Background and Objectives: Glioblastoma (GBM) is the most aggressive form of primary brain tumor, characterised by high recurrence rates and poor patient prognosis. This study aimed to identify gene-expression signatures and molecular networks associated with primary and recurrent GBM to better understand the biological mechanisms underlying tumor progression. Materials and Methods: Gene expression analysis of TCGA data was conducted to identify differentially expressed genes across tumor, recurrent, and normal brain tissues. Analysis of overlapping differentially expressed gene sets revealed both common and specific gene-expression profiles across the groups, highlighting genes potentially involved in GBM recurrence. Gene network and canonical pathway analyses were performed using Ingenuity Pathway Analysis (IPA) to identify key pathways and cellular functions altered in GBM. Results: Our data identified distinct molecular signatures in tumor, recurrent, and normal brain samples, highlighting dysregulated genes associated with cellular growth, proliferation, and movement. Transcriptomic stratification revealed progressive tumor- and recurrence-adapted states, with composite Tumor Scores (TS) and Recurrence Scores (RS) classifying samples into four classes: normal-like, proliferative, transitional, and recurrence-adapted tumor states. Conclusions: These findings provide insights into the signaling networks and biological mechanisms underlying GBM recurrence and may guide the identification of potential therapeutic targets to improve the management of this malignancy.

Existing salvage therapies for recurrent glioblastoma (rGBM) have limited efficacy, with median survival of approximately 9 months. Given the complex molecular heterogeneity of GBM, single-target approaches have consistently failed as a treatment strategy. We conducted a phase 1 clinical trial to assess the feasibility, safety, and efficacy of a genomically-tailored multi-agent regimen in 30 adults with surgically-treated rGBM. Adults with IDH-wildtype glioblastoma (n=29) or grade 4 IDH-mutant astrocytoma (n=1) were consented and underwent clinically-indicated surgery for recurrent disease. Comprehensive genomic profiling was performed on the recurrent tumors, and results for each patient were discussed at an individualized molecular tumor board to determine a personalized treatment regimen combining up to 4 FDA-approved drugs, including one cytotoxic agent as backbone. A total of 12 drugs were used in 18 combinations - the most common regimen was lomustine, afatinib, and abemaciclib (n=8). The most common toxicities included cytopenias, rash, and gastrointestinal symptoms, requiring frequent dose reductions. Measured from surgery at trial enrollment, progression-free survival at 6 months (PFS-6) was 40%, overall survival at 9 months (OS-9) was 73%, and median OS was 12.7 months. After trial therapy, genomic profiling performed on subsequent recurrent tumor specimens identified genetic evolution corresponding to putative treatment resistance mechanisms. Implementation of individualized treatment regimens in a timely fashion was feasible for patients with surgically resectable rGBM. Overall efficacy was not significantly improved compared to a contemporary patient cohort treated without experimental regimens, with full dosing of most combination therapies limited by toxicities.

Glioblastoma recurrence after surgery is a major contributor to its high mortality, primarily occurring near the original tumour margin. Various hydrogels have been developed to fill the post-surgical cavity and deliver drugs to the surrounding brain tissue to eliminate residual cells. However, the impact of tissue, hydrogel, and drug properties on delivery outcomes remains unclear. Here, a parametric study is conducted to investigate these effects using mathematical modelling. The results show that post-surgical oedema strongly influences delivery: longer duration or delayed onset of oedema can homogenise drug distribution, with delayed onset yielding a larger and more sustained therapeutic drug volume. Hydrogels with higher permeability or lower drug affinity enhance early concentration and distribution but decline faster over time. Drugs with lower intracellular partitioning improve early efficacy, whereas those with stronger binding to cellular or extracellular components sustain delivery longer. Lower transvascular permeability and slower elimination further enhance outcomes, while extracellular diffusivity must be optimised to maximise drug concentration and distribution. These findings provide guidance for optimising hydrogel-based drug delivery systems to prevent glioblastoma recurrence.

A phase 1 dose escalation trial of re-irradiation for patients with recurrent glioblastoma.

Vaccine immunotherapy for glioblastoma: How can previous attempts guide us?

A phase 2, open label, clinical trial of pre-surgical and adjuvant treatment of recurrent glioblastoma with tremelimumab and durvalumab alone and in combination.

