Adverse events following infusion of T cells for adoptive immunotherapy: a 10-year experience

Tumor immunity: A brief overview of tumor‑infiltrating immune cells and research advances into tumor‑infiltrating lymphocytes in gynecological malignancies (Review)

Tumor immunity is a promising topic in the area of cancer therapy. The 'soil' function of the tumor microenvironment (TME) for tumor growth has attracted wide attention from scientists. Tumor-infiltrating immune cells in the TME, especially the tumor-infiltrating lymphocytes (TILs), serve a key role in cancer. Firstly, relevant literature was searched in the PubMed and Web of Science databases with the following key words: 'Tumor microenvironment'; 'TME'; 'tumor-infiltrating immunity cells'; 'gynecologic malignancies'; 'the adoptive cell therapy (ACT) of TILs'; and 'TIL-ACT' (https://pubmed.ncbi.nlm.nih.gov/). According to the title and abstract of the articles, relevant items were screened out in the preliminary screening. The most relevant selected items were of two types: All kinds of tumor-infiltrating immune cells; and advanced research on TILs in gynecological malignancies. The results showed that the subsets of TILs were various and complex, while each subpopulation influenced each other and their effects on tumor prognosis were diverse. Moreover, the related research and clinical trials on TILs were mostly concentrated in melanoma and breast cancer, but relatively few focused on gynecological tumors. In conclusion, the present review summarized the biological classification of TILs and the mechanisms of their involvement in the regulation of the immune microenvironment, and subsequently analyzed the development of tumor immunotherapy for TILs. Collectively, the present review provides ideas for the current treatment dilemma of gynecological tumor immune checkpoints, such as adverse reactions, safety, personal specificity and efficacy.

Secondary bone marrow graft loss after third-party virus-specific T cell infusion: Case report of a rare complication

Virus-specific T cells (VST) from partially-HLA matched donors have been effective for treatment of refractory viral infections in immunocompromised patients in prior studies with a good safety profile, but rare adverse events have been described. Here we describe a unique and severe adverse event of VST therapy in an infant with severe combined immunodeficiency, who receives, as part of a clinical trial (NCT03475212), third party VSTs for treating cytomegalovirus viremia following bone marrow transplantation. At one-month post-VST infusion, rejection of graft and reversal of chimerism is observed, as is an expansion of T cells exclusively from the VST donor. Single-cell gene expression and T cell receptor profiling demonstrate a narrow repertoire of predominantly activated CD4+ T cells in the recipient at the time of rejection, with the repertoire overlapping more with that of peripheral blood from VST donor than the infused VST product. This case thus demonstrates a rare but serious side effect of VST therapy.

The Effects of Human Immunodeficiency Virus Type 1 (HIV-1) Antigen-Expanded Specific T-Cell Therapy and Vorinostat on Persistent HIV-1 Infection in People With HIV on Antiretroviral Therapy

BACKGROUND

The histone deacetylase inhibitor vorinostat (VOR) can reverse human immunodeficiency virus type 1 (HIV-1) latency in vivo and allow T cells to clear infected cells in vitro. HIV-specific T cells (HXTCs) can be expanded ex vivo and have been safely administered to people with HIV (PWH) on antiretroviral therapy.

METHODS

Six PWH received infusions of 2 × 107 HXTCs/m² with VOR 400 mg, and 3 PWH received infusions of 10 × 107 HXTCs/m² with VOR. The frequency of persistent HIV by multiple assays including quantitative viral outgrowth assay (QVOA) of resting CD4+ T cells was measured before and after study therapy.

RESULTS

VOR and HXTCs were safe, and biomarkers of serial VOR effect were detected, but enhanced antiviral activity in circulating cells was not evident. After 2 × 107 HXTCs/m² with VOR, 1 of 6 PWH exhibited a decrease in QVOA, and all 3 PWH exhibited such declines after 10 × 107 HXTCs/m² and VOR. However, most declines did not exceed the 6-fold threshold needed to definitively attribute decline to the study intervention.

CONCLUSIONS

These modest effects provide support for the strategy of HIV latency reversal and reservoir clearance, but more effective interventions are needed to yield the profound depletion of persistent HIV likely to yield clinical benefit. Clinical Trials Registration. NCT03212989.

Post-transplant malignancy: Focusing on virus-associated etiologies, pathogenesis, evidence-based management algorithms, present status of adoptive immunotherapy and future directions

Modern immunosuppression has led to a decrease in rejection rates and improved survival rates after solid organ transplantation. Increasing the potency of immunosuppression promotes post-transplant viral infections and associated cancers by impairing immune response against viruses and cancer immunoediting. This review reflects the magnitude, etiology and immunological characteristics of various virus-related post-transplant malignancies, emphasizing the need for future research. A multidisciplinary and strategic approach may serve best but overall literature evidence targeting it is sparse. However, the authors attempted to provide a more detailed update of the literature consensus for the prevention, diagnosis, management and surveillance of post-transplant viral infections and associated malignancies, with a focus on the current role of adoptive immunotherapy and the way forward. In order to achieve long-term patient and graft survival as well as superior post-transplant outcomes, collaborative research on holistic care of organ recipients is imperative.

Safety evaluation of immune-cell therapy for malignant tumor in the Cancer Immune-cell Therapy Evaluation Group (CITEG)

BACKGROUND AIMS

With the aim of strengthening the scientific evidence of immune-cell therapy for cancer and further examining its safety, in October 2015, our hospital jointly established the Cancer Immune-Cell Therapy Evaluation Group (CITEG) with 39 medical facilities nationwide.

METHODS

Medical information, such as patients' background characteristics, clinical efficacy and therapeutic cell types obtained from each facility, has been accumulated, analyzed and evaluated by CITEG. In this prospective study, we analyzed the adverse events associated with immune-cell therapy until the end of September 2022, and we presented our interim safety evaluation.

RESULTS

A total of 3839 patients with malignant tumor were treated with immune-cell therapy, with a median age of 64 years (range, 13-97 years) and a male-to-female ratio of 1:1.08 (1846:1993). Most patients' performance status was 0 or 1 (86.8%) at the first visit, and 3234 cases (84.2%) were advanced or recurrent cases, which accounted for the majority. The total number of administrations reported in CITEG was 31890, of which 960 (3.0%) showed adverse events. The numbers of adverse events caused by treatment were 363 (1.8%) of 19661 administrations of αβT cell therapy, 9 of 845 administrations of γδT-cell therapy (1.1%) and 10 of 626 administrations of natural killer cell therapy (1.6%). The number of adverse events caused by dendritic cell (DC) vaccine therapy was 578 of 10748 administrations (5.4%), which was significantly larger than those for other treatments. Multivariate analysis revealed that αβT cell therapy had a significantly greater risk of adverse events at performance status 1 or higher, and patients younger than 64 years, women or adjuvant immune-cell therapy had a greater risk of adverse events in DC vaccine therapy. Injection-site reactions were the most frequently reported adverse events, with 449 events, the majority of which were associated with DC vaccine therapy. Among all other adverse events, fever (228 events), fatigue (141 events) and itching (131 events) were frequently reported. In contrast, three patients had adverse events (fever, abdominal pain and interstitial pneumonia) that required hospitalization, although they were weakly related to this therapy; rather, it was considered to be the effect of treatment for the primary disease.

CONCLUSIONS

Immune-cell therapy for cancer was considered to be a safe treatment without serious adverse events.

