T-cell therapy in metastatic melanoma: TIL 1383I TCR transduced T cells after infusion and activity in vivo.

Background : CD19-targeted CAR-T therapies have shown promising efficacy in treating B-cell malignancies. However, treatment-related toxicities, such as cytokine-release syndrome (CRS) and CAR T-cell-related encephalopathy syndrome (CRES), have been one of the major obstacles limiting the use of CAR-T therapies. How to minimize occurrence and severity of toxicity while maintaining efficacy is a major focus for T-cell therapies in development. ET019003 is a next generation CD19-targeted T-cell therapy developed by Eureka Therapeutics, built on the proprietary ARTEMISTM T-cell platform. The ET019003 construct is optimized with the co-expression of an ET190L1 Antibody-TCR (Xu et al, 2018) and novel co-stimulation molecule. We are conducting a First-in-human (FIH) study of ET019003 T cells in CD19+ r/r DLBCL patients. Methods: This FIH study aims to evaluate the safety and efficacy of ET019003 T-cell therapy in CD19+ patients with r/r DLBCL. As of July 2019, six subjects were administered ET019003 T cells. These subjects were pathologically confirmed with DLBCL that is CD19+ (by immunohistochemistry), whose disease have progressed or relapsed after 2-5 lines of prior therapies. All were high-risk patients with rapid tumor progression and heavy tumor burden. Each subject had a Ki67 proliferative index over 60%, 2/6 of the subjects had a Ki67 proliferative index over 90%. Moreover, 5/6 of the subjects had extra-nodal involvement. Following a 3-day preconditioning treatment with Fludarabine (25mg/m2/day)/ Cyclophosphamide (250mg/m2/day), patients received i.v. infusions of ET019003 T cells at an initial dose of 2-3×106 cells/kg. Additional doses at 3×106 cells/kg were administered at 14 to 30-day intervals. Adverse events were monitored and assessed based on CTCAE 5.0. Clinical responses were assessed based on Lugano 2014 criteria. Results: As of July 2019, six subjects have received at least one ET019003 T-cell infusion, and four subjects have received two or more ET019003 T-cell infusions. No Grade 2 or higher CRS was observed in the six subjects. One subject developed convulsions and cognitive disturbance. This subject had lymphoma invasion in the central nervous system before ET019003 T-cell therapy. The subject was treated with glucocorticoid and the symptoms resolved within 24 hours. Other adverse events included fever (6/6, 100%), fatigue (3/6, 50%), thrombocytopenia (3/6, 50%), diarrhea (2/6, 33%), and herpes zoster (1/6, 17%). ET019003 T-cell expansion in vivo (monitored by flow cytometry and qPCR) was observed in all six subjects after first infusion. The absolute peak value of detected ET019003 T cells ranged between 26,000 - 348,240 (median 235,500) per ml of peripheral blood. Tmax (time to reach the absolute peak value) was 6 - 14 days (median 7.5 days). For the four subjects who received multiple ET019003 T-cell infusions, the absolute peak values of detected ET019003 T cells after the second infusion were significantly lower than the absolute peak values achieved after the first infusion. For the two subjects who received three or more infusions of ET019003 T cells, no significant ET019003 T-cell expansion in vivo was observed after the third infusion. All six subjects completed the evaluation of clinical responses at 1 month after ET019003 T-cell therapy. All subjects responded to ET019003 T cells and achieved either a partial remission (PR) or complete response (CR). Conclusions: Preliminary results from six CD19+ r/r DLBCL patients in a FIH study show that ET019003 T-cell therapy is safe with robust in vivo T-cell expansion. The clinical study is on-going and we are monitoring safety as well as duration of response in longer follow-up. Reference: Xu et al. Nature Cell Discovery, 2018 Disclosures Liu: Eureka Therapeutics: Employment, Equity Ownership. Chang:Eureka Therapeutics: Equity Ownership. Liu:Eureka Therapeutics: Employment, Equity Ownership.

Download Full-text

124 Functionalizing CAR T cells for selective proliferation and dual-targeting using the meditope technology

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.124 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A133-A133

Author(s):

Cheng-Fu Kuo ◽

Yi-Chiu Kuo ◽

Miso Park ◽

Zhen Tong ◽

Brenda Aguilar ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T Cell Therapy ◽

Car T

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.

