Lymphodepleting Chemotherapy Research Articles

A Phase I Study to Determine the Maximum Tolerated Dose of ex Vivo Expanded Natural Killer Cells Derived from Unrelated, HLA-Disparate Adult Donors

The administration of allogeneic natural killer (NK) cells following a lymphodepleting chemotherapy regimen is emerging as a well-tolerated therapeutic approach in the management of various malignancies. Contrary to the expected complications of allogeneic T cell therapy, there remains no evidence of graft-versus-host disease (GVHD) mediated by NK cells in numerous clinical trials. On the contrary, preclinical and clinical studies suggest that NK cells do not induce GVHD and in fact may prevent its development following allogeneic hematopoietic cell transplantation (HCT). In this study, we sought to determine the maximum tolerated dose of non-HLA-matched donor NK cells derived from peripheral blood and ex vivo expanded using a novel feeder cell platform. In a single-center Phase I clinical trial using a 3×3 design, 9 subjects each received 2 infusions of NK cells 2 weeks apart following a preparative regimen of cyclophosphamide (60 mg/kg i.v.) and fludarabine (25 mg/m2/day i.v for 5 days). No exogenous cytokines were administered. NK cells were administered at 3 dose levels: 1×107/kg, 2.5×107/kg, and 5×107/kg. Three subjects had myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML), and the other 6 subjects had colorectal carcinoma. Recipients were monitored over a 4-week period for GVHD as well as other adverse events and for persistence of donor NK cells in systemic circulation. Disease assessment was started at 28 days following the first NK cell infusion and continued until postinfusion day 100 or disease progression. In all 9 study subjects, there was no occurrence of GVHD and no dose-limiting toxicities that would warrant cohort expansion at any of the 3 planned cell dose levels. Low-level donor NK cell persistence was observed up to 4 weeks after the first NK cell infusion at all dose levels. The best observed response was a complete response with incomplete platelet recovery in a MDS subject who experienced disease relapse after prior allogeneic HCT. Other responses were stable disease in 1 subject with MDS and 2 subjects with colorectal cancer up to postinfusion day 100. This off-the-shelf, third-party NK cell product can be administered safely without inducing GVHD and exhibits in vivo persistence promoted by preparative lymphodepletion alone. The observed clinical responses could be enhanced by administration of exogenous cytokine support, as well as complementary approaches that promote NK cell function in the tumor microenvironment.

An open, single-center, exploratory clinical trial to evaluate the safety and efficacy of RNA CAR-mesothelin T cells in patients with advanced refractory pancreatic cancer.

TPS628 Background: Pancreatic cancer is an aggressive gastrointestinal cancer characterized by late diagnosis initially, prone to distant metastasis and poor prognosis. The current treatment of pancreatic cancer is very limited, resulting in its 5-year survival rate of less than 10%. It is necessary to seek new treatment methods and treatments. Chimeric antigen receptor T (CART) cell therapy has made a breakthrough in hematological malignancies. Therefore, the goal of this clinical trial is to study the safety, efficacy and pharmacokinetics of mRNA-engineered anti-Mesothelin Chimeric Antigen Receptor T-Cell (anti-MESO CAR-T cells) therapy in patients with mesothelin expression-positive, advanced pancreatic tumors that have failed at least first-line or second-line therapy. Methods: The study will adopt the "3+3" dose escalation design exploring two doses of 1×109 and 3×109. The administration is planned to infuse 3 times a week for 2 consecutive weeks. The subjects will receive a total dose of 1x109 RNA transduced anti-MESO CAR-T cells in the first week, following lymphodepleting chemotherapy with cyclophosphamide 300 mg/m2/day and fludarabine 30 mg/m2/day given over 3 days by intravenous infusion. If there is no obvious dose-limiting toxicity (DLT) after the first week of infusion, three times consecutive infusions of 1x109 anti-MESO CAR-T cells each time is planned in the second week. Each subject needs to be observed for at least 2 weeks (14 days) after completing the last infusion. Lymphodepleting chemotherapy will not be repeated prior to additional infusions of anti-MESO CAR-T cells. Clinical trial information: 04981691.

Multi-antigen-targeted T-cell therapy to treat patients with relapsed/refractory breast cancer.