SARS-CoV-2-specific T cell therapy for severe COVID-19: a randomized phase 1/2 trial

Despite advances, few therapeutics have shown efficacy in severe coronavirus disease 2019 (COVID-19). In a different context, virus-specific T cells have proven safe and effective. We conducted a randomized (2:1), open-label, phase 1/2 trial to evaluate the safety and efficacy of off-the-shelf, partially human leukocyte antigen (HLA)-matched, convalescent donor-derived severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells (CoV-2-STs) in combination with standard of care (SoC) in patients with severe COVID-19 compared to SoC during Delta variant predominance. After a dose-escalated phase 1 safety study, 90 participants were randomized to receive CoV-2-ST+SoC (n = 60) or SoC only (n = 30). The co-primary objectives of the study were the composite of time to recovery and 30-d recovery rate and the in vivo expansion of CoV-2-STs in patients receiving CoV-2-ST+SoC over SoC. The key secondary objective was survival on day 60. CoV-2-ST+SoC treatment was safe and well tolerated. The study met the primary composite endpoint (CoV-2-ST+SoC versus SoC: recovery rate 65% versus 38%, P = 0.017; median recovery time 11 d versus not reached, P = 0.052, respectively; rate ratio for recovery 1.71 (95% confidence interval 1.03-2.83, P = 0.036)) and the co-primary objective of significant CoV-2-ST expansion compared to SοC (CoV-2-ST+SoC versus SoC, P = 0.047). Overall, in hospitalized patients with severe COVID-19, adoptive immunotherapy with CoV-2-STs was feasible and safe. Larger trials are needed to strengthen the preliminary evidence of clinical benefit in severe COVID-19. EudraCT identifier: 2021-001022-22 .

Virus-Specific T-Cell Therapy for Viral Infections of the Central Nervous System: A Review

Opportunistic viral infections of the central nervous system represent a significant cause of morbidity and mortality among an increasing number of immunocompromised patients. Since antiviral treatments are usually poorly effective, the prognosis generally relies on the ability to achieve timely immune reconstitution. Hence, strategies aimed at reinvigorating antiviral immune activity have recently emerged. Among these, virus-specific T-cells are increasingly perceived as a principled and valuable tool to treat opportunistic viral infections. Here we briefly discuss how to develop and select virus-specific T-cells, then review their main indications in central nervous system infections, including progressive multifocal leukoencephalopathy, CMV infection, and adenovirus infection. We also discuss their potential interest in the treatment of progressive multiple sclerosis, or EBV-associated central nervous system inflammatory disease. We finish with the key future milestones of this promising treatment strategy.

Tuning CARs: recent advances in modulating chimeric antigen receptor (CAR) T cell activity for improved safety, efficacy, and flexibility

Cancer immunotherapies utilizing genetically engineered T cells have emerged as powerful personalized therapeutic agents showing dramatic preclinical and clinical results, particularly in hematological malignancies. Ectopically expressed chimeric antigen receptors (CARs) reprogram immune cells to target and eliminate cancer. However, CAR T cell therapy's success depends on the balance between effective anti-tumor activity and minimizing harmful side effects. To improve CAR T cell therapy outcomes and mitigate associated toxicities, scientists from different fields are cooperating in developing next-generation products using the latest molecular cell biology and synthetic biology tools and technologies. The immunotherapy field is rapidly evolving, with new approaches and strategies being reported at a fast pace. This comprehensive literature review aims to provide an up-to-date overview of the latest developments in controlling CAR T cell activity for improved safety, efficacy, and flexibility.

Chimeric antigen receptor T cells therapy in solid tumors

Chimeric antigen receptor T cells therapy (CAR-T therapy) is a class of ACT therapy. Chimeric antigen receptor (CAR) is an engineered synthetic receptor of CAR-T, which give T cells the ability to recognize tumor antigens in a human leukocyte antigen-independent (HLA-independent) manner and enables them to recognize more extensive target antigens than natural T cell surface receptor (TCR), resulting in tumor destruction. CAR-T is composed of an extracellular single-chain variable fragment (scFv) of antibody, which serves as the targeting moiety, hinge region, transmembrane spacer, and intracellular signaling domain(s). CAR-T has been developing in many generations, which differ according to costimulatory domains. CAR-T therapy has several limitations that reduce its wide availability in immunotherapy which we can summarize in antigen escape that shows either partial or complete loss of target antigen expression, so multiplexing CAR-T cells are promoted to enhance targeting of tumor profiles. In addition, the large diversity in the tumor microenvironment also plays a major role in limiting this kind of treatment. Therefore, engineered CAR-T cells can evoke immunostimulatory signals that rebalance the tumor microenvironment. Using CAR-T therapy in treating the solid tumor is mainly restricted by the difficulty of CAR-T cells infiltrating the tumor site, so local administration was developed to improve the quality of treatment. The most severe toxicity after CAR-T therapy is on-target/on-tumor toxicity, such as cytokine release syndrome (CRS). Another type of toxicity is on-target/off-tumor toxicity which originates from the binding of CAR-T cells to target antigen that has shared expression on normal cells leading to damage in healthy cells and organs. Toxicity management should become a focus of implementation to permit management beyond specialized centers.

Generation of good manufacturing practice grade virus-specific T cells for the management of post-transplant CMV infections

Adoptive transfer of antigen-specific T cells has recently emerged as a successful strategy to treat viral infections following hematopoietic cell transplantation (HCT). Ex-vivo expanded donor-derived virus-specific T cells (VSTs) can be safe and effective, devoid of all the drug-related adverse effects. The study aimed to manufacture cGMP grade VSTs from healthy donors, characterize the VST product and demonstrate its safety and efficacy. Peripheral blood mononuclear cells (PBMCs) collected from six healthy donors were stimulated with pepmix that mimics the pp65 antigenic epitope of CMV and cultured for 14 days in G-Rex culture tubes. Post pepmix exposure and expansion the median CD3% was 98.8% (range:95.5% to 99.9%) while the median CD4% and CD8% were 49.1% (range:21.3% to 86.6%) and 43.9% (range:12.7% to 75.5%) respectively. The percentage of IFNγ+ cells was much higher among the CD8+ T cells (median - 18.47%; range 6.50% - 45.82%) when compared to CD4+ T cells (median - 2.74%; range 0.47% - 18.58%) and there was a switch from the CD45RA+ naive phenotype to CD45RA- effector memory phenotype in the 4 samples that achieved a >5 fold expansion. The VSTs were cytotoxic to the pepmix pulsed lymphoblasts (efficacy) while they did not induce cytolysis in the lymphoblasts that were not exposed to the pepmix (safety). This feasibility exercise helped us optimize the starting cell dose for the culture and clinical grade culture strategies, subset characterization and cytotoxicity assays. The approach could be applied to the clinical practice where virus-specific T cell infusions could be given for post-transplant viral infections.

