Prolonged Complete Remission Using CAPIZZI-Regimen in Adults with Relapsed B-Cell Precursor Acute Lymphocytic Leukemia with No Access to CAR-T Cells, Inotuzumab or Blinatumomab

CD19-specific chimeric antigen receptor (CAR19) T-cells effectively induce remission of B-cell malignancy, but the cost and complexity of production using viral vectors is a factor limiting widespread application. Furthermore, the small cargo capacity of viral vectors may hamper future development of more heavily engineered CAR T-cells. We demonstrated the feasibility of generating CAR19 T-cells from HLA-matched donors of sibling allogeneic hematopoietic stem cell transplant (HSCT) patients via a simple and inexpensive method using the high-capacity piggyBac transposon. A cohort of 10 patients with relapsed or refractory B-cell acute lymphoblastic leukemia or aggressive lymphoma following HSCT were the first human subjects to receive piggyBac-generated CAR19 T-cells. Treatment with intra-patient escalating doses of CAR19 T-cells was effective, with all 9 evaluable patients achieving complete remission. At a median follow-up of 18.0 months, 5 patients remained in complete remission of B-cell malignancy. One patient died of viral sepsis. Four patients developed cytokine release syndrome of maximum grade 2, and no neurotoxicity or new graft-versus-host disease occurred. However, two patients developed malignant CAR19 T-cell tumors, one of whom was successfully treated; one patient died of the secondary tumor. The piggyBac system represents a feasible alternative to viral vectors for the generation of effective CAR19 T-cells, but its oncogenic potential in the context of the described production process will need to be addressed before any further clinical use is possible. This trial was registered at www.anzctr.org.au as ACTRN12617001579381.

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The response to lymphodepletion impacts PFS in patients with aggressive non-Hodgkin lymphoma treated with CD19 CAR T cells

Blood ◽

10.1182/blood-2018-11-887067 ◽

2019 ◽

Vol 133 (17) ◽

pp. 1876-1887 ◽

Cited By ~ 50

Author(s):

Alexandre V. Hirayama ◽

Jordan Gauthier ◽

Kevin A. Hay ◽

Jenna M. Voutsinas ◽

Qian Wu ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Complete Remission ◽

B Cell ◽

Cytokine Profile ◽

Car T Cells ◽

Non Hodgkin Lymphoma ◽

Cell Immunotherapy ◽

Car T ◽

T Cell Immunotherapy

Abstract Factors associated with durable remission after CD19 chimeric antigen receptor (CAR)-modified T-cell immunotherapy for aggressive B-cell non-Hodgkin lymphoma (NHL) have not been identified. We report multivariable analyses of factors affecting response and progression-free survival (PFS) in patients with aggressive NHL treated with cyclophosphamide and fludarabine lymphodepletion followed by 2 × 106 CD19-directed CAR T cells/kg. The best overall response rate was 51%, with 40% of patients achieving complete remission. The median PFS of patients with aggressive NHL who achieved complete remission was 20.0 months (median follow-up, 26.9 months). Multivariable analysis of clinical and treatment characteristics, serum biomarkers, and CAR T-cell manufacturing and pharmacokinetic data showed that a lower pre-lymphodepletion serum lactate dehydrogenase (LDH) level and a favorable cytokine profile, defined as serum day 0 monocyte chemoattractant protein-1 (MCP-1) and peak interleukin-7 (IL-7) concentrations above the median, were associated with better PFS. MCP-1 and IL-7 concentrations increased after lymphodepletion, and higher intensity of cyclophosphamide and fludarabine lymphodepletion was associated with higher probability of a favorable cytokine profile. PFS was superior in patients who received high-intensity lymphodepletion and achieved a favorable cytokine profile compared with those who received the same intensity of lymphodepletion without achieving a favorable cytokine profile. Even in high-risk patients with pre-lymphodepletion serum LDH levels above normal, a favorable cytokine profile after lymphodepletion was associated with a low risk of a PFS event. Strategies to augment the cytokine response to lymphodepletion could be tested in future studies of CD19 CAR T-cell immunotherapy for aggressive B-cell NHL. This trial was registered at www.clinicaltrials.gov as #NCT01865617.

