scholarly journals Characteristics of Post-Infusion Chimeric Antigen Receptor (CAR) T Cells and Endogenous T Cells Associated with Early and Long-Term Response in Lisocabtagene Maraleucel (liso-cel)-Treated Relapsed or Refractory (R/R) Large B-Cell Lymphoma (LBCL)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3834-3834
Author(s):  
Jerill Thorpe ◽  
Yue Jiang ◽  
Julie A Rytlewski ◽  
Ana Kostic ◽  
Yeonhee Kim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Rna Seq ◽  
Publicly Traded ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Post Infusion ◽  
Term Response

Abstract Background: Liso-cel is an autologous, CD19-directed, defined composition, 4-1BB CAR T cell product administered at equal target doses of CD8 + and CD4 + CAR + T cells. In the pivotal TRANSCEND NHL 001 study (NCT02631044) in patients (pts) with R/R LBCL after ≥ 2 prior lines of therapy, liso-cel demonstrated significant clinical activity with an objective response rate of 73%, complete response (CR) rate of 53%, and median duration of response (DOR) not reached at 12 months' median DOR follow-up, and a low incidence of severe cytokine release syndrome (2%) and neurological events (10%; Abramson et al. Lancet 2020;396:839-852). While CAR T cells have shown remarkable efficacy in treating LBCL, with a well-understood mechanism of direct CAR T cell tumor killing, the contribution of the endogenous immune system in this response is currently unclear. Previously, histologic and gene expression analysis of pre- and posttreatment tumor biopsies from pts who received liso-cel in TRANSCEND NHL 001 showed a relationship between tumor-infiltrating CAR-negative (endogenous) T cells and early and durable response [Reiss et al. Blood 2019;134(suppl 1):202]. Here we examine, by gene expression and flow cytometry, post-infusion characteristics of liso-cel and peripheral endogenous T cells in pts from TRANSCEND NHL 001 with early (CR at 1 or 3 months) and long-term (CR at 9 or 12 months) response versus pts with progressive disease (PD) before or at the same time points. Methods: CAR and endogenous T cells were assayed using a novel cell-sorting and low-input RNA-seq method. CAR and endogenous T cells were isolated from peripheral blood mononuclear cell samples from 39 pts at time to maximum concentration of liso-cel (T max; Day 8-22), 1 month, and 2 months after liso-cel infusion. In addition, samples from 44 pts were assayed only at T max by RNA-seq. A subset of these samples was assessed by flow cytometry for expression of the T cell differentiation markers CD4, CD8, CD45RA, CCR7, CD27, and CD28. All RNA-seq analyses were performed in R version 4.0.2. Differential expression analysis was performed with the DESeq2 package with gene set enrichment analysis using clusterProfiler and GSVA packages with gene sets obtained from MSigDB. Comparisons of 2 groups were made with a Wilcoxon rank sum test. Association with the time-to-event outcome of progression-free survival (PFS) was assessed using Cox proportional hazards model or log rank test. Results: Characteristics consistent with less differentiated CAR T cells and endogenous T cells were significantly associated with early and long-term response. Elevated CAR T cell expression of CD27 at T max was associated with CR at 1 month and longer PFS. Expression of CCR7 by CAR T cells at 1 and 2 months was associated with CR at 9 months. Additionally, at T max, gene sets associated with T cell effector differentiation and metabolism were enriched in CAR T cells from pts with early relapse (pts with CR vs PD at 3 months). In endogenous T cells, elevated expression of CCR7 and CD28 at T max was associated with early response (CR at 1 and 3 months). Additionally, expression of CCR7 and CD28 in T cells isolated at 1 and 2 months was associated with long-term response (CR at 9 and 12 months). Furthermore, expression of the immune checkpoint receptor LAG3 by endogenous T cells was associated with PD from month 3 to month 12. Conclusions: In summary, the data from our study show the relationship between CAR T cell differentiation status and achieving response over time, and provide new evidence for the involvement of endogenous T cells in the therapeutic efficacy of CAR T cell therapy. Disclosures Thorpe: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Jiang: Bristol Myers Squibb: Ended employment in the past 24 months. Rytlewski: Adaptive Biotechnologies: Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months; Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Kostic: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Kim: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Peiser: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company.

scholarly journals Decade-long remissions of leukemia sustained by the persistence of activated CD4+ CAR T-cells

2021 ◽  
Author(s):  
Jan Joseph Melenhorst ◽  
Gregory M Chen ◽  
Meng Wang ◽  
David . L Porter ◽  
Peng Gao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymphocytic Leukemia ◽  
Late Time ◽  
Sustained Remission ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Post Infusion

The adoptive transfer of T lymphocytes reprogrammed to target tumor cells has demonstrated significant potential in various malignancies. However, little is known about the long-term potential and the clonal stability of the infused cells. Here, we studied the longest persisting CD19 redirected chimeric antigen receptor (CAR) T cells to date in two chronic lymphocytic leukemia (CLL) patients who achieved a complete remission in 2010. CAR T-cells were still detectable up to 10+ years post-infusion, with sustained remission in both patients. Surprisingly, a prominent, highly activated CD4+ population developed in both patients during the years post-infusion, dominating the CAR T-cell population at the late time points. This transition was reflected in the stabilization of the clonal make-up of CAR T-cells with a repertoire dominated by few clones. Single cell multi-omics profiling via Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) with TCR sequencing of CAR T-cells obtained 9.3 years post-infusion demonstrated that these long-persisting CD4+ CAR T-cells exhibited cytotoxic characteristics along with strong evidence of ongoing functional activation and proliferation. Our data provide novel insight into the CAR T-cell characteristics associated with long-term remission in leukemia.

