scholarly journals Deterministic Cell Separation Recovers >2-Fold T Cells, and More Naïve T Cells, for Autologous Cell Therapy As Compared to Centrifugally Prepared Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2847-2847
Author(s):  
Yasna Behmardi ◽  
Laurissa Ouaguia ◽  
Laura Jean Healey ◽  
MinJung Kim ◽  
Cole Jones ◽  
...  

Abstract CAR-T autologous cell therapies are delivering impressive results in the clinic. However, there are still significant manufacturing challenges impeding the rapid adoption of these advanced therapies. On the first day of cell processing, most manufacturing approaches require ~5 steps (~4 hours) to obtain a white blood cell (WBC) preparation sufficiently depleted of red blood cells (RBCs) for T-cell selection and activation steps; and involves large cell losses and a great deal of inconsistency. Here we present a single-step procedure that yields >2 fold more cells that centrifugal processing with comparable or better quality in <1 hour. We previously reported a small-scale microfluidic approach using deterministic cell separation (DCS) to effectively isolate and separate WBCs with high recoveries, no loss of WBC subtypes, no cell damage, and greater numbers of central memory T cells than traditional Ficoll-based processing. Extending this work, we now present the results of our fully scaled-up processing of 23 normal donor leukopaks and 4 disease samples using a full-scale DCS prototype. All samples were processed in <45 minutes, with only an additional 10 minutes hands-on time. On average, inclusive of aggregate removal by prefiltering, DCS achieved 88% WBC recovery, 94% RBC removal, and 98% platelet ( PLT) removal from the undiluted leukopak samples (n=23). Furthermore, DCS resulted in a RBC/WBC ratio of 0.1 compared with a ratio of 1.4 for Ficoll. Similarly, the PLT/WBC ratios were 0.89 versus 7.17 for DCS and Ficoll, respectively (n=20). In addition, DCS preparations contained 2-fold more CD3+ T cells (n=17), and, importantly, the CD4+ cells were less differentiated (more cells in naïve and central memory stages) than those recovered by Ficoll. Similarly, DCS processed blood from cancer patients had a ratio of RBC/WBC = 7.0 versus 20.1 for Ficoll, and a PLT/WBC ratio = 0.7 versus 15.6 for Ficoll (n=4). These results demonstrate the capabilities of DCS in processing not only samples from normal donors but also blood from cancer patients with similar efficiencies. Further, with DCS we achieved wash efficiencies of more than 3 log, without the typically associated cell loss, as demonstrated by the removal of viral particles, soluble proteins and cytokines and growth factors present in plasma. Therefore, cells from leukopaks processed by DCS can be washed and collected directly into cell culture media, or other solutions, to ready them for downstream applications without pelleting and repeated washes, greatly simplifying workflows. We integrated our DCS technology into a full scale parallelized, disposable, closed fluid path solution and automated platform prototype, the Curate ® Cell Processing System, capable of processing undiluted leukopacks at rates in excess of 300mL/hour. Designed to process blood products in bags using a single-use cassette containing microfluidic components, the Curate ® delivers a debulked WBC product to a bag. With a hands-on time of only 10 minutes, the Curate ® reduces the time to activation- and expansion-ready cells from leukopaks by 6-fold as compared with centrifugation and elutriation methods (Bowles, et al. Cytotherapy 2018;20(5):S109). The system can process a full leukopak (200-300 mL containing up to 1.2x10 10 WBC) within 40 minutes with a maximal cell throughput of 1.8x10 10 WBC per hour. Additionally, the same Curate ® device can be used to achieve up to 200x10 6 cell/mL in as little as 40 mL of media and without requiring pelleting. In summary, we believe our technology enables a significant breakthrough in the production of CAR-T cells by efficiently recovering more and cleaner total and naÏve T cells, for CAR-T cell production. Furthermore, the closed-system Curate ® will simplify cell processing workflows by reducing the number of cell washing steps, as well as the hands-on time and resources. Supported in part by NIH Grant No 5R42CA228616-03 Disclosures Behmardi: GPB Scientific, Inc: Current Employment. Ouaguia: GPB Scientific, Inc: Current Employment. Healey: GPB Scientific, Inc: Current Employment. Jones: GPB Scientific, Inc: Current Employment. Rahmo: GPB Scientific, Inc: Current Employment. Skelley: GPB Scientific, Inc: Current Employment. Gandhi: GPB Scientific, Inc: Current Employment. Campos-Gonzalez: GPB Scientific, Inc: Current Employment, Current holder of stock options in a privately-held company. Civin: GPB Scientific, Inc: Current holder of individual stocks in a privately-held company. Ward: GPB Scientific, Inc: Current Employment.

2020 ◽  
Vol 117 (37) ◽  
pp. 22910-22919
Author(s):  
Xingkang He ◽  
Xin Yin ◽  
Jing Wu ◽  
Stina L. Wickström ◽  
Yanhong Duo ◽  
...  

