Genetic Engineering Publications - GEG Tech top picks

A study published in Blood Advances reveals that magnetic resonance imaging (MRI) and lumbar puncture (LP) may not be systematically necessary in the diagnosis and management of severe cases of neurotoxicity linked to CAR T cell therapy. Instead, electroencephalogram (EEG), a non-invasive test, has proved useful in the management of these complications. The researchers examined the usefulness of these tests in 190 patients treated with CAR-T at Rennes University Hospital, where during treatment around 48% of patients developed immune effector cell-associated neurotoxicity syndrome (ICANS). The researchers assessed how the different tests affected patient treatment, such as how medications, e.g. antibiotics and anti-epileptic treatments, were prescribed based on abnormal results, and how these treatments altered patient outcomes. The results ultimately revealed that abnormal findings were more common in patients with more severe ICANS. MRI findings were often normal, and although LP and EEG often showed abnormalities, they were more common in more severe cases of ICANS. When it came to therapeutic decisions, MRI rarely led to changes, LP sometimes led to unnecessary treatments in cases of suspected infections, and EEG often resulted in adjustments to antiepileptic drugs.

Cellular senescence is an irreversible cell cycle arrest induced in response to stress. Under stressful conditions, matrix remodeling enzymes and pro-inflammatory cytokines are produced, termed Senescence-Associated Secretory Phenotype (SASP). In young individuals with physiological conditions, such as tumor suppression and wound healing, SASP facilitates the recruitment of immune cells, which facilitate tissue restoration and the elimination of senescent cells. In the elderly, senescent cells accumulate due to reduced immune system function and increased tissue damage. To date, most senescent therapies include small-molecule drugs that require repeated administration and poorly target the affected area. A recent study in Nature Aging evaluates the efficacy of a senolytic therapy based on CAR-T cells. This therapy targets urokinase plasminogen activator receptor (uPAR)-positive cells, which accumulate during aging. In this study, senolytic cell therapies were shown to alleviate symptoms associated with physiological aging, including metabolic dysfunction.

Solid tumors generate anti-immune signals that deactivate CAR T cells, making treatment less effective. To solve this problem, scientists have combined CAR T cells with cytokine injection, which can cause significant unintended toxicities. Researchers replaced the extracellular domain of various cytokine receptors with leucine zippers to create constitutively active receptors. CAR T cells expressing one of these chimeric cytokine receptors had superior antitumor activity against several types of cancer in cell lines and mouse models compared with conventional CAR T cells. Although chimeric cytokine receptors give a constant "on" signal to CAR T cells, they do not induce non-specific proliferation of CAR T cells. The system thus limits the effect of cytokine signaling to modified cells only, reduces the risk of cytokine-related toxicity, and provides a signal that these CAR T cells should function effectively in a suppressive tumor microenvironment. 

Researchers report, in Nature Medicine, the interim results of a first-in-man phase 1 clinical trial evaluating the safety, antitumor activity and immunological characteristics of a genetically engineered natural killer (NKT) cell immunotherapy for neuroblastoma, a childhood tumor that most commonly arises in the adrenal gland. NKT cells were engineered to express a GD2-specific CAR, which enables immune cells to target a molecule found on the surface of neuroblastoma cells, and interleukin-15 a natural protein that supports NKT cell survival. Based on results obtained in 12 patients with recurrent stage 4 neuroblastoma resistant to other therapies, the researchers found that the treatment was safe for all 12 patients on four doses. No dose-limiting toxicities were reported. A further discovery revealed a regulatory gene in NKT cells that could have an impact on treatment efficacy. Leveraging the multiomics platform of key collaborator Immunai, Inc. the researchers discovered that up-regulation of the anti-proliferation factor 1 gene BTG in CAR NKT-infused cells indicates cell exhaustion and limits the functional activity of CAR NKT cells. Conversely, artificially reducing BTG1 expression in CAR NKT cells enhanced their therapeutic activity against neuroblastoma in a mouse model