scholarly journals Decade-long remissions of leukemia sustained by the persistence of activated CD4+ CAR T-cells

2021 ◽  
Author(s):  
Jan Melenhorst ◽  
Gregory Chen ◽  
Meng Wang ◽  
David Porter ◽  
Peng Gao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymphocytic Leukemia ◽  
Late Time ◽  
Sustained Remission ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Post Infusion

Abstract The adoptive transfer of T lymphocytes reprogrammed to target tumor cells has demonstrated significant potential in various malignancies. However, little is known about the long-term potential and the clonal stability of the infused cells. Here, we studied the longest persisting CD19 redirected chimeric antigen receptor (CAR) T cells to date in two chronic lymphocytic leukemia (CLL) patients who achieved a complete remission in 2010. CAR T-cells were still detectable up to 10+ years post-infusion, with sustained remission in both patients. Surprisingly, a prominent, highly activated CD4+ population developed in both patients during the years post-infusion, dominating the CAR T-cell population at the late time points. This transition was reflected in the stabilization of the clonal make-up of CAR T-cells with a repertoire dominated by few clones. Single cell multi-omics profiling via Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) with TCR sequencing of CAR T-cells obtained 9.3 years post-infusion demonstrated that these long-persisting CD4+ CAR T-cells exhibited cytotoxic characteristics along with strong evidence of ongoing functional activation and proliferation. Our data provide novel insight into the CAR T-cell characteristics associated with long-term remission in leukemia.

scholarly journals Decade-Long Remissions of Leukemia Sustained By the Persistence of Activated CD4+ CAR T-Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 166-166
Author(s):  
J. Joseph Melenhorst ◽  
Gregory M Chen ◽  
Meng Wang ◽  
David L. Porter ◽  
Peng Gao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Post Infusion

Abstract The adoptive transfer of chimeric antigen receptor (CAR)-reprogrammed T lymphocytes has demonstrated significant potential in various malignancies. Functional persistence of CAR T-cells in chronic lymphocytic leukemia (CLL) is a key predictor of durable remissions, yet the characteristics of long-term persisting CAR-engineered T cells have not been extensively studied. We here studied the fate of CD19-specific (CAR19) T-cells in two leukemia patients who achieved and sustained a complete remission over a decade ago. Molecular fate mapping was carried out on long-term persisting CAR T cells using lentiviral vector integration site sequencing across multiple time points up to 9.0 and 7.2 years post-infusion in patients 1 and 2, respectively. This analysis revealed little if any CAR T-cell clonal stability in the first 1.6 years in patient 1. Close to year 2 the CAR T cell repertoire stabilized in the first patient, with a strong clonal focusing until the last follow-up. The second patient had episodes of repertoire stability from the first month to approximately 12 months later, as well as from year 1 to 5. The CAR T cell repertoire in both patients were dominated by a few clones which were detected across a multiyear time span. CAR T-cells were still detectable using flow and mass cytometry 10+ years post-infusion. Deep immunophenotyping using a 40-marker mass cytometry panel identified divergence in effector but convergence in memory CAR T cell characteristics, with a prominent highly activated effector-memory CD4+ population developing late after infusion, expressing immune regulatory molecules. The CD4+ CAR T-cells were notable for a subpopulation highly expressing Ki67, suggestive of a proliferative phenotype. Ki67[hi] CD4+ CAR T-cells steadily emerged as the dominant population in both patients: this population constituted 15.9% of CAR T-cells at month 1.8 in patient 1, increasing to 97.0% by year 9.3; and constituted 0.2% of CAR T-cells in patient 2 at month 2.4, increasing to 87.2% by year 7.2. We assessed Ki67 expression in the CD4+ CAR T-cells compared to the CAR-negative T cells from these patients at matched time points, finding that this level of Ki67 expression was strongly CAR T-cell specific. CD8+ CAR T-cells also exhibited a proliferative trend overall, but Ki67 expression was generally lower and less robustly observed compared to the CD4+ CAR T-cell subset. These Ki67[hi] CD4+ T cells expressed a distinct marker profile, including activation markers CD38, HLA-DR, and CD95; transcription factors EOMES and TOX; checkpoint markers CTLA-4, LAG-3, TIGIT; and memory markers CD27 and CCR7. Together, these data suggest two major phases of CAR T-cell therapy responses in these patients: an initial response phase dominated by cytotoxic CD8+ T cells and double-negative Helios[hi] CAR T-cells, and a long-term remission phase dominated by a uniquely proliferative CD4+ CAR T-cell phenotype. To characterize these long-persisting CAR T-cells at a single-cell resolution, we performed CITE-Seq with single-cell T cell receptor-beta VDJ profiling on CAR T-cells obtained 9.3 years post-infusion. These long-persisting CAR T-cells exhibited strong evidence of ongoing activation, proliferation, and aerobic glycolysis despite evidence of chronic antigen-mediated signaling. Our data in aggregate provide important insight into and the development of a long-term memory anti-tumor response, necessary for sustained remission in leukemia following CAR T-cell therapy. Disclosures Porter: Wiley and Sons Publishing: Honoraria; Novartis: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Unity: Patents & Royalties; National Marrow Donor Program: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Membership on an entity's Board of Directors or advisory committees; GenenTech: Current Employment, Current equity holder in publicly-traded company; Incyte: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; DeCart: Membership on an entity's Board of Directors or advisory committees; ASH: Membership on an entity's Board of Directors or advisory committees; American Society for Transplantation and Cellular Therapy: Honoraria. Pruteanu-Malinici: Novartis: Current Employment. Frey: Sana Biotechnology: Consultancy; Novartis: Research Funding; Syndax Pharmaceuticals: Consultancy; Kite Pharma: Consultancy. Gill: Interius Biotherapeutics: Current holder of stock options in a privately-held company, Research Funding; Novartis: Other: licensed intellectual property, Research Funding; Carisma Therapeutics: Current holder of stock options in a privately-held company, Research Funding. Davis: Tmunity Therapeutics: Consultancy, Patents & Royalties, Research Funding; Cellares Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Patents & Royalties. Brogdon: Novartis Institutes for Biomedical Research: Current Employment. Young: Novartis: Patents & Royalties; Tmunity Therapeutics: Patents & Royalties. Levine: Immuneel: Membership on an entity's Board of Directors or advisory committees; In8bio: Membership on an entity's Board of Directors or advisory committees; Immusoft: Membership on an entity's Board of Directors or advisory committees; Akron: Membership on an entity's Board of Directors or advisory committees; Ori Biotech: Membership on an entity's Board of Directors or advisory committees; Vycellix: Membership on an entity's Board of Directors or advisory committees; Avectas: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Other: Co-Founder and equity holder. Siegel: Vetigenics, LLC: Other: Co-Founder and Equity Holder; Verismo Therapeutics, Inc: Other: Co-Founder and Equity Holder. Wherry: Merck: Consultancy; Marengo: Consultancy; Janssen: Consultancy; Related Sciences: Consultancy; Synthekine: Consultancy; Surface Oncology: Consultancy. June: AC Immune, DeCART, BluesphereBio, Carisma, Cellares, Celldex, Cabaletta, Poseida, Verismo, Ziopharm: Consultancy; Tmunity, DeCART, BluesphereBio, Carisma, Cellares, Celldex, Cabaletta, Poseida, Verismo, Ziopharm: Current equity holder in publicly-traded company; Novartis: Patents & Royalties.