Lymphocyte-based immunotherapy has emerged as a breakthrough in cancer therapy for both hematologic and solid malignancies. In a subpopulation of cancer patients, this powerful therapeutic modality converts malignancy to clinically manageable disease. However, the T cell- and chimeric antigen receptor T (CAR-T) cell-mediated antimetastatic activity, especially their impacts on microscopic metastatic lesions, has not yet been investigated. Here we report a living zebrafish model that allows us to visualize the metastatic cancer cell killing effect by tumor- infiltrating lymphocytes (TILs) and CAR-T cells in vivo at the single-cell level. In a freshly isolated primary human melanoma, specific TILs effectively eliminated metastatic cancer cells in the living body. This potent metastasis-eradicating effect was validated using a human lymphoma model with CAR-T cells. Furthermore, cancer-associated fibroblasts protected metastatic cancer cells from T cell-mediated killing. Our data provide an in vivo platform to validate antimetastatic effects by human T cell-mediated immunotherapy. This unique technology may serve as a precision medicine platform for assessing anticancer effects of cellular immunotherapy in vivo before administration to human cancer patients.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5626-5626
Author(s):  
Irene Scarfò ◽  
Kathleen Gallagher ◽  
Marcela V. Maus ◽  
Rebecca Larson ◽  
Maegan Sheehan ◽  
...  

Chimeric antigen receptor T-cells (CAR-T) have emerged as an extremely promising therapy for hematological malignancies. The immunophenotype of apheresis material and the CAR-T cell product is known to be predictive of the likelihood of response to treatment of certain malignancies. Central memory and stem cell-like memory T cell phenotypes are associated with a more sustained proliferative response and long-term CAR-T persistence (Fraietta et al, Nature Medicine, 2018). There is an unmet need for standardized methods and reagents to reliably profile the memory phenotype of CAR-Ts to better evaluate product quality, and support improvements in CAR-T manufacturing. The BD Biosciences dried memory T-cell panel contains a pre-validated mixture of 7 antibodies for the identification of naïve, stem cell memory, central memory and effector memory CD4+ and CD8+ T cell subsets. The pre-mixed dried antibody tube offers consistency in staining profiles over time and reduces the risk of operator errors. Additional drop-in antibodies can complement the panel and enable more in-depth evaluation of the T cell phenotype. Here we demonstrate the use of this panel with drop-in markers to monitor changes in expression of PD-1, TIM-3, LAG-3, HLA-DR, CD45RO, and CXCR3 on T cells transduced to express our novel anti-CD37 CAR. Cells were stained at day 0 prior to transduction, day 7, and following resting and re-stimulation, and acquired on a 12 color BD FACS Lyric. The use of a standardized memory T-cell panel will allow us to more accurately evaluate how T-cell phenotype impacts on the efficacy and longevity of response in patients receiving CAR-T therapies. Disclosures Maus: INFO PENDING: Other: INFO PENDING. Bornheimer:BD Biosciences: Employment. Hanley:BD Biosciences: Employment. Frigault:Novartis: Patents & Royalties: Royalty; Arcellx, Celgene, Foundation Medicine, Kite/Gilead, Nkarta, Novartis, and Xenetic: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1909-1909 ◽  
Author(s):  
Meng Wang ◽  
Iulian Pruteanu ◽  
Adam D. Cohen ◽  
Alfred L. Garfall ◽  
Lifeng Tian ◽  
...  

Despite intense efforts, multiple myeloma remains incurable in most patients with the standard of care therapies. The plasma cell surface receptor B cell maturation antigen (BMCA) is highly expressed by myeloma cells and we recently demonstrated that 12 out of 25 heavily pretreated myeloma patients achieved a partial response or better after anti-BCMA CAR T cell treatment (VGPR, n=5; CR, n=1; sCR, n=1; Cohen et al., 2019, JCI 129(6):2210). To better understand the biological basis of this therapy, we identified key correlates of response using the pre-manufacturing apheresed T cells, the infusion product, and post-infusion T cells from the 25 patients in this cohort. As reported before, the disease characteristics, tumor burden, and CAR transduction efficiency did not correlate with therapy response. CAR T cell expansion, measured by the area under the curve of CAR qPCR in the first 21 days (AUC[0-21]), was highest in responding, lowest in non-responding patients (Jonckheere-Terpstra test, JT = 38, p=1.8x10^-6)(Fig.1A,B). Soluble BCMA, a biomarker of disease burden, shows a similar trend with response (Jonckheere-Terpstra test, JT = 54, p=1.2x10^-4). Furthermore, AUC[0-21] for CAR T cell expansion and soluble BCMA decline also strongly correlated (Spearman's rank correlation test, rho=0.82; p=2.41x10^-6), underscoring the quantitative relationship between CAR T cell expansion and tumor reduction. We have previously shown that response to CAR T cell therapy in CLL is largely determined by T cell memory function. To