Download Full-text

GPRC5D is a target for the immunotherapy of multiple myeloma with rationally designed CAR T cells

Science Translational Medicine ◽

10.1126/scitranslmed.aau7746 ◽

2019 ◽

Vol 11 (485) ◽

pp. eaau7746 ◽

Cited By ~ 49

Author(s):

Eric L. Smith ◽

Kim Harrington ◽

Mette Staehr ◽

Reed Masakayan ◽

Jon Jones ◽

...

Keyword(s):

Multiple Myeloma ◽

T Cells ◽

T Cell ◽

Cell Therapy ◽

B Cell ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell Therapy ◽

Car T

Early clinical results of chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA) for multiple myeloma (MM) appear promising, but relapses associated with residual low-to-negative BCMA-expressing MM cells have been reported, necessitating identification of additional targets. The orphan G protein–coupled receptor, class C group 5 member D (GPRC5D), normally expressed only in the hair follicle, was previously identified as expressed by mRNA in marrow aspirates from patients with MM, but confirmation of protein expression remained elusive. Using quantitative immunofluorescence, we determined that GPRC5D protein is expressed on CD138+ MM cells from primary marrow samples with a distribution that was similar to, but independent of, BCMA. Panning a human B cell–derived phage display library identified seven GPRC5D-specific single-chain variable fragments (scFvs). Incorporation of these into multiple CAR formats yielded 42 different constructs, which were screened for antigen-specific and antigen-independent (tonic) signaling using a Nur77-based reporter system. Nur77 reporter screen results were confirmed in vivo using a marrow-tropic MM xenograft in mice. CAR T cells incorporating GPRC5D-targeted scFv clone 109 eradicated MM and enabled long-term survival, including in a BCMA antigen escape model. GPRC5D(109) is specific for GPRC5D and resulted in MM cell line and primary MM cytotoxicity, cytokine release, and in vivo activity comparable to anti-BCMA CAR T cells. Murine and cynomolgus cross-reactive CAR T cells did not cause alopecia or other signs of GPRC5D-mediated toxicity in these species. Thus, GPRC5D(109) CAR T cell therapy shows potential for the treatment of advanced MM irrespective of previous BCMA-targeted therapy.

Download Full-text

The roles of T cell competition and stochastic extinction events in chimeric antigen receptor T cell therapy

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0229 ◽

2021 ◽

Vol 288 (1947) ◽

Author(s):

Gregory J. Kimmel ◽

Frederick L. Locke ◽

Philipp M. Altrock

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Chimeric Antigen Receptor ◽

Antigen Receptor ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T

Chimeric antigen receptor (CAR) T cell therapy is a remarkably effective immunotherapy that relies on in vivo expansion of engineered CAR T cells, after lymphodepletion (LD) by chemotherapy. The quantitative laws underlying this expansion and subsequent tumour eradication remain unknown. We develop a mathematical model of T cell–tumour cell interactions and demonstrate that expansion can be explained by immune reconstitution dynamics after LD and competition among T cells. CAR T cells rapidly grow and engage tumour cells but experience an emerging growth rate disadvantage compared to normal T cells. Since tumour eradication is deterministically unstable in our model, we define cure as a stochastic event, which, even when likely, can occur at variable times. However, we show that variability in timing is largely determined by patient variability. While cure events impacted by these fluctuations occur early and are narrowly distributed, progression events occur late and are more widely distributed in time. We parameterized our model using population-level CAR T cell and tumour data over time and compare our predictions with progression-free survival rates. We find that therapy could be improved by optimizing the tumour-killing rate and the CAR T cells' ability to adapt, as quantified by their carrying capacity. Our tumour extinction model can be leveraged to examine why therapy works in some patients but not others, and to better understand the interplay of deterministic and stochastic effects on outcomes. For example, our model implies that LD before a second CAR T injection is necessary.