Combinatorial Antigen Targeting Strategy for Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Pinar Ataca Atilla ◽  
Mary K McKenna ◽  
Norihiro Watanabe ◽  
Maksim Mamonkin ◽  
Malcolm K. Brenner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Tumor Control ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Introduction: Efforts to safely and effectively treat acute myeloid leukemia (AML) by targeting a single leukemia associated antigen with chimeric antigen receptor T (CAR T) cells have had limited success. We determined whether combinatorial expression of chimeric antigen receptors directed to two different AML associated antigens would augment tumor eradication and prevent relapse in targets with heterogeneous expression of myeloid antigens. Methods: We generated CD123 and CD33 targeting CARs; each containing a 4-1BBz or CD28z endodomain. We analyzed the anti-tumor activity of T cells expressing each CAR alone or in co-transduction with a CLL-1 CAR with CD28z endodomain and CD8 hinge previously optimized for use in our open CAR-T cell trial for AML (NCT04219163). We analyzed CAR-T cell phenotype, expansion and transduction efficacy by flow cytometry and assessed function by in vitro and in vivo activity against AML cell lines expressing high, intermediate or low levels of the target antigens (Molm 13= CD123 high, CD33 high, CLL-1 intermediate, KG1a= CD123 low, CD33 low, CLL-1 low and HL60= CD123 low, CD33 intermediate, CLL-1 intermediate/high) For in vivo studies we used NOD.SCID IL-2Rg-/-3/GM/SF (NSGS) mice with established leukemia, determining antitumor activity by bioluminescence imaging. Results: We obtained high levels of gene transfer and expression with both single (CD33.4-1BBʓ, CD123.4-1BBʓ, CD33.CD28ʓ, CD123.CD28ʓ, CLL-1 CAR) and double transduction CD33/CD123.4-1BBʓ or CD33/CD123.CD28ʓ) although single-transductants had marginally higher total CAR expression of 70%-80% versus 60-70% after co-transduction. Constructs containing CD28 co-stimulatory domain exhibited rapid expansion with elevated peak levels compared to 41BB co-stim domain irrespective of the CAR specificity. (p<0.001) (Fig 1a). In 72h co-culture assays, we found consistently improved anti-tumor activity by CAR Ts expressing CLL-1 in combination either with CD33 or with CD123 compared to T cells expressing CLL-1 CAR alone. The benefit of dual expression was most evident when the target cell line expressed low levels of one or both target antigens (e.g. KG1a) (Fig 1b) (P<0.001). No antigen escape was detected in residual tumor. Mechanistically, dual expression was associated with higher pCD3ʓ levels compared to single CAR T cells on exposure to any given tumor (Fig 1c). Increased pCD3ʓ levels were in turn associated with augmented CAR-T degranulation (assessed by CD107a expression) in both CD4 and CD8 T cell populations and with increased TNFα and IFNɣ production (p<0.001 Fig 1d). In vivo, combinatorial targeting with CD123/CD33.CD28ʓ and CLL-1 CAR T cells improved tumor control and animal survival in lines (KG1a, MOLM13 and HL60) expressing diverse levels of the target antigens (Fig 2). Conclusion: Combinatorial targeting of T cells with CD33 or CD123.CD28z CARs and CLL-1-CAR improves CAR T cell activation associated with superior recruitment/phosphorylation of CD3ʓ, producing enhanced effector function and tumor control. The events that lead to increased pCD3ʓ after antigen engagement in the dual transduced cells may in part be due to an overall increase in CAR expression but may also reflect superior CAR recruitment after antigen engagement. We are now comparing the formation, structure, and stability of immune synapses in single and dual targeting CARs for AML. Disclosures Brenner: Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Founder; Maker Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Other: Founder; Memmgen: Membership on an entity's Board of Directors or advisory committees; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Atilla:Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: founder; Marker Therapeuticsa: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Memgen: Membership on an entity's Board of Directors or advisory committees; KUUR: Membership on an entity's Board of Directors or advisory committees.