Purpose:Adoptively transferred, ex vivo expanded multi-antigen-targeted T cells (multiTAA-T) represent a new, potentially effective, and nontoxic therapeutic approach for patients with breast cancer (BC). In this first-in-human trial, we investigated the safety and clinical effects of administering multiTAA T cells targeting the tumor-expressed antigens, Survivin, NY-ESO-1, MAGE-A4, SSX2, and PRAME, to patients with relapsed/refractory/metastatic BC.Materials and methods:MultiTAA T-cell products were generated from the peripheral blood of heavily pre-treated patients with metastatic or locally recurrent unresectable BC of all subtypes and infused at a fixed dose level of 2 × 107/m2. Patients received two infusions of cells 4 weeks apart and safety and clinical activity were determined. Cells were administered in an outpatient setting and without prior lymphodepleting chemotherapy.Results:All patients had estrogen receptor/progesterone receptor positive BC, with one patient also having human epidermal growth factor receptor 2-positive. There were no treatment-related toxicities and the infusions were well tolerated. Of the 10 heavily pre-treated patients enrolled and infused with multiTAA T cells, nine had disease progression while one patient with 10 lines of prior therapies experienced prolonged (5 months) disease stabilization that was associated with the in vivo expansion and persistence of T cells directed against the targeted antigens. Furthermore, antigen spreading and the endogenous activation of T cells directed against a spectrum of non-targeted tumor antigens were observed in 7/10 patients post-multiTAA infusion.Conclusion:MultiTAA T cells were well tolerated and induced disease stabilization in a patient with refractory BC. This was associated with in vivo T-cell expansion, persistence, and antigen spreading. Future directions of this approach may include additional strategies to enhance the therapeutic benefit of multiTAA T cells in patients with BC.

Impact of High Disease Burden on Survival in Pediatric Patients with B-ALL Treated with Tisagenlecleucel

CD19-specific chimeric antigen receptor (CAR) T-cell therapies, including the FDA-approved tisagenlecleucel, induce high rates of remission in pediatric patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, post-treatment relapse remains an issue. Optimal management of B-ALL after tisagenlecleucel treatment remains elusive, and continued tracking of outcomes is necessary to establish a standard of care for this population. We sought to evaluate outcomes on the real-world use of tisagenlecleucel in a contemporary pediatric patient population and to identify risk factors influencing event-free survival (EFS) and overall survival (OS). Additionally, we aimed to describe post-tisagenlecleucel management strategies, including use of allogeneic hematopoietic cell transplantation (AlloHCT) or repeat CAR T-cell infusions. We report on 31 pediatric and adolescent and young adult patients (AYA) with B-ALL, treated with lymphodepleting chemotherapy followed by tisagenlecleucel. Patients were treated at Johns Hopkins Hospital and St. Jude Children's Research Hospital between March 2018 and November 2020. Data on patient, disease, and treatment characteristics were collected retrospectively from medical records and described. EFS and OS were estimated by the Kaplan-Meier method and compared by the log-rank test. Single-factor and multiple-factor analysis of EFS and OS were performed by fitting Cox regression models. Of the 30 evaluable patients, 25 (83.3%) experienced a complete response, with 21 having negative minimal residual disease. Treatment was well tolerated, with expected rates of cytokine release syndrome (61.3%) and immune effector cell-associated neurotoxicity (29%). After initial complete response, 12 patients (48%) had subsequent disease recurrence, with CD19-negative relapse (n=6) occurring sooner than CD19-positive relapse (P = .0125). With a median follow-up time of 386 days (range 11-1187 days), the EFS for the entire cohort (n = 31) at 6 and 12 months after infusion was 47% (95% confidence interval [CI], 28.4%-63.4%) and 35.2% (95% CI, 18.4%-52.5%), respectively. In multivariate analysis, high pretreatment leukemic burden (≥5% bone marrow blasts) was an independent risk factor for inferior EFS (HR 5.98 [95% CI, 1.1-32.4], P=.0380) and OS (HR 4.2 [95% CI, 1.33-13.39], P=.0148). Tisagenlecleucel induced high initial response rates in a contemporary cohort of pediatric and AYA patients with B-ALL. However, 48% of patients experienced subsequent disease relapse, including 6 with antigen-escape variants. This highlights a considerable limitation of single-agent autologous CD19-CAR T-cell therapy. Pretreatment leukemic disease burden of ≥5% blasts was significantly associated with worse outcomes in this study, including lower EFS and OS. Our findings suggest that reducing preinfusion leukemic burden is a viable treatment strategy to improve outcomes of CAR T-cell therapy.

Gda-201, a Novel Metabolically Enhanced Allogeneic Natural Killer (NK) Cell Product Yields High Remission Rates in Patients with Relapsed/Refractory Non-Hodgkin Lymphoma (NHL): 2-Year Survival and Correlation with Cytokine IL7

Gda-201, a Novel Metabolically Enhanced Allogeneic Natural Killer (NK) Cell Product Yields High Remission Rates in Patients with Relapsed/Refractory Non-Hodgkin Lymphoma (NHL): 2-Year Survival and Correlation with Cytokine IL7

Phase 1/2 Study of Nexi-001 Donor-Derived Multi-Antigen Specific CD8+ T Cells for the Treatment of Relapsed Acute Myeloid Leukemia (AML) after Allogeneic Hematopoietic Transplantation

Phase 1/2 Study of Nexi-001 Donor-Derived Multi-Antigen Specific CD8+ T Cells for the Treatment of Relapsed Acute Myeloid Leukemia (AML) after Allogeneic Hematopoietic Transplantation

Safety and Efficacy Profile of Autologous CD30.CAR-T-Cell Therapy in Patients with Relapsed or Refractory Classical Hodgkin Lymphoma (CHARIOT Trial)

