• Advances in the Optimization of CAR-T-Cell-Based Therapeutic Approaches to Enhance Antitumor Efficacy in Glioblastoma Treatment
• Adoptive cell therapy with macrophage-drug conjugates facilitates cytotoxic drug transfer and immune activation in glioblastoma models
• Utilization of universal-targeting mSA2 CAR-T cells for the treatment of glioblastoma
• Defining the extracellular matrix for targeted immunotherapy in adult and pediatric brain cancer
• Study of combination CAR T-cell treatment for glioblastoma using mathematical modeling
• Modulating CD226 and PD-(L)1 pathways improves CMV-specific CD8＋T cell responses in the absence of IL-2
• CD70 CAR-T cells empowered by TS-2021 through ex vivo transduction show potent antitumor efficacy against glioblastoma
• The hotspots and publication trends in glioblastoma and CAR-T immunotherapy: A bibliometric analysis

Both CAR-T cell therapy and cancer vaccines are promising immunotherapeutic approaches for glioblastoma (GBM), but their future potential differs in terms of feasibility, scalability, safety, and long-term innovation.

• Cancer Vaccines → more near-term clinical potential
• CAR-T Cell Therapy → more long-term transformative potential (if challenges are overcome)

• Generally safer and better tolerated
• Easier to manufacture and scale
• mRNA platforms enable rapid personalization (e.g., NOA-16 trial)
• Effective in adjuvant settings (post-surgery)
• Combine well with checkpoint inhibitors and radiotherapy

📌 *Example:* The NOA-16 trial showed that 93% of patients generated T cell responses to a personalized mRNA neoantigen vaccine.

• Direct, high-potency tumor killing
• Can be engineered to target multiple antigens or use logic-gated designs
• Living therapy: CAR-T cells persist and expand in vivo
• Success in hematological malignancies inspires innovation in GBM

⚠️ *However:* In glioblastoma, challenges like immune suppression, antigen escape, and the blood-brain barrier remain significant obstacles.

• Next 5–10 years → Cancer vaccines (especially personalized mRNA vaccines) are more likely to be adopted in routine GBM care.
• Beyond 10 years → CAR-T cells, if optimized for brain tumors, may offer curative potential with smart engineering.

• Glioblastoma Immunotherapy
• Glioblastoma CAR-T Cell Therapy
• Cancer Vaccine for Glioma
• Personalized mRNA Neoantigen Vaccine
• NOA-16 Trial
• Checkpoint Inhibitors

Both CAR-T therapy and cancer vaccines aim to stimulate the immune system against glioblastoma (GBM), but they differ fundamentally in their approach, personalization, mechanism of action, and current stage of development.

• CAR-T therapy delivers engineered killer T cells to directly attack GBM cells expressing specific antigens.
• Glioblastoma vaccines aim to educate the immune system to recognize tumor antigens and mount a durable response over time.
• CAR-T is cell-based and active, while vaccines are antigen-based and instructive.
• Both are promising, but vaccines are generally safer and less complex, whereas CAR-T may offer stronger immediate tumor killing if barriers can be overcome.

• Glioblastoma Immunotherapy
• Glioblastoma CAR-T Cell Therapy
• Cancer Vaccine for Glioma
• Checkpoint Inhibitors
• NOA-16 Trial

CAR-T cell therapy (Chimeric Antigen Receptor T cell therapy) is an advanced form of adoptive cellular immunotherapy. It involves engineering a patient’s T cells to express synthetic receptors that specifically recognize antigens on glioblastoma cells, enabling targeted immune attack.

• Glioblastoma is highly resistant to conventional therapies.
• CAR-T therapy bypasses the need for traditional antigen presentation (HLA-independent).
• Offers precision targeting of tumor-specific surface antigens.

1. T cells are extracted from the patient’s blood.
2. T cells are genetically modified to express a **CAR** targeting a tumor antigen.
3. Modified T cells are expanded in the lab.
4. They are reinfused into the patient.
5. CAR-T cells recognize and kill tumor cells expressing the target antigen.

• Antigen heterogeneity → tumor cells may downregulate the target
• Immunosuppressive microenvironment (Tregs, MDSCs, cytokines)
• Blood-brain barrier (BBB) → may limit T cell trafficking
• On-target, off-tumor toxicity → especially with HER2, GD2
• Limited persistence of CAR-T cells in the brain

• Dual- or multi-target CARs to prevent antigen escape
• Armored CARs that secrete cytokines (e.g., IL-12)
• SynNotch circuits for conditional activation
• Intratumoral or intracavitary delivery (e.g., Ommaya reservoir)
• Combination with checkpoint inhibitors or oncolytic viruses

CAR-T cell therapy for glioblastoma offers a highly targeted immunotherapy approach but faces unique challenges due to the brain environment and tumor heterogeneity. While results to date are mixed, ongoing trials and novel CAR designs are working to improve safety, persistence, and efficacy.