Tacrolimus-resistant SARS-CoV-2-specific T cell products to prevent and treat severe COVID-19 in immunosuppressed patients

Solid organ transplant (SOT) recipients receive therapeutic immunosuppression that compromises their immune response to infections and vaccines. For this reason, SOT patients have a high risk of developing severe coronavirus disease 2019 (COVID-19) and an increased risk of death from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Moreover, the efficiency of immunotherapies and vaccines is reduced due to the constant immunosuppression in this patient group. Here, we propose adoptive transfer of SARS-CoV-2-specific T cells made resistant to a common immunosuppressant, tacrolimus, for optimized performance in the immunosuppressed patient. Using a ribonucleoprotein approach of CRISPR-Cas9 technology, we have generated tacrolimus-resistant SARS-CoV-2-specific T cell products from convalescent donors and demonstrate their specificity and function through characterizations at the single-cell level, including flow cytometry, single-cell RNA (scRNA) Cellular Indexing of Transcriptomes and Epitopes (CITE), and T cell receptor (TCR) sequencing analyses. Based on the promising results, we aim for clinical validation of this approach in transplant recipients. Additionally, we propose a combinatory approach with tacrolimus, to prevent an overshooting immune response manifested as bystander T cell activation in the setting of severe COVID-19 immunopathology, and tacrolimus-resistant SARS-CoV-2-specific T cell products, allowing for efficient clearance of viral infection. Our strategy has the potential to prevent severe COVID-19 courses in SOT or autoimmunity settings and to prevent immunopathology while providing viral clearance in severe non-transplant COVID-19 cases.

A Retrospective Analysis: Autologous Peripheral Blood Hematopoietic Stem Cell Transplant Combined With Adoptive T-Cell Therapy for the Treatment of High-Grade B-Cell Lymphoma in Ten Dogs

In humans, a type of cellular immunotherapy, called adoptive T cell transfer (ACT), can elicit curative responses against hematological malignancies and melanoma. ACT using ex vivo expanded peripheral blood T-cells after multiagent chemotherapy enhances tumor-free survival of dogs with B-cell lymphoma (LSA). Since 2008, our group has been performing autologous peripheral blood hematopoietic stem cell transplants (autoPBHSCT) for the treatment of canine high-grade B-cell LSA, although relapse of residual disease is a common cause of reduced survival in ~70% of treated dogs. We reasoned that a more aggressive treatment protocol combining CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy, autoPBHSCT, and ACT to treat 10 dogs with B-cell LSA could lead to better outcomes when compared to dogs treated with CHOP chemotherapy and autoPBHSCT alone. Using this protocol, once dogs achieved complete hematologic reconstitution post-autoPBHSCT, CD3+ CD8+ and CD3+CD4+ T-cells were expanded from the peripheral blood at a commercial laboratory. Two to four ACT infusions were given to each dog, with a total of 23 infusions given. Infusions were administered with no complications or adverse events. The median cell dose for all infusions was 5.62 x 10⁶ cells/kg (range: 2.59 x 10⁶-8.55 x 10⁶ cells/kg). 4/10 (40%) of dogs were cured of their disease (defined as disease-free for ≥2 years post-autoPBHSCT). Our results confirm that the autoPBHSCT protocol did not hinder the in vitro expansion of autologous peripheral blood T-cells and that the final product could be administered safely, with no adverse events recorded. Finally, since only ten dogs were treated, our results can only suggest that the administration of ACT to dogs after multiagent chemotherapy and autoPHSCT did not lead to a statistically significant increase in median disease-free interval and overall survival when compared to dogs who received CHOP chemotherapy and autoPHSCT alone.

Slow-delivery and distributed exchange of cryoprotective agents with hydrogel beads

Intracellular loading of cryoprotective agents (CPAs) into target cells is a critical step for cryopreservation. However, biological membranes are usually much less permeable to CPAs than to water, resulting in high osmotic pressures and osmotic damage during the CPA loading and unloading phases of cryopreservation. Here, we show that calcium alginate hydrogel beads several millimeters in diamater containing CPAs can be admixed with a cell suspension to spontaneously release CPAs in a gradual and distributed manner. We demonstrate that beads containing cell media enable the gradual removal of CPA from Jurkat cells equilibrated in a typical cryopreservation solution of 15% glycerol, protecting the cells from hypotonic damage. We show that the dynamics of CPA exchange are accurately described by a numerical model of free diffusion within the gel. This approach may enable semiautomated and closed methods of gradual CPA exchange from large volume cell suspensions.

Cryopreservation of NK and T Cells Without DMSO for Adoptive Cell-Based Immunotherapy

Dimethylsufoxide (DMSO) being universally used as a cryoprotectant in clinical adoptive cell-therapy settings to treat hematological malignancies and solid tumors is a growing concern, largely due to its broad toxicities. Its use has been associated with significant clinical side effects-cardiovascular, neurological, gastrointestinal, and allergic-in patients receiving infusions of cell-therapy products. DMSO has also been associated with altered expression of natural killer (NK) and T-cell markers and their in vivo function, not to mention difficulties in scaling up DMSO-based cryoprotectants, which introduce manufacturing challenges for autologous and allogeneic cellular therapies, including chimeric antigen receptor (CAR)-T and CAR-NK cell therapies. Interest in developing alternatives to DMSO has resulted in the evaluation of a variety of sugars, proteins, polymers, amino acids, and other small molecules and osmolytes as well as modalities to efficiently enable cellular uptake of these cryoprotectants. However, the DMSO-free cryopreservation of NK and T cells remains difficult. They represent heterogeneous cell populations that are sensitive to freezing and thawing. As a result, clinical use of cryopreserved cell-therapy products has not moved past the use of DMSO. Here, we present the state of the art in the development and use of cryopreservation options that do not contain DMSO toward clinical solutions to enable the global deployment of safer adoptively transferred cell-based therapies.

Chimeric antigen receptor T-cell therapy: An emergency medicine focused review

INTRODUCTION

Several novel cancer therapies have been recently introduced, each with complications that differ from chemotherapy and radiation.

OBJECTIVE

This narrative review discusses complications associated with chimeric antigen receptor (CAR) T-cell therapy for emergency clinicians.

DISCUSSION

Novel immune-based cancer therapies including CAR T-cell therapy have improved the care of patients with malignancy, primarily lymphoma and leukemia. However, severe complications may arise, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). CRS is associated with excessive cytokine release that results in severe end organ injury. Patients present with fever and a range of symptoms based on the affected organs. Grading is determined by the need for cardiopulmonary intervention, while management focuses on resuscitation, evaluation for other concomitant conditions, and treatment with tocilizumab or steroids. ICANS is also associated with cytokine release, causing patients to present with a variety of neurologic features. A grading system is available for ICANS based on feature severity. Management is supportive with steroids. Other complications of CAR T-cell therapy include infusion reactions, hypogammaglobulinemia, tumor lysis syndrome, cytopenias, cardiac toxicity, and graft-versus-host disease.

CONCLUSIONS

Knowledge of this novel cancer therapy class and the potential complications can improve the care of these patients in the emergency department setting.

Tisagenlecleucel Therapy: Nursing Considerations for the Outpatient Setting

OBJECTIVE

Tisagenlecleucel is a CD19-directed, genetically modified, autologous T-cell immunotherapy indicated for pediatric and young adult patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia and for adult patients with relapsed/refractory diffuse large B-cell lymphoma. Treatment with any chimeric antigen receptor (CAR)-T cell therapy is a multistep process in which nurses and nurse practitioners are key to managing patient safety. Managing patients receiving CAR-T cell therapy in the outpatient setting (as Penn does with tisagenlecleucel and lisocabtagene maraleucel) requires an even more complex process. The objective of this manuscript is to provide guidance on the role of nurses in the outpatient administration of tisagenlecleucel therapy and postinfusion care in adult patients with diffuse large B-cell lymphoma. Oncology and apheresis nurses discuss institutional processes and perspectives related to the patient experience with tisagenlecleucel therapy at the Hospital of the University of Pennsylvania.

DATA SOURCES

Author experience.