Safety and Efficacy Profile of Autologous CD30.CAR-T-Cell Therapy in Patients with Relapsed or Refractory Classical Hodgkin Lymphoma (CHARIOT Trial)

Phase 1/2 Study of Nexi-002 Autologous Multi-Antigen-Specific CD8+ T Cells for the Treatment of Relapsed or Refractory Multiple Myeloma

The NEXI-002 study is a prospective, multicenter, open-label phase 1/2 trial designed to characterize the safety, immunologic, and preliminary anti-myeloma activity of the NEXI-002 antigen specific CD8+ T cell product. Multiple myeloma (MM) is an incurable malignancy that occurs predominantly in older patients and is characterized by the growth of malignant plasma cells in the bone marrow. Despite substantial advances in therapy, virtually all patients relapse after treatment, emphasizing the unmet medical need for additional effective treatments. The NEXI-002 product is an autologous non-genetically engineered therapy of CD8+ T cells that recognize HLA 02.01-restricted peptides from the WT1, CD138, CS1, and NY-ESO-1 antigens. This T-cell product includes key memory phenotypes such as stem-like memory, central memory, and effector memory cells. Eligible patients have relapsed or refractory multiple myeloma (RRMM) who have received at least three prior lines of treatment that included at least an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 agent. Three patients were enrolled into the Safety Evaluation phase and received a single infusion of 80 million (M) to 100M cells of NEXI-002 product. In this phase of the study the primary endpoint is safety and secondary endpoints include expansion, persistence, and trafficking of the NEXI-002 cells. Bridging anti-MM treatment was permitted during the manufacture of the cellular product with a wash-out period of at least 14 days prior to lymphodepletion (LD) chemotherapy (intravenous fludarabine 30 mg/m 2 and cyclophosphamide 300 mg/m 2), which was administered on Days -5, -4, and -3 prior to the infusion of the NEXI-002 product up to 72 hours later (Day1). Treatment-related adverse events, including infusion reactions, events that prolong hospitalization post infusion, CRS, and neurotoxicity (ICANS) have not developed in these patients who received the NEXI-002 product. Lymphocyte recovery to baseline levels occurred within a few days after the infusion of the NEXI-002 product, demonstrating robust CD4 and CD8 T cell reconstitution following LD chemotherapy. NEXI-002 antigen specific T cells were detected in peripheral blood (PB) by multimer staining and proliferated over time and trafficked to the bone marrow (BM). The phenotype composition of detectable antigen specific T cells at both sites maintained that of the infused product. These NEXI-002 T cells persisted in PB and BM during follow-up. T-cell receptor (TCR) sequencing assays revealed T cell clones in the NEXI-002 product that were not detected in PB of patients tested at baseline. These clones subsequently expanded and persisted over time in the PB and BM.In conclusion, these results show that infusion of the NEXI-002 product is safe, well tolerated, and capable of generating a cell-mediated immune response that may lead to clinical activity. RNA Seq transcriptional profiling of the CD8+ T cells is planned. Additional patients have recently received NEXI-002 infusions and the trial will continue to be expanded to gain additional safety, immunologic, and clinical activity experience. DisclosuresKnight: Neximmune, Inc: Current Employment. Varela: Nexlmmune: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite: Speakers Bureau. Edavana: Neximmune, Inc: Current Employment. Lu: Neximmune, Inc: Current Employment. Kim: Neximmune, Inc: Current Employment. Suarez: Neximmune, Inc: Current Employment. Oelke: Neximmune, Inc: Current Employment. Bednarik: Neximmune, Inc: Current Employment.

Axicabtagene Ciloleucel in Relapsed or Refractory Large B-Cell Lymphoma Patients in Complete Metabolic Response at Time of Infusion

Axicabtagene Ciloleucel in Relapsed or Refractory Large B-Cell Lymphoma Patients in Complete Metabolic Response at Time of Infusion

Suppressed Fibrinolytic Activity Demonstrated By Simultaneous Thrombin and Plasmin Generation Assay during Cytokine Release Syndrome after CD19 Chimeric Antigen Receptor-Modified T-Cell Therapy

