Advances in chemotherapy and targeted therapies have improved survival in cancer patients with an increase of the incidence of newly diagnosed brain metastases (BMs). Intracranial metastases are symptomatic in 60–70% of patients. Magnetic resonance imaging (MRI) with gadolinium is more sensitive than computed tomography and advanced neuroimaging techniques have been increasingly used in the detection, treatment planning, and follow-up of BM. Apart from the morphological analysis, the most effective tool for characterizing BM is immunohistochemistry. Molecular alterations not always reflect those of the primary tumor. More sophisticated methods of tumor analysis detecting circulating biomarkers in fluids (liquid biopsy), including circulating DNA, circulating tumor cells, and extracellular vesicles, containing tumor DNA and macromolecules (microRNA), have shown promise regarding tumor treatment response and progression. The choice of therapeutic approaches is guided by prognostic scores (Recursive Partitioning Analysis and diagnostic-specific Graded Prognostic Assessment-DS-GPA). The survival benefit of surgical resection seems limited to the subgroup of patients with controlled systemic disease and good performance status. Leptomeningeal disease (LMD) can be a complication, especially in posterior fossa metastases undergoing a “piecemeal” resection. Radiosurgery of the resection cavity may offer comparable survival and local control as postoperative whole-brain radiotherapy (WBRT). WBRT alone is now the treatment of choice only for patients with single or multiple BMs not amenable to surgery or radiosurgery, or with poor prognostic factors. To reduce the neurocognitive sequelae of WBRT intensity modulated radiotherapy with hippocampal sparing, and pharmacological approaches (memantine and donepezil) have been investigated. In the last decade, a multitude of molecular abnormalities have been discovered. Approximately 33% of patients with non-small cell lung cancer (NSCLC) tumors and epidermal growth factor receptor mutations develop BMs, which are targetable with different generations of tyrosine kinase inhibitors (TKIs: gefitinib, erlotinib, afatinib, icotinib, and osimertinib). Other “druggable” alterations seen in up to 5% of NSCLC patients are the rearrangements of the “anaplastic lymphoma kinase” gene TKI (crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib). In human epidermal growth factor receptor 2-positive, breast cancer targeted therapies have been widely used (trastuzumab, trastuzumab-emtansine, lapatinib-capecitabine, and neratinib). Novel targeted and immunotherapeutic agents have also revolutionized the systemic management of melanoma (ipilimumab, nivolumab, pembrolizumab, and BRAF inhibitors dabrafenib and vemurafenib).

Chorea and other movement disorders are rarely described as paraneoplastic. The aim of this study was to describe 13 patients with paraneoplastic chorea and dystonia collected by the members of the paraneoplastic neurological syndrome (PNS) EuroNetwork and to review 29 cases from the literature. We analyzed neurological symptoms, severity of the neurological syndrome, delay in neurological diagnosis, associated cancer, oncological and neurological treatments received, and outcome. Eleven (1.2%) out of 913 patients with PNS were identified in the EuroNetwork register. Two more patients not included in the register were added. The overall population consisted of 13 patients with a median age of 75 years (range 49-82 years). In most patients, the movement disorder was classical choreoathetosis with symmetric involvement of the trunk, neck, and limbs. A minority of patients presented unilateral chorea, dystonia, and orobuccal dyskinesia. Associated symptoms, as polyneuropathy, encephalitis, psychiatric disturbances, or visual defects, were often present. The movement disorder usually had a subacute course. The most frequently associated cancer was small cell lung cancer (SCLC). Lymphoma, bowel, or kidney cancers were also reported. CV2/CRMP5 was the most frequently associated antibody, followed by Hu. Hyperintense lesions of the basal ganglia on T2-weighted images were seldom observed. Response to cancer therapy was observed in a minority of patients, but survival was short (17 months). As in other neurological diseases, movement disorders should also be suspected as paraneoplastic when they develop subacutely in older patients (usually over 50) and often in the presence of other ancillary neurological symptoms.