A new study shows that some effective cancer treatments, such as CAR-T cells, significantly improve quality of life six months after receiving therapy. To conduct the study, researchers recruited 103 patients aged 23 to 90 years with a diagnosis of blood cancer from April 2019 to November 2021. The researchers administered self-reported questionnaires measuring quality of life variables at time intervals including before CAR-T cell infusion and one week, one month, three months, and six months after CAR-T cell infusion. Quality of life was measured using a 27-item questionnaire known as the General Cancer Therapy Functional Assessment, which is composed of four different subscales (physical, functional, emotional, and social). Psychological distress was measured using the Hospital Anxiety and Depression Scale. Finally, major depressive symptoms were measured using the PHQ-9, and symptoms of posttraumatic stress disorder were measured using the Posttraumatic Stress Checklist. While most study participants eventually experienced an improvement in quality of life, approximately 20% of patients experienced persistent physical and psychological symptoms, which at times interfered with their quality of life.

Crystal Mackall remembers her scepticism the first time she heard a talk about a way to engineer T cells to recognize and kill cancer. Sitting in the audience at a 1996 meeting in Germany, the paediatric oncologist turned to the person next to her and said: “No way. That’s too crazy.”

Today, things are different. “I’ve been humbled,” says Mackall, who now works at Stanford University in California developing such cells to treat brain tumours.

CAR T cell therapies are generally optimized for short-term cellular responses and may not allow for long-term systemic eradication of the tumor. To enable precise control of CAR T cell function over time, a first solution has been developed. Researchers have exploited recently developed synthetic Notch receptors to design enhanced CAR T cells with a second receptor. The second receptor can recognize a tumor antigen and then cause the T cell to release the cytokine interleukin-2, but when the CAR T cells are in direct contact with the tumor cells. In a mouse model, the approach enabled CAR T infiltration of solid pancreatic and melanoma tumors, resulting in substantial tumor eradication. In addition, a second solution was developed. Researchers developed a toolbox of 11 programmable synthetic transcription factors that could be activated on demand with timed administration of FDA-approved small-molecule inducers. Using these tools, the authors designed human immune cells that activate proliferation and antitumor activity on demand. The combination of the two technological advances presented will provide an unprecedented ability to precisely control the state of therapeutic cell populations not only at the time of injection but also as the immune response unfolds in the patient.

CAR T cells currently in clinical use are designed to recognize cancer cells directly and have successfully treated several blood cancers. But there have been challenges that prevent their effective use in many solid tumors. Most solid tumors are heavily infiltrated by a type of immune cell called macrophages. Macrophages help tumors grow by blocking the entry of T cells into the tumor tissue, which prevents CAR T cells and the patient's own T cells from destroying the cancer cells. To address this immune suppression at the source, the researchers engineered T cells to make a chimeric antigen receptor that recognizes a molecule on the surface of macrophages. When these CAR T cells encountered a tumor macrophage, the CAR T cell became activated and killed the tumor macrophage. Treating mice with ovarian, lung and pancreatic tumors with these macrophage-targeting CAR T cells reduced the number of tumor macrophages, shrank the tumors and prolonged their survival. The destruction of tumor macrophages allowed the mice's own T cells to access and kill the cancer cells. The researchers further demonstrated that this anti-tumor immunity was induced by the release of the cytokine interferon-gamma by CAR T cells.

Researchers examined two cohorts of patients who received CD19-directed CAR-T cells for non-Hodgkin's lymphoma or B-cell acute lymphoblastic leukemia. The researchers used the first cohort to retrospectively examine the impact of prior antibiotic use on CAR-T clinical outcomes. The second cohort had prospective baseline fecal samples collected before CAR-T cell infusion for subsequent assessment of the fecal microbiome. The investigators determined that the use of certain antibiotics including piperacillin/tazobactam, meropenem, and imipenem/cilastatin, negatively affected OS (HR = 1.71; 95% CI, 1.12-2.59). The investigators also noted a significantly increased risk of immune effector cell-associated neurotoxicity syndrome among the entire cohort evaluated for pre-CAR-T antibiotic use (P = 0.023). Stool samples from the prospective cohort demonstrated an altered fecal microbiome including lower alpha diversity, increased frequency of bacterial dominance, and altered bacterial composition compared with healthy controls. The results of this study suggest that the composition of the gut microbiome affects CAR-T outcomes, but the investigators cautioned that further prospective studies in larger patient populations are needed to confirm the associations.

