Phase II study of bi-weekly temozolomide plus bevacizumab for adult patients with recurrent glioblastoma.

PURPOSE: Bevacizumab is an active anti-angiogenic agent in the treatment of recurrent glioblastoma. Temozolomide can prolong survival in patients with newly diagnosed glioblastoma. At recurrence, alternate dosing of temozolomide has shown to further deplete methyl-guanine-methyltransferase (MGMT) conferring added activity for patients who have progressed on the standard dosing regimen. In this study, bevacizumab plus biweekly temozolomide was evaluated for efficacy in adult patients with recurrent glioblastoma. METHODS: Thirty patients with recurrent glioblastoma were treated with bevacizumab on (10 mg/kg i.v.) days 1 and 15 of a 28-day cycle combined with temozolomide (100 mg/m2) on days 1-5 and 15-19 on a 28-day cycle. Responses were assessed at week 4 and then every 8 weeks. MGMT status and quality of life measures were also assessed. RESULTS: Overall response rate from diagnosis was 51 weeks, the 6-month progression-free survival was 52%, and median time to tumor progression was 5.5 months. CONCLUSION: Bevacizumab plus bi-weekly temozolomide was well tolerated and may be a salvage regimen to be considered in a subset of patients with recurrent glioblastoma.

Exome sequencing reveals new causal mutations in children with epileptic encephalopathies.

PURPOSE: The management of epilepsy in children is particularly challenging when seizures are resistant to antiepileptic medications, or undergo many changes in seizure type over time, or have comorbid cognitive, behavioral, or motor deficits. Despite efforts to classify such epilepsies based on clinical and electroencephalographic criteria, many children never receive a definitive etiologic diagnosis. Whole exome sequencing (WES) is proving to be a highly effective method for identifying de novo variants that cause neurologic disorders, especially those associated with abnormal brain development. Herein we explore the utility of WES for identifying candidate causal de novo variants in a cohort of children with heterogeneous sporadic epilepsies without etiologic diagnoses. METHODS: We performed WES (mean coverage approximately 40×) on 10 trios comprised of unaffected parents and a child with sporadic epilepsy characterized by difficult-to-control seizures and some combination of developmental delay, epileptic encephalopathy, autistic features, cognitive impairment, or motor deficits. Sequence processing and variant calling were performed using standard bioinformatics tools. A custom filtering system was used to prioritize de novo variants of possible functional significance for validation by Sanger sequencing. KEY FINDINGS: In 9 of 10 probands, we identified one or more de novo variants predicted to alter protein function, for a total of 15. Four probands had de novo mutations in genes previously shown to harbor heterozygous mutations in patients with severe, early onset epilepsies (two in SCN1A, and one each in CDKL5 and EEF1A2). In three children, the de novo variants were in genes with functional roles that are plausibly relevant to epilepsy (KCNH5, CLCN4, and ARHGEF15). The variant in KCNH5 alters one of the highly conserved arginine residues of the voltage sensor of the encoded voltage-gated potassium channel. In vitro analyses using cell-based assays revealed that the CLCN4 mutation greatly impaired ion transport by the ClC-4 2Cl(-) /H(+) -exchanger and that the mutation in ARHGEF15 reduced GEF exchange activity of the gene product, Ephexin5, by about 50%. Of interest, these seven probands all presented with seizures within the first 6 months of life, and six of these have intractable seizures. SIGNIFICANCE: The finding that 7 of 10 children carried de novo mutations in genes of known or plausible clinical significance to neuronal excitability suggests that WES will be of use for the molecular genetic diagnosis of sporadic epilepsies in children, especially when seizures are of early onset and difficult to control.