scholarly journals ALLO-715, an Allogeneic BCMA CAR T Therapy Possessing an Off-Switch for the Treatment of Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 591-591 ◽  
Author(s):  
Cesar Sommer ◽  
Bijan Boldajipour ◽  
Julien Valton ◽  
Roman Galetto ◽  
Trevor Bentley ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Expansion ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Autologous chimeric antigen receptor (CAR) T cells targeting B-Cell Maturation Antigen (BCMA) have demonstrated promising clinical activity, inducing durable responses in patients with relapsed/refractory multiple myeloma (MM). Development of autologous CAR T therapies is however limited by logistical challenges and the time required for manufacturing, which has to be done for each patient. In addition, manufacturing may not be feasible in some patients. An allogeneic approach that utilizes engineered cells from a healthy donor could potentially expand patient access to these therapies by providing a readily available off-the-shelf product. We have previously described the screening of a library of single chain variable fragments (scFvs) with high affinity to human BCMA and the identification of candidate BCMA CARs with potent antitumor activity. Here we sought to further characterize ALLO-715, our lead allogeneic BCMA CAR T cell product, for its specificity to human BCMA, antitumor efficacy in vitro using a long-term killing assay and in xenograft mouse models with physiologic levels of human IL-7 and IL-15, and suitability for scale-up manufacturing. Allogeneic ALLO-715 CAR T cells were generated by lentiviral transduction with a second generation CAR construct incorporating a novel scFv derived from a fully-human antibody with high affinity to BCMA (KD value ~ 5 nM, determined at 37°C) and featuring a rituximab-driven off-switch. Transduced T cells were then transfected with mRNAs encoding Transcription Activator-Like Effector Nucleases (TALEN®) designed to specifically disrupt the T cell receptor alpha chain and CD52 loci. These modifications result in a cell product with a lower risk of TCR-mediated graft-versus-host disease and resistance to the CD52 antibody alemtuzumab, a lymphodepleting agent. BCMA CAR T cells exhibited robust cell expansion, with low levels of tonic signaling that resulted in minimal differentiation (> 50% Tscm/Tcm phenotype). In in vitro assays, ALLO-715 CAR T cells displayed potent cytotoxic activity when co-cultured with the target cell lines MM.1S, Molp-8, and BCMA-REH but negligible cytotoxicity against BCMA-negative REH cells. The high proliferative potential indicated by the high frequency of memory T cells was validated in long-term killing assays, where ALLO-715 CAR T cells showed substantial expansion in the presence of MM.1S cells with no evidence of exhaustion or diminished cytolytic activity after seven days of continuous exposure to target. The potency of ALLO-715 CAR T cells was unaffected by high concentrations of soluble BCMA (>10 ug/mL), which has been shown previously to interfere with the activity of some BCMA-specific CARs. In MM xenograft mouse models, ALLO-715 CAR T cells were highly efficacious at single dose. High serum IL-15 levels have been associated with CAR T cell expansion in clinical trials. To evaluate the impact of homeostatic cytokines on CAR T cell survival and antitumor activity in our xenograft models, mice were administered adeno-associated viruses (AAV) for the expression of human IL-7 and IL-15. In the presence of physiological concentrations of these cytokines, enhanced BCMA CAR T cell expansion and anti-tumor activity were observed. To assess potential off-target interactions of ALLO-715 CAR, tissue cross-reactivity studies were carried out on standard human tissue panels using a scFv-human IgG fusion protein. Consistent with the limited expression pattern of BCMA, reactivity was seen on scattered cells in lymphoid tissues such as tonsil and abundantly on BCMA-expressing cell lines, but no appreciable staining was detected in other tissues. We examined BCMA CAR T cells manufactured following a proprietary GMP-like clinical scale process and found that cell expansion and viability, T cell phenotype and in vivo antitumor efficacy were preserved. These results demonstrate the potential of ALLO-715 as a novel allogeneic BCMA CAR T therapy for the treatment of relapsed/refractory MM and other BCMA-positive malignancies. Disclosures Sommer: Allogene Therapeutics: Employment, Equity Ownership, Patents & Royalties. Boldajipour:Pfizer Inc.: Employment, Patents & Royalties. Valton:Cellectis.Inc: Employment, Equity Ownership, Patents & Royalties. Galetto:Cellectis SA: Employment, Equity Ownership, Patents & Royalties. Bentley:Allogene Therapeutics: Employment, Equity Ownership. Sutton:Allogene Therapeutics: Employment, Equity Ownership. Ni:Allogene Therapeutics: Employment, Equity Ownership. Leonard:Allogene Therapeutics: Employment, Equity Ownership. Van Blarcom:Allogene Therapeutics: Employment, Equity Ownership. Smith:Cellectis. Inc: Employment, Patents & Royalties. Chaparro-Riggers:Pfizer Inc.: Employment, Patents & Royalties. Sasu:Allogene Therapeutics: Employment, Equity Ownership, Patents & Royalties.