Download Full-text

Efficient elimination of primary B-ALL cells in vitro and in vivo using a novel 4-1BB-based CAR targeting a membrane-distal CD22 epitope

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-000896 ◽

2020 ◽

Vol 8 (2) ◽

pp. e000896

Author(s):

Talia Velasco-Hernandez ◽

Samanta Romina Zanetti ◽

Heleia Roca-Ho ◽

Francisco Gutierrez-Aguera ◽

Paolo Petazzi ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

T Cell Therapy ◽

High Affinity ◽

Car T Cells ◽

Car T Cell ◽

Car T

BackgroundThere are few therapeutic options available for patients with B-cell acute lymphoblastic leukemia (B-ALL) relapsing as CD19– either after chemotherapy or CD19-targeted immunotherapies. CD22-chimeric antigen receptor (CAR) T cells represent an attractive addition to CD19-CAR T cell therapy because they will target both CD22+CD19– B-ALL relapses and CD19– preleukemic cells. However, the immune escape mechanisms from CD22-CAR T cells, and the potential contribution of the epitope binding of the anti-CD22 single-chain variable fragment (scFv) remain understudied.MethodsHere, we have developed and comprehensively characterized a novel CD22-CAR (clone hCD22.7) targeting a membrane-distal CD22 epitope and tested its cytotoxic effects against B-ALL cells both in in vitro and in vivo assays.ResultsConformational epitope mapping, cross-blocking, and molecular docking assays revealed that the hCD22.7 scFv is a high-affinity binding antibody which specifically binds to the ESTKDGKVP sequence, located in the Ig-like V-type domain, the most distal domain of CD22. We observed efficient killing of B-ALL cells in vitro, although the kinetics were dependent on the level of CD22 expression. Importantly, we show an efficient in vivo control of patients with B-ALL derived xenografts with diverse aggressiveness, coupled to long-term hCD22.7-CAR T cell persistence. Remaining leukemic cells at sacrifice maintained full expression of CD22, ruling out CAR pressure-mediated antigen loss. Finally, the immunogenicity capacity of this hCD22.7-scFv was very similar to that of other CD22 scFv previously used in adoptive T cell therapy.ConclusionsWe report a novel, high-affinity hCD22.7 scFv which targets a membrane-distal epitope of CD22. 4-1BB-based hCD22.7-CAR T cells efficiently eliminate clinically relevant B- CD22high and CD22low ALL primary samples in vitro and in vivo. Our study supports the clinical translation of this hCD22.7-CAR as either single or tandem CD22–CD19-CAR for both naive and anti-CD19-resistant patients with B-ALL.

Download Full-text

TCR-engineered T-cell therapy through personalized identification of CDR3 clonotypes.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e15021 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e15021-e15021

Author(s):

Zishan Zhou ◽

Yue Pu ◽

Shanshan Xiao ◽

Ping Wang ◽

Yang Yu ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Single Cell ◽

Adoptive Cell Therapy ◽

Cell Receptor ◽

Illumina Hiseq ◽

T Cell Therapy ◽

Engineered T Cells

e15021 Background: T-cell receptor (TCR)-engineered T cells are a novel option for adoptive cell therapy used for the treatment of several advanced forms of cancers. Unlike many shared tumor-specific antigens, such as melanoma-associated antigen (MAGE)-A3, MAGE-A4, and New York esophageal squamous cell carcinoma (NY-ESO)-1, neoantigen has garnered much attention as a potential precision immunotherapy. Personalized neoantigen selection serves a broader and more precision future for cancer patients. Methods: Dendritic cells (DCs) derived from adherent monocytes were pulsed with mixed peptides during the maturation phase. CD8+ cells positively selected from PBMCs were incubated with washed DCs. After 21day culture in X-VIVO medium with IL-7 and IL-15, cells were harvested and stimulated with peptides for 6 h. CD137+ cells were sorted by flow cytometric and immediately processed using the 10x Genomic Chromium Single Cell 5' Library & Gel Bead Kit and Chromium Single Cell V(D)J Enrichment Kit. The T-cell TCR libraries were constructed and sequenced on the Illumina HiSeq X Ten platform. The sequencing reads were aligned to the hg38 human reference genome and analyzed using the 10x Genomics Cell Ranger pipeline. The paired TCR α and β chain sequence of each cell was demonstrated with V(D)J analysis. TCR-T cells were constructed using the information of neoantigen specific TCR, and infused to patients. Results: Two patients were treated with the personalized TCR-T treatment. At the first stage, specialized immune cells were harvested and proceeded to single-cell TCR profiling. Then, the single cell sequencing of the first patient's sample revealed the top five neoantigen specific TCR CDR3 clonotypes with the proportion of 25%, 7.67%, 4.81%, 2.79%, and 2.54%, respectively. Similarly, the other patient had the top five TCR CDR3 sequenced with the proportion of 13.38%, 7.04%, 4.21%, 2.83%, and 1.94%, respectively. The results demonstrated that both patients had one or two dominant CDR3 clonotypes, which might reflect the strength of neoantigen in vivo. At the third stage, TCR-T cells were constructed, and infused to the patients. The clinical outcome will be evaluated in the near future. Conclusions: We have generated a pipeline for a highly personalized cancer therapy using TCR-engineered T cells. Although some questions remain to be answered, this novel approach may result in better clinical responses in future treatment.