• Glioblastoma Immunotherapy
• Cancer Vaccine for Glioma
• Checkpoint Inhibitors
• Oncolytic Virus Therapy

CAR-T cell therapy is a cutting-edge immunotherapy approach that has shown promise in the treatment of various cancers, including glioblastoma. Here's an overview of how CAR-T cell therapy is being explored for glioblastoma:

Target Antigen in Glioblastoma:

In the case of glioblastoma, researchers have been investigating various target antigens that are expressed on the surface of glioblastoma cells. EGFRvIII and IL-13Rα2 are examples of such antigens. Collection and Modification:

To begin the CAR-T cell therapy process, T cells are collected from the patient's blood through a process called leukapheresis. These collected T cells are then genetically engineered in a laboratory to express the CAR specific to the glioblastoma antigen.

Expansion and Activation:

After modification, the CAR-T cells are cultured and expanded in large numbers. These engineered CAR-T cells are also activated to enhance their anti-tumor activity.

Infusion:

Once a sufficient number of CAR-T cells have been generated, they are infused back into the patient's bloodstream, similar to a blood transfusion.

Targeting Glioblastoma:

The CAR-T cells circulate within the patient's body and recognize glioblastoma cells that express the specific target antigen. Upon binding to these cancer cells, the CAR-T cells become activated and initiate an immune response against the tumor.

Cytokine Release Syndrome (CRS):

One of the side effects associated with CAR-T cell therapy is CRS, which occurs due to the release of cytokines (immune system signaling molecules) and can lead to flu-like symptoms and, in severe cases, organ dysfunction. Clinical Trials:

CAR-T cell therapy for glioblastoma is still largely in the experimental phase and has been the subject of clinical trials.

These trials aim to evaluate the safety and effectiveness of CAR-T cell therapy in treating glioblastoma patients.

Challenges:

Glioblastoma poses unique challenges because it is located within the brain, which is protected by the blood-brain barrier. This barrier can limit the entry of CAR-T cells into the brain.

Future Directions:

Researchers continue to explore ways to improve the effectiveness of CAR-T cell therapy for glioblastoma, such as developing CAR-T cells that can bypass the blood-brain barrier or combining CAR-T therapy with other treatments. It's important to note that while CAR-T cell therapy has shown promise in some cancers, it is still an area of active research in glioblastoma treatment, and more clinical trials and studies are needed to determine its long-term efficacy and safety in this challenging cancer type.

The CAR-T cells are designed to target a protein called EGFRvIII, which is found on the surface of glioblastoma cells but not on healthy cells. Several clinical trials have shown promising results for this approach, with some patients experiencing significant improvements in survival and quality of life.

However, there are still challenges to overcome in the development of glioblastoma CAR-T cell therapy, including optimizing the design of the CAR-T cells to improve their effectiveness and reducing the risk of side effects such as cytokine release syndrome and neurotoxicity. Ongoing research is focused on addressing these challenges and improving the outcomes of CAR-T cell therapy for glioblastoma and other types of cancer.

Chimeric antigen receptor (CAR) T-cell immunotherapy has been studied in the context of improving these tumors' clinical outcomes. HGG murine models treated with CAR T cells targeting tumor antigens have shown reduced tumor burden and longer overall survival than models without treatment. Subsequent clinical trials investigating the efficacy of CAR T cells have further shown that this therapy could be safe and might reduce tumor burden. However, there are still many challenges that need to be addressed to optimize the safety and efficacy of CAR T-cell therapy in treating HGG patients ¹⁾.

Solid tumor CAR-T cell therapy, and more specifically glioblastoma, is still riddled with challenges preventing its widespread adoption. The on-target/off-tumor toxicity, glioblastoma antigen modulation, tumor heterogeneity, and the immunosuppressive glioblastoma tumor microenvironment.

Cytotoxic T lymphocytes collected from a patient can be genetically modified to express a chimeric antigen receptor (CAR) specific for an identified tumor antigen (TA). These CAR T cells can then be re-administered to the patient to identify and eliminate cancer cells. The impressive clinical responses to TA-specific CAR T cell-based therapies in patients with hematological malignancies have generated a lot of interest in the application of this strategy with solid tumors including GBM. Several clinical trials are evaluating TA-specific CAR T cells to treat GBM. Unfortunately, the efficacy of CAR T cells against solid tumors has been limited due to several factors. These include the immunosuppressive tumor microenvironment, inadequate trafficking and infiltration of CAR T cells, and their lack of persistence and activity. In particular, GBM has specific limitations to overcome including acquired resistance to therapy, limited diffusion across the blood-brain barrier, and risks of the central nervous system toxicity ²⁾

Zhang et al. examined the use of armored CARs to improve the survival and proliferation of CAR T cells. They conclude by discussing the advantages of tandem and synNotch CARs when targeting multiple glioblastoma antigens ³⁾.

