Search Results (82)

Background/Objectives: Mutant isocitrate dehydrogenase (IDH) inhibitors represent a major advance in precision oncology. The recent Food and Drug Administration approval of vorasidenib for IDH-mutant glioma highlights its therapeutic potential in this setting. As this and other mutant IDH inhibitors enter the clinical setting, providers are tasked with staying informed of the evolving therapeutic landscape as more is learned about this unique class of medications. We aimed to summarize insights from preclinical studies and clinical trials exploring their use in IDH-mutant glioma. Methods: We reviewed notable preclinical studies establishing the rationale for targeting mutant IDH. We performed a systematic review of clincaltrials.gov to identify both completed and ongoing interventional IDH-directed trials in patients with IDH-mutant glioma. Results: We identified 8 published and 15 ongoing clinical trials evaluating IDH-directed therapies. IDH inhibitors have been shown to slow and, in some cases, reverse glioma tumor growth, with activity that may extend beyond their currently approved indications. The presence of contrast enhancement is consistently a negative predictor of response for ivosidenib and vorasidenib, although safusidenib and olutasidenib preliminarily may retain efficacy in these cases. Novel approaches such as IDH-directed vaccines and combination therapy using mutant IDH inhibitors with immunotherapy are currently under active investigation. Conclusions: Mutant IDH inhibition is a promising, well-tolerated, and evolving approach for many patients with IDH-mutant glioma. Ongoing research will clarify its optimal clinical utility and potentially expand its indication. Full article

Background/Objectives: This study evaluates intratumoral susceptibility signals (ITSS) as imaging markers for glioma grade prediction and their association with molecular and histopathologic features, in the context of the fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System (WHO CNS5). Methods: We retrospectively analyzed patients with adult diffuse gliomas who underwent pretreatment magnetic resonance imaging. ITSS were semiquantitatively graded by two radiologists: grade 0 (no signal), grade 1 (1–5), grade 2 (6–10), and grade 3 (≥11). Relative cerebral blood volume (rCBV) and tumor volume were also obtained. Histopathologic features included tumor grade, Ki-67, mitotic count, necrosis, microvascular proliferation, and molecular alterations (isocitrate dehydrogenase [IDH], 1p/19q, cyclin-dependent kinase inhibitors 2A and 2B [CDKN2A/B], and p53). Regression models predicted tumor grade (low: 1–2, high: 3–4) using ITSS, tumor volume, and rCBV. ROC curves and diagnostic performance metrics were analyzed. Results: 99 patients were included. ITSS grading correlated with rCBV, tumor volume, mitotic count, Ki-67, and tumor grade (p < 0.001). ITSS grades 0–1 were associated with oligodendrogliomas and astrocytomas (p < 0.001), IDH mutations (p < 0.001), and 1p/19q co-deletions (p = 0.01). ITSS grades 2–3 were linked to glioblastomas (p < 0.001), necrosis (p < 0.001), microvascular proliferation (p < 0.001), and CDKN2A/B homozygous deletions (p = 0.02). Models combining ITSS with rCBV and volume showed AUC of 0.94 and 0.96 (p < 0.001), outperforming univariate models. Conclusions: Semiquantitative ITSS grading correlates with key histopathologic and molecular glioma features. Combined with perfusion and volumetric parameters, ITSS enhance non-invasive glioma grading, in alignment with WHO CNS5. Full article

Acute myeloid leukemia (AML) is characterized by the clonal expansion of myeloid progenitors blocked at various stages of their differentiation process, and drugs that bypass this differentiation block are therapeutically efficient, as shown by retinoic acid and arsenic trioxide in acute promyelocytic leukemia. However, the successful application of differentiation therapy in APL has not translated into clinical benefit for other non-APL subtypes of AML, in which intensive chemotherapy regimens represent the standard of care. However, the development of molecular studies has led to the identification of therapeutic targets (such as mutated proteins and deregulated pathways) and has led to the generation of a new category of specific pharmacologic agents. Some of these agents, such as inhibitors of mutant isocitrate dehydrogenase (IDH1 and IDH2), lysine-specific demethylase-1 (LSD1), and Menin, have shown the capacity to induce leukemic cell differentiation and with significant therapeutic efficacy. Full article

