Efficacy and safety of extended adjuvant temozolomide compared to standard adjuvant temozolomide in glioblastoma: Updated systematic review and meta-analysis

Efficacy and Safety of Prolonged Adjuvant Temozolomide Treatment in Glioblastoma: Prospective Study of 81 Patients Undergoing up to 101 Cycles of Treatment

Background: Although several studies investigated the efficacy of long-term adjuvant temozolomide (TMZ) therapy in glioblastomas (GBs), no univocal data are currently available, and this topic remains controversial. The present study on our ongoing experience aims to assess whether the extended STUPP protocol confers prognostic benefits with acceptable safety. Methods: From 2004 to 2018, 81 patients with a new diagnosis of GB according to the World Health Organization (WHO) 2021 classification, treated with gross total resection (GTR) or subtotal resection (STR), were enrolled. Patients were divided into Group A (long-term TMZ; N = 40) and Group B (standard STUPP protocol; N = 41). Results: In the extended STUPP group, compared with the standard STUPP group, progression-free survival (PFS) and overall survival (OS) were significantly improved (PFS: 27.8 vs. 7.5 months, p = 0.00001; OS: 35.9 vs. 11.3 months, p = 0.0001). To mitigate a potential survival bias, we focused on those in Group B who completed the recommended six cycles. Patients in Group A demonstrated a prolonged OS compared to Group B (27 vs. 10 months, p < 0.001). Similar findings were observed in a focused analysis of patients who had achieved a minimum survival of 12 months (27 vs. 15 months, p < 0.001) or 18 months (34 vs. 24 months, p = 0.044). Conclusions: Our analysis demonstrates a PFS and OS advantage with extended STUPP and suggests that young patients without corpus callosum invasion, with methylguanine-DNA methyltransferase (MGMT) promoter methylation, and treated with GTR are the best candidates. No significant safety difference emerged between extended and standard TMZ treatment.

Morusin regulates the migration of M2 macrophages and GBM cells through the CCL4-CCR5 axis

BACKGROUND

Glioblastoma (GBM) is the most aggressive tumor in the central nervous system. Tumor-associated macrophage (TAMs) represent a major immune cell population in tumor microenvironment (TME) and exert immunosuppressive effects that impede GBM treatment. Morusin is a flavonoid extracted from mulberry trees and has anti-tumor properties against various cancers, including glioma. However, the impact of morusin on the TME of gliomas has not been explored.

METHODS

We evaluated the effect of morusin on the tumor microenvironment using a mouse glioma model through in vivo and in vitro experiments. In vitro experiments demonstrated the effects of morusin on the viability of RAW264.7 and THP1 cells, and the migration ability of M2 macrophages. Furthermore, we investigated the effect of conditioned medium (CM) of morusin-treated M2 macrophages on the migration of glioblastoma cell lines GL261, U87, and U251.

RESULT

Morusin alleviated the GBM progression and prolonged mouse survival by inhibiting the ratio of macrophages to CD206+ macrophages. Mechanistically, we demonstrated that morusin could effectively inhibit the secretion of the chemokine CCL4 in M2 macrophage which consequently decreased CCL4-dependent CCR5 activation. This leads to the reduced migration of both macrophages and glioblastoma cells in TME. These findings provide a strong rationale for the development of morusin as a potential therapeutic agent for GBM, either as a standalone treatment or in combination with other immunotherapeutic strategies, and warrant further preclinical and clinical investigations.

Emerging and Biological Concepts in Pediatric High-Grade Gliomas

Primary central nervous system tumors are the most frequent solid tumors in children, accounting for over 40% of all childhood brain tumor deaths, specifically high-grade gliomas. Compared with pediatric low-grade gliomas (pLGGs), pediatric high-grade gliomas (pHGGs) have an abysmal survival rate. The WHO CNS classification identifies four subtypes of pHGGs, including Grade 4 Diffuse midline glioma H3K27-altered, Grade 4 Diffuse hemispheric gliomas H3-G34-mutant, Grade 4 pediatric-type high-grade glioma H3-wildtype and IDH-wildtype, and infant-type hemispheric gliomas. In recent years, we have seen promising advancements in treatment strategies for pediatric high-grade gliomas, including immunotherapy, CAR-T cell therapy, and vaccine approaches, which are currently undergoing clinical trials. These therapies are underscored by the integration of molecular features that further stratify HGG subtypes. Herein, we will discuss the molecular features of pediatric high-grade gliomas and the evolving landscape for treating these challenging tumors.

Albumin-Based Microneedles for Spatiotemporal Delivery of Temozolomide and Niclosamide to Resistant Glioblastoma

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor. Standard therapy includes maximal surgical resection, radiotherapy, and adjuvant temozolomide (TMZ) administration. However, the rapid development of TMZ resistance and the impermeability of the blood-brain barrier (BBB) significantly hinder the therapeutic efficacy. Herein, we developed spatiotemporally controlled microneedle patches (BMNs) loaded with TMZ and niclosamide (NIC) to overcome GBM resistance. We found that hyaluronic acid (HA) increased the viscosity of bovine serum albumin (BSA) and evidenced that concentrations of BSA/HA exert an impact degradation rates exposure to high-temperature treatment, showing that the higher BSA/HA concentrations result in slower drug release. To optimize drug release rates and ensure synergistic antitumor effects, a 15% BSA/HA solution constituting the bottoms of BMNs was chosen to load TMZ, showing sustained drug release for over 28 days, guaranteeing long-term DNA damage in TMZ-resistant cells (U251-TR). Needle tips made from 10% BSA/HA solution loaded with NIC released the drug within 14 days, enhancing TMZ's efficacy by inhibiting the activity of O6-methylguanine-DNA methyltransferase (MGMT). BMNs exhibit superior mechanical properties, bypass the BBB, and gradually release the drug into the tumor periphery, thus significantly inhibiting tumor proliferation and expanding median survival in mice. The on-demand delivery of BMNs patches shows a strong translational potential for clinical applications, particularly in synergistic GBM treatment.

