scholarly journals Haplo-Identical Non-Gene Editing CD7 CAR T-Cells Induced Bone Marrow and Extramedullary Remission in a Pediatric Patient with TP53 Mutated Relapsed and Refractory Early T-Cell Precursor Lymphoblastic Leukemia/Lymphoma after Haploidentical Hematopoietic Stem Cell Transplantation

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4817-4817
Author(s):  
Haiping Dai ◽  
Yang Lin ◽  
Huimin Meng ◽  
Qingya Cui ◽  
Wenjuan Zhu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Pediatric Patient ◽  
Gene Editing ◽  
Lymphoblastic Leukemia ◽  
Cell Precursor ◽  
Hematopoietic Stem ◽  
Car T Cells ◽  
Car T

Abstract Patients with relapsed/refractory early T-cell precursor lymphoblastic leukemia/lymphoma (ETP-ALL/LBL) respond poorly to traditional therapy and have dismal prognosis. CD7 expresses in almost all blasts of T-cell lymphoma/leukemia and represents one of the most promising therapeutic targets for T-ALL/LBL by CD7 targeted chimeric antigen receptor modified T cell therapy (CD7-CART). Because of shared CD7 expression in the majority of normal T-cell surfaces, we utilized an non-gene editing strategy by co-transducing CAR-T cells with a CD7 protein expression blocker (PEBL), and successfully overcame the fratricide as well as maintain the proliferation and cytotoxicity of CD7-CART-cells. Here, we presented the efficacy and safety results of CD7-CART therapy in a pediatric patient with TP53 mutated ETP-ALL/LBL. The patient was diagnosed with ETP-ALL/LBL at 2016, achieved and maintained complete remission (CR) for 2 years with traditional chemotherapy. The disease relapsed at a month after discontinuation of chemotherapy. He underwent haploidentical HSCT at the second CR, but suffered relapse again 2 years post haplo-HSCT. TP53 mutation（VAF:96.5%） and extensive extramedullary infiltration was detected at relapse. The patient was resistant to venetoclax combined with decitabine, homoharringtonine, aclarubicin, cytarabine and granulocyte colony stimulating factor (G-CSF), high-dose cytarabine combined with cladribine, G-CSF, chidamide and CD38 CART therapy. Nanobody derived CD7-CART cells were manufactured from lymphocytes of the donor. The CART cells were negative for CD7, CD223 and CD279. 70.5% of blasts in the bone marrow aspirates were observed prior to CAR T-cells infusion. A total of 5×10 6/kg CD7-CART-cells were infused. CR was confirmed at day 30 bone marrow evaluation and maintained at the last followup at day 91. Partial remission was achieved as evaluated by PET-CT scan at day 93. Persistence of CD7-CART-cells can be detected with flowcytometry until day 96 post CAR T-cells infusion. Grade 3 cytokine release syndrome with high fever and hypotension were observed, which was relived by tocilizumab and dexamethosone. No organ dysfuction and immune effector cell-associated neurotoxicity syndrome were observed. In general, we showed for the first time that the nanobody derived CD7-CART with PEBL technology was a potent and safe salvage therapy in a relapsed/refractory ETP-ALL/LBL patient with high tumor burden. Disclosures No relevant conflicts of interest to declare.

scholarly journals CAR2.0 Therapy for the Management of Post-Transplantation Relapse of B-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 7-7
Author(s):  
Rui Zhang ◽  
Juan Xiao ◽  
Zhouyang Liu ◽  
Yuan Sun ◽  
Sanfang Tu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Cell Acute Lymphoblastic Leukemia