Background: Cholangiocarcinoma, a malignancy originating from the bile ducts, poses significant treatment challenges due to its typically late diagnosis and limited therapeutic options. However, recent advances in molecular genetics enable more personalized treatment approaches. A notable breakthrough in this context is the identification of isocitrate dehydrogenase (IDH) mutations, particularly IDH1 and IDH2, which occur in a subset of cholangiocarcinoma patients. Those with IDH1/2 mutations may benefit from targeted therapies. For instance, Ivosidenib, an IDH1 inhibitor, has shown efficacy in clinical trials, offering a new therapeutic option for patients with IDH1-mutant cholangiocarcinoma. Developing and implementing standardized protocols for testing and reporting mutation status are crucial for consistency and accuracy in clinical practice. Both the Idylla™ IDH1-2 Mutation Assay Kit as a FastTrack method and Next-Generation Sequencing (NGS) panels play critical roles in molecular characterization of cholangiocarcinoma. Methods: Under this aspect, a set of cholangiocarcinomas was tested using the Idylla™ platform regarding the respective recommended guidelines and standards of DIN EN ISO:17020 and DIN EN ISO:15198. Results: Overall, 25 clinically diagnosed intrahepatic cholangiocarcinomas or Adeno-CUPs were analyzed. IDH1/2 mutations were identified in 68% (17/25) of cases using both methods, with high concordance between NGS and Idylla™ results. Discrepancies were observed in two samples, where Idylla™ detected no mutations, but NGS reported IDH1 and IDH2 mutations, respectively. Conclusions: Idylla^TM offers a rapid, user-friendly, and specific method for detecting IDH1/2 mutations, ideal for immediate clinical needs. NGS, while more time-consuming and costly, provides comprehensive genetic profiles valuable for personalized medicine and research. The choice between these methods should be guided by the clinical context, resource availability, and individual patient needs. For routine diagnostics, we recommend an algorithmic approach starting with the FastTrack method followed by NGS for wildtype cases. Full article

Background: Isocitrate dehydrogenase (IDH) wild-type (wt) glioblastoma is an aggressive malignancy associated with poor clinical outcomes, marked by high heterogeneity and resistance to treatment. This study aims to investigate the prognostic significance of B7-H3 expression in IDH wt glioblastoma and its potential association with clinical outcomes, including overall survival (OS) and progression-free survival (PFS). Additionally, the relationship between B7-H3 and PD-L1 expression was explored. Methods: A retrospective cohort of 86 IDH wt glioblastoma patients, all of whom underwent surgery, radiotherapy, and temozolomide treatment, was analyzed. B7-H3 expression was quantified using an immunoreactivity score (IRS), classifying samples as low (IRS ≤ 4) or high (IRS > 4). PD-L1 expression was evaluated based on tumor and immune cell staining, with >5% positivity indicating significant expression. Results: High B7-H3 expression was significantly associated with poorer OS and PFS. Co-expression of B7-H3 and PD-L1 was prevalent, particularly among younger male patients with unifocal tumors; however, PD-L1 expression did not show a significant correlation with clinical outcomes. Conclusions: B7-H3 appears to be a promising prognostic biomarker in IDH wt glioblastoma and may serve as a target for developing combination therapies, integrating B7-H3-targeting treatments with immune checkpoint inhibitors. Further prospective studies are necessary to validate these findings and to explore potential therapeutic strategies. Full article

Mutations in isocitrate dehydrogenase (IDH) genes are among the most frequently encountered molecular alterations in cholangiocarcinoma (CCA). These neomorphic point mutations endow mutant IDH (mIDH) with the ability to generate an R-enantiomer of 2-hydroxyglutarate (R2HG), a metabolite that drives malignant transformation through aberrant epigenetic signaling. As a result, pharmacologic inhibition of mIDH has become an attractive therapeutic strategy in CCAs harboring this mutation. One such inhibitor, ivosidenib, has already undergone clinical validation and received FDA approval in this disease, but there is still much work to be done to improve outcomes in mIDH CCA patients. In this publication we will review the pathogenesis and treatment of mIDH CCA with special emphasis on novel agents and combinations currently under investigation. Full article