Long-term follow-up of anti-CD19 CAR T-cell therapy for B-cell lymphoma and chronic lymphocytic leukemia.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3012-3012 ◽  
Author(s):  
Kathryn Cappell ◽  
Richard Mark Sherry ◽  
James C. Yang ◽  
Stephanie L. Goff ◽  
Danielle Vanasse ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Long Term Adverse Effects

3012 Background: T cells expressing anti-CD19 chimeric antigen receptors (CARs) can cause complete remissions of relapsed lymphoma. We conducted the first clinical trial of anti-CD19 CAR T cells to show responses against lymphoma. This CAR was later developed as axicabtagene ciloleucel. Here, we aimed to assess the long-term durability of remissions and the long-term adverse effects after anti-CD19 CAR T-cell therapy. Methods: Between 2009 and 2015, we treated 43 patients with anti-CD19 CAR T cells preceded by conditioning chemotherapy of cyclophosphamide plus fludarabine (NCT00924326). Three patients were re-treated for a total of 46 CAR T-cell treatments. Twenty-eight patients had aggressive lymphoma (diffuse large B-cell lymphoma or primary mediastinal B cell lymphoma), eight patients had low-grade lymphoma (five with follicular lymphoma and 1 each with splenic marginal zone lymphoma, mantle cell lymphoma, and unspecified low-grade non-Hodgkin lymphoma), and seven patients had chronic lymphocytic leukemia (CLL). Patients were treated in three cohorts that differed in the CAR T-cell production process and conditioning chemotherapy dose. Results: Of the 43 treated patients, 63% had chemotherapy-refractory lymphoma. Patients had received a median of 4 previous lines of therapy. The median CAR+ T cell dose per kilogram was 2X10^6. The overall remission rate was 76% with 54% complete remissions (CR) and 22% partial remissions (PR). Patients with CR had higher median peak blood CAR levels (86 CAR+ cells/µL) than those who did not have CR (16 CAR+ cells/µL, P= 0.0041). Long-term adverse effects were rare except for B-cell depletion and hypogammaglobulinemia, which both improved over time. Conclusions: This is the longest follow-up study of patients who received anti-CD19 CAR T cells. Anti-CD19 CAR T cells cause highly durable remissions of relapsed B-cell lymphoma and CLL, and long-term adverse effects of anti-CD19 CAR T cells were rare and usually mild. Clinical trial information: NCT00924326 . [Table: see text]

Long-Term Follow-Up of CD19-CAR T-Cell Therapy in Children and Young Adults With B-ALL

2021 ◽  
pp. JCO.20.02262
Author(s):  
Nirali N. Shah ◽  
Daniel W. Lee ◽  
Bonnie Yates ◽  
Constance M. Yuan ◽  
Haneen Shalabi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

PURPOSE CD19 chimeric antigen receptor (CD19-CAR) T cells induce high response rates in children and young adults (CAYAs) with B-cell acute lymphoblastic leukemia (B-ALL), but relapse rates are high. The role for allogeneic hematopoietic stem-cell transplant (alloHSCT) following CD19-CAR T-cell therapy to improve long-term outcomes in CAYAs has not been examined. METHODS We conducted a phase I trial of autologous CD19.28ζ-CAR T cells in CAYAs with relapsed or refractory B-ALL. Response and long-term clinical outcomes were assessed in relation to disease and treatment variables. RESULTS Fifty CAYAs with B-ALL were treated (median age, 13.5 years; range, 4.3-30.4). Thirty-one (62.0%) patients achieved a complete remission (CR), 28 (90.3%) of whom were minimal residual disease−negative by flow cytometry. Utilization of fludarabine/cyclophosphamide–based lymphodepletion was associated with improved CR rates (29/42, 69%) compared with non–fludarabine/cyclophosphamide–based lymphodepletion (2/8, 25%; P = .041). With median follow-up of 4.8 years, median overall survival was 10.5 months (95% CI, 6.3 to 29.2 months). Twenty-one of 28 (75.0%) patients achieving a minimal residual disease−negative CR proceeded to alloHSCT. For those proceeding to alloHSCT, median overall survival was 70.2 months (95% CI, 10.4 months to not estimable). The cumulative incidence of relapse after alloHSCT was 9.5% (95% CI, 1.5 to 26.8) at 24 months; 5-year EFS following alloHSCT was 61.9% (95% CI, 38.1 to 78.8). CONCLUSION We provide the longest follow-up in CAYAs with B-ALL after CD19-CAR T-cell therapy reported to date and demonstrate that sequential therapy with CD19.28ζ-CAR T cells followed by alloHSCT can mediate durable disease control in a sizable fraction of CAYAs with relapsed or refractory B-ALL (ClinicalTrials.gov identifier: NCT01593696 ).