Introduction: Infusion T cells engineering to express CD19-specific chimeric antigen receptor T cells (CAR-T) following lymphodepleting chemotherapy has shown promising efficacy in patients with relapsed and/or refractory CD19-positive B-cell malignancies including B-cell acute lymphoblastic leukemia (B-ALL), and diffuse large B-cell lymphoma (DLBCL). CAR-T therapy can often be associated with cytokine release syndrome (CRS), which has been reported to present severe coagulopathy. Conventional coagulation and fibrinolysis parameters have been reported to worsen in correlation with CRS grading [Hay KA et al. Blood 2017]. In the present study, we hypothesized that the change of balance between coagulation and fibrinolysis due to coagulopathy is associated with CRS after CAR-T therapy. To clarify our hypothesis, we investigated the global coagulation and fibrinolytic function of patients receiving CD19 CAR-T therapy using simultaneous thrombin and plasmin generation assay (T/P-GA). Patients: We enrolled 13 consecutive patients aged 23-69 years (8 males and 5 females, DLBCL; n = 11, B-ALL; n = 2) receiving CD19 CAR-T therapy from May 2020 to December 2020 at a single center in Japan. Due to a history of internal jugular venous thrombosis, one patient received edoxaban, an anticoagulant. Methods: We evaluated the global functions of coagulation and fibrinolysis using T/P-GA [Matsumoto et al. TH 2013]. This clotting was initiated by the mixture of recombinant human tissue factor (Innovin ®, f.c. 1 pM), phospholipid vesicles (f.c. 4 μM), and tissue-type plasminogen activator (f.c. 3.2 nM). We simultaneously monitored thrombin and plasmin generation using thrombin- and plasmin-specific fluorogenic substrate (Z-Gly-Gly-Arg-AMC and BOC-Glu-Lys-Lys-MAC, respectively) in separate microtiter wells. The first derivatives (velocity) of thrombin and plasmin generation were utilized to derive the parameters, lag time (LT), endogenous potential (EP), peak levels (Peak), and time to peak (ttPeak). In this study, EP of thrombin generation (T-EP) and plasmin-peak (P-Peak) were selected as parameters for evaluation. We calculated the ratio of T-EP and P-Peak of patients' plasmas to those of control normal plasma. A ratio > 1.0 was defined as high coagulation or fibrinolytic potential relative to normal. Using fibrinogen (Fbg), D-dimer, and antithrombin (AT), we also monitored the conventional laboratory markers of hemostasis. Soluble IL-2 receptor (sIL-2R) was also measured as a marker of inflammatory cytokines. Day 0 was defined as the day of CAR-T infusion. Plasmas were collected at T0; pre-lymphodepleting chemotherapy, T1; Days -2-0, T2; Days 1-3, T3; Days 4-6, T4; Days 7-9, T5; Days 10-12, T6; Days 13-18, and T7; Days 19-23. Results: All patients had Grade ≤ 2 CRS. Two cases developed CRS-associated coagulopathy, one of whom required fresh frozen plasma transfusion and cryoprecipitate for low Fbg level, and the other required tranexamic acid for hemorrhagic cystitis. The median values of AT remained within the reference value (RV). The median Fbg values were 229-525 mg/dL, and which were significantly greater at T0-T3 than at T5-T7 (p < 0.05). The median D-dimer values were 0.45-3.9 µg/mL, which were within or above the RV with no significant change between time points. The median values of sIL-2R were 819-3,953 U/mL, and which were significantly increased at T3-T4 than at T0-T1 (p < 0.05). T-EP/P-Peak revealed a median of 1,877/21.9, 1,659/18.6, 1,731/19.8, 1,856/15.0, 1,931/16.3, 1,758/18.5, 1,600/19.1, 1,634/20.3, and 1,594/17.4 nM for T0-T7 and control plasma, respectively, indicating the reduced P-Peak ratios (Fig. 1). T-EP ratios showed consistently maintaining > 1 with no significant difference between time points, while P-Peak ratios were significantly lower at T3 and T4 than at T0 (p < 0.01) (median ratios of T-EP/P-peak; T0; 1.23/1.22, T1; 1.08/1.05, T2; 1.12/1.09, T3; 1.23/0.81, T4; 1.27/0.91, T5; 1.19/1.11, T6; 1.07/1.12, and T7; 1.20/1.15, respectively). Conclusion: The results of T/P-GA showed that hemostatic kinetics in patients with Grade ≤ 2 CRS were likely to shift to hypercoagulable states throughout the entire period and that they were likely to experience hypofibrinolytic activity during the CRS phase. These results suggest that the imbalance of coagulation and fibrinolysis might cause organ disorder due to thrombotic tendency associated with CRS after CAR-T therapy. [Display omitted] DisclosuresTakaori-Kondo: Bristol-Myers K.K.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Research Funding; Celgene: Research Funding. Nogami: Chugai Pharmaceutical Co., Ltd.: Consultancy, Research Funding.

Vaccine Titers in Lymphoma Patients Receiving Chimeric Antigen Receptor T Cell Therapy

