Prolonged response of recurrent IDH-wild-type glioblastoma to laser interstitial thermal therapy with pembrolizumab

MR-guided laser interstitial thermal therapy in the treatment of brain tumors and epilepsy

MR-guided Laser Interstitial Thermal Therapy (MRgLITT) is a minimally invasive neurosurgical technique increasingly used for the treatment of drug-resistant epilepsy and brain tumors. Utilizing near-infrared light energy delivery guided by real-time MRI thermometry, MRgLITT enables precise ablation of targeted brain tissues, resulting in limited corridor-related morbidity and expedited postoperative recovery. Since receiving CE marking in 2018, the adoption of MRgLITT has expanded to more than 40 neurosurgical centers across Europe. In epilepsy treatment, MRgLITT can be applied to various types of focal lesional epilepsy, including mesial temporal lobe epilepsy, hypothalamic hamartoma, focal cortical dysplasias, periventricular heterotopias, cavernous malformations, dysembryoplastic neuroepithelial tumors (DNET), low-grade gliomas, tuberous sclerosis, and in disconnective surgeries. In neuro-oncology, MRgLITT is used for treating newly diagnosed and recurrent primary brain tumors, brain metastases, and radiation necrosis. This comprehensive review presents an overview of the current evidence and technical considerations for the use of MRgLITT in treating various pathologies associated with drug-resistant epilepsy and brain tumors.

An Overview on the Physiopathology of the Blood-Brain Barrier and the Lipid-Based Nanocarriers for Central Nervous System Delivery

The state of well-being and health of our body is regulated by the fine osmotic and biochemical balance established between the cells of the different tissues, organs, and systems. Specific districts of the human body are defined, kept in the correct state of functioning, and, therefore, protected from exogenous or endogenous insults of both mechanical, physical, and biological nature by the presence of different barrier systems. In addition to the placental barrier, which even acts as a linker between two different organisms, the mother and the fetus, all human body barriers, including the blood-brain barrier (BBB), blood-retinal barrier, blood-nerve barrier, blood-lymph barrier, and blood-cerebrospinal fluid barrier, operate to maintain the physiological homeostasis within tissues and organs. From a pharmaceutical point of view, the most challenging is undoubtedly the BBB, since its presence notably complicates the treatment of brain disorders. BBB action can impair the delivery of chemical drugs and biopharmaceuticals into the brain, reducing their therapeutic efficacy and/or increasing their unwanted bioaccumulation in the surrounding healthy tissues. Recent nanotechnological innovation provides advanced biomaterials and ad hoc customized engineering and functionalization methods able to assist in brain-targeted drug delivery. In this context, lipid nanocarriers, including both synthetic (liposomes, solid lipid nanoparticles, nanoemulsions, nanostructured lipid carriers, niosomes, proniosomes, and cubosomes) and cell-derived ones (extracellular vesicles and cell membrane-derived nanocarriers), are considered one of the most successful brain delivery systems due to their reasonable biocompatibility and ability to cross the BBB. This review aims to provide a complete and up-to-date point of view on the efficacy of the most varied lipid carriers, whether FDA-approved, involved in clinical trials, or used in in vitro or in vivo studies, for the treatment of inflammatory, cancerous, or infectious brain diseases.

Laser interstitial thermal therapy for recurrent glioblastomas: a systematic review and meta-analysis

We aim to investigate the efficacy and safety of laser interstitial thermal therapy (LITT) in treating recurrent glioblastomas (rGBMs). A comprehensive search was conducted in four databases to identify studies published between January 2001 and June 2022 that reported prognosis information of rGBM patients treated with LITT as the primary therapy. The primary outcomes of interest were progression-free survival (PFS) and overall survival (OS) at 6 and 12 months after LITT intervention. Adverse events and complications were also evaluated. Eight eligible non-comparative studies comprising 128 patients were included in the analysis. Seven studies involving 120 patients provided data for the analysis of PFS. The pooled PFS rate at 6 months after LITT was 25% (95% CI 15-37%, I2 = 53%), and at 12 months, it was 9% (95% CI 4-15%, I2 = 24%). OS analysis was performed on 54 patients from six studies, with an OS rate of 92% (95% CI 84-100%, I2 = 0%) at 6 months and 42% (95% CI 13-73%, I2 = 67%) at 12 months after LITT. LITT demonstrates a favorable safety profile with low complication rates and promising tumor control and overall survival rates in patients with rGBMs. Tumor volume and performance status are important factors that may influence the effectiveness of LITT in selected patients. Additionally, the combination of LITT with immune-based therapy holds promise. Further well-designed clinical trials are needed to expand the application of LITT in glioma treatment.