scholarly journals Preservation of T-Cell Stemness with a Novel Expansionless CAR-T Manufacturing Process, Which Reduces Manufacturing Time to Less Than Two Days, Drives Enhanced CAR-T Cell Efficacy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2848-2848
Author(s):  
Boris Engels ◽  
Xu Zhu ◽  
Jennifer Yang ◽  
Andrew Price ◽  
Akash Sohoni ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Antitumor Efficacy ◽  
Publicly Traded ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract Background: Extended T-cell culture periods in vitro deplete the CAR-T final product of naive and stem cell memory T-cell (T scm) subpopulations that are associated with improved antitumor efficacy. YTB323 is an autologous CD19-directed CAR-T cell therapy with dramatically simplified manufacturing, which eliminates complexities such as long culture periods. This improved T-Charge™ process preserves T-cell stemness, an important characteristic closely tied to therapeutic potential, which leads to enhanced expansion ability and greater antitumor activity of CAR-T cells. Methods: The new T-Charge TM manufacturing platform, which reduces ex vivo culture time to about 24 hours and takes <2 days to manufacture the final product, was evaluated in a preclinical setting. T cells were enriched from healthy donor leukapheresis, followed by activation and transduction with a lentiviral vector encoding for the same CAR used for tisagenlecleucel. After ≈24 hours of culture, cells were harvested, washed, and formulated (YTB323). In parallel, CAR-T cells (CTL*019) were generated using a traditional ex vivo expansion CAR-T manufacturing protocol (TM process) from the same healthy donor T cells and identical lentiviral vector. Post manufacturing, CAR-T products were assessed in T-cell functional assays in vitro and in vivo, in immunodeficient NSG mice (NOD-scid IL2Rg-null) inoculated with a pre-B-ALL cell line (NALM6) or a DLBCL cell line (TMD-8) to evaluate antitumor activity and CAR-T expansion. Initial data from the dose escalation portion of the Phase 1 study will be reported separately. Results: YTB323 CAR-T products, generated via this novel expansionless manufacturing process, retained the immunophenotype of the input leukapheresis; specifically, naive/T scm cells (CD45RO -/CCR7 +) were retained as shown by flow cytometry. In contrast, the TM process with ex vivo expansion generated a final product consisting mainly of central memory T cells (T cm) (CD45RO +/CCR7 +) (Fig A). Further evidence to support the preservation of the initial phenotype is illustrated by bulk and single-cell RNA sequencing experiments, comparing leukapheresis and final products from CAR-Ts generated using the T-Charge™ and TM protocols. YTB323 CAR-T cell potency was assessed in vitro using a cytokine secretion assay and a tumor repeat stimulation assay, designed to test the persistence and exhaustion of the cell product. YTB323 T cells exhibited 10- to 17-fold higher levels of IL-2 and IFN-γ secretion upon CD19-specific activation compared with CTL*019. Moreover, YTB323 cells were able to control the tumor at a 30-fold lower Effector:Tumor cell ratio and for a minimum of 7 more stimulations in the repeat stimulation assay. Both assays clearly demonstrated enhanced potency of the YTB323 CAR-T cells in vitro. The ultimate preclinical assessment of the YTB323 cell potency was through comparison with CTL*019 regarding in vivo expansion and antitumor efficacy against B-cell tumors in immunodeficient NSG mouse models at multiple doses. Expansion of CD3+/CAR+ T-cells in blood was analyzed weekly by flow cytometry for up to 4 weeks postinfusion. Dose-dependent expansion (C max and AUC 0-21d) was observed for both YTB323 and CTL*019. C max was ≈40-times higher and AUC 0-21d was ≈33-times higher for YTB323 compared with CTL*019 across multiple doses. Delayed peak expansion (T max) of YTB323 by at least 1 week compared with CTL*019 was observed, supporting that increased expansion was driven by the less differentiated T-cell phenotype of YTB323. YTB323 controlled NALM6 B-ALL tumor growth at a lower dose of 0.1×10 6 CAR+ cells compared to 0.5×10 6 CAR+ cells required for CTL*019 (Fig B). In the DLBCL model TMD-8, only YTB323 was able to control the tumors while CTL*019 led to tumor progression at the respective dose groups. This ability of YTB323 cells to control the tumor at lower doses confirms their robustness and potency. Conclusions: The novel manufacturing platform T-Charge™ used for YTB323 is simplified, shortened, and expansionless. It thereby preserves T-cell stemness, associated with improved in vivo CAR-T expansion and antitumor efficacy. Compared to approved CAR-T therapies, YTB323 has the potential to achieve higher clinical efficacy at its respective lower doses. T-Charge™ is aiming to substantially revolutionize CAR-T manufacturing, with concomitant higher likelihood of long-term deep responses. Figure 1 Figure 1. Disclosures Engels: Novartis: Current Employment, Current equity holder in publicly-traded company. Zhu: Novartis: Current Employment, Current equity holder in publicly-traded company. Yang: Novartis: Current Employment, Patents & Royalties. Price: Novartis: Current Employment. Sohoni: Novartis: Current Employment. Stein: Novartis: Current Employment. Parent: Novartis: Ended employment in the past 24 months; iVexSol, Inc: Current Employment. Greene: iVexSol, Inc: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Niederst: Novartis: Current Employment, Current equity holder in publicly-traded company. Whalen: Novartis: Current Employment. Orlando: Novartis: Current Employment. Treanor: Novartis: Current Employment, Current holder of individual stocks in a privately-held company, Divested equity in a private or publicly-traded company in the past 24 months, Patents & Royalties: no royalties as company-held patents. Brogdon: Novartis Institutes for Biomedical Research: Current Employment.