BACKGROUND: Allogeneic haematopoietic stem cell transplantation (allo-HCT) is a standard treatment for relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL). However ~30-40% of patients (pts) still relapse after HCT. We report a cohort of 20 r/rB-ALL pts, who relapsed after HCT, and enrolled in the CAR2.0 study receiving one or two types of CAR-T cells targeting various B-ALL antigens. METHOD: Pts with r/r B-ALL who relapsed after allo-HCT and did not have significant active comorbiditeis, were enrolled in the study. The target antigens were determined based on immunostaining of each pt's leukemia cells, and CAR-T infusions included a single, or a combination of CAR-Ts targeting the following antigens: CD19, CD22, CD123 and CD38. T cells were collected from pts (N=4) or their allogeneic donors (N=16) and transduced with an apoptosis-inducible, safety-engineered lentiviral CAR with the following intracellular signaling domains: CD28/CD27/CD3ζ-iCasp9 (4SCAR). Pts received cyclophosphamide/fludarabine lymphodepleting therapy before infusion of 0.2-5.8x106 CAR-T/kg per infusion. In addition to disease response, we carefully monitored the quality of apheresis cells, efficiency of gene transfer, T cell proliferation rate, CAR-T infusion dose, and the CAR-T copy number in peripheral blood. RESULTS: Among the 20 enrolled pts, 11 were <18 years of age, and 7 were BCR- ABL (P190) positive. Before CAR-T treatment, 7 pts had ≤grade 2 active graft-versus-host disease (GVHD), and 13 pts received chemotherapy or targeted therapy after their relapse post HCT. Six pts had extramedullary relapse and 2 of them also had bone marrow relapse. The tumor burden in bone marrow ranged from minimal residual disease (MRD) negative to 66% of blasts, based on flow cytometry before CAR-T therapy. Five pts had >10% blasts in bone marrow, 8 pts had <3% blasts, and 7 pts had MRD negative bone marrow (summarized in the Table below). Based on the GVHD history, chimerism state and the available T-cell sources, 16 pts used allogeneic HCT donor T-cells for CAR-T preparation. All pts were full donor chimeras prior to CAR-T infusion, except one pt who had 41% donor cells in bone marrow. Eleven pts received a single CD19 CAR-T infusion, with a mean dose of 1.6x106 CAR-T/kg, and ten achieved an MRD remission and one had progressive disease (PD) within 60 days by flow cytometry. The remaining 9 pts received 2 CAR-Ts (CD19 plus CD22, CD123 or CD38 CAR-Ts) given on the same day, and resulted in 8 CR and 1 PD within 60 days. After CAR-T infusion, no cytokine release syndrome (CRS) was observed in 8 pts, and 12 pts experienced CRS of grade 1, which was consistent with the previously described low toxicity profile of the 4SCAR design. Acute GVHD ≤ grade 2 developed in 5 pts within one month following CAR-T cell infusion but all responded well to supportive care and/or cyclosporine infusion. The 2 pts who developed PD after CAR-T infusion included the one with 41% donor chimerism and had grade 2 GVHD and active infections before CAR-T infusion. The other pt with PD following CAR-T had severe bone marrow suppression, low leukocyte count, infections and was transfusion dependent before enrollment. This emphasizes the need for controlling comorbidities before infusion of CAR-T cells. In summary, total 18 patients (90%) achieved negative MRD remission within 2 months of therapy with acceptable CRS. Four pts relapsed (after being in remission for 3 months) and 14 pts are in continued remission, 6 of which for > 1 year. None of these 20 pts received a second HCT after CAR-T infusion. GVHD developed in 5/16 (31%) pts after donor source CAR-T cell infusion within one month, but all responded well to treatment. CONCLUSION: This study focuses on CAR-T cell therapy following relapse after HCT. While the expanded study is ongoing, we present results of the first 20 pts. Use of donor-derived or recipient-derived CAR-T products in pts who relapsed after allo-HCT is well tolerated and it may prolong life expectancy of these pts while maintaining good quality of life. Table Disclosures No relevant conflicts of interest to declare.

scholarly journals Local Manufacture of CD19 CAR-T Cells Using an Automated Closed-System: Robust Manufacturing and High Clinical Efficacy with Low Toxicities

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2625-2625
Author(s):  
Olga Molostova ◽  
Larisa Shelikhova ◽  
Dina Schneider ◽  
Rimma Khismatullina ◽  
Yakov Muzalevsky ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Brain Edema ◽  
Transmembrane Domain ◽  
Lymphoblastic Leukemia ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Grade Iii