Background: While CD19 chimeric antigen receptor T cell therapy (CAR-T) therapy does not use myeloablative chemotherapy, patients with aggressive lymphoma treated with CAR-T are immunosuppressed from lymphodepletion chemotherapy, and prolonged B cell aplasia and hypogammaglobulinemia from CAR-T. The impact of CAR-T on immunologic protection from vaccine-preventable diseases (and thus the need to revaccinate) has not been formally studied. We report the vaccine titers of patients treated with CAR-T at Mayo Clinic, Rochester.Methods: We conducted a retrospective chart review of patients who received CAR-T from 9/2018 to 4/2021 for treatment of aggressive lymphoma at Mayo Clinic, Rochester. Data was collected on anti-viral and anti-bacterial titers prior to CAR-T infusion and at month 3 post CAR-T. Clinical assays for vaccine titers were used for patient assessment and threshold for clinical assays was used to define antibody titer as positive or negative.Results: In our cohort of 87 CAR-T patients, 83 (94%) patients were infused with axicabtagene ciloleucel, 4 (5%) patients received brexucabtagene autoleucel and 1 (1%) received tisagenlecleucel. Prior to CAR-T therapy, positive titer rate was highest for tetanus and lowest for Streptococcus pneumoniae (Strep PNA). Similar trends were seen whether patients had autologous stem cell transplant (ASCT) within 2 years of CAR-T (i.e. within immunization timeframe post ASCT) or not (Table 1).At 3 months post CAR-T, overall seropositivity rates were similar when compared to pre-CAR-T levels for the prior transplant and no prior transplant group. For patients who had received intravenous immunoglobulin (IVIG) supplement prophylactically (for IVIG<400 mg/dl), seropositivity rate for Strep PNA remained zero (Table 1). Among the 30 patients who received IVIG, variable rate of conversion from negative to positive titers were seen for measles (1/2, 50%), mumps (3/5, 60%), rubella (3/4, 75%), varicella-zoster (VZV, 4/4, 100%), hepatitis A (8/9, 89%) and hepatitis B (10/12, 83%).For patients who did not receive IVIG prophylaxis after CAR-T, seropositivity rate for hepatitis A and B was low. In addition, some of these patients had a loss of seropositivity for Strep PNA (2/5, 40%) and hepatitis A (1/4, 25%).Conclusion: The presence of protective vaccine titers is variable for patients receiving CAR-T therapy, regardless of recent ASCT. The loss of protective titers post CAR-T was low. The need for immunization post CAR-T may remain important regardless of transplant status prior to CAR-T. Prophylactic IVIG does not confer complete immunization protection. Optimal timing for immunization post CAR-T is probably unknown and may need to be considered earlier for patients not on prophylactic IVIG. Further study with longer follow-up is needed to inform the need for immunization and optimal timing post CAR-T. [Display omitted] DisclosuresBennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Paludo: Karyopharm: Research Funding. Wang: LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; Genentech: Research Funding; Novartis: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; InnoCare: Research Funding. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Sorrento: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Vineti: Consultancy; Juno: Consultancy; Legend: Consultancy; Gamida Cell: Consultancy; Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Takeda: Research Funding.

Outreach: Results from a Phase 2 Study of Lisocabtagene Maraleucel (liso-cel) Administered As Inpatient (Inpt) or Outpatient (Outpt) Treatment in the Nonuniversity Setting in Patients (Pts) with R/R Large B-Cell Lymphoma (LBCL)

Outreach: Results from a Phase 2 Study of Lisocabtagene Maraleucel (liso-cel) Administered As Inpatient (Inpt) or Outpatient (Outpt) Treatment in the Nonuniversity Setting in Patients (Pts) with R/R Large B-Cell Lymphoma (LBCL)

Six-Month Follow-up for Infectious Complications after Lymphodepletion and Application of CD19-Chimeric Antigen Receptor T (CAR-T) Cell Therapy

Background: In the past years, chimeric antigen receptor T (CAR-T) cell therapy targeting CD19 have been shown to be a new and effective treatment option in patients with relapsed/refractory non-Hodgkin lymphoma (NHL) and acute lymphoblastic leukemia (ALL). However, infections with severe and potentially life-threatening complications can be induced by either lymphodepleting chemotherapy and/or the infusion of CAR-T cells, while side effects such as cytokine release syndrome (CRS) might further complicate differential diagnosis.Methods: Infections and complications were evaluated during inpatient treatment as well as in a follow-up period of the first six months after dosing. Eighty-one dosings of CAR-T cells in seventy-three adult patients with either NHL (88%) or ALL (12%) were analyzed. Bacterial and viral pathogen were detected with blood cultures or examination of potential sources of infection such as catheter tips. Panel and serum testing for viral infection was carried out either as a screening or in case of suspicion, while fungal infections were diagnosed according to the 2008 revised European Organization for Research and Treatment of Cancer (EORTC) Consensus Group criteria to determine proven, probable and possible invasive fungal disease.Results: In 52 patients (64%, Table 1) fever was detected following lymphodepletion and CAR-T cell dosing . Microbiological or radiological findings were seen in 20% of cases. Of those, eight were of bacterial (10%), three of viral (4%), and five of fungal (6%) origin. Overall, more lines of therapy as well as more severe CRS were associated with early infection. Cytokine release syndrome was diagnosed in 41 patients (51%, Table 1), with a simultaneous detection in five bacterial (6%), two viral (2%), and five fungal (6%) infections (Figure 1). In the six months follow-up period seven patients with fever (9%) had microbiological or radiological findings, in most cases during the first 90 days after CAR T cell infusion (6 patients, 7%). Only one patient died of infection (pathogen: cytomegalovirus).Conclusions: Infections are common in CAR-T cell patients; therefore, fast and suitable identification and initiation of treatment are important in the heavily pretreated and immunocompromised patient population. While infectious complications are mostly manageable, the frequency of infectious complications in patients receiving CAR-T cell therapy underlines the value of standardized anti-infective prophylaxis and supportive therapy for reduction of morbidity and mortality. [Display omitted] DisclosuresSchubert: Gilead: Consultancy. Sauer: Pfizer: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Matterhorn Biosciences AG: Consultancy, Other: DSMB/SAB Member; Takeda: Consultancy, Other: DSMB/SAB Member. Schmitt: Hexal: Other: Travel grant; TolerogenixX Ltd: Current Employment; Therakos/Mallinckrodt: Research Funding; Jazz Pharmaceuticals: Other: Travel grant. Müller-Tidow: Bioline: Research Funding; Pfizer: Research Funding; Janssen: Consultancy, Research Funding. Dreger: AbbVie: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Speakers Bureau; Bluebird Bio: Consultancy; BMS: Consultancy; Novartis: Consultancy, Speakers Bureau; Janssen: Consultancy; Gilead Sciences: Consultancy, Speakers Bureau; Riemser: Consultancy, Research Funding, Speakers Bureau; Roche: Consultancy, Speakers Bureau. Schmitt: Bluebird Bio: Other: Travel grants; MSD: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Travel grants, Research Funding; Hexal: Other: Travel grants, Research Funding; Kite Gilead: Other: Travel grants; Apogenix: Research Funding; TolerogenixX: Current holder of individual stocks in a privately-held company.