Choi and Yin presented the perspective on genetically modifying CAR constructs, overcoming T cell dysfunctions, and developing additional treatments that can improve CAR T cell effectiveness, such as functionality, persistence, and infiltration into tumor sites. Effectively improved CAR T cells may offer patients with GBM new treatment opportunities ⁴⁾

CARs incorporate antigen-recognition moieties that endow autologous T-cells with specificity against glioblastoma antigens (e.g. IL-13Rα2, EGFRvIII, and HER2). Compelling anti-tumor effects of such therapy have been shown in murine glioblastoma models. In humans, five-phase I/II studies on IL-13Rα2-, EGFRvIII-, and HER2-directed CAR T-cells for the treatment of glioblastoma patients have been published suggesting an acceptable safety profile. However, anti-tumor effects fell short of expectations in these initial clinical studies. Tumor heterogeneity, antigen loss, and the immunosuppressive tumor microenvironment are among the most important factors to limit the efficacy of CAR T-cell therapy in glioblastoma. Novel target antigens, modification of CAR T-cell design, the combination of CAR T-cell therapy with other therapeutic approaches, but also the use of CAR NK-cells or CAR macrophages may optimize anti-tumor effects. Numerous clinical trials studying such approaches are ongoing, as well as several preclinical studies. With an increasing understanding of immune-escape mechanisms of glioblastoma and novel manufacturing techniques for CARs, CAR T-cells may provide clinically relevant activity in glioblastoma. This review focuses on the use of CAR T-cells in glioblastoma but also introduces the basic structure, mechanisms of action, and relevant side effects of CAR T-cells ⁵⁾.

In 2020 Land et al. reviewed the CAR design and technical innovations, the major targets that are in pre-clinical and clinical development with a focus on Glioblastoma, and multiple strategies developed to improve CAR T cell efficacy ⁶⁾.

Zheng Y, Gao N, Fu YL, Zhang BY, Li XL, Gupta P, Wong AJ, Li TF, Han SY. Generation of regulable EGFRvIII targeted chimeric antigen receptor T cells for adoptive cell therapy of glioblastoma. Biochem Biophys Res Commun. 2018 Nov 5. pii: S0006-291X(18)32327-1. doi: 10.1016/j.bbrc.2018.10.151. [Epub ahead of print] PubMed PMID: 30409424.

Current clinical trials take a multifaceted approach with the intention of harnessing the intrinsic cytotoxic capabilities of the immune system to directly target glioblastoma cancer stem cells (gCSC) or indirectly disrupt their stromal microenvironment. Monoclonal antibodies (mAbs), dendritic cell (DC) vaccines, and chimeric antigen receptor (CAR) T cell therapies have emerged as the most common approaches, with particular iterations incorporating cancer stem cell antigenic markers in their treatment designs. Ongoing work to determine the comprehensive antigenic profile of the gCSC in conjunction with efforts to counter the immunosuppressive microenvironment holds much promise in future immunotherapeutic strategies against Glioblastoma. Given recent advancements in these fields, Esparza etal. believe there is tremendous potential to improve outcomes of Glioblastoma patients in the continuing evolution of immunotherapies targeted to cancer stem cell populations in Glioblastoma ⁷⁾.

A study has shown that CAR T cells were effective in migrating to and attacking tumors that express a specific protein called CD70. This indicates that CAR T cells can be used against solid tumors, which have been historically difficult to treat using this therapy.

Chemotaxis and Immune Recruitment: The researchers analyzed cytokines and chemokines (signaling molecules in the immune system) and used in situ imaging to understand how immune cells are recruited to the tumor site. They found that immune cells were drawn to the tumors through a process called chemotaxis, which is a response to specific chemical signals. This suggests a mechanism by which CAR T cells can target solid tumors.

Effector to Target Ratio: The balance between the number of immune cells (effectors) and tumor cells (targets) is crucial for the overall effectiveness of CAR T cell therapy. This ratio was found to play a significant role in the therapy's anti-tumor function. It implies that having the right number of CAR T cells relative to the tumor cells is important for success.

Differential Gene Expression: By collecting single cells from the tumor environment and examining their genetic activity (transcriptomic profiling), the researchers identified differences in gene expression among different immune subpopulations. This suggests that not all immune cells in the tumor environment behave the same way, and understanding these differences can be valuable for optimizing CAR T cell therapy.

Statement of Significance: This section highlights the importance of the study's findings. It notes that while CAR T cells have been successful in treating blood cancers, their effectiveness in solid tumors has been limited due to physical barriers in these tumors. The study's innovative three-dimensional in vitro model allows for a more detailed examination of how CAR T cells interact with solid tumors at the single-cell level. The research provides valuable insights into the complex dynamics of CAR T cell function in solid tumors, which can inform future research and development efforts to improve this promising cancer treatment approach.

In summary, this study demonstrates that CAR T cells can be effective against solid tumors expressing CD70 and sheds light on the mechanisms by which they work. It also underscores the importance of understanding the immune cell-tumor interactions at a detailed level for the development of better cancer therapies ⁸⁾.