Glioblastoma, the most prevalent and aggressive brain tumor, presents significant challenge due to its rapid proliferation, invasive nature, and resistance to conventional therapies. Current treatments, including surgery, radiation, and chemotherapy, frequently lead to recurrence, underscoring the urgent need for innovative solutions. This work develops and evaluates bioinspired adhesive membranes designed as novel strategy to address glioblastoma recurrence post-surgery. Inspired by mussel adhesion, these membranes exhibit strong bioadhesion in wet environments and incorporate various phenolic-based compounds. Among tested combinations, a membrane with catechin demonstrates specific cytotoxic effect on human glioblastoma cells. This effect is investigated through in vitro assays using glioblastoma cell lines, including primary cell cultures. Exposure to this membrane induces changes in cell morphology and internal structures, and alterations in cell adhesion and migration. Additionally, the use of glioblastoma spheroids and ex vivo tissues allow us to mimic glioblastoma microenvironment and assess the membrane efficacy. Reactive oxygen species are suggested to play a main role in the cytotoxic effect, counteracted by the antioxidant N-acetylcysteine. Finally, a comprehensive proteomic study elucidates biological mechanisms underlying the membrane performance. This research highlights the potential of mussel-inspired advanced scaffolds as a localized approach in glioblastoma therapy, suggesting a path for effective anticancer strategies.

Reactive oligodendrocytes promote glioblastoma progression through CCL5/CCR5-mediated glioma stem cell maintenance.

This study evaluated tislelizumab combined with low-dose bevacizumab in recurrent glioblastoma (rGBM), assessing efficacy, safety, and mechanisms of immune escape. This randomized phase 2 trial divided patients into treatment arms with distinct strategies. Longitudinal tumor in situ fluid (TISF) samples were collected for molecular analysis to monitor genome evolution. Immunohistochemical markers in paired primary and recurrent tumor specimens were analyzed to assess therapy-induced immune resistance. A total of 109 patients were included, with 59 in the control group and 50 in the experimental group. No grade 4 adverse events or treatment discontinuations occurred in the experimental group. The experimental group demonstrated a median overall survival of 13.3 months, compared to 6.6 months in the control group. The objective response rate and disease control rate were 32.6% and 79.1%, respectively. Post-treatment TISF analysis revealed a 68.4% reduction in detectable genomic alterations. Immunophenotypic analysis of paired tumor samples showed increased infiltration of CD163+ macrophages and elevated GDF-15 expression in recurrent tumors. This study shows that combining tislelizumab and low-dose bevacizumab improves survival in rGBM patients with good safety and tolerability. Dynamic changes in TISF-based molecular markers reflect genomic evolution and predict prognosis. Increased CD163+ cell infiltration in recurrent tumors may activate M2 macrophages, promoting tumor growth and immune evasion. Elevated GDF-15 levels may further suppress antitumor immunity, facilitating immune escape.

Near complete response recurrent glioblastoma after treatment with [131I]-Iodofalan.

Glioblastoma (GBM) remains the most common and lethal adult malignant primary brain cancer with few treatment options. A significant issue hindering GBM therapeutic development is intratumor heterogeneity and plasticity. GBM tumors contain neoplastic cells within a fluid spectrum of diverse transcriptional states. Identifying effective therapeutics requires a platform that predicts the differential sensitivity and resistance of these states to various treatments. Here, we develop scFOCAL (Single-Cell Framework for -Omics Connectivity and Analysis via L1000), to quantify the cellular drug sensitivity and resistance landscape. Using single-cell RNA sequencing of newly diagnosed and recurrent GBM tumors, we identify compounds from the LINCS L1000 database with transcriptional response signatures selectively discordant with distinct GBM cell states, and leverage this capability to predict combination synergy. We validate the significance of these findings in vitro, ex vivo, and in vivo, and identify a combination of an OLIG2 inhibitor and Depatux-M for the treatment of GBM. Our studies suggest that scFOCAL identifies cell states that are sensitive and resistant to targeted therapies in GBM using a measure of cell and drug connectivity, which can be applied to identify new synergistic combinations.

Glioblastoma multiforme (GBM), the most aggressive primary brain tumor, demonstrates persistent resistance to immunotherapy due to its profoundly immunosuppressive microenvironment and markedly limited T cell infiltration. In this context, we engineered a STING agonist–incorporated prodrug hydrogel that orchestrates dual activation of innate and adaptive immunity to prevent postoperative GBM recurrence. We found that this in situ–forming hydrogel integrates seamlessly with tumor resection procedures, serves as a drug depot for sustained tumoral releases of therapeutic agents, and thus reprograms the tumor microenvironment by promoting M1 macrophage polarization, suppressing regulatory T cell activity, and enhancing cytotoxic T lymphocyte infiltration, thereby establishing a robust antitumor immune response. As a postoperative adjuvant therapy, the hydrogel effectively inhibits orthotopic GBM recurrence and extends animal survival while establishing durable immune memory against tumor rechallenge. Our findings demonstrate the translational potential of immunologically engineered hydrogels for STING-activated immunotherapy in preventing postresection GBM recurrence.