Introduction CD19 CAR-T cell products were recently approved as therapy for B-lineage malignancies. We initiated an IIT trial where manufacture of CAR-T cells was performed locally using a unique CD19 CAR with potent anti-leukemic effects. Patients and methods A total of 37 pts with relapsed/refractory B-acute lymphoblastic leukemia (12 female, 25 male, median age 10 y) were screened, 27 pts were enrolled for a trial, 10 were eligible for compassionate use of CD19 CAR-T cell therapy. Sixteen patients had relapsed B-ALL after haploidentical HSCT, 19 pts refractory relapse, 2 induction failure, 13 patients had previous blinatumomab infusion. Eighteen patients had >20% blast cells, median bone marrow leukemia burden for patients with full blown disease was 89%, 19 pts had minimal residual disease (MRD) >0.1% in BM, 3 had skeletal involvement with multiple mass lesions, one had CNS involvement. The CliniMACS Prodigy T cell transduction (TCT) process was used to produce CD19 CAR-T cells. The automated production included CD4/CD8 selection, CD3/CD28 stimulation with MACS GMP T Cell TransAct and transduced with lentiviral vector expressing the CD19CAR gene (second generation CD19.4-1BB zeta with alternate transmembrane domain derived from the TNF superfamily) (Lentigen, Miltenyi Biotec company). T cells were expansion over 10 days in the presence of serum-free TexMACS GMP Medium supplemented with MACS GMP IL-7 and IL-15. Final product was administered without cryopreservation to the patients after fludarabine/cyclophosphamide preconditioning. All patients received prophylactic tocilizumab at 8mg/kg before CAR-T cell infusion. Patients did not receive HSCT as consolidation after CAR-T therapy. Results Thirty-five manufacturing cycles were successful. Median transduction efficacy was 60% (20-80). Median expansion of T cells was x 46 (18-51). CD4:CD8 ratio in the final product was 0.73. The cell products were administered at a dose of 3*106/kg of CAR-T cells in 4 pts, 1*106/kg in 9 pts, 0.5*106/kg in 14 pts, 0.1*106/kg in 8 pts. Two patients received 0.1*106/kg of CAR-T cells produced from haploidentical donors. The cytokine release syndrome (CRS) occurred in 22 (59%) pts and was mostly mild and moderate: grade I - 15 pts, grade II- 4 pts, grade III - 2 pt, grade IV - 1 pt. CAR-T cell related encephalopathy occurred in 15 (40%). Grade I-II neurotoxicity developed in 10 pts, grade III - in 2 pt, grade IV - 1 pt, grade V - 2 pt. In one patient with grade V neurotoxicity concomitant K. pneumonia encephalitis was documented. Severe (grade 3-5) CRS and neurotoxicity were associated exclusively with large leukemia burden (>20% in the bone marrow) at enrollment, p=0,002. Thirty-one patient was evaluable for response at day 28. Four pts had persistent leukemia. In 27 (87%) cases Flow MRD-negative remission was achieved. Disease relapse after initial response was registered in 9 (33%) cases (7 patients had CD19 negative, 2 had CD19 positive relapse). At the moment of reporting, 10 patients have died (3 due to sepsis, 1 due to brain edema, 1 due to brain edema and K. pneumonia encephalitis, 5 due to progression of disease or relapse). Twenty-seven pts are alive, 19 in complete remission with a median follow up of 223 days (41-516 days). Conclusion CliniMACS Prodigy TCT process is a robust CAR-T cell manufacturing platform that enables rapid and flexible provision of CAR-T cells to patients in need. Significant toxicity of CD19 CAR-T cells was associated exclusively with high leukemia burden at enrollment. In the absence of HSCT consolidation relapse rate exceeds 30%. Disclosures Schneider: Lentigen Technology, A Miltenyi Biotec Company: Employment. Preussner:Miltenyi Biotec: Employment. Rauser:Miltenyi Biotec: Employment. Orentas:Lentigen Technology Inc., a Miltenyi Biotec Company: . Dropulic:Lentigen Technology, A Miltenyi Biotec Company: Employment. Maschan:Miltenyi Biotec: Other: lecture fee.

Effect of chimeric antigen receptor-modified T (CAR-T) cells on responses in children with non-CNS extramedullary relapse of CD19+ acute lymphoblastic leukemia (ALL).

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10507-10507 ◽  
Author(s):  
Mala Kiran Talekar ◽  
Shannon L. Maude ◽  
George E Hucks ◽  
Laura S Motley ◽  
Colleen Callahan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Phase 1 ◽  
Single Agent ◽  
Prior History ◽  
Hematopoietic Stem ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

