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

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.

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

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.

scholarly journals Killing Mechanisms of Chimeric Antigen Receptor (CAR) T Cells

2019 ◽  
Vol 20 (6) ◽  
pp. 1283 ◽  
Author(s):  
Mohamed-Reda Benmebarek ◽  
Clara Karches ◽  
Bruno Cadilha ◽  
Stefanie Lesch ◽  
Stefan Endres ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Effective adoptive T cell therapy (ACT) comprises the killing of cancer cells through the therapeutic use of transferred T cells. One of the main ACT approaches is chimeric antigen receptor (CAR) T cell therapy. CAR T cells mediate MHC-unrestricted tumor cell killing by enabling T cells to bind target cell surface antigens through a single-chain variable fragment (scFv) recognition domain. Upon engagement, CAR T cells form a non-classical immune synapse (IS), required for their effector function. These cells then mediate their anti-tumoral effects through the perforin and granzyme axis, the Fas and Fas ligand axis, as well as the release of cytokines to sensitize the tumor stroma. Their persistence in the host and functional outputs are tightly dependent on the receptor’s individual components—scFv, spacer domain, and costimulatory domains—and how said component functions converge to augment CAR T cell performance. In this review, we bring forth the successes and limitations of CAR T cell therapy. We delve further into the current understanding of how CAR T cells are designed to function, survive, and ultimately mediate their anti-tumoral effects.

Interventions and Outcomes of Adult Patients with B-ALL Progressing After CD19 Chimeric Antigen Receptor T Cell Therapy

Blood ◽  
2021 ◽  
Author(s):  
Kitsada Wudhikarn ◽  
Jessica R Flynn ◽  
Isabelle Rivière ◽  
Mithat Gonen ◽  
Xiuyan Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Adult Patients ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

CD19-targeted chimeric antigen receptor (CAR) T cell therapy has become a breakthrough treatment for patients with relapsed/refractory B acute lymphoblastic leukemia (B-ALL). However, despite the high initial response rate, the majority of adult patients with B-ALL progress after CD19 CAR T therapy. Data on the natural history, management, and outcome of adult B-ALL progressing after CD19 CAR T cells have not been described in detail. Herein, we report comprehensive data of 38 adult B-ALL patients who progressed after CD19 CAR T therapy at our institution. The median time to progression after CAR T therapy was 5.5 months. Median survival after post-CAR T progression was 7.4 months. A high disease burden at the time of CAR T cell infusion was significantly associated with risk of post-CAR T progression. Thirty patients (79%) received salvage treatment for post-CAR T disease progression and 13 patients (43%) achieved complete remission (CR), but remission duration was short. Notably, 7 of 12 patients (58.3%) achieved CR after blinatumomab and/or inotuzumab administered after post-CAR T failure. Multivariate analysis demonstrated longer remission duration from CAR T cells was associated with superior survival after progression following CAR T therapy. In conclusion, overall prognosis of adult B-ALL patients progressing after CD19 CAR T cells was poor though a subset of patients achieved sustained remissions to salvage treatments including blinatumomab, inotuzumab and re-infusion of CAR T cells. Novel therapeutic strategies are needed to reduce risk of progression after CAR T therapy and improve outcomes of these patients.

scholarly journals Distribution Measurements of Chimeric Antigen Receptor-Modified T Cells Against CD19

2020 ◽  
Author(s):  
Zhitao Ying ◽  
Ting He ◽  
Xiaopei Wang ◽  
Wen Zheng ◽  
Ningjing Lin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Target Cells ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract Backgroud: The unprecedented efficacy of chimeric antigen receptor (CAR) T-cell immunotherapy of CD19+ B-cell malignancies has opened a new and useful way for the treatment of malignant tumor. Nonetheless, there are still formidable challenges in the field of CAR-T cell therapy, such as the biodistribution of CAR-T cells in vivo.Methods: We demonstrated the distribution of CAR-T cells in the absence of target cells or with target cells in the mice and the dynamic changes in the patient blood over time after infusion were deteced by qPCR and FACS. Results: CAR-T cells still proliferated in the mice without target cells and peaked at 2 weeks. However, CAR-T cells did not increase significantly in the presence of target cells within 2 weeks after infusion, but expanded at 6 weeks. In the clinical trial, we found that CAR-T cells peaked at 7-21days after infusion and can last for as long as 510 days in the peripheral blood of patients. Simultaneously, mild side-effects were noted which can be effectively controlled within two months in these patients.Conclusions: CAR-T cells can expand themselves with or without target cells in mice. CAR-T cells can persistence for a long time in patients.