Early Signals of Anti-Tumor Efficacy and Safety with Autologous CD5.CAR T-Cells in Patients with Refractory/Relapsed T-Cell Lymphoma

Early Signals of Anti-Tumor Efficacy and Safety with Autologous CD5.CAR T-Cells in Patients with Refractory/Relapsed T-Cell Lymphoma

Viability of Chimeric Antigen Receptor T Cell Therapy in Latin America

Introduction: Treatment of diffuse large B cell lymphoma (DLBCL) may be a challenge for Latin American countries. Thus, novel strategies to reduce the economic burden of oncological care are necessary. In Brazil, the DLBCL annual incidence is approximately 6.000 cases, among which 30% will relapse or become refractory (R/R). In this scenario, the limited access to the new therapies reinforce the need to develop new local technologies and improve research initiatives. Here we report the development and clinical application of a Brazilian platform to manufacture genetically modified T-cells to treat patients with R/R leukemia and lymphomas, which may also help reverse the poor prognosis of these patients in low and middle-income countries. Patients and Methods: All patients were referred to our center to consider compassionate use of anti-CD19 CAR-T cell therapy. The treatment was authorized by the local medical ethical committee. Once patients were deemed to be eligible for CAR-T, they were scheduled for lymphopheresis and the cells were processed and cryopreserved. During the manufacturing process and after completion of lymphophersis, all three patients received bridging therapy. Prior to infusion of CAR-T, patients were given lymphodepletion chemotherapy with cyclophosphamide and fludarabine for 3 days. Patients were monitored daily for the occurrence of cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS), which were graduated according to the criteria of the American Society for Transplantation and Cellular Therapy. These treatments were only available because we developed a Brazilian platform to manufacture genetically modified T-cells. Firstly, we developed and validated in vitro and in vivo anti-CD19 CAR T cell expression, expansion, and cytotoxicity. Secondly, in-house lentiviral good-manufacturing practice (GMP) protocols were established for clinical purposes. Thirdly, we upscaled the manufacturing process into the GMP facility originally developed for MSCs and adapted it to genetically modified T-cells. Finally, in-house procedures to deliver anti-CD19 CAR T cells for clinical use were established according to the Brazilian Health Regulatory Agency (ANVISA) policies. Once these steps were implemented, we were able to treat the first three patients of a patient with CAR-T cells produced in Latin America. Results: Two patients presented CAR-T cell expansion after the procedure (Figure 1). Within thirty days after the infusion one patient achieved complete response, one had partial response and one was not evaluated (Table 1). All patients had CRS and only one had ICANS. Two patients died, one from infection and other from intracranial hemorrhage due to domestic accident, — and — days after CAR-T cell infusion, respectively. Discussion: At least two of the reported patients presented improvement of their disease. The other one died before the expected response could have been evaluated. None of the patients died from complications related to manufacturing or infusion procedures, highlighting an acceptable safety profile of the platform. Although these are preliminary results, the CAR-T cell expansion profile, presence of systemic inflammatory response and lack of early disease progression suggest the treatment effectiveness. Conclusion: Apart from all the scientific challenges, this experience highlights the feasibility to implement a viable and efficient CAR-T platform in middle-income countries. Besides, implementation of advanced cellular therapy can also contribute to enhancing the quality of other cellular therapies. [Display omitted] DisclosuresGuerino-Cunha: Novartis: Other: Speaker; BMS: Other: Speaker; Janssen: Other: Speaker. Calado: Instituto Butantan: Consultancy; Alexion Brasil: Consultancy; Team Telomere, Inc.: Membership on an entity's Board of Directors or advisory committees; Novartis Brasil: Honoraria; Agios: Membership on an entity's Board of Directors or advisory committees; AA&MDS International Foundation: Research Funding.