Patients with recurrent high-grade glioblastoma have a median survival of 6-8 months, with limited therapeutic options. In recent years, interest has grown in applying chimeric antigen receptor T (CAR-T) cells to solid cancers, including advanced gliomas. Here we generated off-the-shelf CRISPR-Cas9-edited IL-13Rα2-specific allogeneic universal CAR-T cells (MT026) by disrupting the endogenous TCR to prevent graft-versus-host disease and knocking out HLA class I molecules to mitigate the host-versus-graft response, and observed minimal NK-cell-mediated rejection in preclinical studies. In a first-in-human, single-center, open-label investigator-initiated trial (ChiCTR2000028801) in patients with high-grade glioma with prior therapy failure and short life expectancy, intrathecal injection of MT026 via lumbar puncture (1.0-3.0×10^7 cells per dose) demonstrated favorable tolerability and safety (primary outcome), pharmacokinetic characteristics, and preliminary clinical activity (secondary outcomes). Among the five patients enrolled, one achieved a complete response and three achieved partial responses. No grade ≥3 adverse events were observed; the predominant treatment-related toxicities were grade 1-2 pyrexia, hypoxia, and vomiting. Trial enrolment was halted after enrolment of the first five patients, however these preliminary clinical data support the potential benefit of locally administered allogeneic universal CAR-T cell therapy for recurrent glioblastoma.

Bevacizumab combined with irinotecan or temozolomide in recurrent glioblastoma: a Turkish Oncology Group (TOG) study.

BackgroundManagement of recurrent glioblastoma (rGBM) remains challenging, particularly for deep-seated or eloquent recurrences not amenable to open surgery, and no standardized effective treatment exists for recurrent disease. European data on MR-guided laser interstitial thermal therapy (LITT) are scarce. This study presents the first Scandinavian experience with LITT for IDH-wild-type rGBM, within publicly funded healthcare systems providing population-wide access to care.MethodsRetrospective data from 30 consecutive patients with histologically confirmed IDH-wild-type rGBM treated with LITT at two Scandinavian centers between January 2019 and May 2024 were analyzed. Demographics, ECOG performance status, procedural parameters, adverse events, and survival outcomes were collected. Kaplan–Meier estimates were used for progression-free survival (PFS) and overall survival (OS).ResultsMean age was 57 years (SD 10.2); 83% had pre-LITT ECOG 0. Complete and ≥ 90% ablation of contrast enhancement was achieved in 83% and 97% of cases, respectively. Median hospital stay was 1 day, with 87% discharged by day 2. Adverse events occurred in 33%, predominantly transient neurological deficits (27%) and infections (7%); 10% had persistent deficits. Median OS after LITT was 13.5 months (95% CI 11.6–20.5) and median PFS was 4.3 months (95% CI 2.6–9.1); 37% remained progression-free at 6 months.ConclusionsLITT was feasible and well tolerated in this two-center Scandinavian cohort, with short hospitalization and low morbidity. Survival outcomes were within the range reported in previous international series. While these findings provide preliminary real-world data on LITT use within Scandinavian publicly funded healthcare systems, the limited sample size and retrospective design preclude definitive conclusions. Prospective, controlled studies are warranted to clarify the clinical role of LITT in recurrent glioblastoma.

Significant heterogeneity in the immune microenvironment of Glioblastoma, IDH-wildtype (GBM), has been reported, necessitating a standardized approach to evaluate immune infiltration in the context of emerging immunotherapies. To address this, we developed and validated a standardized immunohistochemistry-based scoring system for quantifying immune cell infiltration in formalin-fixed, paraffin-embedded (FFPE) tissue. Paired primary and recurrent GBM specimens from 20 adult patients were labeled for CD3, CD8, CD45, CD68, and PD-1, and scored across six anatomical regions, including intra- and peritumoral, meningeal, and normal brain areas. The scoring system demonstrated excellent interrater (ICC = 0.932) and intrarater (ICC = 0.953) reliability. CD68+ and CD45+ cells were most numerous across all regions. CD3+ and CD8+ cells concentrated more in the perivascular area rather than within the parenchyma. No significant differences in immune infiltration were observed between primary and recurrent GBM. Cox proportional-hazards analysis showed worse survival with higher CD8+ and CD45+ infiltration in primary GBM, and higher CD45+ and CD68+ infiltration in recurrent GBM. In conclusion, we propose a feasible, cost-efficient, and robust method to assess immune infiltration on FFPE material, enabling standardized comparison of inflammation, with applications for ongoing clinical trials.

Engineering focused ultrasound for glioblastoma.

Oncolytic virotherapy: Molecular mechanisms, delivery strategies, and translational insights.

Incorporation of intraoperative confocal laser endomicroscopy into the routine workflow of brain surgery.

Endothelial cells sense temozolomide resistance to facilitate monocyte-derived macrophage infiltration in glioblastoma.