syndrome following Adoptive Transfer of Costimulated Autologous T Cells

PDF file - 24K

Purpose:To study the biology and identify markers of severe cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) in children after chimeric antigen receptor T-cell (CAR T) treatment.Experimental Design:We used comprehensive proteomic profiling to measure over 1,400 serum proteins at multiple serial timepoints in a cohort of patients with B-cell acute lymphoblastic leukemia treated with the CD19-targeted CAR T CTL019 on two clinical trials.Results:We identified fms-like tyrosine kinase 3 (FLT3) and mast cell immunoglobulin-like receptor 1 (MILR1) as preinfusion predictive biomarkers of severe CRS. We demonstrated that CRS is an IFNγ-driven process with a protein signature overlapping with hemophagocytic lymphohistiocytosis (HLH). We identified IL18 as a potentially targetable cytokine associated with the development of ICANS.Conclusions:We identified preinfusion biomarkers that can be used to predict severe CRS with a sensitivity, specificity, and accuracy superior to the current gold standard of disease burden. We demonstrated the fundamental role of the IFNγ pathway in driving CRS, suggesting CRS and carHLH are overlapping rather than distinct phenomena, an observation with important treatment implications. We identified IL18 as a possible targetable cytokine in ICANS, providing rationale for IL18 blocking therapies to be translated into clinical trials in ICANS.

Purpose: Myeloma-directed cellular immune responses after autologous stem cell transplantation (ASCT) may reduce relapse rates. We studied whether coinjecting the TLR-3 agonist and vaccine adjuvant Poly-ICLC with a MAGE-A3 peptide vaccine was safe and would elicit a high frequency of vaccine-directed immune responses when combined with vaccine-primed and costimulated autologous T cells.Experimental Design: In a phase II clinical trial (NCT01245673), we evaluated the safety and activity of ex vivo expanded autologous T cells primed in vivo using a MAGE-A3 multipeptide vaccine (compound GL-0817) combined with Poly-ICLC (Hiltonol), granulocyte macrophage colony-stimulating factor (GM-CSF) ± montanide. Twenty-seven patients with active and/or high-risk myeloma received autografts followed by anti-CD3/anti-CD28–costimulated autologous T cells, accompanied by MAGE-A3 peptide immunizations before T-cell collection and five times after ASCT. Immune responses to the vaccine were evaluated by cytokine production (all patients), dextramer binding to CD8+ T cells, and ELISA performed serially after transplant.Results: T-cell infusions were well tolerated, whereas vaccine injection site reactions occurred in >90% of patients. Two of nine patients who received montanide developed sterile abscesses; however, this did not occur in the 18 patients who did not receive montanide. Dextramer staining demonstrated MAGE-A3–specific CD8 T cells in 7 of 8 evaluable HLA-A2+ patients (88%), whereas vaccine-specific cytokine-producing T cells were generated in 19 of 25 patients (76%). Antibody responses developed in 7 of 9 patients (78%) who received montanide and only weakly in 2 of 18 patients (11%) who did not. The 2-year overall survival was 74% [95% confidence interval (CI), 54%–100%] and 2-year event-free survival was 56% (95% CI, 37%–85%).Conclusions: A high frequency of vaccine-specific T-cell responses were generated after transplant by combining costimulated autologous T cells with a Poly-ICLC/GM-CSF–primed MAGE-A3 vaccine. Clin Cancer Res; 20(5); 1355–65. ©2013 AACR.

Purpose: Children with high-risk neuroblastoma have a poor prognosis with chemotherapy alone, and hematopoietic stem cell transplantation offers improved survival. As a dose-escalation strategy, tandem transplants have been used, but are associated with persistent immunocompromise. This study evaluated the provision of an autologous costimulated, activated T-cell product to support immunologic function.Experimental Design: Nineteen subjects with high-risk neuroblastoma were enrolled in a pilot phase and 23 subjects were entered in to the randomized study. Immunologic reconstitution was defined by flow cytometric and functional assays. Next-generation sequencing was conducted to identify changes to the T-cell repertoire. Twenty-two patients were vaccinated to define effects on antibody responses.Results: Subjects who received their autologous costimulated T-cell product on day 2 had significantly superior T-cell counts and T-cell proliferation compared with those who received T cells on day 90. Early administration of autologous T cells suppressed oligoclonality and enhanced repertoire diversity. The subjects who received the day 2 T-cell product also had better responses to the pneumococcal vaccine.Conclusions: The infusion of activated T cells can improve immunologic function especially when given early after transplant. This study showed the benefit of providing cell therapies during periods of maximum lymphopenia. Clin Cancer Res; 18(24); 6732–41. ©2012 AACR.

Purpose:Tisagenlecleucel is an anti-CD19 chimeric antigen receptor (CAR19) T-cell therapy approved for the treatment of children and young adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL).Patients and Methods:We evaluated the cellular kinetics of tisagenlecleucel, the effect of patient factors, humoral immunogenicity, and manufacturing attributes on its kinetics, and exposure-response analysis for efficacy, safety and pharmacodynamic endpoints in 79 patients across two studies in pediatric B-ALL (ELIANA and ENSIGN).Results:Using quantitative polymerase chain reaction to quantify levels of tisagenlecleucel transgene, responders (N = 62) had ≈2-fold higher tisagenlecleucel expansion in peripheral blood than nonresponders (N = 8; 74% and 104% higher geometric mean Cmax and AUC0-28d, respectively) with persistence measurable beyond 2 years in responding patients. Cmax increased with occurrence and severity of cytokine release syndrome (CRS). Tisagenlecleucel continued to expand and persist following tocilizumab, used to manage CRS. Patients with B-cell recovery within 6 months had earlier loss of the transgene compared with patients with sustained clinical response. Clinical responses were seen across the entire dose range evaluated (patients ≤50 kg: 0.2 to 5.0 × 106/kg; patients >50 kg: 0.1 to 2.5 × 108 CAR-positive viable T cells) with no relationship between dose and safety. Neither preexisting nor treatment-induced antimurine CAR19 antibodies affected the persistence or clinical response.Conclusions:Response to tisagenlecleucel was associated with increased expansion across a wide dose range. These results highlight the importance of cellular kinetics in understanding determinants of response to chimeric antigen receptor T-cell therapy.

Supplementary Data from Comprehensive Serum Proteome Profiling of Cytokine Release Syndrome and Immune Effector Cell–Associated Neurotoxicity Syndrome Patients with B-Cell ALL Receiving CAR T19

Supplementary Figures 1-6 from Multiple Injections of Electroporated Autologous T Cells Expressing a Chimeric Antigen Receptor Mediate Regression of Human Disseminated Tumor

Supplementary Figure 5 from Targeting HER-2/neu in Early Breast Cancer Development Using Dendritic Cells with Staged Interleukin-12 Burst Secretion

Supplementary Figure 4 from Targeting HER-2/neu in Early Breast Cancer Development Using Dendritic Cells with Staged Interleukin-12 Burst Secretion

Supplementary Table 1 from Targeting HER-2/neu in Early Breast Cancer Development Using Dendritic Cells with Staged Interleukin-12 Burst Secretion