Researchers have shown that a synthetic IL-9 receptor allows anti-cancer T cells to do their job without the need for chemo or radiation. T cells modified with the synthetic IL-9 receptor were potent against tumours in mice, as published in Nature. This group of researchers were interested in testing modified versions of the synthetic receptor that transmit other cytokine signals from the common gamma chain family: IL-4, -7, -9 and -21. Of the synthetic common gamma chain signals, the IL-9 signal was worth studying and unlike other cytokines, IL-9 signalling is not generally active in naturally ocurring T cells. The synthetic IL-9 signal gave the T cells a unique blend of stem cell and killer cell qualities that made them more robust in fighting tumours. In particular, the researchers targeted two types of difficult-to-treat cancer models in mice: pancreatic cancer and melanoma. They used T cells targeted to the cancer cells via the natural T cell receptor or a chimeric antigen receptor (CAR). In all cases, T cells engineered with synthetic IL-9 receptor signalling were superior and helped cure some tumours in mice when they could not do otherwise. 

Many people are excluded from CAR T cell-based treatments because of its cost. One reason for the high cost is that the manufacturing process is complex, time-consuming and must be individually tailored to each cancer patient. So to address this challenge, the researchers created a biotechnology called Multifunctional Alginate Scaffolds for T cell Engineering and Release (MASTER) that is a biocompatible sponge-like material. To begin treatment, the researchers isolate the patient's T cells and mix these naive T cells with the modified virus. The researchers pour this mixture onto MASTER, which absorbs it. MASTER is decorated with the antibodies that activate the T cells, so the cell activation process begins almost immediately. Meanwhile, MASTER is surgically implanted into the patient. After implantation, as the T cells become activated, they begin to respond to the modified viruses, which reprogram them into CAR-T cells. MASTER is also imbued with interleukin factors that promote cell proliferation. After implantation, these interleukins begin to leach out, promoting rapid proliferation of CAR-T cells. In a proof-of-concept study involving lymphoma in mice, researchers found that this treatment was faster and more effective than conventional CAR-T cell cancer treatment. 

MB-106 is a fully humanized, autologous, modified CAR T cell therapy that targets the CD20 protein on the surface of cancer cells. The researchers based the new agent on work done at the Fred Hutchinson Cancer Research Center, which is now collaborating with Mustang Bio to develop the cell therapy. MB-106 differs from approved commercial CAR T cell therapies in that it contains both the CD28 and 4-1BB costimulatory domains. Researchers modified its manufacturing process in 2019 to combine CD4-positive and CD8-positive cell culture for the final infusion product. Resarch team conducted a single-center phase 1/phase 2 dose escalation study to evaluate the safety and efficacy of MB-106 in patients with relapsed or refractory CD20-positive B-cell non-Hodgkin's lymphoma and chronic lymphocytic leukemia. Nineteen of 20 patients (95%) achieved a response to a single infusion of MB-106. Twelve patients (65%) achieved a complete response. The CD20-directed CAR-T in this study will be better tolerated and may serve as an alternative for patients whose disease does not express the CD19 antigen.

Glioblastoma (GBM) is the most common and aggressive type of cancerous brain tumor in adults. People with GBM generally expect to live 12 to 18 months after diagnosis. Despite decades of research, there is no known cure for GBM, and treatments have only a limited effect on extending an individual's life expectancy. However, researchers have tested a technology that delivers CAR-T cells targeting two proteins commonly found in brain tumors: epidermal growth factor receptor (EGFR), estimated to be present in 60% of all GBMs, and interleukin-13 receptor alpha 2 (IL13Rα2), which is expressed in over 75% of GBMs. While CAR-T cell therapy for blood cancers is usually administered intravenously, the researchers administered these dual-targeted CAR-T cells intrathecally, by injection into the cerebrospinal fluid, so that the modified cells could reach the tumors more directly in the brain. Magnetic Resonance Imaging scans taken 24 to 48 hours after administration of dual-targeted CAR-T cells targeting EGFR and IL13Rα2 revealed a reduction in tumor size in all six patients, and these reductions were maintained up to several months later in a subgroup of patients. 