find if this extends to myeloma, we immunophenotyped apheresed T cells (or CAR-T precursor cells) and infusion product from the 25 patients. Phenotypically distinct T cell subpopulations were identified using shared-nearest-neighbor clustering method (PMID: 31178118) and their correlation with response to CAR T cell treatment was evaluated. This analysis revealed that among CD4+ and CD8+ CAR-T precursor cells, subpopulations representing naive and central memory T cells were enriched in T cells from responding patients, while non-responders displayed a distinctly activated effector phenotype at baseline. Additional analyses showed that apheresed CD8+ and CD4+ T cells from responder patients were non-cycling, granzyme B-negative, CTLA4[low] but otherwise largely immune checkpoint inhibitor-negative. CD8+ CAR-T precursor cells isolated from non-responders exhibited high expression levels of TIM3 or LAG3, and/or granzyme B, but not PD1, CTLA4, CD45RO or CD27. These data confirm the high activation, potential exhaustion and end-stage differentiation state of CAR-T precursor cells in this group. Similar analyses of infusion product CAR T cells did not reveal subpopulations associated with response. Clustering analysis of CD8+ CAR T cells within 20 days after infusion revealed a BCMA CAR-expressing cluster enriched in responding patients: a non-cycling, negatively regulated, Eomes-expressing central memory subset (cluster 0; Fig. 1E). Non-responding patients CAR-T cells displayed high levels of granzyme B and PD1 expression but were otherwise devoid of signs of activation (cluster 8; Fig. 1F). Furthermore, the abundance of CD8+ CAR-T cells with cluster 0 and 8 phenotype correlated significantly with in vivo expansion (AUC[0-21]; Fig. 1C). Four patients with a sufficiently high proportion of CAR expressing cells were phenotyped up to 125 days post-infusion. This analysis showed that the highly activated CAR T cell clusters 2 and 5 dominated at early phases post infusion but was rapidly replaced by non-cycling CAR T cells with downregulated CTLA4 and LAG3 but maintained expression of PD1 and TIM3 (cluster 0; Fig. 1D). Patient 27 with VGPR had a prominent effector population four months after infusion. BCMA-redirected CD4+ CAR T cells showed an enrichment of central memory phenotype CAR T cells in responding patients early after infusion, with high expression of Eomes, TIM3, and other immune checkpoint inhibitor molecules. This cluster also dominated the CD4 T cell repertoire in the first four months after infusion in the four responding patients. In conclusion, our data suggest that strategies to promote expression of Eomes and central memory function and reduce exhaustion in BCMA CAR T cells will enhance clinical activity. Further, these results underscore the "self-sustaining" feature of successful CAR T cell therapies in myeloma. Disclosures Pruteanu: Novartis: Employment. Cohen:Poseida Therapeutics, Inc.: Research Funding. Garfall:Tmunity: Honoraria, Research Funding; Amgen: Research Funding; Novartis: Patents & Royalties: inventor on patents related to tisagenlecleucel (CTL019) and CART-BCMA, Research Funding; Janssen: Research Funding; Surface Oncology: Consultancy. Lacey:Novartis: Patents & Royalties: Patents related to CAR T cell biomarkers; Tmunity: Research Funding; Novartis: Research Funding. Fraietta:Tmunity: Research Funding; Cabaletta: Research Funding; LEK Consulting: Consultancy. Brogdon:Novartis: Employment. Davis:Tmunity: Research Funding; Cabaletta: Research Funding. Levine:Tmunity Therapeutics: Equity Ownership; Avectas: Membership on an entity's Board of Directors or advisory committees; Vycellix: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Novartis: Consultancy, Patents & Royalties, Research Funding; Cure Genetics: Consultancy; Incysus: Membership on an entity's Board of Directors or advisory committees; Brammer Bio: Membership on an entity's Board of Directors or advisory committees; CRC Oncology: Consultancy. Milone:Novartis: Research Funding; Novartis: Patents & Royalties: patents related to tisagenlecleucel (CTL019) and CART-BCMA. Stadtmauer:Janssen: Consultancy; Tmunity: Research Funding; Amgen: Consultancy; Abbvie: Research Funding; Novartis: Consultancy, Research Funding; Takeda: Consultancy; Celgene: Consultancy. June:Novartis: Research Funding; Tmunity: Other: scientific founder, for which he has founders stock but no income, Patents & Royalties. Melenhorst:National Institutes of Health: Research Funding; Parker Institute for Cancer Immunotherapy: Research Funding; Novartis: Research Funding, Speakers Bureau; Colorado Clinical and Translational Sciences Institute: Membership on an entity's Board of Directors or advisory committees; Stand Up to Cancer: Research Funding; Incyte: Research Funding; IASO Biotherapeutics, Co: Consultancy; Simcere of America, Inc: Consultancy; Shanghai Unicar Therapy, Co: Consultancy; Genentech: Speakers Bureau.


2020 ◽  
Vol 11 ◽  
Author(s):  
Silvia Arcangeli ◽  
Laura Falcone ◽  
Barbara Camisa ◽  
Federica De Girardi ◽  
Marta Biondi ◽  
...  