Download Full-text

Quality Assessment of Pre-Clinical Studies of Chimeric Antigen Receptor T-Cell Therapy Products: A Point of Focus On Safety

Current Drug Safety ◽

10.2174/1574886316666210728101333 ◽

2021 ◽

Vol 16 ◽

Author(s):

Vikas Maharshi ◽

Diksha Diksha ◽

Pooja Gupta

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Chimeric Antigen Receptor ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T Cell Therapy ◽

Car T

Background: Serious adverse reactions have been reported with the use of chimeric antigen receptor (CAR) T-cell therapy in clinical setting despite the success of these products in pre-clinical stages of development. Objective: We evaluated the quality of available pre-clinical safety data of CAR T-cell therapy products. Methods: A 21 items safety-checklist was designed specifically for CAR T-cell. Literature was searched using search/MeSH terms in PubMed (October 2019 – February 2020). Studies were screened from title and abstract. Original pre-clinical researches related to CAR T-cell anti-cancer therapy were included. Results: Of the search results, 152 studies (3 in vivo, 39 in vitro, and 110 combined) were included. Only 7.9% studies were specifically designed to evaluate/ improve product safety. Eleven studies included target antigen(s) and no study included co-stimulatory molecule(s) expressed exclusively by tumor tissue and/or CAR T-cells. One study used CRISPR-Cas9 for CAR gene insertion. The use of switch-off mechanism and purity assessment of CAR T-cell products were reported in 13.2% and 8.6% studies respectively. Of the 149 studies with in vivo component, immuno-competent animal models were used in 24.8%. Measurement of blood pressure, temperature, body weight and serum cytokines were reported in 0, 2.7, 29.2 and 27.4% studies respectively. The tissue distribution and CAR T-cells persistence were reported in 26.5% studies. Conclusion: Majority of the checklist parameters were not reported in the pre-clinical publications to be adequately predictive of the safety of CAR T-cells in a clinical setting.

Download Full-text

A Novel Bioluminescent Mouse Model for Optimization of Adoptive T Cell Therapy

Blood ◽

10.1182/blood.v128.22.2162.2162 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2162-2162

Author(s):