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Safety and Efficacy of CD19-CAR T Cells in Richter's Transformation after Targeted Therapy for Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood-2020-138904 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 40-40

Author(s):

Ohad Benjamini ◽

Avichai Shimoni ◽

Michal Besser ◽

Noga Shem-Tov ◽

Ivetta Danylesko ◽

...

Keyword(s):

T Cells ◽

Targeted Therapy ◽

Cell Therapy ◽

B Cell ◽

Research Funding ◽

Remission Rate ◽

Lymphocytic Leukemia ◽

Car T Cells ◽

Car T ◽

Grade 3

Background: Richter's transformation (RT) is a rare complication of Chronic Lymphocytic Leukemia (CLL), usually into clonally related diffuse large B cell lymphoma (DLBCL). Currently there is no effective therapy to RT and CLL relapse after targeted therapy. Chimeric antigen receptor-modified T (CART) cells directed to CD19+ B-cell malignancies have promising results in relapsed DLBCL. However, its effectiveness in CLL relapse after targeted therapy and RT is less clear and no systematic reports are available. Methods: From July 2019 to May 2020 we enrolled eight CLL patients with disease transformation after chemoimmunotherapy and therapy with BTK and/or BCL2 inhibitors as part of single center phase 2 CAR T-cell therapy in B-cell malignancies (NCT02772198). Following lymphodepletion consisting of cyclophosphamide and fludarabine patients received an infusion of locally produced 1x106 CD19-CART- cells/kg, which were generated by modifying autologous T cells with retroviral vector encoding a CAR comprising FMC63 anti-CD19 ScFv linked to a CD28 costimulatory domain, and CD3-zeta intracellular signaling domain. Results: All 8 patients (pts) were relatively young with median age at CLL diagnosis of 56y (47-62). Disease transformation developed after a median of 8 years (range 1-16) from CLL diagnosis. Patients treated with CD19-CAR T-cells at median age of 64 y (54-73) having median comorbidity G-CIRS score 2 (0-5), performance status ECOG 1 (0-2) and CCT 66ml/min (26-89). Pts had history of CLL with del17p/TP53 in 83%, 5/6 available, del11q 2/6 prior to transformation. Disease transformation included RT in 6 pts with DLBCL, 1 accelerated CLL and 1 prolymphocytic transformations. Among RT pts 67% (4/6) had advanced stage DLBCL, 50% (3/6) extarnodal and 33% (2/6) bulky disease. Patients received median of 3 (0-5) CLL therapies and 2 (1-3) large cell lymphoma directed therapy. CLL therapies included chemoimunotherpay: 5 Fludarabine, cyclophosphamide, rituximab/obinutuzumab (FCR/FCO), 1 bendamustin rituximab (BR); 5 dual targeted therapy (ibrutinib and Venetoclax), 2 ibrutinib only, 1 venetoclax only. Last CLL treatment was Venetoclax in 71% (5/7) and ibrutinib in 29% (2/7) with 32 (range 15-39) months duration on ibrutinib and 10 (2-17) months on venetoclax. The reason for ibrutinib discontinuation was CLL progression (PD) in 5, disease transformation in 2, and venetocalx discontinuation due to progressive disease (PD) - 4 and transformation - 2. Post transformation all RT pts were treated with R-CHOP, second line tx 2, one patient with prolymphocytic transformation was treated with alemtuzumab, allo-SCT, ibrutinib and venetoclax. All pts had PD before treatment with CAR T-cells, 63% (5/8) had elevated LDH and 5/8 evaluable PET CT before treatment had deauville score (DS) 5 with median SUVmax 8.7 (3.7-21). After infusion of CAR T-cells 7 patients had cytokine release syndrome (CRS), 4 grade 1 and 3 grade 3-4 that required tocilizumab. Three patients had CNS toxicity, two grade 3. Seventy five percent (6/8) developed neutropenia, (3/8) grade 3-4, all neutropenia resolved except in one patient that succumbed to PD, 2 pts had infections (campylobacter and H1N1 influenza, each). There were no fatalities due to CAR T-cell toxicity. There were two fatalities due to disease progression. All 71% (5/8) responders achieved complete response with DS1 in PET CT scan on day 28. After median follow up duration of 6 (4-10) months, 2 patients proceeded to allo-SCT. Conclusion: CD19-CART-cell therapy in CLL patients with disease transformation is safe and has high complete remission rate with promising clinical response. Long term remission rate after CD19-CART-cell therapy for RT needs to be further evaluated in more patients. Disclosures Benjamini: Abbvie Inc: Consultancy, Research Funding. Tadmor:AbbVie: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Medison: Consultancy, Speakers Bureau; Neopharm: Consultancy, Speakers Bureau; 6. Novartis Israel Ltd., a company wholly owned by Novartis Pharma AG: Consultancy, Speakers Bureau. Fineman:Abbvie Inc: Consultancy, Research Funding. Jacobi:Novartis: Consultancy. Avigdor:Takeda, Gilead, Pfizer: Consultancy, Honoraria; Janssen, BMS: Research Funding.