Immunotherapeutic Strategies for the Treatment of Glioblastoma: Current Challenges and Future Perspectives

Despite decades of research and the best up-to-date treatments, grade 4 Glioblastoma (GBM) remains uniformly fatal with a patient median overall survival of less than 2 years. Recent advances in immunotherapy have reignited interest in utilizing immunological approaches to fight cancer. However, current immunotherapies have so far not met the anticipated expectations, achieving modest results in their journey from bench to bedside for the treatment of GBM. Understanding the intrinsic features of GBM is of crucial importance for the development of effective antitumoral strategies to improve patient life expectancy and conditions. In this review, we provide a comprehensive overview of the distinctive characteristics of GBM that significantly influence current conventional therapies and immune-based approaches. Moreover, we present an overview of the immunotherapeutic strategies currently undergoing clinical evaluation for GBM treatment, with a specific emphasis on those advancing to phase 3 clinical studies. These encompass immune checkpoint inhibitors, adoptive T cell therapies, vaccination strategies (i.e., RNA-, DNA-, and peptide-based vaccines), and virus-based approaches. Finally, we explore novel innovative strategies and future prospects in the field of immunotherapy for GBM.

Laser Interstitial Thermal Therapy Induces Robust Local Immune Response for Newly Diagnosed Glioblastoma With Long-term Survival and Disease Control

Laser interstitial thermal therapy (LITT) is a minimally invasive neurosurgical technique used to ablate intra-axial brain tumors. The impact of LITT on the tumor microenvironment is scarcely reported. Nonablative LITT-induced hyperthermia (33-43˚C) increases intra-tumoral mutational burden and neoantigen production, promoting immunogenic cell death. To understand the local immune response post-LITT, we performed longitudinal molecular profiling in a newly diagnosed glioblastoma and conducted a systematic review of anti-tumoral immune responses after LITT. A 51-year-old male presented after a fall with progressive dizziness, ataxia, and worsening headaches with a small, frontal ring-enhancing lesion. After clinical and radiographic progression, the patient underwent stereotactic needle biopsy, confirming an IDH-WT World Health Organization Grade IV Glioblastoma, followed by LITT. The patient was subsequently started on adjuvant temozolomide, and 60 Gy fractionated radiotherapy to the post-LITT tumor volume. After 3 months, surgical debulking was conducted due to perilesional vasogenic edema and cognitive decline, with H&E staining demonstrating perivascular lymphocytic infiltration. Postoperative serial imaging over 3 years showed no evidence of tumor recurrence. The patient is currently alive 9 years after diagnosis. Multiplex immunofluorescence imaging of pre-LITT and post-LITT biopsies showed increased CD8 and activated macrophage infiltration and programmed death ligand 1 expression. This is the first depiction of the in-situ immune response to LITT and the first human clinical presentation of increased CD8 infiltration and programmed death ligand 1 expression in post-LITT tissue. Our findings point to LITT as a treatment approach with the potential for long-term delay of recurrence and improving response to immunotherapy.

Advances in Treatment of Isocitrate Dehydrogenase (IDH)-Wildtype Glioblastomas

PURPOSE OF REVIEW

The management of isocitrate dehydrogenase (IDH)-wildtype glioblastomas is an area of unmet need. Despite multimodal therapy incorporating maximal safe resection, radiotherapy, and temozolomide, clinical outcomes remain poor. At disease progression or relapse, available systemic agents such as temozolomide, lomustine, and bevacizumab have limited efficacy. We review the recent advances in the treatment of IDH-wildtype glioblastomas.

RECENT FINDINGS

A broad repertoire of systemic agents is in the early stages of development, encompassing the areas of precision medicine, immunotherapy, and repurposed medications. The use of medical devices may present opportunities to bypass the blood-brain barrier. Novel clinical trial designs aim to efficiently test treatment options to advance the field. There are a number of emerging treatment options for IDH-wildtype glioblastomas which are undergoing evaluation in clinical trials. Advances in our scientific understanding of IDH-wildtype glioblastomas offer hope and the prospect of incremental improvements in clinical outcomes.

Understanding the activity of antibody-drug conjugates in primary and secondary brain tumours

Antibody-drug conjugates (ADCs), a class of targeted cancer therapeutics combining monoclonal antibodies with a cytotoxic payload via a chemical linker, have already been approved for the treatment of several cancer types, with extensive clinical development of novel constructs ongoing. Primary and secondary brain tumours are associated with high mortality and morbidity, necessitating novel treatment approaches. Pharmacotherapy of brain tumours can be limited by restricted drug delivery across the blood-brain or blood-tumour barrier, although data from phase II studies of the HER2-targeted ADC trastuzumab deruxtecan indicate clinically relevant intracranial activity in patients with brain metastases from HER2⁺ breast cancer. However, depatuxizumab mafodotin, an ADC targeting wild-type EGFR and EGFR variant III, did not provide a definitive overall survival benefit in patients with newly diagnosed or recurrent EGFR-amplified glioblastoma in phase II and III trials, despite objective radiological responses in some patients. In this Review, we summarize the available data on the central nervous system activity of ADCs from trials involving patients with primary and secondary brain tumours and discuss their clinical implications. Furthermore, we explore pharmacological determinants of intracranial activity and discuss the optimal design of clinical trials to facilitate development of ADCs for the treatment of gliomas and brain metastases.