10507 Background: Anti-CD19 CAR-T cell therapies have shown high efficacy in inducing durable marrow responses in patients with relapsed/refractory CD19+ ALL. We now report on outcome of 10 patients with extramedullary (EM) involvement of ALL treated with CAR-T, including 5 patients who had EM disease at time of infusion. Methods: We identified patients treated on pediatric phase 1/2a trials of murine (CTL019) or humanized (CTL119) anti-CD19 CAR-T cells for isolated EM or BM/EM relapse of ALL. EM relapse was defined as involvement of non-CNS site by imaging +/- pathology within 12 months (mos) of infusion. Post infusion, patients had diagnostic imaging done at 1, 3, 6, 9, and 12 mos. Results: Among 97 patients receiving CAR-T, ten (CTL019, n=6; CTL119, n=4) were identified who had EM involvement on average 2.3 mos (range 0-9 mos) prior to infusion; including 5/10 at time of infusion. Sites of EM relapses included testes, sinus, parotid, bone, uterus, kidney and skin, and 5 patients had multiple sites of EM involvement. Patients ranged from 2-4 relapses of their ALL pre-CAR-T. Two had isolated EM relapse (sites were parotid and multifocal bony lesions in one; testis and sinus in second). All 10 patients had undergone hematopoietic stem cell transplantation prior to EM relapse, 2 had received radiation directed to the EM site prior to CAR-T. Five patients evaluated by serial imaging had objective responses: 2 had resolution of EM disease by day 28; 2 had resolution by 3 mos; 1 had continued decrease in size of uterine mass at 3 and 6 mos and underwent hysterectomy at 8 mos with no evidence of disease on pathology. In the 4 patients with prior history of skin or testicular involvement, there was no evidence by exam at day 28. One patient had progressive EM disease within 2 weeks of CAR-T cell infusion and died at 6 weeks. Three relapsed with CD19+ disease [1 skin/medullary- died at 38 mos post CAR-T; 2 medullary (1 died at 17 mos, 1 alive at 28 mos)]. The remaining 6 are alive and well at median follow-up of 10 mos (range 3-16 mos) without recurrence of disease. Conclusions: Single agent CAR-T immunotherapy can induce potent and durable responses in patients with EM relapse of their ALL. Clinical trial information: NCT01626495, NCT02374333.

scholarly journals Sequential CD19- and CD22-CART Cell Therapies for Relapsed B-Cell Acute Lymphoblastic Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2126-2126 ◽  
Author(s):  
Shuangyou Liu ◽  
Biping Deng ◽  
Yuehui Lin ◽  
Zhichao Yin ◽  
Jing Pan ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Hematopoietic Stem ◽  
Free Survival ◽  
Car T Cells ◽  
Car T

Abstract With traditional therapies, the prognosis of relapsed acute lymphoblastic leukemia (ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is extremely poor. Chimeric antigen receptor (CAR) T cell therapy targeting at CD19 has demonstrated a significant efficacy on refractory/relapsed (r/r) B-ALL, but single-target CART could not maintain a long-term remission. Recently, CD22-CART has also shown an exciting result in r/r B-ALL. Here we sequentially applied CD19- and CD22-specific CART cells to treat relapsed B-ALL post-HSCT and observed the therapeutic effect. From June 30,2017 through May 31,2018, twenty-four B-ALL patients (pts) relapsing after allo-HSCT with both antigens CD19 and CD22 expression on blasts were enrolled, the median age was 24 (2.3-55) years. Seventeen pts had hematologic relapse, 6 with both bone marrow and extramedullary (EM) involvements and 1 with EM disease (EMD) only. Fourteen pts had failed to previous therapies including chemotherapy, donor lymphocyte infusion, interferon and even murinized CD19-CART in other hospitals. Recipient-derived donor T cells were collected for producing CAR-T cells, which were transfected by a lentiviral vector encoding the CAR composed of CD3ζ and 4-1BB. Eighteen pts were initially infused with murinized CD19-CART, then humanized CD22-CART; while 6 pts (5 failed to prior murinized CD19-CART and 1 had bright CD22-expression) were initially infused with humanized CD22-CART, then humanized CD19-CART. The time interval between two infusions was 1.5-6 months based on patients' clinical conditions. The average dose of infused CAR T cells was 1.4×105/kg (0.4-9.2×105/kg) for CD19 and 1.9×105/kg (0.55-6.6×105/kg) for CD22. All patients received fludarabine with or without cyclophosphamide prior to each infusion, some pts accepted additional chemo drugs to reduce the disease burden. Treatment effects were evaluated on day 30 and then monthly after each CART, minimal residual disease (MRD) was detected by flow cytometry (FCM) and quantitative PCR for fusion genes, EMD was examined by PET-CT, CT or MRI. Sixteen patients finished sequential CD19- and CD22-CART therapies. Three cases could not undergo the second round of CART infusion (1 died, 1 gave up and 1 developed extensive chronic graft-versus-host disease (GVHD)). The rest of 5 pts are waiting for the second CART. After first T-cell infusion, 20/24 (83.3%) pts achieved complete remission (CR) or CR with incomplete count recovery (CRi), MRD-negative was 100% in CR or CRi pts, 3 (12.5%) cases with multiple EMD obtained partial remission (PR), and 1 (4.2%) died of severe cytokine release syndrome (CRS) and severe acute hepatic GVHD. Sixteen patients (15 CR and 1 PR) underwent the second CART therapy. Before second infusion, 3/15 pts in CR became MRD+ and others remained MRD-. On day 30 post-infusion, 1 of 3 MRD+ pts turned to MRD-, 1 maintained MRD+ ( BCR/ABL+) and 1 had no response then hematologic relapse later. The PR patient still had not obtained CR and then disease progressed. As of 31 May 2018, at a median follow-up of 6.5 (4-10) months, among 16 pts who received sequential CD-19 and CD-22 CART therapies, 1 had disease progression, 2 presented with hematological relapse and 2 with BCR/ABL+ only, the overall survival (OS) rate was 100% (16/16), disease-free survival (DFS) was 81.3% (13/16) and MRD-free survival was 68.8% (11/16). CRS occurred in 91.7% (22/24) pts in the first round of T-cell infusion, most of them were mild-moderate (grade I-II), merely 2 pts experienced severe CRS (grade III-IV). The second CART only caused grade I or no CRS since the leukemia burden was very low. GVHD induced by CART therapy was a major adverse event in these post-HSCT patients. After the first CART, 7/24 (29.2%) pts experienced GVHD, of them, 4 presented with mild skin GVHD, 2 with severe hepatic GVHD (1 recovered and 1 died), and 1 developed extensive chronic GVHD. No severe GVHD occurred in the second infusion. Our preliminary clinical study showed that for B-ALL patients who relapsed after allo-HSCT, single CD19- or CD22- CART infusion resulted in a high CR rate of 83.3%, sequentially combined CD19- and CD22-CART therapies significantly improved treatment outcome with the rate of OS, DFS and MRD-free survival being 100%, 81.3% and 68.8%, respectively, at a median follow-up of 6.5 months. The effect of CART on multiple EMD was not good and CART induced GVHD needs to be cautious. Disclosures No relevant conflicts of interest to declare.