Extended dosing (12 cycles) vs conventional dosing (6 cycles) of adjuvant temozolomide in adults with newly diagnosed high-grade gliomas: a randomized, single-blind, two-arm, parallel-group controlled trial

Purpose

Maximum safe surgical resection followed by adjuvant chemoradiation and temozolomide chemotherapy is the current standard of care in the management of newly diagnosed high grade glioma. However, there are controversies about the optimal number of adjuvant temozolomide cycles. This study aimed to compare the survival benefits of 12 cycles against 6 cycles of adjuvant temozolomide adults with newly diagnosed high grade gliomas.

Methods

Adult patients with newly diagnosed high grade gliomas, and a Karnofsky performance status>60%, were randomized to receive either 6 cycles or 12 cycles of adjuvant temozolomide. Patients were followed-up for assessment of overall survival (OS) and progression-free survival (PFS) by brain MRI every 3 months within the first year after treatment and then every six months.

Results

A total of 100 patients (6 cycles, 50; 12 cycles, 50) were entered. The rate of treatment completion in 6 cycles and 12 cycles groups were 91.3% and 55.1%, respectively. With a median follow-up of 26 months, the 12-, 24-, 36-, and 48-month OS rates in 6 cycles and 12 cycles groups were 81.3% vs 78.8%, 58.3% vs 49.8%, 47.6% vs 34.1%, and 47.6% vs 31.5%, respectively (p-value=.19). Median OS of 6 cycles and 12 cycles groups were 35 months (95% confidence interval (CI), 11.0 to 58.9) and 23 months (95%CI, 16.9 to 29.0). The 12-, 24-, 36-, and 48- month PFS rates in 6 cycles and 12 cycles groups were 70.8% vs 56.9%, 39.5% and 32.7%, 27.1% vs 28.8%, and 21.1% vs 28.8%, respectively (p=.88). The Median PFS of 6 cycles and 12 cycles groups was 18 months (95% CI, 14.8 to 21.1) and 16 (95% CI, 11.0 to 20.9) months.

Conclusion

Patients with newly diagnosed high grade gliomas treated with adjuvant temozolomide after maximum safe surgical resection and adjuvant chemoradiation do not benefit from extended adjuvant temozolomide beyond 6 cycles.

Trial registration

Prospectively registered with the Iranian Registry of Clinical Trials: IRCT20160706028815N3. Date registered: 18/03/14.

A combined analysis of two prospective randomised studies exploring the impact of extended post-radiation temozolomide on survival outcomes in newly diagnosed glioblastoma

PURPOSE

The optimal duration of post-radiation temozolomide in newly diagnosed glioblastoma remains unclear, with no published phase III randomised trials. Standard-of-care stipulates 6 months. However, in routine care, it is often extended to 12 months, despite lacking robust supporting data.

METHODS

GEINO14-01 (Spain) and EX-TEM (Australia) studies enrolled glioblastoma patients without progression at the end of 6 months post-radiation temozolomide. Participants were randomised 1:1 to six additional months of temozolomide or observation. Primary endpoint was 6-month progression free survival from date of randomisation (6mPFS). Secondary endpoints included overall survival (OS) and toxicity. 204 patients were required to detect an improvement in 6mPFS from 50 to 60% (80% power). Neither study recruited sufficient patients. We performed a combined analysis of individual patient data.

RESULTS

205 patients were recruited: 159 in GEINO14-01 (2014-2018) and 46 in EX-TEM (2019-2022). Median follow-up was 20.0 and 14.5 months. Baseline characteristics were balanced. There was no significant improvement in 6mPFS (57.2% vs 64.0%, OR0.75, p = 0.4), nor across any subgroups, including MGMT methylated; PFS (HR0.92, p = 0.59, median 7.8 vs 9.7 months); or OS (HR1.03, p = 0.87, median 20.1 vs 19.4 months). During treatment extension, 64% experienced any grade adverse event, mainly fatigue and gastrointestinal (both 54%). Only a minority required treatment changes: 4.5% dose delay, 7.5% dose reduction, 1.5% temozolomide discontinuation.

CONCLUSION

For glioblastoma patients, extending post-radiation temozolomide from 6 to 12 months is well tolerated but does not improve 6mPFS. We could not identify any subset that benefitted from extended treatment. Six months should remain standard-of-care.

Pseudoprogression versus true progression in glioblastoma: what neurosurgeons need to know

Management of patients with glioblastoma (GBM) is complex and involves implementing standard therapies including resection, radiation therapy, and chemotherapy, as well as novel immunotherapies and targeted small-molecule inhibitors through clinical trials and precision medicine approaches. As treatments have advanced, the radiological and clinical assessment of patients with GBM has become even more challenging and nuanced. Advances in spatial resolution and both anatomical and physiological information that can be derived from MRI have greatly improved the noninvasive assessment of GBM before, during, and after therapy. Identification of pseudoprogression (PsP), defined as changes concerning for tumor progression that are, in fact, transient and related to treatment response, is critical for successful patient management. These temporary changes can produce new clinical symptoms due to mass effect and edema. Differentiating this entity from true tumor progression is a major decision point in the patient's management and prognosis. Providers may choose to start an alternative therapy, transition to a clinical trial, consider repeat resection, or continue with the current therapy in hopes of resolution. In this review, the authors describe the invasive and noninvasive techniques neurosurgeons need to be aware of to identify PsP and facilitate surgical decision-making.