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CAR T-Cell Therapy in Hematologic Malignancies: Clinical Role, Toxicity, and Unanswered Questions

American Society of Clinical Oncology Educational Book ◽

10.1200/edbk_320085 ◽

2021 ◽

pp. 1-20

Author(s):

Saar Gill ◽

Jennifer N. Brudno

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Hodgkin Lymphoma ◽

Lymphoblastic Leukemia ◽

Hematologic Malignancies ◽

Lymphocytic Leukemia ◽

Car T Cells ◽

Car T Cell ◽

Car T

At the time of writing, five anti-CD19 CAR T-cell products are approved by the U.S. Food and Drug Administration for seven different indications in lymphoid malignancies, including B-cell non-Hodgkin lymphoma, pediatric B-cell acute lymphoblastic leukemia, and multiple myeloma. CAR T cells for chronic lymphocytic leukemia, acute myeloid leukemia, and less common malignancies such as T-cell lymphomas and Hodgkin lymphoma are being tested in early-phase clinical trials worldwide. The purpose of this overview is to describe the current landscape of CAR T cells in hematologic malignancies, outline their outcomes and toxicities, and explain the outstanding questions that remain to be addressed.

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Chimeric Antigen Receptor (CAR) T Cells Targeting the CD19 Antigen for the Treatment of Pediatric Relapsed B Cell ALL

Blood ◽

10.1182/blood.v124.21.3716.3716 ◽

2014 ◽

Vol 124 (21) ◽

pp. 3716-3716 ◽

Cited By ~ 1

Author(s):