scholarly journals Posttransplant chimeric antigen receptor therapy

Blood ◽  
2018 ◽  
Vol 131 (10) ◽  
pp. 1045-1052 ◽  
Author(s):  
Melody Smith ◽  
Johannes Zakrzewski ◽  
Scott James ◽  
Michel Sadelain
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Cell Surface Molecule ◽  
Hematopoietic Stem ◽  
Car T Cells ◽  
Car T

Abstract Therapeutic T-cell engineering is emerging as a powerful approach to treat refractory hematological malignancies. Its most successful embodiment to date is based on the use of second-generation chimeric antigen receptors (CARs) targeting CD19, a cell surface molecule found in most B-cell leukemias and lymphomas. Remarkable complete remissions have been obtained with autologous T cells expressing CD19 CARs in patients with relapsed, chemo-refractory B-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma. Allogeneic CAR T cells may also be harnessed to treat relapse after allogeneic hematopoietic stem cell transplantation. However, the use of donor T cells poses unique challenges owing to potential alloreactivity. We review different approaches to mitigate the risk of causing or aggravating graft-versus-host disease (GVHD), including CAR therapies based on donor leukocyte infusion, virus-specific T cells, T-cell receptor–deficient T cells, lymphoid progenitor cells, and regulatory T cells. Advances in CAR design, T-cell selection and gene editing are poised to enable the safe use of allogeneic CAR T cells without incurring GVHD.

scholarly journals Haploidentical Donor-Derived CAR-T Cells Are Safely and Effectively Co-Infused with the Haploidentical Graft, Depleted of Ab T Cells: Report of Case Series

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1736-1736
Author(s):  
Larisa Shelikhova ◽  
Olga Molostova ◽  
Arina Rakhteenko ◽  
Rimma Khismatullina ◽  
Julia Abugova ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Median Time ◽  
Lymphoblastic Leukemia ◽  
Hematopoietic Stem ◽  
Platelet Recovery ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Grade 3

