Advances in the Immunotherapeutic Potential of Isocitrate Dehydrogenase Mutations in Glioma

Unlocking therapeutic synergy: IDH inhibitors and immunotherapy combination in preclinical and clinical IDH mutant glioma models - A systematic review

(1) Background: Over 80 % of low-grade gliomas have IDH mutations, leading to 2-hydroxyglutarate accumulation, an oncometabolite that promotes gliomagenesis by altering metabolism and impairing anti-tumour immunity. Previously, treatment options included surgical resection (debulking) with or without chemo/radiotherapy based on tumour risk. Vorasidenib, an IDH inhibitor (IDHi), demonstrates promising activity in IDH-mutant low-grade gliomas. While immunotherapy has succeeded in other solid tumours, its efficacy as a single agent in gliomas remains limited. This review explores potential synergies between IDHi and immunotherapy in IDH-mutant glioma across preclinical and clinical studies; (2) Methods: A systematic review (Prospero: CRD42024523861) was performed using Medline, Cochrane, EMBASE and ClinicalTrials.Gov. Findings were summarised using descriptive analysis without meta-analysis; (3) Results: This review included four preclinical murine and two clinical studies. Preclinical findings suggest that combining IDHi with immunotherapy enhances anti-tumour immunity and survival. Clinical trials are underway, but limitations include small sample sizes and treatment heterogeneity; (4) Conclusions: The high certainty of evidence and satisfactory risk of bias provide further rationale for future research investigating this combination, including larger randomised, blinded studies with standardised treatment regimens to validate preclinical findings and enhance translational relevance. Moreover, future preclinical studies should integrate multiple cell-line models, including patient-derived models.

Targeting IDH1 mutation-driven Nrf2 signaling to suppress malignant behavior in fibrosarcoma cells

Isocitrate dehydrogenase 1 (IDH1) mutations are prevalent in various cancers and have significant implications for tumor biology. It is known that cancer cells with IDH1 mutations, particularly R132C or R132H, exhibit decreased production of nicotinamide adenine dinucleotide phosphate and thus impaired glutathione synthesis. This study investigated the roles of IDH1 mutations in the regulation of nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated signaling pathways in fibrosarcoma HT1080 cells harboring the IDH1 R132C mutation. Knockdown of IDH1 using siRNA in HT1080 cells inhibited Nrf2 stabilization and reduced the expression of antioxidant genes, thereby providing favorable conditions for cancer progression. In addition, inhibition of IDH1 decreased reactive oxygen species (ROS) production and impaired cell migration, highlighting its role in promoting malignant behavior such as colony-forming ability. Small molecule inhibitors targeting the IDH1 R132 mutation suppressed cell migration and colony formation in HT1080 cells. Moreover, we observed that IDH and Nrf2 contribute to immune evasion by modulating the expression of programmed death-ligand 1 (PD-L1) in HT1080 cells. Altogether, our findings provide valuable insights for the development of therapeutic approaches for IDH1-mutant cancers. We suggest targeting the IDH1-Nrf2 axis as a strategy to regulate the immune response and inhibit cell migration in fibrosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-025-00284-1.

IDH-mutant gliomas in children and adolescents - from biology to clinical trials

Gliomas account for nearly 30% of all primary central nervous system (CNS) tumors in children and adolescents and young adults (AYA), contributing to significant morbidity and mortality. The updated molecular classification of gliomas defines molecularly diverse subtypes with a spectrum of tumors associated with age-distinct incidence. In adults, gliomas are characterized by the presence or absence of mutations in isocitrate dehydrogenase (IDH), with mutated IDH (mIDH) gliomas providing favorable outcomes and avenues for targeted therapy with the emergence of mIDH inhibitors. Despite their rarity, IDH mutations have been reported in 5-15% of pediatric glioma cases. Those with primary mismatch-repair deficient mIDH astrocytomas (PMMRDIA) have a particularly poor prognosis. Here, we describe the biology of mIDH gliomas and review the literature regarding the emergence of mIDH inhibitors, including clinical trials in adults. Given the paucity of clinical trial data from pediatric patients with mIDH glioma, we propose guidelines for the inclusion of pediatric and AYA patients with gliomas onto prospective trials and expanded access programs as well as the potential of combined mIDH inhibition and immunotherapy in the treatment of patients with PMMRDIA at high risk of progression.