scholarly journals The Enhanced Functionality of Low-Affinity CD19 CAR T Cells Is Associated with Activation Priming and Polyfunctional Cytokine Phenotype

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 52-53
Author(s):  
Ilaria M. Michelozzi ◽  
Eduardo Gomez-Castaneda ◽  
Ruben V.C. Pohle ◽  
Ferran Cardoso Rodriguez ◽  
Jahangir Sufi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Rna Seq ◽  
Car T Cells ◽  
Car T ◽  
Functional Phenotype

We have recently described a low-affinity second-generation anti-CD19 Chimeric Antigen Receptor (CAR) (CAT), characterized by faster antigen dissociation rate which showed enhanced expansion, cytotoxicity and anti-tumour efficacy compared with the high affinity (FMC63 based) CAR used in Tisagenlecleucel in pre-clinical models. Furthermore, CAT CAR T cells showed an excellent toxicity profile, enhanced in vivo expansion and long-term persistence in a Phase I clinical study (Ghorashian et al Nature Med 2019). However the molecular mechanisms behind the improved properties of CAT CAR T cells remain unknown. Herein, we performed a systematic in vitro characterization of the transcriptomic (bulk RNA-seq) and protein (CyTOF) changes occurring in CAR T cells expressing a low-affinity (CAT) vs high affinity (FMC63) anti-CD19 CARs following stimulation with CD19 expressing targets. Untransduced (UT) controls and T cells lentivirally transduced to express CAT or FMC63 CD19 CARs were compared both at baseline and following stimulation with CD19+ Acute Lymphoblastic Leukaemia cell line NALM6. In Principal Component Analysis for both RNA-seq and protein results, we found that the major variance across conditions was explained by CD19-mediated CAR T activation. Strikingly, unstimulated CAT CAR T cells showed an intermediate degree of activation between UT T cells and antigen stimulated CAR T cells. Indeed, when comparing RNA-seq results of unstimulated CAT vs FMC63, we found enhanced expression (FDR <0.1) of genes involved in cytotoxicity (GNLY, GZMK) and T cell activation (HLA-DRA and HLA-DPA1) (Figure 1a), confirmed at protein level by CyTOF. This "activation priming" observed in CAT CAR T cells was associated with and may be driven by residual CD19-expressing B-cells present in the manufacture product, preferentially inducing a T Central Memory (TCM) phenotype in CAT vs FMC63, in both CD4 and CD8 T cells. Such priming is likely to be instrumental to CAT CAR T cells more potent cytotoxic response upon NALM6 stimulation, when they displayed further increase in the expression of immune stimulatory cytokines (IFNG, CSF2), chemokines (CCL3L1, CCL4, CXCL8) and IFNg responsive genes (CIITA) by RNA-seq, as well as augmented T cell activation (CD25, NFAT1) and proliferation (pRB) markers by CyTOF. To identify the mechanisms underlying the stronger basal activation of CAT CAR T cells, we analysed cytokine expression at the single cell level by mass cytometry. Interestingly, rather than an increment in the expression of individual cytokines, we found that the distinctive feature of CAT CAR T cells was a shift toward a cytokine polyfunctional phenotype, with a marked increase in the proportion of cells co-expressing 3 or more cytokines (17.50% CAT vs 7.33% FMC63) (Figure 1b). Of note, cytokine polyfunctionality (expression of more than 1 cytokine/cell) in pre-infusion CAR T cell products has been associated to improved clinical efficacy. The functional phenotype observed in CAT CAR T cells was linked to the preferential activation of the p38 MAPK phospo-signalling, which is activated downstream of TCR CD3ζ chain (present in the CARs) but is also central to cytokine-dependent T cell activation in memory T cells. Interestingly, cytokine polyfunctional CAT CAR T cells were enriched in the CD3+CD19+ trogocytic (trog+) population, found at higher proportion in CAT vs FMC63 at 24h post antigen stimulation. Although trogocytosis has been associated to CAR T cell fratricide killing, trog+ CAT CAR T cells displayed higher levels of proliferation (pRB), activation (CD25, NFAT1) and cytotoxic (Granzyme B, Perforin B) markers, pointing at a stimulatory role of trogocytosis over fratricide killing, potentially due to the low-affinity CAR T cells distinctive property of better discriminating between low (trog+ CAR T cells) and high (tumour cells) target expression levels. In conclusion, we described the molecular mechanisms underlying the low affinity CAT CAR T cells functional phenotype. Our results show that the potent and long-term anti-tumour responses observed with CAT may be sustained by the establishment of CAR T cells self-reinforcing circuits activated through polyfunctional cytokine crosstalk. This work may inform the future design of versatile CAR T cells, capable of balancing safety, efficacy and long-term persistence. Disclosures Ghorashian: Amgen: Honoraria; UCLB: Patents & Royalties; Novartis: Honoraria. Pule:Autolus: Current Employment, Other: owns stock in and receives royalties, Patents & Royalties; UCLB: Patents & Royalties; Mana Therapeutics: Other: entitled to share of revenue from patents filed by UCL.

scholarly journals Effects of Prior Exposure to Tec Kinase(BTK/ITK) Inhibitors on Kte-X19 Products