Abstract Introduction Autologous chimeric antigen receptor (CAR) T cells induce high rate of deep remissions among children with relapsed/refractory B-precursor acute lymphoblastic leukemia (R/R B-ALL). In a significant proportion of patients true cure is achieved only with HSCT as post-CAR-T consolidation. Seeking to combine the cytoreductive and curative power of HSCT with the antigen-specific activity of CAR-T we devised an approach with simultaneous infusion of haploidentical ab T cell-depleted graft and CAR-T cells, derived from the same donor. The approach was offered to patients with R/R B-ALL on a compassionate use basis and here the first experience is summarized. Patients and methods A total of 11 patients with relapsed/refractory BCP-ALL (n-10) and Burkitt leukemia(n-1), (5 female, 6 male, median age 8,3 y) were treated. Three patients had relapsed BCP-ALL after both haploidentical HSCT and autologous CD19 CAR-T cell, 3 after haploidentical HSCT, 2 after autologous CD19 CAR-T cell, 3 after intensive chemotherapy +/- blinatumomab (n=2). Seven patients had CD19 and CD22 positive leukemic cells in bone marrow (MRD+ n=1, >20% blasts n=6), 2 pts had MRD-level disease with CD22 positive blast cells and 2 pts were in CR2. Peripheral blood mononuclear cells used to produce CAR T cells were provided by the patient's transplant donor. The CliniMACS Prodigy T cell transduction (TCT) process was used to produce CD19 and СD19/22CAR-T cells. Five (45%) pts received treosulfan-based myeloablative preparative regimen, while TBI-based regimen was used in 6 (55%) pts. GvHD prophylaxis included tocilizumab at 8 mg/kg on day -1 and abatacept at 10 mg/kg on day -1, +7, +14, +28. Final product was administered without cryopreservation to the patients: 10 pts received allogeneic CAR T cell with haploidentical (n=10) and match related (n=1) TCRαβ-depleted graft (CD19 CAR- T cell n=1 and CD19/22 CAR- T cell n=10). The CAR-T cell product was administered at a dose of 0,1*10 6/kg of CAR-T cells in all pts. The median dose of CD34+ cells was 8.5 x10 6/kg (range 5-15), αβ T cells - 56x10 3/kg (range 9-172). Results Primary engraftment was achieved in 10 of 11 pts (non-engraftment patient relapsed early), the median time to neutrophil and platelet recovery was 13 and 14 days, respectively. Cytokine release syndrome occurred in 7 patients (63%) and all were grade ≤3. Six patients (54%) had neurologic events (ICANS grade 3, n=1). No aGVHD 3-4 were observed, 4 pts developed grade 2 aGVHD (skin and gut). The median time to CAR-T cell peak expansion was 14 days (7-28). The median time to CAR-T cell persisted was 6 months (2-12) and B cell aplasia was 7 months. All engrafted patients achieved CR (MRD negative) at day +28 after CAR-T cell therapy, one patient died due to Mucormycosis at day +31. One patient relapsed after 2 months after HST. Eight patients are alive in CR with a median follow up 291 days (85-388). Conclusion Our early experience suggests that haploidentical CAR-T cells can be safely infused simultaneously with the hematopoietic stem cell graft on the platform of ab T cell depletion. The infusions did not compromise engraftment and GVHD control, while specific CAR-T toxicity was mild and manageable. We have documented allogeneic haploidentical CAR-T expansion and persistence. Prospective testing of the approach is warranted. Disclosures Maschan: Miltenyi Biotec: Speakers Bureau.

scholarly journals Treatment Outcome of Pediatric B-ALL with Bone Marrow and Extramedullary Relapse by Anti-CD19 CAR-T

2021 ◽  
Author(s):  
Xinyu Wan ◽  
Fan Yang ◽  
Xiaomin Yang ◽  
tianyi Wang ◽  
Lixia Ding ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Lentiviral Vector ◽  
Lymphoblastic Leukemia ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Hematopoietic Stem ◽  
Car T Cells ◽  
Car T ◽  
Extramedullary Relapse

Background: Anti-CD19 Chimeric Antigen Receptor T-Cell Immunotherapy (19CAR-T) has achieved impressive clinical achievements in both adult and pediatric relapsed/refractory (r/r) B-lineage acute lymphoblastic leukemia (B-ALL). However, the application and effect of CAR-T therapy in B-ALL patients with extramedullary relapse are rarely issued even disqualified in some clinical trials. Here, we examined the efficacy of 19CAR-T in patients with both bone marrow and extramedullary involvement. Methods: CAR-T cells were generated by a lentiviral vector transfection into primary human T lymphocytes to express anti-CD19 and anti-CD22 single chain antibody fragments (scFvs) with the cytoplasmic domains of 4-1BB and CD3ζ. Patients diagnosed as r/r B-ALL with extramedullary origination were infused with anti-CD19 CAR-T cells. The clinical responses were evaluated by bone marrow aspiration, imaging, and flow cytometry examination. Results: A total of 8 patients received 19CAR-T infusion and all of them acquired complete remission (CR), in which only 1 patient was bridged to hematopoietic stem cell transplantation (HSCT). Even though there were 3 patients relapsed after infusion, they received 19/22CAR-T infusion sequentially and acquired the second remission. To date, 5 patients are continuous CR, and all patients are still alive. The mean follow-up time was 21.9 months while the 24-month estimated event-free survival (EFS) is 51.4%. Conclusions: Anti-CD19 CAR-T therapy can lead to clinical remission for extramedullary relapsed pediatric B-ALL patients. However, the problem of CD19+ relapses after CAR-T remained to be solved. For patients relapsing after CAR-T, the second CAR-T therapy suggests creating another opportunity of remission for subsequent HSCT.