CONCLUSION

Nurses are vital for the success of the patient management processes involved with tisagenlecleucel therapy. Nurses must be thoroughly educated in tisagenlecleucel therapy and adverse event management and be able to effectively communicate all aspects of therapy among the multidisciplinary team of the hospital, the product manufacturer, and patients and families. Establishment of the nurse cellular therapy coordinator at the Hospital of the University of Pennsylvania was advantageous in facilitating effective communication in all these situations.

IMPLICATIONS FOR NURSING

This encompassing approach to patient management is particularly necessary during administration of tisagenlecleucel therapy and other CAR-T cell therapies that are managed in the outpatient setting.

Autologous EBV-specific T cell treatment results in sustained responses in patients with advanced extranodal NK/T lymphoma: results of a multicenter study

We conducted a phase II clinical trial to develop an autologous EBV-specific T cell product (baltaleucel T) for advanced, relapsed ENKTL. Among 47 patients who provided whole blood starting material for manufacturing the product, 15 patients received a median of 4 doses of baltaleucel T. Thirty-two (68%) patients did not receive baltaleucel-T due to manufacturing failure, rapid disease progression, and death. Of the 15 patients, 10 patients had measurable disease at baseline (salvage cohort), and 5 patients had no disease at baseline assessment (adjuvant cohort). In the 15 patients, the median follow-up duration was 10.2 months (range 2.0-23.5 months), median progression-free survival (PFS) was 3.9 months, and the median overall survival (OS) was not reached. Patients in the salvage cohort achieved a 30% complete response (CR) and a 50% overall response rate (ORR). In the adjuvant cohort, disease progression was reported in three patients and two patients did not relapse during study follow-up. When we compared survival outcomes of seven responders and eight non-responders, the PFS (P = 0.001) and OS (P = 0.014) of responders proved statistically superior to that of non-responders. Baltaleucel-T was well tolerated. We have performed a phase II clinical trial of autologous EBV-specific T cell treatment (baltaleucel-T) in R/R ENKTL. Autologous EBV-specific T cells were well tolerated and demonstrated single-agent activity in R/R ENTKL.

Infusion reactions in natural killer cell immunotherapy: a retrospective review

BACKGROUND AIMS

The use of natural killer (NK) cells as a cellular immunotherapy has increased over the past decade, specifically in patients with hematologic malignancies. NK cells have been used at the authors' institution for over 15 years. Most patients have a reaction to NK cell infusion. The authors retrospectively analyzed the reactions associated with NK cell infusions to characterize the types of reactions and investigate why some patients have higher-grade reactions than others.

METHODS

A retrospective chart review of NK cell infusions was performed at the authors' institution under nine clinical protocols from 2008 to 2016. An infusion reaction was defined as any symptom from the time of NK cell infusion up to 4 h after infusion completion. The severity of infusion reactions was graded based on Common Terminology Criteria for Adverse Events, version 4. Two major endpoints of interest were (i) infusion reaction with any symptom and (ii) grade ≥3 infusion reaction. Multivariable logistic regression models were used to investigate the association between variables of interest and outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained for each variable.

RESULTS

A total of 130 patients were receiving NK cell infusions at the authors' institution. The most common reported symptom was chills (n = 110, 85%), which were mostly grade 1 and 2, with only half of patients requiring intervention. There were 118 (91%) patients with infusion reactions, and only 36 (28%) were grade 3. There was one life-threatening grade 4 reaction, and no death was reported due to infusion reaction. Among grade ≥3 reactions, cardiovascular reactions (mainly hypertension) were the most common, and less than half of those with hypertension required intervention. NK cell dose was not associated with any of the grade 3 infusion reactions, whereas monocyte dose was associated with headache (grade ≤3, OR, 2.17, 95% CI, 1.19-3.97) and cardiovascular reaction (grade ≥3, OR, 2.13, 95% CI, 1.13-3.99). Cardiovascular reaction (grade ≥3) was also associated with in vitro IL-2 incubation and storage time. Additionally, there was no association between grade ≥3 infusion reactions and overall response rate (OR, 0.75, 95% CI, 0.29-1.95).

CONCLUSIONS

The majority of patients who receive NK cell therapy experience grade 1 or 2 infusion reactions. Some patients experience grade 3 reactions, which are mainly cardiovascular, suggesting that close monitoring within the first 4 h is beneficial. The association of monocytes with NK cell infusion reaction relates to toxicities seen in adoptive T-cell therapy and needs further exploration.

"Cerberus" T Cells: A Glucocorticoid-Resistant, Multi-Pathogen Specific T Cell Product to Fight Infections in Severely Immunocompromised Patients

Adoptive immunotherapy (AI) with pathogen-specific T cells is a promising alternative to pharmacotherapy for the treatment of opportunistic infections after allogeneic hematopoietic cell transplantation or solid organ transplantation. However, clinical implementation of AI is limited to patients not receiving high-dose steroids, a prerequisite for optimal T-cell function, practically excluding the most susceptible to infections patients from the benefits of AI. To address this issue, we here rapidly generated, clinical doses of a steroid-resistant T-cell product, simultaneously targeting four viruses (adenovirus, cytomegalovirus, Epstein Barr virus, and BK virus) and the fungus Aspergillus fumigatus, by genetic disruption of the glucocorticoid receptor (GR) gene using CRISPR/CAS9 ribonucleoprotein delivery. The product, “Cerberus” T cells (Cb-STs), was called after the monstrous three-headed dog of Greek mythology, due to its triple potential; specificity against viruses, specificity against fungi and resistance to glucocorticoids. Following efficient on-target GR disruption and minimal off-target editing, the generated Cb-STs maintained the characteristics of pentavalent-STs, their unedited counterparts, including polyclonality, memory immunophenotype, specificity, and cytotoxicity while they presented functional resistance to dexamethasone. Cb-STs may become a powerful, one-time treatment for severely immunosuppressed patients under glucocorticoids who suffer from multiple, life-threatening infections post-transplant, and for whom therapeutic choices are limited.

Current immunotherapy in gastrointestinal malignancies A Review

Immunotherapy is an extremely important breakthrough and an exciting new modality of treatment for a wide spectrum of cancers. It is focused around developing agents to stimulate or suppress the immune system, in a specific manner, to fight off a wide spectrum of diseases, particularly cancers. Traditional therapies available for the treatment of cancers include surgical intervention, chemotherapy, radiation therapy or a combination of these, which tend to be very non-specific. However, immunotherapy shows a stark difference from conventional therapy, in fact, that it has a high level of specificity for the tumor-specific antigens. The recent success of cancer immunotherapies in clinical trials is slowly revolutionizing the landscape for cancer therapy. The US Food and Drug Administration has approved numerous agents, after clinical trials showed promising results, for the treatment of multiple cancers. The role of immunotherapy in gastrointestinal cancers has also been very promising, particularly in patients with advanced metastatic disease or malignancies refractory to initial treatment. In this review of literature, we detail and discuss the immunotherapy agents approved for the treatment of GI cancers and glance at the future of immunotherapy for patients with these cancers.