The Evolution of Laser-Induced Thermal Therapy for the Treatment of Gliomas

Laser-induced thermal therapy (LITT) has evolved over the past two decades to treat a number of intracranial pathologies. Although it initially emerged as a salvage treatment of surgically inoperable tumors or recurrent lesions that had exhausted more conventional treatments, it is now being used as a primary, first-line treatment in certain instances with outcomes comparable to traditional surgical resection. The authors discuss the evolution of LITT in the treatment of gliomas and future directions, which may further enhance the efficacy of this procedure.

Laser Interstitial Thermal Therapy for the Treatment of Primary and Metastatic Brain Tumors: A Systematic Review and Meta-Analysis

BACKGROUND

Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for intracranial tumors that are challenging to treat via traditional methods; however, its safety and efficacy are not yet well validated in the literature. The objectives of the study were to assess the available evidence of the indications and adverse events (AEs) of LITT and 1-year progression-free survival and 1-year overall survival in the treatment of primary and secondary brain tumors.

METHODS

A comprehensive literature search was conducted through the databases PubMed, Embase, and the Cochrane Library until October 2021. Comparative and descriptive studies, except for case reports, were included in the meta-analysis. Separate analyses by tumor type (high-grade gliomas, including World Health Organization grade 4 astrocytomas [which include glioblastomas] as a specific subgroup; low-grade gliomas; and brain metastases) were conducted. Pooled effect sizes and their 95% confidence intervals (CI) were generated via random-effects models.

RESULTS

Forty-five studies met the inclusion criteria, yielding 826 patients for meta-analysis. There were 829 lesions in total, of which 361 were classified as high-grade gliomas, 116 as low-grade gliomas, 337 as metastatic brain tumors, and 15 as nonglial tumors. Indications for offering LITT included deep/inaccessible tumor (12 studies), salvage therapy after failed radiosurgery (9), failures of ≥2 treatment options (3), in pediatric patients (4), patient preference (1); indications were nonspecific in 12 studies. Pooled incidence of all (minor or major) procedure-related AEs was 30% (95% CI, 27%-40%) for all tumors. Pooled incidence of neurologic deficits (minor or major) was 16% (12%-22%); postprocedural edema 14% (8%-22%); seizure 6% (4%-9%); hematoma 20% (14%-29%); deep vein thrombosis 19% (11%-30%); hydrocephalus 8% (5%-12%); and wound infection 5% (3%-7%). One-year progression-free survival was 18.6% (11.3%-29.0%) in high-grade gliomas, 16.9% (11.6%-24.0%) among the grade 4 astrocytomas; and 51.2% (36.7%-65.5%) in brain metastases. One-year overall survival was 43.0% (36.0%-50.0%) in high-grade glioma, 45.9% (95% CI, 37.9%-54%) in grade 4 astrocytomas; 93.0% (42.3%-100%) in low-grade gliomas, and 56.3% (47.0%-65.3%) in brain metastases.

CONCLUSIONS

New neurologic deficits and postprocedural edema were the most reported AEs after LITT, albeit mostly transient. This meta-analysis provides the best statistical estimates of progression and survival outcomes based on the available information. LITT is generally a safe procedure for selected patients, and future well-designed comparative studies on its outcomes versus the current standard of care should be performed.

Comparison of Immune Checkpoint Molecules PD-1 and PD-L1 in Paired Primary and Recurrent Glioma: Increasing Trend When Recurrence

Purpose: This study aims to investigate PD-1/PD-L1 expression patterns in paired primary and recurrent gliomas. Methods: From January 2008 to December 2014, 42 patients who underwent surgical resections of primary and recurrent gliomas were retrospectively included. PD-1/PD-L1 protein expression in tumors was evaluated through immunohistochemistry. Results: In primary gliomas, PD-1 and PD-L1 expression was evident in 9 (22.0%) and 14 (33.3%) patients. In the paired recurrent glioma, PD-1 and PD-L1 expression was evident in 25 (61.0%) and 31 (74.0%) lesions. Both PD-1 and PD-L1 showed significantly enhanced expression after recurrence (p < 0.005; p < 0.005). For PD-L1 expression in recurrent gliomas, the adjuvant therapy group showed significantly increased expression compared to primary gliomas (p < 0.005). For PD-1- primary gliomas, if the matched recurrent gliomas showed PD-1+, the PFS became worse than the remaining recurrent gliomas PD-1- (12.7 vs. 25.9 months, p = 0.032). Interestingly, for PD-L1- primary gliomas, if the matched recurrent gliomas showed PD-L1+, the OS became better than the remaining recurrent gliomas PD-L1- (33.8 vs. 17.5 months, p < 0.001). Conclusions: In the study, we found the expression of PD-1/PD-L1 increased significantly in recurrent gliomas and the elevated level of PD-L1 was tightly associated with adjuvant treatment, suggesting the potential therapeutic and predictive value of PD-1 and PD-L1 in the treatment of recurrent gliomas.