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4553-4553 ◽  
Author(s):  
Fenlu Zhu ◽  
Nirav N Shah ◽  
Dina Schneider ◽  
Huiqing Xu ◽  
Katherine Chaney ◽  
...  

Abstract Adoptive cell therapy with autologous CAR-T cells has induced remarkable responses in patients with treatment-refractory hematologic malignancies, which has led to FDA approvals for two CAR-T products. However, limitations exist with commercial CAR-T centralized production: (1) off-site manufacturing can take several weeks and requires shipping from and to the treating facility; (2) off-site manufacturing limits treatment options for progressing patients; (3) high cost of the commercial products may limit their availability. To address these challenges, we used the fully automated Miltenyi CliniMACS Prodigy device, a GMP-compliant closed system, to manufacture autologous CAR-T cells for a Phase I trial (NCT03019055) evaluating a first-in-human bi-specific CAR that targets CD19 and CD20 (CD20.19 CAR). CAR-T manufacturing was performed exclusively using the CliniMACS Prodigy device and reagents obtained from Miltenyi Biotec. Production was performed within the Medical College of Wisconsin (MCW) Cell Therapy Laboratory, an ISO7 air handling environment. Manufacturing was set at 14 days, and production was as follows. First, peripheral blood mononuclear cells (MNC) were collected by apheresis, with a collection goal of 4 blood volumes to eliminate risk of a low CD3 yield in heavily pre-treated patients. Next, MNC were loaded onto the Prodigy, and CD4 and CD8 T cells enriched by positive immunomagnetic selection. To start the culture process, enriched T cells were suspended in TexMACS medium supplemented with 3% human AB serum and 200 U/mL IL-2, and TransACT reagent was added to stimulate the T cells in the Prodigy cell culture chamber. The following day (day 1), lentiviral vector expressing anti-CD19 and anti-CD20 (in tandem) with CD3ζ and 4-1BB stimulatory domains was added to the stimulated cells. Culture washes and feedings were done on days 5, 6, 8, 10 and 12 of manufacture, and final products harvested on Day 14. Protein L staining was used to detect expression of CD20.19 CAR on the T cells. On Day 14, eligible patients received fresh CAR-T cells, while for others the product was cryopreserved and administered on a later date. To date, the MCW Cell Therapy Laboratory has successfully generated CAR-T cell products for all 6 patients enrolled thus far on the Phase 1 clinical trial with no production failures (Table 1). Three patients received cryopreserved product and 3 patients received fresh product. The enriched T cells were 94.3% CD3+ (87.8-97.4%), and average T cell recovery from the apheresis cell products was 65.2% (54.2-80.0%). Protein L staining indicated 20.8% average CD20.19 CAR expression. Patient CAR-T cells were able to kill CD19+ and CD20+ target cells in vitro and produce IFN-gamma in response to the same target cells. An average yield of 5.9e+8 (4.3-7.9e+8) CAR T cells was obtained at harvest, which exceeded the required cell dose for all patients. The CAR-T cells were comprised of both CD4 and CD8 T cells, with higher expression on CD4 T cells; average CAR-T CD4:CD8 ratio on the final products was 2.8. The majority of T cells (average of 81.5%) had an effector-memory phenotype. In-process testing performed on Day 8 of manufacturing demonstrated sufficient numbers of CAR-T cells needed for patient infusions were already present, and that the CAR-T cells only expanded an additional 1.9 to 3.5-fold between Days 8 and 14. In conclusion, we have successfully demonstrated feasibility for point-of-care CAR-T cell production for clinical use from patient apheresis products utilizing the CliniMACS Prodigy device. Time to production was efficient (14 days), and patient-derived CAR-T cell products were reproducibly generated in a standard cell processing laboratory within an academic medical center. A major clinical advantage of CAR-T cells generated on-site is the flexibility in treatment. Patients can receive cells either immediately (i.e., fresh) or the cells can be cryopreserved for later infusion if the patient is not able to receive fresh cells. Based on our results, we intend to decrease the cell processing time to 10 days. Disclosures Zhu: Lentigen Technology Inc., A Miltenyi Biotec Company: Research Funding. Shah:Juno Pharmaceuticals: Honoraria; Oncosec: Equity Ownership; Geron: Equity Ownership; Exelexis: Equity Ownership; Miltenyi: Other: Travel funding, Research Funding; Lentigen Technology: Research Funding. Schneider:Lentigen Technology Inc., A Miltenyi Biotec Company: Employment. Keever-Taylor:Medical College of Wisconsin: Research Funding. Dropulic:Lentigen, A Miltenyi Biotec company: Employment. Orentas:Lentigen Technology Inc., A Miltenyi Biotec Company: Employment. Hari:Bristol-Myers Squibb: Consultancy, Research Funding; Amgen Inc.: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Kite Pharma: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Spectrum: Consultancy, Research Funding; Sanofi: Honoraria, Research Funding. Johnson:Miltenyi: Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 812-812 ◽  
Author(s):  
Xiuli Wang ◽  
Ryan Urak ◽  
Miriam Walter ◽  
Lihong Weng ◽  
Laura Lim ◽  
...  