Gastrointestinal Adverse Effects of Immunotherapeutic Agents: A Systematic Review

The utilization of immunotherapy is increasing to the point of becoming the fifth pillar of management alongside surgical intervention, chemotherapy, radiotherapy and targeted therapy. However, gastrointestinal adverse effects and toxicities have been frequently cited with its use. As per literature, the most common adverse effect of immune checkpoint inhibitors is watery and non-bloody diarrhea. Adoptive cell therapy can lead to delayed, on-target but off-tumor adverse effects which are unknown and may be life-threatening. The use of anti-angiogenic monoclonal antibodies can lead to bowel perforations, whereas epidermal growth factor receptor inhibitors and anti-HER2 agents are frequently associated with diarrhea. Minimal adverse effects have been associated with therapeutic cancer vaccines; however, additional studies are needed to determine their efficacy and potential toxicities. To provide an in-depth review of the gastrointestinal side effects of immunotherapeutic agents, we performed a thorough literature search using multiple online search engines such as PubMed, Google Scholar and Ovid MEDLINE, along with a review of the guidelines from the United States Food and Drug Administration (FDA) and the Cancer Research Institute on immunotherapy. In this systematic review, we detail the gastrointestinal adverse effects of immunotherapy and describe their management. With the advent of newer immunotherapeutic agents and the consistent approval of current agents by FDA for a wide spectrum of cancers, it is vital for physicians to familiarize themselves with their adverse effects for prompt diagnosis and early intervention to decrease adverse outcomes.

SARS-CoV-2-specific T cells are rapidly expanded for therapeutic use and target conserved regions of the membrane protein

T-cell responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described in recovered patients, and may be important for immunity following infection and vaccination as well as for the development of an adoptive immunotherapy for the treatment of immunocompromised individuals. In this report, we demonstrate that SARS-CoV-2-specific T cells can be expanded from convalescent donors and recognize immunodominant viral epitopes in conserved regions of membrane, spike, and nucleocapsid. Following in vitro expansion using a good manufacturing practice-compliant methodology (designed to allow the rapid translation of this novel SARS-CoV-2 T-cell therapy to the clinic), membrane, spike, and nucleocapsid peptides elicited interferon-γ production, in 27 (59%), 12 (26%), and 10 (22%) convalescent donors (respectively), as well as in 2 of 15 unexposed controls. We identified multiple polyfunctional CD4-restricted T-cell epitopes within a highly conserved region of membrane protein, which induced polyfunctional T-cell responses, which may be critical for the development of effective vaccine and T-cell therapies. Hence, our study shows that SARS-CoV-2 directed T-cell immunotherapy targeting structural proteins, most importantly membrane protein, should be feasible for the prevention or early treatment of SARS-CoV-2 infection in immunocompromised patients with blood disorders or after bone marrow transplantation to achieve antiviral control while mitigating uncontrolled inflammation.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of lymphoma

The recent development and clinical implementation of novel immunotherapies for the treatment of Hodgkin and non-Hodgkin lymphoma have improved patient outcomes across subgroups. The rapid introduction of immunotherapeutic agents into the clinic, however, has presented significant questions regarding optimal treatment scheduling around existing chemotherapy/radiation options, as well as a need for improved understanding of how to properly manage patients and recognize toxicities. To address these challenges, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in lymphoma to develop a clinical practice guideline for the education of healthcare professionals on various aspects of immunotherapeutic treatment. The panel discussed subjects including treatment scheduling, immune-related adverse events (irAEs), and the integration of immunotherapy and stem cell transplant to form recommendations to guide healthcare professionals treating patients with lymphoma.

CAR T-cell therapy-related neurotoxicity in paediatric acute lymphocytic leukaemia

BACKGROUND

The advent of chimeric antigen receptor (CAR) T-cell therapy has created a paradigm shift in the management of patients with refractory B-cell acute lymphocytic leukaemia (ALL). The aim of this study is to correlate imaging findings of CAR T-cell therapy related neurotoxicity with clinical course and eventual clinical outcome, with the hope that it will bring us a step closer to the identification of potential imaging biomarkers that may allow more accurate prognostication and risk stratification of patients.

PROCEDURE

Our imaging database was queried from January 2018 to April 2020 to identify paediatric patients who fulfil the following criteria: (a) diagnosed with ALL, (b) underwent CAR T-cell therapy, and (c) had magnetic resonance imaging (MRI) brain studies performed before and after CAR T-cell therapy. A total of seven patients were included and all MRI studies were analysed by a paediatric neuroradiologist for the presence of acute neuroimaging findings post CAR T-cell infusion. Acute neuroimaging findings are defined as new imaging findings detected within 28 days of CAR T-cell infusion.

RESULTS

Three out of four patients with acute neuroimaging findings had sustained complete remission for more than 6 months, while all three patients without acute neuroimaging findings had positive minimal residual disease (MRD) within 1 month. Both patients with acute diffuse leptomeningeal enhancement showed clinical improvement within 1-2 days.

CONCLUSIONS

Acute neuroimaging findings may be a potential imaging biomarker for peak neurotoxicity and treatment response, and it is not necessarily associated with poor outcome, as previously reported.

Side-effect management of chimeric antigen receptor (CAR) T-cell therapy

Chimeric antigen receptor (CAR) T cells directed against the B-cell marker CD19 are currently changing the landscape for treatment of patients with refractory and/or relapsed B-cell malignancies. Due to the nature of CAR T cells as living drugs, they display a unique toxicity profile. As CAR T-cell therapy is extending towards other diseases and being more broadly employed in hematology and oncology, optimal management strategies of side-effects associated with CAR T-cell therapy are of high relevance. Cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and cytopenias constitute challenges in the treatment of patients with CAR T cells. This review summarizes the current understanding of CAR T-cell toxicity and its management.

Virus-Specific T Cell Therapies for HIV: Lessons Learned From Hematopoietic Stem Cell Transplantation

Human immunodeficiency virus (HIV) has caused millions of deaths and continues to threaten the health of millions of people worldwide. Despite anti-retroviral therapy (ART) substantially alleviating severity and limiting transmission, HIV has not been eradicated and its persistence can lead to other health concerns such as cancer. The only two cases of HIV cure to date are HIV⁺ cancer patients receiving an allogeneic hematopoietic stem cell transplantation (allo-HSCT) from a donor with the CCR5 Δ32 mutation. While this approach has not led to such success in other patients and is not applicable to HIV⁺ individuals without cancer, the encouraging results may point toward a breakthrough in developing a cure strategy for HIV. Adoptive transfer of virus-specific T cells (VSTs) post HSCT has been effectively used to treat and prevent reactivation of latent viral infections such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV), making VSTs an attractive therapeutic to control HIV rebound. Here we will discuss the potential of using adoptive T cell therapies in combination with other treatments such as HSCT and latency reversing agents (LRAs) to achieve a functional cure for HIV.

Assessment and management of cytokine release syndrome and neurotoxicity following CD19 CAR-T cell therapy

Introduction: The success of CD19 chimeric antigen receptor (CAR)-T cell therapy for treatment of CD19 positive malignancies has led to the FDA approval of two CD19 CAR-T cell products, tisagenlecleucel and axicabtagene ciloleucel, and ongoing clinical trials of new products. Cytokine release syndrome (CRS) and neurotoxicity are common toxicities associated with CD19 CAR-T cell therapies.Areas covered: This review will discuss CRS and neurotoxicity associated with CD19 CAR-T cell therapies, including clinical presentation, risk factors, pathophysiology, and therapeutic or prophylactic interventions.Expert opinion: In conjunction with improved understanding of the pathophysiology of CRS and neurotoxicity, we expect that the recent development of consensus guidelines for the evaluation of these toxicities will enhance management of patients undergoing CD19 CAR-T cell therapies.

