Portnow, Jana

Abstract Current assessments of brain permeability rely predominantly on drug delivery to contrast-enhancing tumor regions. However, substantial portions of central nervous system (CNS) tumors reside within non-enhancing brain (NEB), where drug concentrations frequently remain subtherapeutic. This collaborative Adult Brain Tumor Consortium and Food and Drug Administration workshop aimed to identify criteria for defining NEB permeability to accomplish 2 critical objectives: (1) allocate clinical trial resources toward agents achieving therapeutic NEB concentrations and (2) minimize systemic toxicity when CNS benefit is improbable. The workshop systematically evaluated permeability assessment modalities, including drug physicochemical properties, in vitro blood-brain barrier models, and penetration into cerebrospinal fluid and normal rodent brain. Methodological approaches to determine requisite NEB drug concentrations and approaches to measuring NEB pharmacokinetics and pharmacodynamics were examined. This culminated in developing the Non-Enhancing Brain Permeability Index (NEBPI), which assigns therapeutic agents to 3 categories: sufficiently permeable, insufficiently permeable, or impermeable. The NEBPI provides a standardized framework to assist investigators and regulatory agencies to evaluate NEB penetration before human efficacy studies are initiated for agents that require direct tumor contact. Assessing NEB drug penetration is critical to improving outcomes in CNS tumors and reducing the incidence of brain metastases in systemic malignancies.

Abstract BACKGROUND Selinexor (SEL) is a first-in-class XPO1 inhibitor with potent antitumor activity through the nuclear retention and reactivation of tumor suppressor proteins, reduced translation of oncogenes, and decreased expression of anti-apoptotic proteins. As a single agent, SEL has demonstrated brain penetration and clinically relevant responses in glioblastoma. We seek to enhance the effect and benefit of SEL by priming with temozolomide (TMZ). METHODS Through an NCI Project Team, we developed a multi-institutional phase I/II clinical trial which opened across the NCI Experimental Therapeutics Clinical Trial Network. Eligibility included histologically confirmed 1st recurrent MGMT promoter methylated glioblastoma. We evaluated safety, tolerability, and dose finding with an IQ 3 + 3 design of TMZ 150mg/m2 on days 1-5 of a 28-day cycle plus SEL on days 8 and 15. RESULTS From October 2022 to March 2024, we enrolled 12 patients (n=11 evaluable) into phase I of the study. Patient characteristics included 82% male, median age 62 (range 50-77), 64% white. The median number of cycles administered was 6 (range 1-12). Two dose levels (SEL 60mg and SEL 80mg) were evaluated. No dose-limiting toxicities (DLTs) were observed. The most common treatment related adverse events were nausea (58%), decreased platelet count (50%), fatigue (50%), constipation (42%), vomiting (25%), decreased lymphocyte count (25%), and decreased neutrophil count (25%). Grade 3+ treatment related adverse events included nausea, grade 3 (n=1); decreased lymphocyte count, grades 3-4 (n=2); and anorexia, grade 3 (n=1). Phase I has completed enrollment and the recommended phase II dose will be SEL 80mg. Additional results will be presented. CONCLUSION Results suggest that a sequential dosing regimen of SEL+TMZ is feasible, well-tolerated, and may minimize the cumulative toxicity of SEL. The phase II randomized portion of this trial is enrolling nationwide and will investigate efficacy and candidate molecular signatures of vulnerability (NCI #10505, NCT05432804).

Abstract BACKGROUND Selinexor (SEL) is a first-in-class XPO1 inhibitor with potent antitumor activity via tumor suppressor protein nuclear localization and reactivation, oncoprotein translation suppression, and DNA repair inhibition. As a single agent, SEL has demonstrated adequate brain penetration and clinically relevant responses in glioblastoma. We seek to enhance the effect and benefit of SEL by priming with temozolomide (TMZ). METHODS We developed in vitro and in vivo studies to rationally design a phase I/II trial to evaluate the safety and efficacy of the sequential combination of SEL+TMZ. Sequential treatment of U87 cells and intracranial mouse xenografts demonstrated superior DNA damage (ɣH2A.X, cleaved PARP) and overall survival compared to combination or single-agent therapy (HR 0.25 [95% CI, 0.07-0.84]; p = 0.01, log-rank). We used the top-scoring pair method to identify a 6 gene-pair RNAseq signature associated with response to SEL. RESULTS Based on preclinical findings, we developed and opened a multi-institutional phase I/II clinical trial in October 2022. Eligibility includes histologically confirmed 1st recurrent MGMT promoter methylated glioblastoma. Primary objectives are safety and preliminary efficacy. Secondary objectives are overall response rate, efficacy, and prospective validation of a molecular signature of response. Phase I dose finding by IQ 3 + 3 (n = 12) involves TMZ 150mg/m2 on days 1-5 of a 28-day cycle plus SEL on days 8 and 15. Phase II will involve randomization (n = 72) to the RP2D of SEL+TMZ versus monotherapy TMZ. Using proportional hazards regression, RHR 0.5 with p < 0.1 will demonstrate sufficient efficacy. We have enrolled 3 participants in dose level 1 (SEL 60mg) with no dose-limiting toxicities (DLTs) observed. Additional preliminary results will be presented. CONCLUSION Preliminary results suggest that a sequential dosing regimen of SEL+TMZ is feasible and initial dose is well-tolerated and may minimize the cumulative toxicity of SEL. The trial is currently enrolling nationwide (NCI #10505, NCT05432804).