Safety and Efficacy of Fully Human BCMA CAR T Cells in Combination with a Gamma Secretase Inhibitor to Increase BCMA Surface Expression in Patients with Relapsed or Refractory Multiple Myeloma

Safety and Efficacy of Fully Human BCMA CAR T Cells in Combination with a Gamma Secretase Inhibitor to Increase BCMA Surface Expression in Patients with Relapsed or Refractory Multiple Myeloma

Bortezomib, Lenalidomide and Dexamethasone (VRd) Followed By Ciltacabtagene Autoleucel Versus Vrd Followed By Lenalidomide and Dexamethasone (Rd) Maintenance in Patients with Newly Diagnosed Multiple Myeloma Not Intended for Transplant: A Randomized, Phase 3 Study (CARTITUDE-5)

Bortezomib, Lenalidomide and Dexamethasone (VRd) Followed By Ciltacabtagene Autoleucel Versus Vrd Followed By Lenalidomide and Dexamethasone (Rd) Maintenance in Patients with Newly Diagnosed Multiple Myeloma Not Intended for Transplant: A Randomized, Phase 3 Study (CARTITUDE-5)

CD19 CAR-T Cell Therapy in Children with Relapsed and Refractory B-ALL

IntroductionCD19 CAR-T is a highly effective therapy among children with relapsed/refractory B-ALL. The optimal approach to delivery of this therapy and the best post-remission strategy remain to be established. We have tested in a prospective academic trial CD19 CAR-T cells manufactured at the point-of-care based on the automatic bioreactor platform. Based on the results of the first part of the trial, a toxicity mitigation strategy with conditional split dosing and refined post-remission therapy based on allogeneic HSCT was implemented. We report here the results of toxicity mitigation strategy approach as well as the long-term outcome with regard to the HSCT consolidation.Patients and methodsA total of 57 pts with relapsed/refractory B-ALL were screened, 54 pts were included in the trial, and additional 3 pts were eligible for compassionate use of CD19 CAR-T cell therapy. The CliniMACS Prodigy T-cell transduction process with lentiviral second generation CD19.4-1BB zeta vector (Lentigen, Miltenyi Biotec) was used for CAR-T manufacturing. All patients received prophylactic tocilizumab before CAR-T cells infusion.In the first part of trial 33 pts received lymphodepleting chemotherapy containing cyclophosphamide (750 mg/m2) and fludarabine (120 mg/m2), CAR-T cells was administered in dose-escalating regimen (0.1, 0.5, 1, and 3х10 6/kg b.w.).After the interim analysis, treatment scheme was modified to adapt the lymphodepletion therapy and the starting CAR-T dose to the leukemia burden. Twenty-four consecutive pts were divided into “low leukemia burden” (n=10) and “highleukemia burden” (n=14) groups, based on the threshold of 15% leukemic cells in the bone marrow.Patients with low leukemia burden received the same lymphodepletion chemotherapy as in the first part of the trial, and a single fixed dose of CAR-T cells at 1x10 6/kg b.w.Patients with high leukemia burden received an escalated lymphodepletion (fludarabine 120 mg/m 2, cyclophosphamide 750 mg/m 2, cytarabine 900 mg/m 2, etoposide 450 mg/m 2, dexamethasone 30 mg/m 2) and a divided dose of CAR-T. Day 0 CAR-T dose was set at 0.1 x10 6/kg. The second dose of 0.9x10 6/kg b.w. was administered between day 7 and day 14 if the following criteria were met: bone marrow leukemia burden by flow cytometry < 15% and CRS and/or ICANS grade within 3 previous days does not exceed grade 2.ResultsThirty patients included in the first part of the trial, were evaluable for response at day 28, and 27 (90%) of them had MRD-negative remission. Interim analysis showed that grade 3-5 CRS and neurotoxicity were associated exclusively with large leukemia burden (>15% blasts in the bone marrow) at the enrollment (p=0,003).With the risk-adapted strategy (part 2 of the trial), 8 patients (80%) with low leukemic burden achieved CR at day 28, and all patients (100%) with high leukemic burden achieved complete remission on day 28. In the high burden cohort 4 patients received the second CAR-T infusion, while the remaining 10 patients did not receive second dose due to either toxicity grade ³2 (4 pts), or persistence of >15% blast cells in bone marrow (6 pts). There were no cases of grade IV-V toxicity among patients with high leukemia burden, Table 1.For all patients the median follow-up for survivors was 490 days (287-1193), the cumulative incidence of relapse after initial response was 69.6%, median time to relapse was 250 days (58-696). HSCT during the CR was performed in 15 patients. The median time between first CAR-T infusion and HSCT was 96 days (41-292). Three patients (20%) relapsed early after HSCT (88, 114 and 155 days). Event-free and overall survival for the total cohort was 19.6% and 56.4%, respectively. Among the 34 pts, who did not receive HSCT in CR after CAR-T therapy, EFS and OS were 14.7% and 55.7%. Among the 15 pts, who received HSCT as consolidation, EFS and OS were 86.1% and 80%, p-value for HSCT vs no HSCT 0.125 (OS) and 0.0001 (EFS).ConclusionLow doses of non-cryopreserved CAR-T cells (0.1*10 6/kg), manufactured at the point-of-care, demonstrated high efficacy in patients with high initial leukemia burden, as well as favorable profile of life-threatening toxicity. The proposed risk-adapted strategy of CAR-T dosing allows to achieve high remission rate in all patients (with high and low leukemic mass). HSCT is likely to be a necessary modality for consolidation and long-term maintenance of remission after CAR-T therapy among a majority of patients with advanced B-ALL. [Display omitted] DisclosuresMaschan: Miltenyi Biotec: Speakers Bureau.