Abstract Multiple myeloma (MM) is an incurable malignancy of plasma cells even with great advances in treatment. Chimeric Antigen Receptor (CAR) directed T cell therapy, which can specifically recognize tumor associated antigens and kill tumor cells in an MHC independent manner, is a promising approach for hematological malignancy. There are several candidate antigens for CAR T cell targeting of multiple myeloma, including BCMA and CS1. Our goal is to develop novel CARs for the treatment of MM and explore the potential benefits of combinatorial therapy of CAR T cells and immunomodulatory drugs (IMiDs) such as lenalidomide. In the present study, we redirected central memory T cells to express second-generation CARs specific for either CS1 or BCMA that incorporate CD28 signaling moieties. Central memory T cells were activated by CD3/CD28 bead stimulation, transduced with lentivirus encoding the CAR construct, and expanded ex vivo. The engineered and expanded CS1 and BCMA CAR T cells exhibited similar phenotypes and comparable in vitro effector function. However, once adoptively transferred into MM tumor-bearing NOD/Scid IL2RγCnull (NSG) mice by intravenous injection of 1x10^6 CAR T cells, CS1 CAR T cells exhibited superior antitumor activity over BCMA CART cells and significantly prolonged mouse survival (P<0.01). To further improve the anti-MM activity of CAR T cell therapy, we investigated the effects of lenalidomide on CS1 CAR T cell function against MM. Central memory T cells were activated and transduced with lentivirus encoding CS1 CAR and then expanded in vitro in the presence of 0, 1 or 10mM lenalidomide for 3-4 weeks and then effector function was evaluated. We found that CD8+ CAR T cells were preferentially expanded over CD4+ CAR T cells in a dose-dependent manner. Lenalidomide-treated CAR T cells secreted higher levels of Th1 cytokines such as IFN-gamma, TNF-alpha, and IL-2, but reduced Th2 cytokines such as IL-4 and IL-10 upon antigen stimulation as compared with untreated CAR T cells. Meanwhile we observed that lenalidomide greatly improved the maintenance of T cell memory markers (CD62L, CD28, and CD27) in the culture and enhanced the formation of immune synapses between CAR T cells and MM cells. RNA-seq analysis revealed that more than 600 genes were differentially expressed among the lenalidomide treated and un-treated CD8+CAR+ T cells. Among those, expression of immune synapse related genes such as cell junction and biological assembly is significantly increased with lenalidomide treatment. Moreover, lenalidomide results in elevated gene transcrips characteristic of memory, homing and cytolytic function of CAR T cells. To test the synergistic effects, MM bearing mice were treated with a single infusion of 1x10^6 CS1 CAR T cells (i.v) on day 0 and/or 5-7.5mgkg-1 of lenalidomide daily (i.p.) initiating on day 0 for 30 days. CS1 CAR T cells and lenalidomide exhibited synergistic anti-MM activity in vivo when MM mice received combinatorial treatment. The combination therapy significantly inhibited tumor growth in vivo, prolonged mouse survival (P<0.01) and improved CAR T cell persistence in mice as compared to single-agent treatment. Taken together, these findings indicate that lenalidomide plays a co-stimulatory role in immune modulation of CAR T cells and strengthens the anti-tumor activity of CS1 CAR T cells in vivo. Rational combination of these immunotherapeutic regimens is an effective strategy and the planned clinical trial will use a combination of lenalidomide and CS1 CAR T cells for increasing treatment efficacy. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 610-610 ◽  
Author(s):  
Leslie Popplewell ◽  
Xiuli Wang ◽  
Suzette Blanchard ◽  
Jamie Wagner ◽  
Araceli Naranjo ◽  
...  