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of the following adult CNS cancers: glioma (WHO grade 1, WHO grade 2–3 oligodendroglioma [1p19q codeleted, IDH- mutant], WHO grade 2–4 IDH- mutant astrocytoma, WHO grade 4 glioblastoma), intracranial and spinal ependymomas, medulloblastoma, limited and extensive brain metastases, leptomeningeal metastases, non–AIDS-related primary CNS lymphomas, metastatic spine tumors, meningiomas, and primary spinal cord tumors. The information contained in the algorithms and principles of management sections in the NCCN Guidelines for CNS Cancers are designed to help clinicians navigate through the complex management of patients with CNS tumors. Several important principles guide surgical management and treatment with radiotherapy and systemic therapy for adults with brain tumors. The NCCN CNS Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel’s most recent recommendations regarding molecular profiling of gliomas.

Abstract BACKGROUND Standard of care (SOC) and patient survival in glioblastoma have changed little in the past 17 years. We evaluated in a phase 3 trial whether adding an autologous tumor lysate-loaded dendritic cell vaccine (murcidencel) to SOC extends survival. Patients and METHODS Newly diagnosed glioblastoma patients were randomized 2:1 to either murcidencel or placebo. Under a crossover design, all patients could receive murcidencel following tumor recurrence. All parties remained blinded regarding treatments before recurrence. Patients thus received murcidencel at new diagnosis (nGBM) or at recurrence (rGBM) following crossover from placebo. The primary and secondary endpoints compare overall survival (OS) with contemporaneous, matched external controls. Four sets of analyses were conducted to ensure rigorous matching of the controls, reduce biases, and confirm the robustness of the results. RESULTS 331 patients were enrolled. With the crossover, 89% received murcidencel. Median OS (mOS) for nGBM patients (n = 232) was 19.3 months from randomization (22.4 months from surgery) with murcidencel vs. 16.5 months from randomization in the controls (HR = 0.80, p = 0.002). Survival at 48 months from randomization was 15.7% vs. 9.9%, and at 60 months was 13% vs. 5.7%. For rGBM (n = 64), mOS was 13.2 months from relapse vs. 7.8 months in the controls (HR = 0.58, p < 0.001). Survival at 24 months post-recurrence was 20.7% vs. 9.6%, and at 30 months post-recurrence was 11.1% vs 5.1%. In nGBM patients with methylated MGMT (n = 90), mOS was 30.2 months from randomization (33 months from surgery) with murcidencel vs. 21.3 months from randomization in the controls (HR = 0.74, p = 0.027). The treatment was well tolerated, with only 5 serious adverse events deemed at least possibly related to the vaccine. CONCLUSION Clinically meaningful and statistically significant survival extension was seen in both nGBM and rGBM patients treated with murcidencel and SOC compared with contemporaneous, matched external controls who received SOC alone.

Abstract Isocitrate dehydrogenase (IDH) mutant gliomas are the most common adult, malignant primary brain tumors diagnosed in patients younger than 50, constituting an important cause of morbidity and mortality. In recent years, there has been significant progress in understanding the molecular pathogenesis and biology of these tumors, sparking multiple efforts to improve their diagnosis and treatment. In this consensus review from the Society for Neuro-Oncology (SNO), the current diagnosis and management of IDH-mutant gliomas will be discussed. In addition, novel therapies, such as targeted molecular therapies and immunotherapies, will be reviewed. Current challenges and future directions for research will be discussed.

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.