Background/Objectives: Anaplastic oligodendrogliomas (AOs) are central nervous system (CNS) World Health Organization (WHO) grade 3 gliomas characterized by isocitrate dehydrogenase (IDH) mutation (m)IDH and 1p/19q codeletion. AOs are typically treated with surgery and chemoradiation. However, chemoradiation can cause detrimental late neurocognitive morbidities and an accelerated disease course. The recently regulatory-approved vorasidenib, a brain-penetrating oral inhibitor of IDH1/2, has altered the treatment paradigm for recurrent/residual non-enhancing surgically resected CNS WHO grade 2 mIDH gliomas. Though vorasidenib can delay the time to chemoradiation for grade 2 gliomas, the implications for vorasidenib in non-grade 2 mIDH gliomas are not well understood. Results: We present a case of a 71-year-old male with a grade 3 non-enhancing oligodendroglioma successfully treated with vorasidenib with an 11% reduction in residual tumor volume. Vorasidenib was well tolerated in our patient with a mild elevation in his liver transaminases that resolved following a brief interruption in treatment. Conclusions: Our case suggests that vorasidenib may impart therapeutic benefits in this setting. This case illustrates the need for further investigation into these less commonly addressed scenarios and treatment strategies that extend beyond current guidelines. Full article

The term chondrosarcoma refers to a rare and heterogeneous group of malignant cartilaginous tumors that are typically resistant to chemotherapy and radiotherapy. Metastatic chondrosarcoma has a poor prognosis, and effective systemic therapies are lacking. Isocitrate dehydrogenase (IDH) mutations represent a potential therapeutic target, but IDH inhibitors alone have shown limited clinical efficacy to date. Although the role of conventional chemotherapy is still subject to debate, some evidence suggests it may provide therapeutic benefits in advanced cases. In this study, we aimed to identify effective compounds for combination therapy in chondrosarcoma. Using high-throughput screening, we evaluated a panel of anticancer agents in IDH1-mutant chondrosarcoma cell lines and their mutant IDH1 knockout derivatives. The top 20 most potent compounds were identified across all cell lines, irrespective of IDH mutation status. Representative drugs selected for further investigation included docetaxel, methotrexate, panobinostat, idarubicin, camptothecin, and pevonedistat. These drugs inhibited colony formation, induced apoptosis and cell cycle arrest, and exhibited synergistic antitumor activity in two-drug combinations. In conclusion, we identified several highly effective agents with potent anti-tumor activity in chondrosarcoma cells, independent of IDH mutation status. These agents represent promising candidates for chondrosarcoma therapy and warrant further preclinical investigation and potential inclusion in clinical trials. Full article

Mutations of isocitrate dehydrogenase 1 (IDH1) are key biomarkers for glioma classification, but current methods for detection of mutated IDH1 (mIDH1) require invasive tissue sampling and cannot be used for longitudinal studies. Positron emission tomography (PET) imaging with mIDH1-selective radioligands is a promising alternative approach that could enable non-invasive assessment of the IDH status. In the present work, we developed efficient protocols for the preparation of four ¹⁸F-labeled derivatives of the mIDH1-selective inhibitor olutasidenib. All four probes were characterized by cellular uptake studies with U87 glioma cells harboring a heterozygous IDH1 mutation (U87-mIDH) and the corresponding wildtype cells (U87-WT). In addition, the most promising probe was evaluated by PET imaging in healthy mice and mice bearing subcutaneous U87-mIDH and U87-WT tumors. Although all four probes inhibited mIDH1 with variable potencies, only one of them ([¹⁸F]mIDH-138) showed significantly higher in vitro uptake into U87-mIDH compared to U87-WT cells. In addition, PET imaging with [¹⁸F]mIDH-138 in mice demonstrated good in vivo stability and low non-specific uptake of the probe, but also revealed significantly higher uptake into U87-WT compared to U87-mIDH tumors. Finally, application of a two-tissue compartment model (2TCM) to the PET data indicated that preferential tracer uptake into U87-WT tumors results from higher specific binding rather than from differences in tracer perfusion. In conclusion, these results corroborate recent findings that mIDH1-selective inhibition may not directly correlate with mIDH1-selective target engagement and indicate that in vivo engagement of wildtype and mutated IDH1 may be governed by factors that are not faithfully reproduced by in vitro assays, both of which could complicate development of PET probes. Full article