scholarly journals Corticosteroids Do Not Influence the Efficacy and Kinetics of CAR-T Cells for B-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 228-228 ◽  
Author(s):  
Shuangyou Liu ◽  
Biping Deng ◽  
Jing PAN ◽  
Zhichao Yin ◽  
Yuehui Lin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Lymphoblastic Leukemia ◽  
High Dose ◽  
Car T Cells ◽  
Steroid Group ◽  
Car T ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Kinetics Of

Cytokine release syndrome (CRS) is the most prominent and potentially life-threatening toxicity caused by chimeric antigen receptor (CAR) T cell therapy, therefore, effectively controlling severe CRS is critical to ensure patient safety. Tocilizumab, an interleukin-6 receptor antagonist, has been widely used to treat CRS, whereas it is not clear if corticosteroids could be as another optimal choice for managing CRS. We applied corticosteroids instead of tocilizumab as the first-line agent to control CRS in patients with relapsed/refractory B-cell acute lymphoblastic leukemia during CAR-T therapy. The impacts of steroids on treatment efficiency and kinetics of CAR-T cells were assessed by comparing two groups of patients who did (42 cases) or did not (26 cases) receive steroids. Patients followed up less than one month (went to other hospitals for transplantation or died within one month) were excluded. Treatment effects were evaluated on day 30 after T-cell infusion and then monthly in follow-up patients. Minimal residual disease (MRD) was detected by multiparameter flow cytometry (FCM) and quantitative PCR for fusion genes. The dynamic monitoring of CAR-T cells was performed through flow cytometric quantitation of FITC+CD3+ T cells. B-cell aplasia (BCA) was assayed by FCM. Dexamethasone or methylprednisolone or both (alternately) were administrated. Dexamethasone was used in most cases especially for patients with neurologic symptoms; methylprednisolone was preferred for patients with pulmonary or liver dysfunction, and patients accepting high dose steroids. Steroids started with low dose and could be increased if symptoms were not resolved, for severe CRS, steroids would be escalated up to dexamethasone 20mg/m2/d or more higher up to methylprednisolone 10mg/kg/d. Once CRS was improved, steroids were rapidly reduced and stopped. A total of 68 patients (28 adults and 40 children younger than 18 years) were included, 22 (32.4%) presented with extramedullary diseases (EMD), bone marrow blasts in patients without EMD varied between 5%-96.5%, 31 (45.6%) patients had an allogeneic transplantation, 54 (79.4%) cases received CD19-specific and 14 (20.6%) received CD22-specific CAR-T therapy. Forty-two (61.8%) cases, including all (10) of grade III CRS, 68.2% (30/44) of grade II CRS and 2 patients with no CRS but with GVHD (1 case) or neurotoxicity (1 case), were administered steroids, among them, 23/42 (54.8%) received high dose steroids (>10mg/m2/d dexamethasone or equivalent), the duration of steroid use was 1-16 days (78.6% <= 7 days); whereas 26 (38.2%) patients were not given any steroids but the supportive care. We found that there was no difference either in complete remission (CR) rate (95.2% vs 92.3%, p=.344) or in MRD negative CR rate (80.0% vs 79.2%, p=.249) between steroid and non-steroid group, verified that corticosteroids even high dose steroids did not influence the treatment response. Furthermore, we investigated the dynamics of CAR-T cells. Firstly, the expansion of CAR-T cells in peripheral blood (PB) was evaluated, the average CAR-T cell counts in steroid group were significantly higher than those in non-steroid group on D11 (p=.0302), D15 (p=.0053), D20 (p=.0045) and D30 (p=.0028), except for D7 when CAR-T cells began to expand (p=.9815), this demonstrated that steroids did not suppress the proliferation of CAR-T cells in PB. Secondly, the percentages of patients with detectable CAR-T cells in bone marrow (BM) and cerebrospinal fluid (CSF) were compared between steroid and non-steroid group, there were no differences both in BM (85.2% vs 78.6%, p=.923) and in CSF (68.6% vs 57.9%, p=.433), which implied steroids did not influence the trafficking of T-cells to BM and CSF. Thirdly, we monitored B-cell aplasia (BCA) in part of patients followed-up more than 2 months without further treatments, the percentages of patients with BCA in steroid group had no significant differences compared to non-steroid group at 2-month (p=.086) and 3-month (p=.146). Later, although limited cases left, in the steroid group, 100% of patients (4-month, 7/7; 5-month, 7/7; 6-month, 5/5) still maintained BCA and CR, indicating that corticosteroids did not impact the duration of functional CAR-T cells. In conclusion, corticosteroids do not compromise the treatment efficacy and kinetics of CAR-T cells, could be as a feasible and effective approach to manage CAR-T associated CRS. Disclosures No relevant conflicts of interest to declare.