Traditional CAR-T cells, while effective against liquid cancers, face challenges in solid tumors: the cells wear out and ultimately fail to destroy the cancer completely. Ground-breaking research is providing an innovative approach to this challenge. Researchers are introducing CAR-T cells that excrete the IL-10 molecule. In other words, the cell has been designed to produce its own "drug" to stay healthy in the tumor's hostile environment. In the laboratory, this innovative CAR-T therapy systematically eradicated cancerous tumors in mouse models. What's more, in ongoing clinical trials, eleven patients have appeared to achieve complete remission with this treatment, representing a 100% success rate to date. Notably, the evidence from the laboratory study suggests the long-term efficacy of the therapy, and indicates that its manufacture could be both faster and more cost-effective than current methods 

Until now, researchers have lacked the tools to create a targeted cell therapy approach that could work on all the different forms of blood and bone marrow cancers. A new solution could solve a major problem in immunotherapy, namely the inability to target surface markers present on both cancerous and healthy cells. In the study, published today in Science Translational Medicine, researchers used CAR T cells engineered to target CD45, a surface marker present on almost all blood cells, including almost all blood cancer cells. Since CD45 is also found on healthy blood cells, the research team used CRISPR base editing to develop a method called "epitope editing" to overcome the challenges of an anti-CD45 strategy, which would otherwise result in potentially lethal low blood counts and threatening side effects. The modified version of CD45 still functions, but differs sufficiently from normal CD45 for anti-CD45 CAR T cells not to recognize and attack it. This study lays the foundations for a more universal approach that could potentially extend CAR T cell therapy to all blood cancers. 

Immunotherapy, particularly CAR T-Cell cancer therapy, extends the lives of many patients. But sometimes the therapy randomly migrates to places it shouldn't go, sneaking into the lungs or other non-cancerous tissue and causing toxic side effects. However, a team of researchers has discovered the molecule responsible for guiding T cells to tumors, setting the stage for scientists to improve the revolutionary treatment. Their discovery of the crucial migration control gene that expresses ST3GAL1 is the result of "unbiased genomic screening": researchers used a state-of-the-art CRISPR technique to edit thousands of genes expressed in T cells, then tested the migration control capabilities of these genes, one by one over a period of nearly four years, in mouse models. The next step is to find a drug that can manipulate the key T cell protein, ST3GAL1. If the study progresses as planned, such a drug could be added to the CAR T-cell regimen to ensure that the T cells reach their targets

Pancreatic cancer is an incurable form of cancer and gene therapies are currently in clinical trials to treat this deadly disease. A comprehensive review of gene and cell biotherapies in development to combat pancreatic cancer is published in the peer-reviewed journal Human Gene Therapy. The article, "Pancreatic Cancer Cell and Gene Biotherapies: Past, Present and Future," by corresponding author Pierre Cordelier of the University of Toulouse, and co-authors describes ongoing gene therapy clinical trials. In addition to gene therapies, the authors discuss vaccines, chimeric antigen receptor (CAR) T-cell therapy, suicide genes and oncolytic viruses.

Until recently, most CAR-T therapies were made from the patient's own cells, but the long-term commercial viability of cell therapies of all types will rely on "allogeneic" cells, therapeutic cells mass-produced and grown from a source outside the patient. However, the recipient's immune system is likely to treat all outside cells as foreign and reject them. Immune rejection of therapeutic cells, such as CAR-T cells, mediated by antibodies, as opposed to chemical aggression initiated by them, has proven to be particularly challenging to resolve. This is a factor that hinders the development of these treatments. Researchers have therefore developed a method to catch antibodies before they bind to cells, preventing the activation of the immune response. The researchers genetically engineered three types of cells :  insulin-producing islet cells, thyroid cells and CAR-T cells, so that each type makes and displays a large number of a protein called CD64 on their surface. On these engineered cells, CD64, which tightly binds the antibodies responsible for this type of immune rejection, acted as a kind of decoy, capturing the antibodies and binding them to the engineered cell, so that they would not activate the immune cells. The new strategy is described in Nature Biotechnology.