Engineering light-controllable CAR T cells for cancer immunotherapy

T cells engineered to express chimeric antigen receptors (CARs) can recognize and engage with target cancer cells with redirected specificity for cancer immunotherapy. However, there is a lack of ideal CARs for solid tumor antigens, which may lead to severe adverse effects. Here, we developed a light-inducible nuclear translocation and dimerization (LINTAD) system for gene regulation to control CAR T activation. We first demonstrated light-controllable gene expression and functional modulation in human embryonic kidney 293T and Jurkat T cell lines. We then improved the LINTAD system to achieve optimal efficiency in primary human T cells. The results showed that pulsed light stimulations can activate LINTAD CAR T cells with strong cytotoxicity against target cancer cells, both in vitro and in vivo. Therefore, our LINTAD system can serve as an efficient tool to noninvasively control gene activation and activate inducible CAR T cells for precision cancer immunotherapy.

T-Cell Receptor Stimulation Enhances the Expansion and Function of CD19 Chimeric Antigen Receptor-Expressing T Cells

PURPOSE

Current protocols for CD19 chimeric antigen receptor-expressing T cells (CD19.CAR-T cells) require recipients to tolerate preinfusion cytoreductive chemotherapy, and the presence of sufficient target antigen on normal or malignant B cells.

PATIENTS AND METHODS

We investigated whether additional stimulation of CD19.CAR-T cells through their native receptors can substitute for cytoreductive chemotherapy, inducing expansion and functional persistence of CD19.CAR-T even in patients in remission of B-cell acute lymphocytic leukemia. We infused a low dose of CD19.CAR-modified virus-specific T cells (CD19.CAR-VST) without prior cytoreductive chemotherapy into 8 patients after allogeneic stem cell transplant.

RESULTS

Absent virus reactivation, we saw no CD19.CAR-VST expansion. In contrast, in patients with viral reactivation, up to 30,000-fold expansion of CD19.CAR-VSTs was observed, with depletion of CD19⁺ B cells. Five patients remain in remission at 42-60+ months.

CONCLUSIONS

Dual T-cell receptor and CAR stimulation can thus potentiate effector cell expansion and CAR-target cell killing, even when infusing low numbers of effector cells without cytoreduction.

Immunotherapy of Relapsed and Refractory Solid Tumors With Ex Vivo Expanded Multi-Tumor Associated Antigen Specific Cytotoxic T Lymphocytes: A Phase I Study

PURPOSE

Tumor-associated antigen cytotoxic T cells (TAA-Ts) represent a new, potentially effective and nontoxic therapeutic approach for patients with relapsed or refractory solid tumors. In this first-in-human trial, we investigated the safety of administering TAA-Ts that target Wilms tumor gene 1, preferentially expressed antigen of melanoma, and survivin to patients with relapsed/refractory solid tumors.

MATERIALS AND METHODS

TAA-T products were generated from autologous peripheral blood and infused over three dose levels: 1, 2, and 4 × 10⁷ cells/m². Patients were eligible for up to eight infusions administered 4 to 7 weeks apart. We assessed dose limiting toxicity during the first 45 days after infusion. Disease response was determined within the context of a phase I trial.

RESULTS

There were no dose-limiting toxicities. Of 15 evaluable patients, 11 (73%) with stable disease or better at day 45 postinfusion were defined as responders. Six responders remain without progression at a median of 13.9 months (range, 4.1 to 19.9 months) after initial TAA-Ts. Patients who were treated at the highest dose level showed the best clinical outcomes, with a 6-month progression-free survival of 73% after TAA-T infusion compared with a 38% 6-month progression-free survival with prior therapy. Antigen spreading and a reduction in circulating tumor-associated antigens using digital droplet polymerase chain reaction was observed in patients after TAA-T infusion.

CONCLUSION

TAA-Ts safely induced disease stabilization, prolonged time to progression, and were associated with antigen spreading and a reduction in circulating tumor-associated antigen DNA levels in patients with relapsed/refractory solid tumors without lymphodepleting chemotherapy before infusion. TAA-Ts are a promising new treatment approach for patients with solid tumors.

Toxicities of CD19 CAR-T cell immunotherapy

CD19-targeted chimeric antigen receptor (CAR)-modified T (CAR-T) cell immunotherapy has demonstrated impressive results in B-cell malignancies, and CAR-T cell therapies targeting other antigens are in development for other cancers. Cytokine release syndrome (CRS) and neurotoxicity can be life-threatening in a subset of patients. The severity of CRS and neurotoxicity can be impacted by the disease burden, lymphodepletion regimen, and CAR-T cell dose. Tocilizumab and corticosteroids have been used to manage these toxicities, enabling CD19 CAR-T cells to be administered without obvious compromise in efficacy. Consensus criteria for grading and managing toxicities will facilitate the widespread application of this treatment modality.

Critical testing and parameters for consideration when manufacturing and evaluating tumor-associated antigen-specific T cells

The past year has seen remarkable translation of cellular and gene therapies, with U.S. Food and Drug Administration (FDA) approval of three chimeric antigen receptor (CAR) T-cell products, multiple gene therapy products, and the initiation of countless other pivotal clinical trials. What makes these new drugs most remarkable is their path to commercialization: they have unique requirements compared with traditional pharmaceutical drugs and require different potency assays, critical quality attributes and parameters, pharmacological and toxicological data, and in vivo efficacy testing. What's more, each biologic requires its own unique set of tests and parameters. Here we describe the unique tests associated with ex vivo-expanded tumor-associated antigen T cells (TAA-T). These tests include functional assays to determine potency, specificity, and identity; tests for pathogenic contaminants, such as bacteria and fungus as well as other contaminants such as Mycoplasma and endotoxin; tests for product characterization, tests to evaluate T-cell persistence and product efficacy; and finally, recommendations for critical quality attributes and parameters associated with the expansion of TAA-Ts.

CAR T Cell Toxicity: Current Management and Future Directions

By late 2018, 2 chimeric antigen receptor T (CAR T) cell products have been approved by US and European regulatory authorities. Tisagenlecleucel (Kymriah, Novartis) is indicated in the treatment of patients up to 25 years of age with B-cell acute lymphoblastic leukemia (ALL) that is refractory or in second or later relapse, or adult patients with large B-cell lymphoma relapsed or refractory (r/r) after 2 or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL) not otherwise specified, high grade B-cell lymphoma and DLBCL arising from follicular lymphoma. Axicabtagene ciloleucel (Yescarta, Kite) is indicated for the treatment of adult patients with large B-cell lymphoma relapsed or refractory after 2 or more lines of systemic therapy, including DLBCL not otherwise specified, primary mediastinal large B-cell lymphoma, high grade B-cell lymphoma, and DLBCL arising from follicular lymphoma (ZUMA-1 trial). This review will offer a practical guide for the recognition and management of the most important toxicities related to the use of the current commercial CAR T cells, and also highlight strategies to diminish these side effects in the future.

Virus-Specific T Cells: Current and Future Use in Primary Immunodeficiency Disorders

Viral infections are common and can be potentially fatal in patients with primary immunodeficiency disorders (PIDDs). Because viral susceptibility stems from poor to absent T-cell function in most patients with moderate to severe forms of PIDD, adoptive immunotherapy with virus-specific T cells (VSTs) has been used to combat viral infections in the setting of hematopoietic stem cell transplantation in multiple clinical trials. Most trials to date have targeted cytomegalovirus, EBV, and adenovirus either alone or in combination, although newer trials have expanded the number of targeted pathogens. Use of banked VSTs produced from third-party donors has also been studied as a method of expanding access to this therapy. Here we review the clinical experience with VST therapy for patients with PIDDs as well as future potential targets and approaches for the use of VSTs to improve clinical outcomes for this specific patient population.