Kevin J. Curran ◽

Isabelle Riviere ◽

Rachel Kobos ◽

Nancy A. Kernan ◽

Farid Boulad ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

Complete Remission ◽

B Cell ◽

Chimeric Antigen Receptor ◽

Pediatric Patients ◽

Elevated Serum ◽

Car T Cells ◽

Car T

Abstract T cells can be genetically modified to target tumor antigens through the expression of a chimeric antigen receptor (CAR). CAR T cells targeting the CD19 antigen is a novel therapeutic approach for patients with relapsed B cell acute lymphoblastic leukemia (B-ALL). We have previously demonstrated that CAR T cells have a significant clinical benefit in adult patients with relapsed B-ALL. The primary objective of this study (NCT01860937) is to extend the use and test the safety of CD19 specific CAR T cells in children with relapsed CD19+ B-ALL. To date, 11 pediatric patients with very high risk (VHR) or relapsed B-ALL have been enrolled on protocol with a median age of 13 years (range 2-23 years) at time of T cell collection. We have treated 4 pediatric patients with relapsed B-ALL (ages 13, 14, 19, and 22 years) using patient derived T cells expressing a CD19 specific CAR (19-28z). Complete response (complete remission or complete remission with incomplete count recovery) occurred in 2/4 (50%) patients. Severe cytokine release syndrome (sCRS) defined by fever for ≥3 consecutive days, elevated serum cytokine levels, and one clinical sign of toxicity (hypotension, hypoxia, neurologic disorder including altered mental status, obtundation, and/or seizure) occurred in both patients who responded to CAR T cells. Morphologic disease (≥5% bone marrow blasts) at time of treatment was present in three patients including both patients with sCRS. Systemic immunosuppressants (corticosteroids or anti-IL6 receptor antibody tocilizumab) abrogated clinical symptoms of sCRS. Elevated serum cytokines of IFN-g (>20 fold), fractalkine (>20 fold), Flt-3L (>55 fold), IL-5 (>15 fold), IL-6 (>100 fold), and IL-10 (>15 fold) were demonstrated in patients with sCRS. Monitoring of bone marrow demonstrated peak 19-28z CAR T-cell detection within 1-2 weeks following infusion with gradual contracture over 2-3 months. These early results demonstrate the feasibility and significant clinical impact of this approach in patients with relapsed B-ALL. To more rapidly generate statistically relevant data, demonstrate the “exportability” of this technology between academic institutions, and offer this therapeutic option to a broader number of pediatric patients with chemo-refractory B-ALL our trial will expand into a phase I multicenter clinical trial with a collaborating institution. Subsequent cohorts of patients will receive 19-28z CAR T cells and will be evaluated for toxicity, persistence of CAR T cells, and for anti-leukemic efficacy. Disclosures Off Label Use: CAR T cells for relapsed B-ALL. Riviere:Juno Therapeutics: Consultancy, Scientific co-founder and Stock holder Other. Boulad:Genzyme Sanofi: Trials partially funded by Genzyme Sanofi Other. Sadelain:Juno Therapeutics: Consultancy, Scientific co-founder and Stock holder Other. Brentjens:Juno Therapeutics: Consultancy, Scientific co-founder and Stock holder Other.

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Multi-Center Clinical Trial of CAR T Cells in Pediatric/Young Adult Patients with Relapsed B-Cell ALL

Blood ◽

10.1182/blood.v126.23.2533.2533 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2533-2533 ◽

Cited By ~ 8

Author(s):