scholarly journals Toxicities of chimeric antigen receptor T cells: recognition and management

Blood ◽  
2016 ◽  
Vol 127 (26) ◽  
pp. 3321-3330 ◽  
Author(s):  
Jennifer N. Brudno ◽  
James N. Kochenderfer
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Chimeric antigen receptor (CAR) T cells can produce durable remissions in hematologic malignancies that are not responsive to standard therapies. Yet the use of CAR T cells is limited by potentially severe toxicities. Early case reports of unexpected organ damage and deaths following CAR T-cell therapy first highlighted the possible dangers of this new treatment. CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines released by infused CAR T cells can lead to widespread reversible organ dysfunction. CRS is the most common type of toxicity caused by CAR T cells. Neurologic toxicity due to CAR T cells might in some cases have a different pathophysiology than CRS and requires different management. Aggressive supportive care is necessary for all patients experiencing CAR T-cell toxicities, with early intervention for hypotension and treatment of concurrent infections being essential. Interleukin-6 receptor blockade with tocilizumab remains the mainstay pharmacologic therapy for CRS, though indications for administration vary among centers. Corticosteroids should be reserved for neurologic toxicities and CRS not responsive to tocilizumab. Pharmacologic management is complicated by the risk of immunosuppressive therapy abrogating the antimalignancy activity of the CAR T cells. This review describes the toxicities caused by CAR T cells and reviews the published approaches used to manage toxicities. We present guidelines for treating patients experiencing CRS and other adverse events following CAR T-cell therapy.

scholarly journals Metabolic and Mitochondrial Functioning in Chimeric Antigen Receptor (CAR)—T Cells

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1229
Author(s):  
Ali Hosseini Rad S. M. ◽  
Joshua Colin Halpin ◽  
Mojtaba Mollaei ◽  
Samuel W. J. Smith Bell ◽  
Nattiya Hirankarn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Metabolic State ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized adoptive cell therapy with impressive therapeutic outcomes of >80% complete remission (CR) rates in some haematological malignancies. Despite this, CAR T cell therapy for the treatment of solid tumours has invariably been unsuccessful in the clinic. Immunosuppressive factors and metabolic stresses in the tumour microenvironment (TME) result in the dysfunction and exhaustion of CAR T cells. A growing body of evidence demonstrates the importance of the mitochondrial and metabolic state of CAR T cells prior to infusion into patients. The different T cell subtypes utilise distinct metabolic pathways to fulfil their energy demands associated with their function. The reprogramming of CAR T cell metabolism is a viable approach to manufacture CAR T cells with superior antitumour functions and increased longevity, whilst also facilitating their adaptation to the nutrient restricted TME. This review discusses the mitochondrial and metabolic state of T cells, and describes the potential of the latest metabolic interventions to maximise CAR T cell efficacy for solid tumours.

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

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.

scholarly journals Profile of Capillary-Leak Syndrome in Patients Received Chimeric Antigen Receptor T Cell Therapy

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5204-5204 ◽  
Author(s):  
Yongxian Hu ◽  
Jingjing Feng ◽  
Mi Shao ◽  
He Huang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Capillary Leak Syndrome ◽  
Capillary Leak ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T