HIV-Specific, Ex Vivo Expanded T Cell Therapy: Feasibility, Safety, and Efficacy in ART-Suppressed HIV-Infected Individuals

Adoptive T cell therapy has had dramatic successes in the treatment of virus-related malignancies and infections following hematopoietic stem cell transplantation. We adapted this method to produce ex vivo expanded HIV-specific T cells (HXTCs), with the long-term goal of using HXTCs as part of strategies to clear persistent HIV infection. In this phase 1 proof-of-concept study (NCT02208167), we administered HXTCs to antiretroviral therapy (ART)-suppressed, HIV-infected participants. Participants received two infusions of 2 × 107 cells/m2 HXTCs at a 2-week interval. Leukapheresis was performed at baseline and 12 weeks post-infusion to measure the frequency of resting cell infection by the quantitative viral outgrowth assay (QVOA). Overall, participants tolerated HXTCs, with only grade 1 adverse events (AEs) related to HXTCs. Two of six participants exhibited a detectable increase in CD8 T cell-mediated antiviral activity following the two infusions in some, but not all, assays. As expected, however, in the absence of a latency reversing agent, no meaningful decline in the frequency of resting CD4 T cell infection was detected. HXTC therapy in ART-suppressed, HIV-infected individuals appears safe and well tolerated, without any clinical signs of immune activation, likely due to the low residual HIV antigen burden present during ART.

Adoptive cell transfer using autologous tumor infiltrating lymphocytes in gynecologic malignancies

During the last decade, the field of cancer immunotherapy has been entirely transformed by the development of new and more effective treatment modalities with impressive response rates and the prospect of long survival. One of the major breakthroughs is adoptive cell transfer (ACT) based on autologous T cells derived from tumor-infiltrating lymphocytes (TILs). TIL-based ACT is a highly personalized cancer treatment. T cells are harvested from autologous fresh tumor tissues, and after ex vivo activation and extensive expansion, are reinfused to patients. TIL-based therapies have only been offered in small phase I/II studies in a few centers given the highly specialized care required, the complexity of TIL production and the very intensive nature of the three-step treatment protocol. The treatment includes high-dose lymphodepleting chemotherapy, the infusion of the expanded and activated T cells and interleukin-2 (IL-2) injections to increase survival of the T cells. Despite the limited data on ACT, the small published studies consistently confirm an impressive clinical response rate of up to 50% in metastatic melanoma patients, including a significant proportion of patients with durable complete response. These remarkable results justify the need for larger clinical trials in other solid tumors, including gynecologic malignancies. In this review we provide an overview of the current clinical results, future applications of TIL-based ACT in gynecologic malignancies, and on risks and challenges associated with modern T cell therapy.

Specific Adoptive T-Cell Therapy for Viral and Fungal Infections

Despite advances in anti-infective agents, viral and fungal infections after hematopoietic stem cell transplantation (HSCT) continue to cause life-threatening complications that limit the success of HSCT. Early adoptive T-cell immunotherapy studies showed that administration of allogeneic virus-specific cytotoxic T lymphocytes (vCTL) can prevent and control viral infections and reconstitute antiviral immunity to cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Advances in immunobiology, in vitro culture technology, and current good manufacturing practice (cGMP) have provided opportunities for advancing adoptive cell therapy for viral infections: (1) T cells have been expanded targeting multiple pathogens; (2) vCTL production no longer requires viral infection or viral vector transduction of antigen-presenting cells (APCs); (3) the source of lymphocytes is no longer restricted to donors who are immune to the pathogens; (4) naive T cells have been redirected with chimeric antigen receptor T cells (CARTs) or armed with bispecific antibody-armed T cells (BATs) to mediate vCTL activity; (5) these technologies could be combined to targeted multiple viral or fungal pathogens; and (6) pathogen-specific T-cell products manufactured from third parties and banked for “off-the-shelf” use post-HSCT may soon become a reality.

Virus-Specific T Cells for the Immunocompromised Patient

While progress has been made in the treatment of both hematologic cancers and solid tumors, chemorefractory or relapsed disease often portends a dismal prognosis, and salvage chemotherapy or radiation expose patients to intolerable toxicities and may not be effective. Hematopoietic stem cell transplant offers the promise of cure for many patients, and while mismatched, unrelated or haploidentical donors are increasingly available, the recipients are at higher risk of severe immunosuppression and immune dysregulation due to graft versus host disease. Viral infections remain a primary cause of severe morbidity and mortality in this patient population. Again, many therapeutic options for viral disease are toxic, may be ineffective or generate resistance, or fail to convey long-term protection. Adoptive cell therapy with virus-specific T cells (VSTs) is a targeted therapy that is efficacious and has minimal toxicity in immunocompromised patients with CMV and EBV infections in particular. Products have since been generated specific for multiple viral antigens (multi-VST), which are not only effective but also confer protection in 70–90% of recipients when used as prophylaxis. Notably, these products can be generated from either virus-naive or virus-experienced autologous or allogeneic sources, including partially matched HLA-matched third-party donors. Obstacles to effective VST treatment are donor availability and product generation time. Banking of third-party VST is an attractive way to overcome these constraints and provide products on an as-needed basis. Other developments include epitope discovery to broaden the number of viral antigens targets in a single product, the optimization of VST generation from naive donor sources, and the modification of VSTs to enhance persistence and efficacy in vivo.

Genetic Modification of T Cells with Chimeric Antigen Receptors: A Laboratory Manual

Redirected T cells genetically modified with a chimeric antigen receptor (CAR) have induced spectacular remissions of refractory leukemia/lymphoma in early phase trials, attracting interest to use CAR T cells in a variety of other applications including solid cancer and nonmalignant diseases. However, extensive preclinical explorations demand highly effective and robust procedures for the genetic modification of blood T cells; the same applies for engineering with a recombinant T cell receptor. We present laboratory procedures in a step-by-step protocol to engineer human and mouse T cells with a CAR by γ-retro- or lentiviral transduction for further preclinical testing.

Chimeric Antigen Receptors: A Cell and Gene Therapy Perspective

Chimeric antigen receptors (CARs) are synthetic receptors that reprogram T lymphocytes to target chosen antigens. The targeting of CD19, a cell surface molecule expressed in the vast majority of leukemias and lymphomas, has been successfully translated in the clinic, earning CAR therapy a special distinction in the selection of "cancer immunotherapy" by Science as the breakthrough of the year in 2013. CD19 CAR therapy is predicated on advances in genetic engineering, T cell biology, tumor immunology, synthetic biology, target identification, cell manufacturing sciences, and regulatory compliance-the central tenets of CAR therapy. Here, we review two of these foundations: the genetic engineering approaches and cell types to engineer.

Intravenous mesenchymal stromal cell therapy for inflammatory bowel disease: Lessons from the acute graft versus host disease experience

Bone marrow-derived mesenchymal stromal cells (BMSCs) are primitive, supportive cells of the bone marrow with tri-lineage potential to differentiate into bone, cartilage, fat and muscle. These cells possess both in vitro and in vivo immunomodulatory and wound-healing properties. Several studies have demonstrated efficacy of intravenously administered BMSCs in treating acute graft-versus-host disease (GvHD). Use of intravenous (IV) BMSCs in inflammatory bowel diseases (IBD) in humans has been limited to small studies in adults, but results have been promising. There remain many unanswered questions regarding safety, tolerability, effectiveness and optimal use of BMSCs to treat IBD, particularly in immunocompromised patients. This article reviews the evidence for using BMSCs to treat acute GvHD and how this experience may inform the potential use of BMSCs as a treatment for IBD.

