Safety of intra-arterial chemotherapy with or without osmotic blood–brain barrier disruption for the treatment of patients with brain tumors

Efficacy and safety of intra-arterial chemoperfusion as palliative treatment of symptomatic primary brain malignancies

BACKGROUND

To retrospectively analyze the safety and efficacy of intra-arterial chemoperfusion (IAC) for symptomatic patients with recurrent or post-therapeutic progressive primary malignant brain tumors in regard to safety, survival and therapy response as a palliative treatment.

METHODS

Thirty-nine patients (24 men, 15 women; mean age: 52) who were treated by IAC in 181 sessions (mean: 4.6 sessions/patient) were enrolled and evaluated in this study. Out of total 39 patients with primary malignant brain tumor, 27 (69 %) were diagnosed with glioblastoma. The overall survival (OS) was calculated using the Kaplan-Meier method. Therapy response was determined according to RECIST 1.1.

RESULTS

All IAC treatments were performed without major adverse events or treatment-related deaths. The median OS time was 10.3 months (95 %CI: 0.6 - 19.9). The median PFS time was 5.9 months (95 %CI: 3.6 - 8.3). The rate of partial response was 10.8 % (4/37) and stable disease was achieved in 56.8 % (21/37) of patients. Progressive disease was observed in 32.4 % of cases (12/37). There were no cases of complete response. In two cases RECIST could not be analyzed due to loss of radiological follow-up.

CONCLUSION

This study could show that IAC may serve as a safe palliative strategy for symptomatic patients with recurrent or post-therapeutic progressive primary malignant brain tumors.

Optimization of Intra-Arterial Administration of Chemotherapeutic Agents for Glioblastoma in the F98-Fischer Glioma-Bearing Rat Model

Glioblastoma (GBM) is a difficult disease to treat for different reasons, with the blood-brain barrier (BBB) preventing therapeutic drugs from reaching the tumor being one major hurdle. The median overall survival is only 14.6 months after the standard first line of treatment. At relapse, there is no recognized standard second-line treatment. Our team uses intra-arterial (IA) chemotherapy as a means to bypass the BBB, hence achieving an overall median survival of 25 months. However, most patients eventually fail the treatment and progress. This is why we wish to expand our portfolio of options in terms of chemotherapy agents available for IA administration. In this study, we tested topotecan, cytarabine, and new formulations of carboplatin and paclitaxel by IA administration in the F98-Fischer glioma-bearing rat model as a screening tool for identifying potential candidate drugs. The topotecan IA group showed increased survival compared to the intravenous (IV) group (29.0 vs. 23.5), whereas the IV cytarabine group survived longer than the IA group (26.5 vs. 22.5). The new formulation of carboplatin showed a significant increase in survival compared to two previous studies with the conventional form (37.5 vs. 26.0 and 30.0). As for paclitaxel, it was too neurotoxic for IA administration. Topotecan and the new formulation of carboplatin demonstrated significant results, warranting their transition for consideration in clinical trials.

H3K27-Altered Diffuse Midline Glioma of the Brainstem: From Molecular Mechanisms to Targeted Interventions

Pediatric high-grade gliomas are a devastating subset of brain tumors, characterized by their aggressive pathophysiology and limited treatment options. Among them, H3 K27-altered diffuse midline gliomas (DMG) of the brainstem stand out due to their distinct molecular features and dismal prognosis. Recent advances in molecular profiling techniques have unveiled the critical role of H3 K27 alterations, particularly a lysine-to-methionine mutation on position 27 (K27M) of the histone H3 tail, in the pathogenesis of DMG. These mutations result in epigenetic dysregulation, which leads to altered chromatin structure and gene expression patterns in DMG tumor cells, ultimately contributing to the aggressive phenotype of DMG. The exploration of targeted therapeutic avenues for DMG has gained momentum in recent years. Therapies, including epigenetic modifiers, kinase inhibitors, and immunotherapies, are under active investigation; these approaches aim to disrupt aberrant signaling cascades and overcome the various mechanisms of therapeutic resistance in DMG. Challenges, including blood-brain barrier penetration and DMG tumor heterogeneity, require innovative approaches to improve drug delivery and personalized treatment strategies. This review aims to provide a comprehensive overview of the evolving understanding of DMG, focusing on the intricate molecular mechanisms driving tumorigenesis/tumor progression and the current landscape of emerging targeted interventions.

Current immunotherapeutic approaches to diffuse intrinsic pontine glioma

Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumour that occurs in the pons of the brainstem and accounts for over 80% of all brainstem gliomas. The median age at diagnosis is 6-7 years old, with less than 10% overall survival 2 years after diagnosis and less than 1% after 5 years. DIPGs are surgically inaccessible, and radiation therapy provides only transient benefit, with death ensuing from relentless local tumour infiltration. DIPGs are now the leading cause of brain tumour deaths in children, with a societal cancer burden in years of life lost (YLL) of more than 67 per individual, versus approximately 14 and 16 YLL for lung and breast cancer respectively. More than 95 clinical drug trials have been conducted on children with DIPGs, and all have failed to improve survival. No single or combination chemotherapeutic strategy has been successful to date because of our inability to identify targeted drugs for this disease and to deliver these drugs across an intact blood-brain barrier (BBB). Accordingly, there has been an increased focus on immunotherapy research in DIPG, with explorations into treatments such as chimeric antigen receptor T (CAR-T) cells, immune checkpoint blockades, cancer vaccines, and autologous cell transfer therapy. Here, we review the most recent advances in identifying genetic factors influencing the development of immunotherapy for DIPG. Additionally, we explore emerging technologies such as Magnetic Resonance-guided Focused Ultrasound (MRgFUS) in potential combinatorial approaches to treat DIPG.

Strategies to Improve Drug Delivery Across the Blood-Brain Barrier for Glioblastoma

PURPOSE OF REVIEW

Glioblastoma remains resistant to most conventional treatments. Despite scientific advances in the past three decades, there has been a dearth of effective new treatments. New approaches to drug delivery and clinical trial design are needed.

RECENT FINDINGS

We discuss how the blood-brain barrier and tumor microenvironment pose challenges for development of effective therapies for glioblastoma. Next, we discuss treatments in development that aim to overcome these barriers, including novel drug designs such as nanoparticles and antibody-drug conjugates, novel methods of drug delivery, including convection-enhanced and intra-arterial delivery, and novel methods to enhance drug penetration, such as blood-brain barrier disruption by focused ultrasound and laser interstitial thermal therapy. Lastly, we address future opportunities, positing combination therapy as the best strategy for effective treatment, neoadjuvant and window-of-opportunity approaches to simultaneously enhance therapeutic effectiveness with interrogation of on-treatment biologic endpoints, and adaptive platform and basket trials as imperative for future trial design. New approaches to GBM treatment should account for the blood-brain barrier and immunosuppression by improving drug delivery, combining treatments, and integrating novel clinical trial designs.