Identification and validation of ion channels-related mRNA prognostic signature for glioblastomas

Glioblastomas (GBM) is a kind of malignant brain tumor with poor prognosis. Identifying new biomarkers is promising for the treatment of GBM. The mRNA-seq and clinical data were obtained from The Cancer Genome Atlas and the Chinese Glioma Genome Atlas databases. The differentially expressed genes were identified using limma R package. The prognosis-related genes were screened out and a risk model was constructed using univariate, least absolute shrinkage and selection operator, and multivariate Cox analysis. Receiver operating characteristic curve was used to assess the efficiency of model. Kaplan-Meier survival curve was applied for the survival analysis. Mutation analysis was conducted using maftools package. The effect of immunotherapy was analyzed according to TIDE score, and the drug sensitivity analysis was performed. The Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis enrichment analyses were performed for the functional analysis. The regulatory network was constructed by STRING and Cytoscape software. RT-qPCR was performed to validate the expression of 3 hub genes in vitro. A risk model was constructed based on 3 ion channels related genes (gap junction protein beta 2 [GJB2], potassium voltage-gated channel subfamily h member 6 [KCNH6], and potassium calcium-activated channel subfamily n member 4 [KCNN4]). The risk score and hub genes were positively correlated with the calcium signaling pathway. Patients were divided into 2 groups based on the risk score calculated by 3 signatures. The infiltration levels of T cell, B lineage, monocytic lineage, and neutrophils were increased in high risk group, while TIDE score was decreased. IC50 of potential drugs for GBM treatment was elevated in the high risk group. Furthermore, GJB2, KCNH6, and KCNN4 were oncogenic, and GJB2 and KCNN4 were upregulated, while KCNH6 was downregulated in high risk group and GBM cells. The regulatory network showed that KCNH6 was targeted by more miRNA and transcription factors and KCNN4 interacted with more drugs. We constructed a three-signature risk model, which could effectively predict the prognosis of GBM development. Besides, KCNH6 and KCNN4 were respectively considered as the targets of molecular targeted treatment and chemotherapy.

IDH Mutations in Glioma: Molecular, Cellular, Diagnostic, and Clinical Implications

In 2021, the World Health Organization classified isocitrate dehydrogenase (IDH) mutant gliomas as a distinct subgroup of tumors with genetic changes sufficient to enable a complete diagnosis. Patients with an IDH mutant glioma have improved survival which has been further enhanced by the advent of targeted therapies. IDH enzymes contribute to cellular metabolism, and mutations to specific catalytic residues result in the neomorphic production of D-2-hydroxyglutarate (D-2-HG). The accumulation of D-2-HG results in epigenetic alterations, oncogenesis and impacts the tumor microenvironment via immunological modulations. Here, we summarize the molecular, cellular, and clinical implications of IDH mutations in gliomas as well as current diagnostic techniques.

Tumor Metabolism: A New Field for the Treatment of Glioma

The clinical treatment of glioma remains relatively immature. Commonly used clinical treatments for gliomas are surgery combined with chemotherapy and radiotherapy, but there is a problem of drug resistance. In addition, immunotherapy and targeted therapies also suffer from the problem of immune evasion. The advent of metabolic therapy holds immense potential for advancing more efficacious and tolerable therapies against this aggressive disease. Metabolic therapy alters the metabolic processes of tumor cells at the molecular level to inhibit tumor growth and spread, and lead to better outcomes for patients with glioma that are insensitive to conventional treatments. Moreover, compared with conventional therapy, it has less impact on normal cells, less toxicity and side effects, and higher safety. The objective of this review is to examine the changes in metabolic characteristics throughout the development of glioma, enumerate the current methodologies employed for studying tumor metabolism, and highlight the metabolic reprogramming pathways of glioma along with their potential molecular mechanisms. Importantly, it seeks to elucidate potential metabolic targets for glioblastoma (GBM) therapy and summarize effective combination treatment strategies based on various studies.

Targeting Isocitrate Dehydrogenase (IDH) in Solid Tumors: Current Evidence and Future Perspectives

The isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) enzymes are involved in key metabolic processes in human cells, regulating differentiation, proliferation, and oxidative damage response. IDH mutations have been associated with tumor development and progression in various solid tumors such as glioma, cholangiocarcinoma, chondrosarcoma, and other tumor types and have become crucial markers in molecular classification and prognostic assessment. The intratumoral and serum levels of D-2-hydroxyglutarate (D-2-HG) could serve as diagnostic biomarkers for identifying IDH mutant (IDHmut) tumors. As a result, an increasing number of clinical trials are evaluating targeted treatments for IDH1/IDH2 mutations. Recent studies have shown that the focus of these new therapeutic strategies is not only the neomorphic activity of the IDHmut enzymes but also the epigenetic shift induced by IDH mutations and the potential role of combination treatments. Here, we provide an overview of the current knowledge about IDH mutations in solid tumors, with a particular focus on available IDH-targeted treatments and emerging results from clinical trials aiming to explore IDHmut tumor-specific features and to identify the clinical benefit of IDH-targeted therapies and their combination strategies. An insight into future perspectives and the emerging roles of circulating biomarkers and radiomic features is also included.