Researchers have bolstered the power of chimeric antigen receptor (CAR)-T cancer therapies, which use genetically altered T cells to seek out tumours and mark them for destruction. Now scientists have further engineered the cells to contain switches that allow control over when and where the cells are active. This helps them to infiltrate tumours and dodge immune-suppressing defences.

A small clinical trial has shown that researchers can use CRISPR gene editing to alter immune cells so that they will recognize mutated proteins specific to a person’s tumours. Those cells can then be safely set loose in the body to find and destroy their target.

Currently, too few CAR T cells become memory cells that persist and create more T cells in the long term. However, a group of researchers recently showed that the distribution of the c-Myc protein in a parental T cell may be important for this process and published this work in the journal Nature. The researchers knew that a daughter cell with more c-Myc became an effector cell. In this study, the team found that the protein complex cBAF (canonical Brg1/Brg-associated factor) interacted with c-Myc. Daughter cells with high concentrations of cBAF and c-Myc became effector T cells. The cBAF binds certain regions of chromatin, proteins on DNA. The discovery suggests that it can guide the fate of cells, what type of T cells they become, by controlling the expression of effector cell-related genes. The distribution of cBAF occurs in the first activated T cell that begins the adaptive immune response; therefore, the researchers realized that cell fate is decided early in the immune response. The researchers used the molecular information they discovered. They applied a cBAF inhibitor during CAR T cell activation to generate more memory T cells. In a preclinical model, T cells treated with an inhibitor-controlled tumor growth better than untreated cells. The treated cells also survived longer and in greater numbers.

Genetically modified immune cells successfully target specific cancer cells that may be responsible for the relapse of acute myeloid leukemia (AML). In a study published on 28 April in Nature Communications, the researchers developed a CAR T cell therapy (UCART123) targeting CD123, which is found on leukemia stem cells and enables T cells to seek out and attack cancer cells. When the team tested the UCART123 cells in a mouse model of AML, they found that the therapy effectively eliminated leukemia cells and prolonged survival. The scientists also devised a highly sensitive monitoring strategy to detect any residual cancer cells and assess the persistence of UCART123 cells. Finally, they demonstrated that UCART123 cells have specificity against leukemia cells, with minimal toxicity to normal blood cells in mice. The preclinical results led to a Phase 1 clinical trial testing UCART123 in patients with relapsed/refractory AML at several sites across the US, including New York-Presbyterian/Weill Cornell Medical Center. The results of the preclinical study suggest that UCART123 cells are highly selective and specific in targeting AML. 

Clinicians treating patients with CAR T cells have become adept at identifying and treating acute neurotoxicity, a common adverse event associated with the therapy. Researchers at Mount Sinai published a case study in Nature Medicine of a patient who developed a neurocognitive, hypokinetic movement disorder with features of Parkinson's disease after receiving the CAR-T therapy targeting the B-cell maturation antigen (BCMA) called ciltacabtagene autoleucel in the CARTITUDE-1 clinical trial. Since reports of this toxicity have not been observed with CD19-directed CAR-T therapies for other blood cancers, it appears to be specifically associated with BCMA-directed CAR-T. As it turns out, Parekh and colleagues found that BCMA is expressed on certain brain cells, and they saw evidence that BCMA-targeted CAR-T cells entered the patient's cerebrospinal fluid and crossed the blood-brain barrier. With ciltacabtagene autoleucel poised to become the second BCMA-directed CAR-T to gain commercial approval later this year, clinicians should discuss the potential benefits and risks of the therapy with their patients. They also need to be vigilant about screening for late neurological toxicities until researchers can make improvements to the new CAR-T constructs to mitigate the risk.