Martin Szyska ◽

Stefanie Herda ◽

Stefanie Althoff ◽

Andreas Heimann ◽

Tra My Dang ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Tumor Model ◽

Effector Function ◽

Tumor Rejection ◽

Adoptive T Cell Therapy ◽

T Cell Therapy ◽

The Impact

Abstract Adoptive T cell therapy (ATT) is a promising option for the treatment of solid cancers. However, various defense mechanisms acquired by the tumor during evolution prevent transferred T cells (TC) to unfold their full potential. A combination of ATT with accessory therapeutic approaches including checkpoint inhibition and targeted therapy could lift TC inhibition and efficiently shift the immune balance towards tumor rejection. An in-vivo analysis of the impact of combination strategies on the outcome of ATT would greatly enhance the search for an optimal accessory to ATT therapy. We generated the transgenic mouse line BLITC (bioluminescence imaging of T cells) expressing an NFAT (nuclear factor of activated T cell)-dependent Click-beetle luciferase (Na et. al, 2010) and a constitutive Renilla Luciferase, allowing us to monitor migration and activation of transferred TCs in vivo. In order to analyze crucial ATT parameters in a clinically relevant tumor model, BLITC mice were crossed to the two HY-TCR transgenic mice Marilyn (CD4: H-2Ab-Dby) and MataHari (CD8: H-2Db-Uty) to generate TCs that could be monitored for in-vivo infiltration, local activation and rejection of established (> 0,5 cm x 0,5 cm / ≥10 days growth) H-Y expressing MB49 tumors. In order to better reflect the clinical situation, we lymphodepleted tumor-bearing immunocompetent albino B6 mice with fludarabine (FLu) and/or cyclophosphamide (CTX) prior to ATT. Transferred TCs were FACSorted and injected after an optional culture expansion phase. As shown before for freshly injected tumor cells (Perez-Diez, 2007), we observed a superior response of tumor-antigen specific CD4+ TCs compared to CD8+ TCs against established tumors. Whereas 5*106 CD8+ T cells hardly attenuated tumor growth, even as few as 5000 H-Y TCR-transgenic CD4+ T cells rejected tumors in most mice, depending on the lymphodepleting treatment (Figure A - remission rates in parentheses). Tumor infiltration and activation of adoptively transferred TCs was monitored in-vivo by the respective bioluminescent reporters. Around day 4 and 6, CD4+ TCs migrated from tumor-draining lymph nodes into the tumor environment and persisted until rejection. Interestingly, activation of CD4+ TCs was only transient (between days 4 and 7) in all mice, independent of therapy outcome (in Figure B shown for refractory tumor). Whereas loss of activation signal during remission was correlated with tumor clearance and decline of effector function, in refractory tumors it suggests a rapid inactivation of infiltrating TCs by the tumor microenvironment. Our data indicate that the failure of tumor rejection is not caused by impaired peripheral expansion or tumor homing but rather by inhibition of TC effector function. Responsible mechanisms and counter-acting therapeutic interventions are the focus of ongoing studies. In summary, the BLITC reporter system facilitates analysis of therapeutic parameters for ATT in a well-established solid tumor model. Using BLITC mice for transduction with TCR or CAR expression cassettes could allow rapid monitoring of on-target as well as undesired off-target effects in virtually any tumor setting. Future experiments will focus on the beneficial effects of combination treatments on the activation of adoptively transferred TCs. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Development of CAR-T Cell Therapy for B-ALL Using a Point-of-Care Approach

10.1101/770297 ◽

2019 ◽

Cited By ~ 1

Author(s):

Luiza de Macedo Abdo ◽

Luciana Rodrigues Carvalho Barros ◽

Mariana Saldanha Viegas ◽

Luisa Vieira Codeço Marques ◽

Priscila de Sousa Ferreira ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

B Cell ◽

Point Of Care ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell Therapy ◽

Car T

AbstractRecently approved by the FDA and European Medicines Agency, CAR-T cell therapy is a new treatment option for B-cell malignancies. Currently, CAR-T cells are manufactured in centralized facilities and face bottlenecks like complex scaling up, high costs and logistic operations. These difficulties are mainly related to the use of viral vectors and the requirement to expand CAR-T cells to reach the therapeutic dose. In this paper, by using Sleeping Beauty-mediated genetic modification delivered by electroporation, we show that CAR-T cells can be generated and used without the need for ex vivo activation and expansion, consistent with a point-of-care (POC) approach. Our results show that minimally manipulated CAR-T cells are effective in vivo against RS4;11 leukemia cells engrafted in NSG mice even when inoculated after only 4 hours of gene transfer. In an effort to better characterize the infused CAR-T cells, we show that 19BBz T lymphocytes infused after 24h of electroporation (where CAR expression is already detectable) can improve the overall survival and reduce tumor burden in organs of mice engrafted with RS4;11 or Nalm-6 B cell leukemia. A side-by-side comparison of POC approach with a conventional 8-day expansion protocol using Transact beads demonstrated that both approaches have equivalent antitumor activity in vivo. Our data suggests that POC approach is a viable alternative for the generation and use of CAR-T cells, overcoming the limitations of current manufacturing protocols. Its use has the potential to expand CAR immunotherapy to a higher number of patients, especially in the context of low-income countries.

Download Full-text