The landscape of novel strategies for acute myeloid leukemia treatment: Therapeutic trends, challenges, and future directions

Acute myeloid leukemia (AML) is a highly heterogeneous subtype of hematological malignancies with a wide spectrum of cytogenetic and molecular abnormalities, which makes it difficult to manage and cure. Along with the deeper understanding of the molecular mechanisms underlying AML pathogenesis, a large cohort of novel targeted therapeutic approaches has emerged, which considerably expands the medical options and changes the therapeutic landscape of AML. Despite that, resistant and refractory cases caused by genomic mutations or bypass signalling activation remain a great challenge. Therefore, discovery of novel treatment targets, optimization of combination strategies, and development of efficient therapeutics are urgently required. This review provides a detailed and comprehensive discussion on the advantages and limitations of targeted therapies as a single agent or in combination with others. Furthermore, the innovative therapeutic approaches including hyperthermia, monoclonal antibody-based therapy, and CAR-T cell therapy are also introduced, which may provide safe and viable options for the treatment of patients with AML.

TERT mutations-associated alterations in clinical characteristics, immune environment and therapy response in glioblastomas

OBJECTIVE TERT: is the most frequently mutated gene in adult glioblastomas (GBMs) defined by the 2021 World Health Organization classification system. The present study aims to explore differences in clinical characteristics and immune microenvironment between TERT mutant and wild-type GBM.

METHODS

Three GBM-related cohorts consisting of 205 GBM patients in our cohort, 463 GBM patients without immune checkpoint inhibitor(ICI) therapy and 1465 tumour patients (including 92 GBM cases) receiving ICI treatment in the MSK cohort were included. Retrospective analysis and immunohistochemistry assay were used for investigating the local (including tumour cells, local immune cells, and seizures) and systemic (including circulating immune cells, coagulation-related functions, and prognosis) effects of TERT mutations. Besides, differences in genetic alterations and immunotherapy responses between TERT mutant and wild-type GBMs were also explored.

RESULTS

We found that TERT mutant and wild-type GBMs possessed similar initial clinic symptoms, circulating immune microenvironment and immunotherapy response. With respect to that in TERT wild-type GBMs, mutations in TERT resulted in higher levels of tumour-infiltrating neutrophils, prolonged coagulation time, worse chemotherapy response and poorer overall survival.

CONCLUSION

Mutations in TERT alter the local immune environment and decrease the sensitivity of GBM to chemotherapy.

Mutant IDH in Gliomas: Role in Cancer and Treatment Options

Altered metabolism is a common feature of many cancers and, in some cases, is a consequence of mutation in metabolic genes, such as the ones involved in the TCA cycle. Isocitrate dehydrogenase (IDH) is mutated in many gliomas and other cancers. Physiologically, IDH converts isocitrate to α-ketoglutarate (α-KG), but when mutated, IDH reduces α-KG to D2-hydroxyglutarate (D2-HG). D2-HG accumulates at elevated levels in IDH mutant tumours, and in the last decade, a massive effort has been made to develop small inhibitors targeting mutant IDH. In this review, we summarise the current knowledge about the cellular and molecular consequences of IDH mutations and the therapeutic approaches developed to target IDH mutant tumours, focusing on gliomas.

Local and systemic effects of IDH mutations on primary glioma patients

Adult gliomas are divided into isocitrate dehydrogenase (IDH) wild-type and IDH mutant subtypes according to the new 2021 World Health Organization classification system. However, the local and systemic effects of IDH mutations on primary glioma patients are not well illustrated. Retrospective analysis, immune-cell infiltration analysis, meta-analysis, and immunohistochemistry assay were applied in the present study. The results from our cohort showed that IDH mutant gliomas own a lower proliferating rate compared to that in wild-type gliomas. Patients with mutant IDH exhibited a higher frequency of seizures in both our cohort and the cohort from the meta-analysis. Mutations in IDH result in lower levels of intra-tumour but higher levels of circulating CD4+ and CD8+ T lymphocytes. Levels of neutrophils in both intra-tumour and circulating blood were lower in IDH mutant gliomas. Moreover, IDH mutant glioma patients receiving radiotherapy in combination with chemotherapy exhibited better overall survival with respect to radiotherapy alone. Mutations in IDH alters the local and circulating immune microenvironment, and increases the sensitivity of tumour cell to chemotherapy.

Isocitrate dehydrogenase mutations in gliomas: A review of current understanding and trials

Isocitrate dehydrogenase (IDH) is a key enzyme in normal metabolism and homeostasis. However, mutant forms of IDH are also defining features of a subset of diffuse gliomas. In this review, we highlight current techniques targeting IDH-mutated gliomas and summarize current and completed clinical trials exploring these strategies. We discuss clinical data from peptide vaccines, mutant IDH (mIDH) inhibitors, and PARP inhibitors. Peptide vaccines have the unique advantage of targeting the specific epitope of a patient's tumor, inducing a highly tumor-specific CD4+ T-cell response. mIDH-inhibitors, on the other hand, specifically target mutant IDH proteins in cancer cell metabolism and thus help halt gliomagenesis. We also explore PARP inhibitors and their role in treating diffuse gliomas, which exploit IDH-mutant diffuse gliomas by allowing the persistence of unrepaired DNA complexes. We summarize various completed and current trials targeting IDH1 and IDH2 mutations in diffuse gliomas. Therapies targeting mutant IDH have significant promise in treating progressive or recurrent IDH-mutant gliomas and may significantly change treatment paradigms in the next decade.