Dissecting the prognostic signature of patients with astrocytoma isocitrate dehydrogenase-mutant grade 4: a large multicenter, retrospective study.

BACKGROUND: The World Health Organization (WHO) 2021 classification of central nervous system (CNS) tumors classified astrocytoma isocitrate dehydrogenase-mutant (A IDHm) with either microvascular proliferation and/or necrosis or homozygous deletion of CDKN2A/B as CNS grade 4 (CNS WHO G4), introducing a distinct entity and posing new challenges to physicians for appropriate management and prognostication. PATIENTS AND METHODS: We retrospectively collected information about patients diagnosed with A IDHm CNS WHO G4 at three reference neuro-oncological Italian centers and correlated them with survival. RESULTS: A total of 133 patients were included. Patients were young (median age 41 years) and most received post-operative treatment including chemo-radiation (n = 101) and/or temozolomide maintenance (n = 112). With a median follow-up of 51 months, the median overall survival (mOS) was 31.2 months, with a 5-year survival probability of 26%. In the univariate analysis, complete resection (mOS: 40.2 versus 26.3 months, P = 0.03), methyl-guaninemethyltransferase (MGMT) promoter methylation (mOS: 40.7 versus 18 months, P = 0.0136), and absence of telomerase reverse transcriptase (TERT) promoter mutation (mOS: 40.7 versus 18 months, P = 0.0003) correlated with better prognosis. In the multivariate models, lack of TERT promoter mutation [hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.07-0.82, P = 0.024] and MGMT methylation (HR 0.40, 95% CI 0.20-0.81, P = 0.01) remained associated with improved survival. CONCLUSIONS: This is the largest experience in Western countries exploring the prognostic signature of patients with A IDHm CNS G4. Our results show that MGMT promoter methylation and TERT promoter mutation may impact clinical outcomes. This may support physicians in prognostication, clinical management, and design of future studies of this distinct diagnostic entity.

REGOMA-OSS: a large, Italian, multicenter, prospective, observational study evaluating the efficacy and safety of regorafenib in patients with recurrent glioblastoma.

BACKGROUND: In the randomized phase II REGOMA trial, regorafenib showed promising activity in patients with recurrent glioblastoma. We conducted a large, multicenter, prospective, observational study to confirm the REGOMA data in a real-world setting. PATIENTS AND METHODS: The major inclusion criteria were histologically confirmed diagnosis of glioblastoma according to the World Health Organization (WHO) 2016 classification and relapse after radiotherapy with concurrent/adjuvant temozolomide treatment, good performance status [Eastern Cooperative Oncology Group performance status (ECOG PS 0-1)] and good liver function. Regorafenib was administered at the standard dose of 160 mg/day for 3 weeks on/1 week off. Brain magnetic resonance imaging was carried out within 14 days before starting regorafenib and every 8-12 weeks. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate, disease control rate (DCR), safety and health-related quality of life. The Response Assessment in Neuro-Oncology (RANO) criteria were used for response evaluation and Common Terminology Criteria for Adverse Events (CTCAE) version 5 for assessment of adverse events (AEs). RESULTS: From September 2020 to October 2022, 190 patients with recurrent glioblastoma were enrolled from 30 cancer centers in Italy: their median age was 58.5 years [interquartile range (IQR) 53-67 years], 68% were male and 85 (44.7%) were in optimal clinical condition (ECOG PS 0). The number of patients taking steroids at baseline was 113 (60%); the second surgery was carried out in 39 (20.5%). O6-methylguanine-DNA methyltransferase (MGMT) was methylated in 80 patients (50.3%) and 147 (92.4%) of the patients analyzed had isocitrate dehydrogenase (IDH) wild type. The median follow-up period was 20 months (IQR 15.6-25.5 months). The median OS was 7.9 months ([95% confidence interval (CI) 6.5-9.2 months] and the median PFS was 2.6 months (95% CI 2.3-2.9 months). Radiological response was partial response and stable disease in 13 (7.3%) and 26 (14.6%) patients, respectively, with a DCR of 21.9%. The median number of regorafenib cycles per patient was 3 (IQR 2.0-4.0). Grade 3-4 drug-related adverse events were reported in 22.6% of patients. A dose reduction due to AEs was required in 36% of patients. No deaths were considered as treatment-related AEs. CONCLUSIONS: This large, real-world observational study showed similar OS with better tolerability of regorafenib in patients with relapsed glioblastoma compared with the REGOMA study.