EBV-Directed T Cell Therapeutics for EBV-Associated Lymphomas

Epstein Barr virus (EBV) is a human gamma herpes virus that establishes latency in B cells after primary infection. EBV generally only causes a mild, self-limiting viral illness but is also associated with several malignancies including posttransplantation lymphoproliferative disorder in the immunosuppressed host as well as Hodgkin and non-Hodgkin lymphoma in the immune competent host. The expression of EBV antigens by lymphoma has important applications as targets for adoptive T cell therapy. However, as many lymphomas only express subdominant EBV antigens that are less immunogenic, novel strategies are needed to manufacture EBV-specific T cell products specific for Latent Membrane Protein 1 (LMP1) and LMP2, which are expressed in lymphomas with type II and III latency. While several techniques for manufacturing EBV-CTLs are described in the literature, this chapter focuses on one method for generating Good Manufacturing Practice (GMP)-compliant EBV-specific T cell products that are enriched with LMP1 and LMP2.

Putting a price tag on novel autologous cellular therapies

Cell therapies, especially autologous therapies, pose significant challenges to researchers who wish to move from small, probably academic, methods of manufacture to full commercial scale. There is a dearth of reliable information about the costs of operation, and this makes it difficult to predict with confidence the investment needed to translate the innovations to the clinic, other than as small-scale, clinician-led prescriptions. Here, we provide an example of the results of a cost model that takes into account the fixed and variable costs of manufacture of one such therapy. We also highlight the different factors that influence the product final pricing strategy. Our findings illustrate the need for cooperative and collective action by the research community in pre-competitive research to generate the operational models that are much needed to increase confidence in process development for these advanced products.

Adoptive immunotherapy for primary immunodeficiency disorders with virus-specific T lymphocytes

BACKGROUND

Viral infections are a leading fatal complication for patients with primary immunodeficiencies (PIDs) who require hematopoietic stem cell transplantation (HSCT). Use of virus-specific T lymphocytes (VSTs) has been successful for the treatment and prevention of viral infections after HSCT for malignant and nonmalignant conditions. Here we describe the clinical use of VSTs in patients with PIDs at 4 centers.

OBJECTIVE

We sought to evaluate the safety and efficacy of VSTs for treatment of viral infections in patients with PIDs.

METHODS

Patients with PIDs who have received VST therapy on previous or current protocols were reviewed in aggregate. Clinical information, including transplantation details, viral infections, and use of antiviral and immunosuppressive pharmacotherapy, were evaluated. Data regarding VST production, infusions, and adverse reactions were compared.

RESULTS

Thirty-six patients with 12 classes of PID diagnoses received 37 VST products before or after HSCT. Twenty-six (72%) patients had received a diagnosis of infection with cytomegalovirus, EBV, adenovirus, BK virus, and/or human herpesvirus 6. Two patients were treated before HSCT because of EBV-associated lymphoproliferative disease. Partial or complete responses against targeted viruses occurred in 81% of patients overall. Time to response varied from 2 weeks to 3 months (median, 28 days). Overall survival at 6 months after therapy was 80%. Four patients had graft-versus-host disease in the 45 days after VST infusion, which in most cases was therapy responsive.

CONCLUSION

VSTs derived from either stem cell donors or third-party donors are likely safe and effective for the treatment of viral infections in patients with PIDs.

HIV-specific CD8⁺ T cells and HIV eradication

After the success of combination antiretroviral therapy (cART) to treat HIV infection, the next great frontier is to cure infected persons, a formidable challenge. HIV persists in a quiescent state in resting CD4+ T cells, where the replicative enzymes targeted by cART are not active. Although low levels of HIV transcripts are detectable in these resting cells, little to no viral protein is produced, rendering this reservoir difficult to detect by the host CD8+ T cell response. However, recent advances suggest that this state of latency might be pharmacologically reversed, resulting in viral protein expression without the adverse effects of massive cellular activation. Emerging data suggest that with this approach, infected cells will not die of viral cytopathic effects, but might be eliminated if HIV-specific CD8+ T cells can be effectively harnessed. Here, we address the antiviral properties of HIV-specific CD8+ T cells and how these cells might be harnessed to greater effect toward achieving viral eradication or a functional cure.

Immunotherapy in Multiple Myeloma Using Cancer-Testis Antigens

Context:

Multiple myeloma (MM) is a B-cell malignancy characterized by monoclonal expansion of abnormal plasma cells in the bone marrow. It accounts for 10% of hematological malignancies. Although patients respond to a wide range of anticancer modalities, relapse occurs in a significant number of the cases. Immunotherapeutic approaches have been evolved to tackle this problem. Cancer-testis antigens CTAs as a group of tumor-associated antigens are appropriate targets for cancer immunotherapy as they have restricted expression pattern in normal tissues except for testis which is an immune-privileged site. Expression of these antigens has been assessed in different malignancies including MM.

Evidence Acquisition:

We performed a computerized search of the MEDLINE/PubMed databases with key words: multiple myeloma, cancer-testis antigen, and cancer stem cell and immunotherapy.

Results:

Several CTAs including NY-ESO-1, MAGE and GAGE family have been shown to be expressed in MM patients. Cellular and humoral immune responses against these antigens have been detected in MM patients.

Conclusions:

The frequent and high expression level of CTAs in MM patients shows that these antigens can be applied as cancer biomarkers as well as targets for immunotherapy in these patients.

Adoptive transfer of Aspergillus-specific T cells as a novel anti-fungal therapy for hematopoietic stem cell transplant recipients: Progress and challenges

Although newer antifungal drugs have substantially altered the natural history of invasive aspergillosis, the disease still accounts for significant morbidity and mortality in hematopoietic stem cell transplant recipients. Both the evidence supporting a protective role of T cells against this fungal pathogen and the documented efficacy of adoptive transfer of antigen-specific T cells for prophylaxis and treatment of viral infections post-transplant have stimulated much interest towards development of Aspergillus-specific T cells (Asp-STs) for adoptive immunotherapy in the allogeneic transplant setting. In contrast to the remarkable progress with virus-specific T cells, clinical development of fungus-specific T cells is still in its infancy. Several groups have characterized Asp-STs in healthy individuals and patients with malignant hematological diseases, while others sought to develop GMP-compliant methods of expanding or bioengineering Asp-STs ex vivo as immunotherapy. This review highlights the recent advances in this field, and discusses critical issues involved in development and protocol design of Asp-ST immunotherapy.

Challenges and Opportunities for T-Cell-Mediated Strategies to Eliminate HIV Reservoirs

HIV's ability to establish latent reservoirs of reactivation-competent virus is the major barrier to cure. "Shock and kill" methods consisting of latency-reversing agents (LRAs) followed by elimination of reactivating cells through cytopathic effects are under active development. However, the clinical efficacy of LRAs remains to be established. Moreover, recent studies indicate that reservoirs may not be reduced efficiently by either viral cytopathic or CD8(+) T-cell-mediated mechanisms. In this perspective, we highlight challenges to T-cell-mediated elimination of HIV reservoirs, including characteristics of responding T cells, aspects of the cellular reservoirs, and properties of the latent virus itself. We also discuss potential strategies to overcome these challenges by targeting the antiviral activity of T cells toward appropriate viral antigens following latency.