How hematopoietic stem and progenitor cell (HSPC) fate decisions are affected by genetic alterations acquired during AML leukemogenesis is poorly understood and mainly explored in animal models. Here, we study isocitrate dehydrogenase (IDH) gene mutations in the human model of HSPC and discuss the available literature on this topic. IDH1/2 mutations occur in ~20% of AML cases, are recognized among the mutations earliest acquired during leukemogenesis, and are targets of specific inhibitors (ivosidenib and enasidenib, respectively). In order to investigate the direct effects of these mutations on HSPCs, we expressed IDH1-R132H or IDH2-R140Q mutants into human CD34+ healthy donor cells via lentiviral transduction and analyzed the colony-forming unit (CFU) ability. CFU ability was dramatically compromised with a complete trilineage block of differentiation. Strikingly, the block was reversed by specific inhibitors, confirming that it was a specific effect induced by the mutants. In line with this observation, the CD34+ leukemic precursors isolated from a patient with IDH2-mutated AML at baseline and during enasidenib treatment showed progressive and marked improvements in their fitness over time, in terms of CFU ability and propensity to differentiate. They attained clonal trilinear reconstitution of hematopoiesis and complete hematological remission. Full article

Despite the better understanding of the molecular mechanisms contributing to the pathogenesis of acute myeloid leukemia (AML) and improved patient survival in recent years, AML therapy still remains a clinical challenge. For this reason, it is important to search for new therapies that will enable the achievement of remission. Recently, the Food and Drug Administration approved three mutant IDH (mIDH) inhibitors for the treatment of AML. However, the use of mIDH inhibitors in monotherapy usually leads to the development of resistance and the subsequent recurrence of the cancer, despite the initial effectiveness of the therapy. A complete understanding of the mechanisms by which IDH mutations influence the development of leukemia, as well as the processes that enable resistance to mIDH inhibitors, may significantly improve the efficacy of this therapy through the use of an appropriate synergistic approach. The aim of this literature review is to present the role of IDH1/IDH2 mutations in the pathogenesis of AML and the results of clinical trials using mIDH1/IDH2 inhibitors in AML and to discuss the challenges related to the use of mIDH1/IDH2 inhibitors in practice and future prospects related to the potential methods of overcoming resistance to these agents. Full article

Isocitrate dehydrogenase 1 (IDH1) is a necessary enzyme for cellular respiration in the tricarboxylic acid cycle. Mutant isocitrate dehydrogenase 1 (mIDH1) has been detected overexpressed in a variety of cancers. mIDH1 inhibitor ivosidenib (AG-120) was only approved by the Food and Drug Administration (FDA) for marketing, nevertheless, a range of resistance has been frequently reported. In this study, several mIDH1 inhibitors with the common backbone pyridin-2-one were explored using the three-dimensional structure–activity relationship (3D-QSAR), scaffold hopping, absorption, distribution, metabolism, excretion (ADME) prediction, and molecular dynamics (MD) simulations. Comparative molecular field analysis (CoMFA, R² = 0.980, Q² = 0.765) and comparative molecular similarity index analysis (CoMSIA, R² = 0.997, Q² = 0.770) were used to build 3D-QSAR models, which yielded notably decent predictive ability. A series of novel structures was designed through scaffold hopping. The predicted pIC₅₀ values of C3, C6, and C9 were higher in the model of 3D-QSAR. Additionally, MD simulations culminated in the identification of potent mIDH1 inhibitors, exhibiting strong binding interactions, while the analyzed parameters were free energy landscape (FEL), radius of gyration (Rg), solvent accessible surface area (SASA), and polar surface area (PSA). Binding free energy demonstrated that C2 exhibited the highest binding free energy with IDH1, which was −93.25 ± 5.20 kcal/mol. This research offers theoretical guidance for the rational design of novel mIDH1 inhibitors. Full article

