Fat, Mary Jane Lim

Abstract Oncogenic BRAF alterations occur in a subset of diffuse gliomas across WHO grades and are increasingly identified through modern molecular diagnostics. In addition to standard glioma therapies, targeted treatments are available for patients with BRAF-altered glioma supported by variable evidence spanning randomized trials, single-arm studies, and real-world evidence. This joint consensus review from the Society for Neuro-Oncology (SNO) and the European Association of Neuro-Oncology (EANO) synthesizes current knowledge on the diagnosis and management of BRAF-altered gliomas across age groups, tumor grades, and lines of therapy. Particular emphasis is placed on expert consensus in clinical scenarios where high-quality trial evidence remains limited. The review addresses rationale testing for BRAF alterations, selection, and monitoring of targeted therapies, management of treatment-related toxicities, approaches to resistance, and priorities for future research. It aims to provide practical, evidence-based guidance for clinicians while highlighting gaps to inform prospective studies.

Abstract Recurrent or refractory IDH-mutant (mt) gliomas represent a population with significant unmet clinical need. The Notch ligand delta-like 3 (DLL3) is a tumor-associated antigen that is highly and homogeneously expressed in IDH-mt gliomas but absent in normal brain tissue, making it an attractive therapeutic target. Tarlatamab is a half-life extended bispecific T-cell engager that targets DLL3 and CD3 to redirect cytotoxic T cells toward DLL3-expressing tumor cells. Given the specific expression of DLL3 in IDH-mt gliomas and promising activity of tarlatamab in other DLL3-positive tumors, this study investigates the safety, efficacy, and intracranial activity of tarlatamab in this patient population. TARGID is an open-label, phase II trial enrolling adult patients with histologically confirmed IDH1 or IDH2-mt astrocytoma or oligodendroglioma following up to two prior lines of systemic therapies. The study comprises two cohorts. Cohort 1 (n=10) includes patients with resectable disease who will receive up to three cycles of tarlatamab prior to surgery; postoperative continuation is permitted. The primary endpoint for this cohort is the change in CD8+ T-cell infiltration in tumor tissue and blood. Cohort 2 (n=34) includes patients with unresectable disease and uses a Simon’s optimal two-stage design (H0: P ≤ 0.1 versus H1: P ≥ 0.25). In the 1st stage, 13 patients will be accrued. If 2 or more responses are observed, 21 additional patients will be enrolled. Tarlatamab is administered intravenously at 10 mg every two weeks, following a 1 mg priming dose on Cycle 1 Day 1. The primary endpoint is objective response rate by RANO 2.0. Exploratory endpoints include DLL3 expression, circulating biomarkers, and immune correlatives. The trial is currently in activation, with first patient enrollment anticipated in Q3 2025. The study is supported by the provision of study drug from Amgen as an investigator-initiated trial.