Kevin J. Curran ◽

Isabelle Riviere ◽

Lewis B. Silverman ◽

Rachel Kobos ◽

Neerav Shukla ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

Complete Remission ◽

B Cell ◽

Research Funding ◽

Adult Patients ◽

Lymphocyte Function ◽

Car T Cells ◽

Car T

Abstract T cells can be genetically modified to target tumor antigens through the expression of a chimeric antigen receptor (CAR). CAR T cells targeting the CD19 antigen is a novel therapeutic approach for patients with relapsed B cell acute lymphoblastic leukemia (B-ALL). We have previously demonstrated that CAR T cells have a significant clinical benefit in adult patients with relapsed B-ALL. The primary objective of this study (NCT01860937) is to extend the use and test the safety of CD19 specific CAR T cells in a multicenter trial for children and young adults with relapsed CD19+ B-ALL. To date, 24 patients with very high risk (VHR) or relapsed B-ALL have been enrolled on protocol with a median age of 12 years (range 2-20 years) at time of T cell collection. We have treated 9 patients with relapsed B-ALL with a median age 15 years (range 3-22 years) using patient derived T cells expressing a CD19 specific CAR (19-28z). Patients received a dose of 1-3 x 10^6 CAR T cells/kg and complete response (complete remission or complete remission with incomplete count recovery) occurred in 5/9 (55%) patients. Significantly, correlations with response included lower disease burden (as assessed by bone marrow cellularity; p<0.02) and fold expansion following CD3/28 bead activation during the generation of CAR T cells (p<0.02). Specifically, BM cellularity ≤50% and fold expansion (average >150 vs <40 fold expansion) was seen in responders compared to non-responders. Pre-collection peripheral blood absolute lymphocyte count, lymphocyte proliferative response (phytohemagglutinin proliferation assay), and CD3 absolute count did not correlate with response in this small sample size. Development of fever and cytokine release syndrome (CRS) occurred in responders including grade I-II (n=2) and grade III-IV (n=3). Systemic immunosuppressants (corticosteroids or anti-IL6 receptor antibody tocilizumab) abrogated clinical symptoms of CRS. Elevated serum cytokines of IFN-g (>20 fold), fractalkine (>20 fold), Flt-3L (>55 fold), IL-5 (>15 fold), IL-6 (>100 fold), and IL-10 (>15 fold) were demonstrated in patients with CRS. Monitoring of bone marrow demonstrated peak 19-28z CAR T cell detection within 1-2 weeks following infusion with gradual contracture over 1-2 months. These early results demonstrate the feasibility and significant clinical impact of this approach in patients with relapsed B-ALL. In an effort to more rapidly generate statistically relevant data, demonstrate the "exportability" of this technology between academic institutions, and offer this therapeutic option to a broader number of pediatric patients with chemo-refractory B-ALL we have expanded this trial to include a collaborating institution. The objective of our trial is not to provide an intent-to-treat cohort, but rather demonstrate the tolerability of this technology in patients with relapsed B-ALL. Furthermore, patients meeting disease eligibility were not pre-screened for lymphocyte function prior to collection and/or treatment. Subsequent cohorts of patients will receive 19-28z CAR T cells and will be evaluated for toxicity, persistence of CAR T cells, and for anti-leukemic efficacy. Disclosures Curran: Juno Therapeutics: Consultancy. Off Label Use: CAR T cells for B-ALL. Riviere:Juno Therapeutics: Other: Co-founder, stockholder and consultant. Prockop:Atara Biotherapeutics: Other: I have no financial disclosures, but Atara Biotherapeutics has exercised a licensing agreement with Memorial Sloan Kettering Cancer Center and MSKCC and some investigators at MSKCC have a financial interest in Atara.. Park:Actinium Pharmaceuticals, Inc.: Research Funding; Juno Therapeutics: Consultancy. O'Reilly:Atara Biotherapeutics: Research Funding. Sadelain:Juno Therapeutics: Other: Co-founder, stockholder and consultant. Brentjens:Juno Therapeutics: Other: Co-founder, stockholder and consultant.

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Autologous-Collected Donor-Derived CD19-Directed Chimeric Antigen Receptor (CD19-CAR) T Cells Induce a Complete Remission in Chemotherapy-Refractory Childhood Acute Lymphocytic Leukemia (ALL) Relapsing After Allogeneic Hematopoietic Stem Cell Transplantation (HSCT).

Blood ◽

10.1182/blood.v120.21.2609.2609 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2609-2609

Author(s):

Daniel W. Lee ◽

Maryalice Stetler-Stevenson ◽

Marianna Sabatino ◽

Barbara Tumaini ◽

Kelly Richards ◽

...

Keyword(s):