The advent of comprehensive genomic profiling using next-generation sequencing (NGS) has unveiled an abundance of potentially actionable genetic aberrations that have shaped our understanding of the cancer biology landscape. Isocitrate dehydrogenase (IDH) is an enzyme present in the cytosol (IDH1) and mitochondria (IDH2 and IDH3). In the mitochondrion, it catalyzes the irreversible oxidative decarboxylation of isocitrate, yielding the production of α-ketoglutarate and nicotinamide adenine dinucleotide phosphate (NADPH) as well as carbon dioxide (CO₂). In the cytosol, IDH catalyzes the decarboxylation of isocitrate to α-ketoglutarate as well as the reverse reductive carboxylation of α-ketoglutarate to isocitrate. These rate-limiting steps in the tricarboxylic acid cycle, as well as the cytoplasmic response to oxidative stress, play key roles in gene regulation, cell differentiation, and tissue homeostasis. Mutations in the genes encoding IDH1 and IDH2 and, less commonly, IDH3 have been found in a variety of cancers, most commonly glioma, acute myeloid leukemia (AML), chondrosarcoma, and intrahepatic cholangiocarcinoma. In this paper, we intend to elucidate the theorized pathophysiology behind IDH isomer mutation, its implication in cancer manifestation, and discuss some of the available clinical data regarding the use of novel IDH inhibitors and their role in therapy. Full article

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor. Standard treatments including surgical resection, radiotherapy, and chemotherapy, have failed to significantly improve the prognosis of glioblastoma patients. Currently, immunotherapeutic approaches based on vaccines, chimeric antigen-receptor T-cells, checkpoint inhibitors, and oncolytic virotherapy are showing promising results in clinical trials. The combination of different immunotherapeutic approaches is proving satisfactory and promising. In view of the challenges of immunotherapy and the resistance of glioblastomas, the treatment of these tumors requires further efforts. In this review, we explore the obstacles that potentially influence the efficacy of the response to immunotherapy and that should be taken into account in clinical trials. This article provides a comprehensive review of vaccine therapy for glioblastoma. In addition, we identify the main biomarkers, including isocitrate dehydrogenase, epidermal growth factor receptor, and telomerase reverse transcriptase, known as potential immunotherapeutic targets in glioblastoma, as well as the current status of clinical trials. This paper also lists proposed solutions to overcome the obstacles facing immunotherapy in glioblastomas. Full article

Isocitrate dehydrogenase (IDH) mutant gliomas are a primary malignancy of the central nervous system (CNS) malignancies, most commonly affecting adults under the age of 55. Standard of care therapy for IDH-mutant gliomas involves maximal safe resection, radiotherapy, and chemotherapy. However, despite good initial responses to multimodality treatment, recurrence is virtually universal. IDH-mutant gliomas represent a life-limiting prognosis. For this reason, there is a great need for novel treatments that can prolong survival. Uniquely for IDH-mutant gliomas, the IDH mutation is the direct driver of oncogenesis through its oncometabolite 2-hydroxygluterate. Inhibition of this mutated IDH with a corresponding reduction in 2-hydroxygluterate offers an attractive treatment target. Researchers have tested several IDH inhibitors in glioma through preclinical and early clinical trials. A phase III clinical trial of an IDH1 and IDH2 inhibitor vorasidenib yielded promising results among patients with low-grade IDH-mutant gliomas who had undergone initial surgery and no radiation or chemotherapy. However, many questions remain regarding optimal use of IDH inhibitors in clinical practice. In this review, we discuss the importance of IDH mutations in oncogenesis of adult-type diffuse gliomas and current evidence supporting the use of IDH inhibitors as therapeutic agents for glioma treatment. We also examine unresolved questions and propose potential directions for future research. Full article