Tisagenlecleucel Therapy Is Safe and Effective for Children with Down Syndrome with ALL in First Relapse

Introduction: Children with Down Syndrome (DS) have a 20-fold increased incidence of acute lymphoblastic leukemia (ALL) and a 70% higher risk of relapse than children with ALL and no DS. Treatment for DS children with relapsed ALL is challenging due to the high treatment-related mortality associated with both intensive chemotherapy and hematopoietic stem cell transplantation (HSCT) as well as high rates of second relapse. Outcomes for relapsed ALL in DS are dismal, with recent studies citing an event-free survival (EFS) as low as 17%. Alternative treatment approaches are needed for this patient population. Treatment with anti-CD19 chimeric antigen receptor T-cells (CARTs) have shown high remission rates in patients with multiple relapsed/refractory ALL with an acceptable safety profile. CARTs are generally not indicated for first relapse of ALL; DS-specific indications for CARTs do not exist. In Ontario, due to the specific susceptibility of children with DS-ALL, CARTs were made available to this population upon first relapse. We describe the population-based Canadian experience using CARTs for first relapse of DS-ALL.Methods: Efficacy and safety data on all children referred for CARTs at the Hospital for Sick Children, in Toronto, Canada were retrospectively collected in a central database and validated by treating clinicians. Here we report all patients with DS suffering a first relapse of ALL at age <18 years referred for commercially available CARTs (tisagenlecleucel) between 2019 and 2021.Results: Five patients with DS received tisagenlecleucel for first relapse of ALL during the study period. Median age at original diagnosis was 6.3 years (range 3.4-11.5). Four patients presenting with National Cancer Institute (NCI) standard risk and one with NCI high-risk disease were initially treated on Children's Oncology Group based protocols. Four patients presented with relapse >36 months from diagnosis and one patient with early relapse. Mononuclear cells were successfully collected for all patients on the first attempt. Patients were bridged from collection to infusion with low intensity chemotherapy regimens. Tisagenlecleucel was successfully manufactured for all patients and infused at a median of 69 days (range 56-101) from collection of T cells. Four patients developed CRS: two patients grade 1, one patient grade 2, and one patient grade 4 requiring ICU care and treatment with tocilizumab and steroid. All patients achieved minimal residual disease (MRD) negative remission one month after infusion, with B-cell aplasia. Two patients showed early (< 6months post infusion) B-cell recovery consistent with CAR T-cell loss; both received off-label reinfusions of tisagenlecleucel and again achieved B-cell aplasia. One patient had a seizure with the first Fludarabine dose of lymphodepleting (LD) chemotherapy for re-infusion and was found to have elevated intracranial pressure. After treatment with Topiramate and anti-seizure prophylaxis the patient tolerated LD chemotherapy without further neurological events. No patient received further ALL therapy; none went on to HSCT. One patient suffered a CD19-negative relapse 7 months post infusion and was transitioned to palliative-intent treatment. Two patients developed prolonged neutropenia with one patient showing recovery (ANC>1x10E9/l) at 5 months post infusion and the patient who had relapsed disease remained neutropenic until relapse. Infectious complications in the first 6 months post infusion were rare. One patient, who was not neutropenic, required two hospital admissions for line related sepsis. With a median follow-up time of 519 days (range 197-785), the 1-year estimated EFS and overall survival were both 80% (95 th confidence interval 52-100%; Figure 1).Conclusions: Tisagenlecleucel was safe and effective in a small cohort of children with DS and first relapse of CD19+ ALL, with achievement of long-term remissions without further therapy, and an EFS superior to that seen in historical cohorts. Rate of acute complications were not increased compared with reported outcomes in patients without DS. Further evaluation of tisagenlecleucel in this setting is warranted. [Display omitted] DisclosuresKrueger: KITE/Gilead: Consultancy; Novartis: Consultancy; SOBI: Consultancy. Whitlock: Sobi Pharmaceuticals: Consultancy; Novartis: Research Funding; Amgen; Jazz Pharmaceuticals: Honoraria. Gupta: Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure:tisagenlecleucel for early B-cell recovery

Allogeneic CAR-T PBCAR0191 with Intensified Lymphodepletion Is Highly Active in Patients with Relapsed/Refractory B-Cell Malignancies

Allogeneic CAR-T PBCAR0191 with Intensified Lymphodepletion Is Highly Active in Patients with Relapsed/Refractory B-Cell Malignancies