Abstract Background: Autologous T cells modified to express a chimeric antigen receptor (CAR-T) has demonstrated exciting efficacy in treating leukemia and there has been some reports about the toxicities recently. However, the spectrum of capillary-leak syndrome (CLS) associated with CAR-T cell therapy has not been systematically evaluated, which can be a life threatening complication as results of the cytokine release syndrome (CRS). Therefore, as the use of CAR-T therapy continues to expand to broader applications, it is prudent to characterize the profile of CLS to help providers guide safe management. Method: We reviewed all acute lymphoblastic leukemia (ALL) patients who had participated in the clinical trial from our center to receive CAR-T therapy between 2016-2018. Patients analyzed in the study received either CD19 CAR-T cells or CD19 plus CD22 CAR-T cells. The diagnosis of CLS includes edema, acute hypotension and hemoconcentration with hypoproteinemia or hypoalbuminemia. CRS grading was evaluated with Lee's criteria for CRS. Result: 42 ALL patients were included in this study with the mean age of 27(8-52) years old. 11(11/42, 26.2%) patients were diagnosed as CLS and 31 were not. It was observed that CLS was more common in patients who developed severe CRS. Patients with CLS was found to have high rate of hypotension and use of gamma globulin.(Table 1) Top level concentration of serum IL-6 in CLS patients was much higher than that in non-CLS patients (16438.7 vs 3292.7 pg/mL, p=0.0016), which is consistent with the well recognized concept of IL-6 as an indicator of CRS.(Figure 1) It is important to notice that CLS patients had lower levels of serum total protein (TP, 43.7 vs 52.8 g/L, p=0.0005) and serum albumin (ALB, 27.4 vs 33.8 g/L, p=0.0011), while the hemoglobin (HGB) concentration showed no difference, suggesting that TP and ALB might be better indicators for CLS than HGB, although hemoconcentration, hypoproteinemia and hypoalbuminemia are both important in diagnosis.(Figure 2) Moreover, there was no significant difference in age, gender, Ph type of ALL, type of CAR-T cells infused and death ratio.(Table 1) Although CRS has been reported to be related with disease burden before the therapy, our data showed no difference of it between the patients with and without CLS. Conclusion: In conclusion, we have evaluated a basic profile of CLS among CAR-T patients in our center and the study indicates that CLS warrants extra attention for patients who receive CAR-T therapy. Further investigations are required to elucidate best practices for prevention and management of CLS in CAR-T therapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals Clinical Development and Manufacture of Chimeric Antigen Receptor T cells and the Role of Leukapheresis

2017 ◽  
Vol 13 (01) ◽  
pp. 28 ◽  
Author(s):  
Andrew Fesnak ◽  
Una O’Doherty ◽  
◽  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Large Scale ◽  
Mononuclear Cells ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Adoptive transfer of chimeric antigen receptor (CAR) T cells is a powerful targeted immunotherapeutic technique. CAR T cells are manufactured by harvesting mononuclear cells, typically via leukapheresis from a patient’s blood, then activating, modifying the T cells to express a transgene encoding a tumour-specific CAR, and infusing the CAR T cells into the patient. Gene transfer is achieved through the use of retroviral or lentiviral vectors, although non-viral delivery systems are being investigated. This article discusses the challenges associated with each stage of this process. Despite the need for a consistent end product, there is inherent variability in cellular material obtained from critically ill patients who have been exposed to cytotoxic therapy. It is important to carefully select target antigens to maximise effect and minimise toxicity. Various types of CAR T cell toxicity have been documented: this includes “on target, on tumour”, “on target, off tumour” and “off target” toxicity. A growing body of clinical evidence supports the efficacy and safety of CAR T cell therapy; CAR T cells targeting CD19 in B cell leukemias are the best-studied therapy to date. However, providing personalised therapy on a large scale remains challenging; a future aim is to produce a universal “off the shelf” CAR T cell.

scholarly journals A comprehensive review on: Chimeric Antigen Receptor (CAR) T-cell therapy in cancer treatment

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
Bikash Pal ◽  
Bornika Chattaraj ◽  
Purnima Agrawal
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Great Promise ◽  
T Cell Therapy ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Chimeric antigen receptor T-cells or CAR T-cell therapy is a newly discovered method that has shown great promise for the global patient population to cure cancer. Chimeric antigen receptor T-cells are generally prepared by removing T-cells from the patients’ blood and modifying them using genetic engineering, to express a Chimeric Antigen Receptor on their surface. The studies done so far have shown its major effectiveness against Beta-cell malignancy, ovarian carcinoma, and lymphoblastic leukemia. The therapy can cause Cytokine Release Syndrome, neurotoxicity syndrome, tumor lysis, etc. as its major adverse event. But recent improvements in the therapy has proved that these adverse events can be effectively minimized to a great extent. The future of CAR T-cell therapy is very promising and is expected to fulfil all global regulatory requirements as well as overcome any manufacturing and toxicological obstacles and become available for a large number of populations. This review is based on the overall prospects of CAR T-cell therapy, the major toxicity related problems, and the prospect of this therapy.

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