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3849-3849
Author(s):  
Irene Scarfò ◽  
Kathleen M.E. Gallagher ◽  
Mark B. Leick ◽  
Michael C. Kann ◽  
Justin Budka ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Stock Options ◽  
Effector Function ◽  
Prior Exposure ◽  
Publicly Traded ◽  
Car T Cells ◽  
Car T ◽  
Post Infusion ◽  
Privately Held

Abstract Introduction: Frequent and durable responses were recently reported in relapsed or refractory (R/R) mantle cell lymphoma (MCL) patients treated with KTE-X19, an autologous CD19-targeted chimeric antigen receptor-engineered T-cell (CAR-T) product (Wang et al. N Engl J Med. 2020). Most patients enrolled had received at least one line of Tec kinase inhibitor prior to KTE-X19 manufacturing, either in the form of ibrutinib, a Bruton's tyrosine kinase (BTK) and Inducible T cell kinase (ITK) inhibitor, or acalabrutinib, a more selective BTK inhibitor. Pharmacokinetic expansion of KTE-X19 was higher in ibrutinib-treated patients relative to acalabrutinib-treated patients. We previously showed that prolonged exposure to ibrutinib enhanced T cell effector function and proliferation in patients with CLL (Fraietta et al, Blood, 2016). To assess the impact of Tec kinase inhibitor on KTE-X19 products and downstream clinical outcomes, we examined the phenotype, transcriptional profile and cytokine production of KTE-X19 infusion products and post-infusion lymphocytes from patients with R/R MCL treated on the Zuma-2 study. Study Design and Methods: We evaluated biospecimens from MCL patients who enrolled on the Zuma-2 clinical trial (NCT02601313) and who were previously treated with ibrutinib (n=14) or acalabrutinib (n=6). Samples analyzed consisted of KTE-X19 CAR T products and peripheral blood mononuclear cells (PBMC) collected 7 days after infusion. Lymphocytes were assessed for CAR expression, T cell phenotype, transcriptional profile and cytokine production. In addition, CAR T cell phenotypes and cytokines were profiled following co-culture of KTE-X19 with CD19 + Toledo cells (DLBCL). Results: Flow cytometric analysis of KTE-X19 demonstrated similar distributions of CD4+ and CD8+ T cells and comparable frequencies of central and effector memory populations in the CAR+ T cells derived from patients with prior exposure to ibrutinib vs. acalabrutinib. T helper subset analysis trended towards enrichment of Th1/Th17 populations within the CAR+ CD4+ cells of the ibrutinib cohort. This finding was further supported by transcriptional profiling of sorted CAR+ T cells from infusion products, where Th1/Th17, Jak/STAT and activation-related genes were enriched in the cohort with prior ibrutinib exposure. In addition, the Th1 phenotype was more frequent in PBMC of ibrutinib-exposed patients (8/14) compared to acalabrutinib-exposed patients (1/4). Interestingly, a shift from a central memory-dominant product towards an effector memory phenotype was observed in peripheral CD4+ and CD8+ CAR T cells in the ibrutinib cohort, whereas acalabrutinib post-infusion CAR T cells maintained a central memory phenotype. In vitro stimulation of KTE-X19 CAR-T infusion products with tumor cells resulted in a significant enrichment of the Th1 population in patients who had received ibrutinib compared to those that received acalabrutinib (p=0.0058). Following stimulation, CAR-T cells from the acalabrutinib cohort produced higher levels of Th2 cytokines, including IL-4, IL-5, and IL-13 as well as GM-CSF compared to the ibrutinib cohort. Conclusions: Analysis of KTE-X19 infusion products and day 7 post-infusion PBMC demonstrated that CAR T cells from patients with prior ibrutinib exposure have a Th1 predominant phenotype, suggesting that ibrutinib but not acalabrutinib promotes Th1 differentiation and effector function, potentially through the inhibition of ITK. Furthermore, our data suggest that inhibition of non-BTK targets such as ITK may play a role in driving a Th17 phenotype. Prior exposure to ibrutinib may increase CAR T cell effector function to a greater extent than exposure to acalabrutinib to enhance clinical outcome in patients with MCL. Disclosures Budka: Kite Pharma: Current Employment. Sowrirajan: Kite Pharma: Current Employment. Nguyen: Kite Pharma: Current Employment. Shen: Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment, Other: Leadership role, Patents & Royalties; Atara: Current Employment, Current equity holder in publicly-traded company, Other: Leadership role, Patents & Royalties. Bot: Kite, a Gilead Company: Current Employment; Gilead Sciences: Consultancy, Current equity holder in publicly-traded company, Other: Travel support. Maus: Agenus: Consultancy; Arcellx: Consultancy; Astellas: Consultancy; AstraZeneca: Consultancy; Atara: Consultancy; Bayer: Consultancy; BMS: Consultancy; Cabaletta Bio (SAB): Consultancy; CRISPR therapeutics: Consultancy; In8bio (SAB): Consultancy; Intellia: Consultancy; GSK: Consultancy; Kite Pharma: Consultancy, Research Funding; Micromedicine: Consultancy, Current holder of stock options in a privately-held company; Novartis: Consultancy; Tmunity: Consultancy; Torque: Consultancy, Current holder of stock options in a privately-held company; WindMIL: Consultancy; Adaptimmune: Consultancy; tcr2: Consultancy, Divested equity in a private or publicly-traded company in the past 24 months; century: Current equity holder in publicly-traded company; ichnos biosciences: Consultancy, Current holder of stock options in a privately-held company.

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