Abstract Autologous stem cell transplantation (ASCT) remains an important consolidative therapy for patients with recurrent non-Hodgkin lymphoma (NHL), but is limited by the high incidence of NHL relapse. We report a Phase I clinical trial of ASCT followed by CD19-specific CD28-costimulatory chimeric antigen receptor (CD19:28z-CAR) T cells, with the goal of reducing NHL relapse rates. Safety and feasibility were the primary objectives, with CAR T cell persistence and expansion in the myeloablative ASCT setting as secondary objectives. This study examines safety and feasibility for two manufacturing platforms that differed in the T cell subset composition used for CAR engineering. Initially, the T cell population for CAR transduction was central memory (Tcm)-enriched: participants' peripheral blood mononuclear cells (PBMC) were depleted for CD14+ monocytes, CD25+ Tregs, and CD45RA+ naïve and stem-memory T cells, after which they were selected for CD62L+ Tcm (Wang et al. Blood;127:2980). Based on comparative preclinical data, a second arm was added to the trial to evaluate a Tn/mem-derived manufacturing platform that enriched central memory, naïve, and stem memory T cells (no CD45RA+ depletion). Either Tcm- or Tn/mem-enriched T cells were activated with CD3/CD28 beads, transduced with lentiviral vector encoding the CD19:28z-CAR, and expanded ex vivo. This phase I trial used the toxicity equivalence range design (Blanchard and Longmate. Contemp Clin Trials; 32;114) with an equivalence range for DLTs of 0.20-0.35 and a target toxicity rate of 0.25. The first 3 participants on each arm were followed one at a time, with later accrual in cohorts of 3. Twenty-three participants underwent ASCT and received CD19:28z-CAR T cells 2 days post stem cell infusion at the assigned dose level (DL): 17 on the Tcm arm (DL 50 million [M] CAR+ T cells [n=3], 200 M [n=5], 600 M [n=9]); 6 on the Tn/mem arm (DL 200 M). Participants were followed for dose limiting toxicity (DLT) for 28 days. Table 1 shows results by arm and DL. Both arms demonstrated safety and feasibility. There was no delayed hematopoietic reconstitution on either arm. On the Tcm arm, the only DLT was at DL 600 M (1 of 9 at 600 M). The Tn/mem arm was opened at 200 M and 6 participants were treated with no DLTs. The dose was not escalated as the protocol management team had seen activity at the 200M level in 2 other trials using the Tn/mem product. Tcm Arm: Fourteen of 17 participants (82%) had a diagnosis of diffuse large B-cell lymphoma (DLBCL) and 3 had mantle cell lymphoma. The mean age of the participants on the Tcm arm was 57 (35-75). The median number of prior chemotherapy regimens was 2 (1-5). The median progression-free survival (PFS) was 34.6 months 95% CI [21.8, undefined]. Seven of 17 participants (41%) have progressed, 1 died in remission of unrelated intracranial hemorrhage (6%), 7 (41%) remain in CR and are still in follow-up, and 2 are lost to follow-up (12%). All 17 participants achieved a CR or a continuing CR after ASCT and T cells. Tn/mem arm: Five of 6 participants (83%) had a DLBCL diagnosis, and 1 was NHL not otherwise specified. The mean age of the participants was 50 (40-72). The median number of prior chemotherapy regimens was 2.5 (1-3). The median follow-up time for the Tn/mem arm was 12 months, with median PFS not yet reached. One of 6 (17%) has progressed, 4 (66%) remain in CR and are still in follow-up, and 1 is lost to follow-up (17%). Five of 6 (83%) participants achieved a best response of CR or continuing CR after therapy. Several differences were observed between the manufacturing platforms. Since the Tn/mem production platform has fewer depletion steps, it resulted in a higher product yield, which shortened the ex vivo expansion period by 4.1 days (95% CI [1.5%, 6.6%]) from 18.9 days (15-24) for Tcm to 14.8 days (12-18) for Tn/mem (P<0.005). Notably in the ASCT minimal disease burden setting, the Tn/mem-derived CD19:28z-CAR T cell products exhibited significantly higher in vivo CAR T cell expansion compared to Tcm products at the 200M DL (Figure 1). We conclude that although both Tcm- and Tn/mem-enriched CD19CAR T cell therapies are safe, the Tn/mem product is more promising due to its 1) shorter production time, 2) higher cell yield, and 3) better in vivo expansion, despite the low antigen drive in these patients post-salvage and ASCT therapy. Longer follow-up for the 2-year PFS secondary objective will indicate if improved Tn/mem expansion impacts tumor control. Disclosures Wang: Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding. Budde:Mustang Therapeutics: Consultancy, Other: Licensing Agreement, Patents & Royalties, Research Funding. Brown:Mustang Therapeutics: Consultancy, Other: Licensing Agreement, Patents & Royalties, Research Funding. Forman:Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4190-4190
Author(s):  
Zhen Jin ◽  
Han Liu ◽  
Molly Allen ◽  
Xiaoyang Li ◽  
Rufang Xiang ◽  
...  