Siglec-6 is a novel target for CAR T-cell therapy in acute myeloid leukemia (AML)

Blood ◽  
2021 ◽  
Author(s):  
Hardikkumar Jetani ◽  
Almudena Navarro-Bailón ◽  
Marius Maucher ◽  
Silke Frenz ◽  
Christina Mathilde Verbruggen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Hematopoietic Stem ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Novel Target

Acute myeloid leukemia (AML) is attractive for the development of CAR T-cell immunotherapy because AML blasts are susceptible to T-cell-mediated elimination. Here, we introduce sialic-acid-binding immunoglobulin-like lectin (Siglec)-6 as a novel target for CAR T-cells in AML. We designed a Siglec-6-specific CAR with a targeting-domain derived from a human monoclonal antibody JML‑1. We found that Siglec-6 is prevalently expressed on AML cell lines and primary AML blasts, including the subpopulation of AML stem cells. Treatment with Siglec-6-CAR T-cells confers specific anti-leukemia reactivity that correlates with Siglec-6-expression in pre-clinical models, including induction of complete remission in a xenograft AML model in immunodeficient mice (NSG/U937). In addition, we confirmed Siglec-6-expression on transformed B-cells in chronic lymphocytic leukemia (CLL) and show specific anti-CLL-reactivity of Siglec-6-CAR T-cells in vitro. Of particular interest, we found that Siglec-6 is not detectable on normal hematopoietic stem and progenitor cells (HSC/P) and that treatment with Siglec-6-CAR T-cells does not affect their viability and lineage differentiation in colony-formation assays. These data suggest that Siglec-6-CAR T-cell therapy may be used to effectively treat AML without a need for subsequent allogeneic hematopoietic stem cell transplantation. In mature normal hematopoietic cells, we detected Siglec-6 in a proportion of memory (and naïve) B-cells and basophilic granulocytes, suggesting the potential for limited on-target/off-tumor reactivity. The lacking expression of Siglec-6 on normal HSC/P is a key differentiator from other Siglec-family members (e.g. Siglec-3=CD33) and other CAR target antigens, e.g. CD123, that are under investigation in AML and warrants the clinical investigation of Siglec-6-CAR T-cell therapy.

CAR T cells targeting CD99 as an approach to eradicate T-cell Acute Lymphoblastic Leukemia without normal blood cells toxicity

2021 ◽  
Author(s):  
Jiangzhou Shi ◽  
Zijian Zhang ◽  
Hong Cen ◽  
Han Wu ◽  
Shangkun Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bone Marrow Cells ◽  
Clinical Success ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cells ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T ◽  
Pilot Clinical Study

Abstract CAR T cell therapy has shown dramatic clinical success in relapsed or refractory (r/r) B-ALL and other haematological malignancies. However, the loss of specific antigens, cell fratricide, T cell aplasia, and normal T cell separation are challenges in treating T cell leukemia/lymphoma with CAR T therapy. CD99 is a promising antigen to target T-ALL and AML as it is expressed on the majority of T-ALL and AML. Here, we isolated a low-affinity CD99 (12E7) antibody, which specifically recognizes leukemia cells over normal bone marrow cells. T cells transduced with an anti-CD99-specific CAR that contained the 12E7 scFv expanded with minor fratricide, maintained their cytotoxic function and mediated powerful antitumour effects. Subsequently, we conducted a pilot clinical study to evaluate the safety and feasibility of therapy with anti-CD99 CAR T cells in 4 patients with r/r T-LBL (n=1), AML (n=2) or myeloid sarcoma (MS) (n=1). The clinical overall response rate (ORR) was 50% (2/4 patients), and 1 patients (25%) achieved complete remission (CR) for 2 month. Mild cytokine release syndrome (CRS) occurred in 2 patients and the CRS no more than grade 2. Together, our results demonstrate that anti-CD99 CAR T cells specifically recognize and efficiently eliminate CD99+ leukemia cells.

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