To report the efficacy and tolerability of lacosamide as an add-on treatment in patients with gliomas and uncontrolled seizures despite conventional antiepileptic drugs (AEDs). We conducted an observational study on 71 patients to describe patterns of response to lacosamide and the association between clinico-pathological factors and seizure control. We observed at 3, 6 and 9 months a seizure reduction ≥ 50% in 74.6, 76 and 86.2% of patients and a seizure freedom in 42.2, 43 and 50%, respectively. The median number of seizures in the 3 months before treatment was 13, and decreased to 3 between baseline and 6 months, and to 0.5 between 6 and 9 months. The best seizure response was observed at 3 months (62%). Sixty per cent of patients displayed the maximum seizure control with doses of lacosamide of 100-250 mg/day, while 21% needed doses up to 400 mg/day. Seizure reduction ≥ 50% and seizure freedom were higher in patients who received lacosamide as first add-on compared to those who received a later adjunctive therapy. A reduction ≥ 50% of seizures was observed in a proportion of patients with progressive disease on MRI. Age > 45 years (OR 0.11, 95% CI 0.02-0.63, p = 0.013) was a significant predictor of seizure freedom at 9 months on multivariate analysis. The study suggests that lacosamide, when added to any baseline AEDs, is effective in obtaining a high seizure reduction and seizure freedom regardless of the tumor activity and response to antineoplastic therapies.

TMZ has a role in recurrent chemo-naïve adult patients with intracranial ependymoma, regardless of tumor grade and MGMT methylation. We suggest that, after failure of surgery and radiotherapy, TMZ should be considered as a possible first-line treatment for recurrent ependymoma.

Abstracts iii21NEURO-ONCOLOGY • MAY 2017 characterized, potential paracrine effects influencing antitumor immunity remain enigmatic. However, they are important to decipher, as immunotherapies targeting IDH1-mutant gliomas are emerging. AIM: This study aimed at characterizing a potential cell-specific modulatory role of the oncometabolite R-2-HG in shaping the immune microenvironment of IDH1-mutant gliomas. METHODS AND RESULTS: By means of expression dataset analyses, syngeneic murine tumor models and human glioma tissue, as well as a novel astrocyte-specific IDH1R132H-knock in model, we demonstrate that R-2-HG impairs endogenous and IDH1(R132H)-specific antitumor T cell immunity. This is underlined by functional and transcriptomic analyses of myeloid cells indicating a R-2-HG-driven induction of tolerogenicity and compromised antigen presentation. Metabolomic profiling was complemented by mitochondrial respiration assays, calcium measurements and pathway analyses in primary human and mouse immune cells to delineate key molecular mechanisms by which tumor-derived R-2-HG corrupts the glioma immunoenvironment. The functional relevance of R-2-HG-mediated impairment of antitumor immunity was demonstrated in vivo and potential pharmacological strategies abrogating its effects were assessed. CONCLU-SION: Glioma-derived R-2-HG impairs antitumor immunity by affecting both infiltrating T-cells and the associated myeloid compartment, thus contributing to tumorigenesis and resistance to therapy. Immunotherapeutic strategies against IDH-mutant gliomas may benefit from approaches to prevent excess R-2-HG production or its uptake by immune cells. BACKGROUND: Despite available treatment options for patients (pts) with recurrent glioblastoma (GBM), < 5% of pts survive 5 years beyond initial diagnosis, and no single-agent therapy has demonstrated a survival benefit in the second-line setting, including bevacizumab (bev), which is approved for the treatment of recurrent disease. Nivolumab (nivo), a fully human IgG4 monoclonal antibody that inhibits the programmed death 1 receptor, has provided clinical benefit in multiple cancer types. In cohort 2 of the open-label, phase 3 CheckMate 143 study (NCT02017717), the efficacy and safety of nivo was compared with that of bev in pts with GBM experiencing their first recurrence after prior radiotherapy (RT) and temozolomide (TMZ). METHODS: Pts with no prior VEGF therapy were randomized 1:1 to receive nivo 3 mg/kg Q2W or bev 10 mg/kg Q2W until confirmed disease progression; pts were stratified by the presence/absence of measurable disease. The primary endpoint was overall survival (OS); secondary endpoints were 12-mo OS rate and investigator-assessed progression-free survival (PFS) and objective response rate (ORR) per Response Assessment in Neuro-Oncology criteria. RESULTS: At the time of final analyses (Jan 20, 2017), 369 pts were randomized to the nivo (n = 184) or bev (n = 185) treatment arms; of these pts, 182 received nivo and 165 received bev. At baseline, most pts in the nivo (...