Abstract Background CD19-CAR T cells with costimulatory ligand of CD28 or 4-1BB have acquired well response in ALL and CLL, whereas it shows less effective in B-cell NHL. The microenvironment of lymphomas is much more complicated than that of leukemia, which containing physical barriers and higher immunosuppression levels preventing lymphoma cells from T cell attack. To overcome such T cell toleration, one can optimize T cell fitness by adding co-stimulatory domain or polarizing T cell differentiation. Some pre-clinical studies have reported the 3rd generation of CD19-CAR T cells with CD28 and 4-1BB domain in treating ALL, but the results were in controversy. Lenalidomide has been proved to have direct anti-tumor effects in killing DLBCL cell lines except its immunomodulatory functions. Therefore, we did preliminary investigation in vitro to seek whether the combination of lenalidomide and CD19 CAR-T cells with both CD28 and 4-1BB costimulatory domain could acquire better effects Method We first verified the proliferation inhibition of lenalidomide in treating both ABC-DLBCL cell lines (Su-DHL2 and OCI-Ly3) and GCB-DLBCL cell line OCI-Ly1. CY cell was primary cells isolated from GCB-DLBCL patients in Rui-jin Hospital. Under the maximum observed plasma concentration of lenalidmomide (2.2¦ÌM), the growth inhibition in both GCB-CY and OCI-Ly1 cell line was minimal, whereas the impact on ABC-DLBCL cell lines was more obvious. We further examined the efficiency of lenalidomide in vivo using a patient-derived mouse model. The primary lymphoma cells were obtained from a ABC-DLBCL patient and subcutaneously transplanted into NOD/SCID mouses. However, daily treated with lenalidomide could not delay the tumor growth (p>0.05) (Fig A, B, C). We next isolated CD3+ T cells from healthy donors, expanded with CD3/CD28 beads. The pLenti-EF1¦Á-CD19-28-BB-¦Æ-mcherry lentiviral vectors was generated and transduced in the expanded T cells to generate CD19 CAR-T cells. T cells transduced with pLenti-EFI¦Á-Actin-mcherry lentiviral vector were used as control. CD19-CAR T cells and T cells transdued with Actin-mcherry were pretreated with 2¦ÌM lenalidomide for 72 hours. LDH assay was then performed to identify the cytotoxicity of CD19-CAR T cells against CY in 7 hours. We found that lenalidomide substantially enhanced the anti-tumor function of CD19 CAR T cells and it also promoted the CD19-CAR T cells proliferation to some extent (Fig D, E). We therefore used three DLBCL patients CAR-T cells to identify the cytokine secretion. It was found that lenalidomide promoted Th1-biased cytokines secretion (IL-2, IFN-¦Ã, TNF-¦Á) and decreased Th2-biased cytokines (IL-6, IL-10). Interestingly, CAR-T cells secreted less IFN-¦Ã and TNF-¦Á but more IL-6 and IL-10 in killing OCI-Ly3 compared with OCI-Ly1 and CY (Fig F). The results leaded us to next determine the CD19-CAR T cell differentiation. A comparable increase of CD8+CD45RA-CD62L+ CD19 CAR T cells was observed as well as the CD4+CCR6-CCR4-CXCR3+ subset, indicating lenalidomide could induce CD19 CAR T cells differentiate to CD8+ central memory T cells and Th1 cells (Fig G). As the central memory T cells are more likely to home to the lymph nodes, we found that lenalidomide considerably increased the CD19-CAR T cell migration toward CCL21 and CCL19 in transwell system (Fig H). Conclusion In conclusion, our results indicate that lenalidomide could polarize CD19-CAR T cells to CD8 TCM and Th1 subset, which might contribute to the enhanced antitumor function of CD19 CAR-T cells. Meanwhile, by overexpressed CD62L, lenalidomide could promote the migrating capability of CD19 CAR-T cells. More in-vivo work shall be done to determine the combination therapy in the future. Figure 1 Figure 1. Figure 2 Figure 2. Figure 3 Figure 3. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2171-2171
Author(s):  
Noga Or Geva ◽  
Rotem Gidron ◽  
Aloukick Kumar Singh ◽  
Rakefet Sidlik Muskatel ◽  
Yair Reisner

Abstract We recently demonstrated that mouse anti-3rd party central memory CD8 veto cells (Tcm) enable engraftment of fully mis-matched T cell depleted bone marrow (TDBM) in sublethally irradiated (5.5 Gy TBI) recipients (Eran et al. Blood 2013). Here we found that Tcm generated from (host x donor)F1 or fully allogeneic donors were able to engraft and sustain their presence in such sub-lethally irradiated mice in the absence of TDBM transplants. Limiting dilution analysis revealed that the reactivity of host T cells (HTC) against donor spleen cells was significantly diminished in the chimeric mice treated with Tcm, whereas reactivity against 3rd party was comparable betweenTcm treated and non-treated mice (Fig. 1). This specific immune tolerance indicated that vetoTcm could potentially enable the use of 'off-the-shelf' allogeneic CAR T cells or any other genetically modified T cells from the same donor. To further investigate this possibility, we tested the ability of Tcmveto cells to enable engraftment of CD8 T cells from OT1 mice, expressing a transgenic T cell receptor (TCR) directed againstovalbumin (OVA) residues 257-264 in the context of H2Kb MHC-I. To that end, 1x106 OT1 CD8 T cells (H2b) were infused into Balb/c (H2Dd) recipients sublethally irradiated with 5.25 Gy TBI in the presence or absence of different doses of veto Tcm. As shown in Fig. 2, when tested at 2 months