Flow Cytometry ◽

T Cells ◽

B Cells ◽

Complete Remission ◽

Lymphocytic Leukemia ◽

Maximum Temperature ◽

Cytokine Release ◽

Cytokine Release Syndrome ◽

Car T Cells ◽

Car T

Abstract Abstract 2609 Children with relapsed or chemotherapy-refractory ALL have a poor prognosis despite the use of aggressive therapies such as HSCT. Chimeric antigen receptor modified T cells targeting the B-cell antigen CD19 have been reported to be effective in adults with B-cell lymphomas and chronic lymphocytic leukemia. We conducted pre-clinical studies with a CD19-CAR consisting of a CD19-specific scFv and the CD28 and CD3z signaling domains. These cells generated significant levels of IFNg, TNFa, and IL-2 in response to ALL blasts and rapidly eradicated human ALL in murine xenografts. We developed a Phase I clinical trial of CD19-CAR modified autologous T cells for children with CD19+ hematologic malignancies. HSCT-na•ve and post-transplant patients are eligible, and cells are collected directly from patients in both cases. CD19-CAR T cells are manufactured in a semi-closed system over an 11-day period. We report results with the first patient, a 13-year old with chemotherapy-refractory ALL that had relapsed after 2 prior matched related donor HSCTs. Peripheral blood (PB) mononuclear cells were collected from the patient on Day -11 by apheresis. T cells were positively selected and activated by incubation with anti-CD3/anti-CD28 paramagnetic beads in IL-2 for 48 hours then transduced with the CD19-CAR gene via retroviral supernatant for an additional 48 hours. Beads were removed and the expanding CD19-CAR T cells were maintained in culture with IL-2 until harvested for infusion on Day 0. A 59-fold expansion of CAR T cells with 65% transduction efficiency was achieved. The patient was pre-treated with fludarabine (25 mg/m2/day on Days -4, -3, -2) and cyclophosphamide (900 mg/m2 on Day -2) prior to the infusion of 1×106 CAR-transduced T cells/kg. The patient developed signs and symptoms of cytokine release syndrome (CRS) on Day +5 with full resolution by Day +11. Manifestations included fever (maximum 41°C), rigors (Grade 1), and hypotension (Grade 2), the latter of which was responsive to two IV fluid boluses. The patient also developed an erythematous rash (Grade 1) of the extremities from Days +7 to +12 and bilateral scrotal swelling and pain (Grade 1) from Days +8 to +10, which was associated with increased testicular blood flow by ultrasound. Cytokine analysis revealed high levels of IL-6 (53.1 pg/ml; normal <5), GM-CSF (59.4 pg/ml; normal <7.8) and IFNg (44.7 pg/ml; normal <15.6). As IL-6 induces release of C-reactive protein (CRP) from the liver, we monitored CRP levels, which mirrored the time course of CRS (Figure). Broad-spectrum antibiotics were administered for neutropenic fever, although all cultures were negative. No other therapeutic interventions were provided aside from routine supportive care. Figure. Maximum temperature in each 24-hour period (Tmax, red solid line) and CRP (blue solid line) correlate with cytokine release syndrome. Dotted lines indicate upper limits of normal. PB flow cytometry performed prior to cell infusion demonstrated 0.04% blasts and 1% normal B-cells. Repeat analysis after infusion revealed clearance of blasts, gradually decreasing B cells, and a maximum of 0.07% CD19CAR T cells (Days +3, +6, and +27). Re-staging evaluation on Day +27 revealed achievement of a complete remission with bone marrow (BM) blasts decreasing from 30% pre to 3% (flow cytometry 5% to 0.6%) and cerebrospinal fluid (CSF) blasts decreasing from 1.5% to 0%. 0.4% of BM T cells expressed the CD19CAR. (Table) Figure. Maximum temperature in each 24-hour period (Tmax, red solid line) and CRP (blue solid line) correlate with cytokine release syndrome. Dotted lines indicate upper limits of normal. PB flow cytometry performed prior to cell infusion demonstrated 0.04% blasts and 1% normal B-cells. Repeat analysis after infusion revealed clearance of blasts, gradually decreasing B cells, and a maximum of 0.07% CD19CAR T cells (Days +3, +6, and +27). Re-staging evaluation on Day +27 revealed achievement of a complete remission with bone marrow (BM) blasts decreasing from 30% pre to 3% (flow cytometry 5% to 0.6%) and cerebrospinal fluid (CSF) blasts decreasing from 1.5% to 0%. 0.4% of BM T cells expressed the CD19CAR. (Table) Day % BM Blasts (Flow) BM CAR % of T cells % PB Blasts PB CAR % of T cells PB B Cells % % CSF Blasts % CSF CAR Pre 30 (5) 0 0.04 0 1 1.5 0 +3 0 0.07 0.9 +6 0 0.07 0.2 +13 0 0 0.1 +27 3 (0.6) 0.4 0.01 0.07 0.06 0 0 Conclusions: A complete remission was successfully induced in a child with chemotherapy-refractory ALL and post-transplant relapse using a single infusion of autologous-collected, donor-derived T cells modified with a CD19-CAR. Treatment was well tolerated and was only associated with mild CRS that was characterized by high levels of IL-6, INFg, and GM-CSF but not IL-1b or TNFa. CRP levels can be used as a readily available biomarker of IL-6-associated CRS. To our knowledge, this is the first CAR-based therapy to be utilized in the post-allogeneic setting using donor-derived T cells collected directly from a pediatric patient. Disclosures: No relevant conflicts of interest to declare.

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CD22-Targeted Chimeric Antigen Receptor (CAR) T Cells Containing The 4-1BB Costimulatory Domain Demonstrate Enhanced Persistence and Superior Efficacy Against B-Cell Precursor Acute Lymphoblastic Leukemia (ALL) Compared To Those Containing CD28

Blood ◽

10.1182/blood.v122.21.1431.1431 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1431-1431 ◽

Cited By ~ 3

Author(s):

Waleed Haso ◽

Haiying Qin ◽

Ling Zhang ◽

Rimas J Orentas ◽

Terry J Fry

Keyword(s):

T Cells ◽

B Cell ◽

Lymphoblastic Leukemia ◽

Cell Precursor ◽

Car T Cells ◽

Car T ◽

Anti Tumor Activity

Abstract B cell precursor acute lymphoblastic leukemia (BCP-ALL) remains a leading cause of death from childhood cancers despite survival rates exceeding 80%. Antibody-based CAR-engineered T cells can recognize and eliminate tumors by binding directly to a surface antigen independent from MHC restriction. CAR immunotherapy against BCP-ALL has demonstrated impressive responses and sustained remission in clinical trials targeting CD19. However, some patients receiving the CD19 CAR T cells relapse with a CD19 negative leukemia. Thus, additional CAR targets are needed. CD22 is a Siglec family lectin consisting of 7 extracellular Ig domains that is expressed on the cell surface from the pre-B cell stage of development through mature B cells and is expressed on most B cell hematologic malignancies. We previously generated a second-generation (CD3-Zeta + CD28 costimulatory domain) anti-CD22 CAR derived from a membrane proximal epitope binding scFv (m971-28z) with potent activity in vivo (Haso W et al, Blood 2013). In clinical trials T cells expressing CD19-targeted CAR with 4-1BB costimulatory domains on CD19 CARs show prolonged persistence. To improve long-term persistence of the CD22 CAR, we re-engineered our CAR vector to include a 4-1BB signaling domain (m971-BBz). In vitro data using m971-BBz improved proliferation and expansion compared to m971-28z especially when lower concentrations of IL2 were included in the culture media. When no IL2 was added to the media only the 4-1BB containing CAR expanded. No difference in killing was detected in in vitro cytotoxicity assays. We next evaluated anti-tumor activity and persistence in the NSG mouse model engrafted with the NALM6-GL cell line on day 0 and treated with CAR T cells on day 3 to directly compare the efficacy of m971-28z and m971-BBz modified T cells activated with either OKT3 or anti-CD3/CD28 beads. m971-BBz outperformed m971-28z in terms of in vivo anti-tumor activity and long-term persistence. This effect was only detected when anti-CD3/CD28 beads were used for T cell expansion. OKT3-activated cells failed to persist and demonstrated inferior antitumor activity compared to bead-expanded T cells irrespective of the costimulatory domain and despite a higher percentage of CD8 T cells with significantly better cytotoxicity in vitro. Interestingly, early peripheral blood numbers of CAR T cells in recipients of bead-expanded products demonstrated a predominance of CD4+CAR T cells consistent with preinfusion CD4/CD8 ratios. At later time points this ratio decreased with a predominance of CD8+CAR T cells. In mice receiving m971-28z CAR the CD8+CAR T cells failed to persist resulting in leukemic relapse. Furthermore, direct comparison to the CD19 CAR (FMC63-BBz) in vivo showed that the anti-CD22 CAR (m971-BBz) has equivalent activity. We conclude that anti-CD3/CD28 bead-activated T cells modified to express an anti-CD22 CAR with a 4-1BB costimulatory domain demonstrates potent antitumor activity with long-term leukemic control and offers a promising therapeutic option for pediatric ALL. Disclosures: No relevant conflicts of interest to declare.

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Posttransplant chimeric antigen receptor therapy

Blood ◽

10.1182/blood-2017-08-752121 ◽

2018 ◽

Vol 131 (10) ◽

pp. 1045-1052 ◽

Cited By ~ 29

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.

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