post-transplant, OT1 cells could not be detected in the peripheral blood of untreated recipient mice, while they were readily detectable in mice receiving 2x106 Tcm (0.78±0.36), reaching a higher level (1.18± 0.61) upon infusion of 5x106Tcm. To evaluate the functionality of the engrafted OT1 T cells in the chimeric mice, we developed and calibrated a new murine model, using a melanoma B16-cell line of C57BL background that expresses the ovalbumin peptide and the tdTomatomarker (B16-OVA-tdTomato) (Fig 3A). In this model, we tried to mimic a state of minimal residual disease by injecting a small number of B16-OVAtdTomato melanoma cells (0.25x106) into syngeneic C57BL mice; we then treated the mice with sublethal irradiation (6Gy TBI) to simulate treatment of the tumor, but also to clear out space for the T-cell adoptive transfer. Finally, we injected 1x106 naïve OT-1 cells generated on a (Balb x-OT1-CD45.1+RAG2-) F1 background in the presence or absence of Balb/c veto Tcm (5x106), and followed the development of the tumor. We found thatBalb/c vetoTcm prolonged the engraftment of the transgenic donor-derived F1 OT1 CD8 T cells inBalb/c recipients, thereby enabling significantly improved control of tumor growth when tested at day 20 post-transplant ( p<0.05). In contrast non OVA-expressing tumor cells grew at the same rate in all treatment groups, thereby demonstrating the specificity of the anti-tumor effect (Fig.3B). Previous studies demonstrated that Tcmare depleted of GVH reactivity by virtue of their culture with 3rd party stimulators under cytokine starvation. Our present results demonstrate that suchTcm veto cells can pave the way for functional engraftment of CD8 T cells with genetically modified specificity. Taken together, these results provide a proof of concept for the potential clinical use of such veto cells to enable therapy with 'off-the-shelf ' allogeneic CAR T cells. The relative ease of growing humanTcm in large numbers over a short period of time (9-12 days) suggests that it could be possible to harvest byleukapheresis from a single donor, a sufficient number of cells, to support CAR therapy for more than 50 allogeneic recipients. * N.O.G and R.G equally contributed Disclosures Or Geva: Yeda LTD: Patents & Royalties. Gidron:Yeda LTD: Patents & Royalties. Reisner:Cell Source LTD: Consultancy, Equity Ownership, Patents & Royalties, Research Funding.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1114-1114 ◽  
Author(s):  
Xiuli Wang ◽  
ChingLam W Wong ◽  
Ryan Urak ◽  
Wen-Chung Chang ◽  
Elizabeth E. Budde ◽  
...  

Abstract Multiple myeloma (MM), a plasma cell malignancy, accounts for approximately 1 percent of all cancers and slightly more than 10 percent of hematologic malignancies in the United States. Approximately 20,000 new cases will be diagnosed this year and over 11,000 people will die from this disease. Current therapies for MM often induce remission, but nearly all patients eventually relapse and die. T-cell mediated anti-tumor therapies using genetically modify T cells with specific chimeric antigen receptors (CARs) have non-overlapping activity, toxicity and tumor resistance profiles compared to conventional chemotherapeutic agents. The main challenge in designing a CAR T cell immunotherapeutic approach is identifying the best antigen for tumor targeting. CS-1 is a cell surface glycoprotein of the signaling lymphocyte activation molecule (SLAM) receptor family that is highly and selectively expressed on normal plasma cells and MM cells, with lower expression on NK cells and little or no expression on normal tissues. This unique expression pattern and proven clinical benefit of CS-1 monoclonal antibody for the treatment of relapsed MM makes CS-1 a good target for CAR T cell therapy. Central memory T cells (TCM) from PBMC were isolated using a two-step process on the AutoMACS device to first deplete CD14+, CD45RA+ and CD25+ cells, then to positively select CD62L+ cells. These TCM undergo anti-CD3/CD28 bead stimulation and transduction with a lentiviral vector encoding CS-1 CAR containing a CD28 co-stimulatory domain and two mutations on IgG4 linker CH-2 portion to ensure enhanced potency and persistence after adoptive transfer. Gene modified CS-1 CAR T cells specifically lysed MM.1S, a MM cell line, in 4-hour 51Cr release assays and all the CAR+ cells expressed 107a upon co-cultured with the MM.1S cells. To investigate the potency of the CS-1CAR T cells, 2x106 MM.1S cells that were engineered to express GFP firefly luciferase were inoculated into NSG mice by tibia injection. 7 days post tumor engraftment, 1x106 CS-1 CAR T cells were intravenously injected into the tumor bearing mice. In contrast to untreated and mock cell treated mice in which tumor progressed rapidly systemically, single intravenous infusion of CS-1 CAR T cells induced dramatic tumor regression and significantly prolonged survival. In addition to CS-1, CD44v6 and BCMA are antigens that have also been shown to be over-expressed on MM tumor cells. We therefore compared the two CARs with CS-1 CAR for their anti-MM activity. Based on our studies, targeting CS-1 resulted in the best efficacy (Figure 1) and would be an attractive strategy for development of a clinical trial. Disclosures No relevant conflicts of interest to declare.


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