Journal of neuro-oncology
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Journal of neuro-oncology · May 2006
Retrospective analysis of the efficacy and tolerability of levetiracetam in brain tumor patients.
Seizures are a common complication of primary (PBT) and metastatic (MBT) brain tumors, affecting approximately 50% of all patients during the course of their illness. Anti-convulsant therapy of these tumor-induced seizures is often inadequate with conventional anti-epileptic drugs (AEDs), due to a variety of factors, including activation of glutaminergic NMDA receptors, immune-mediated neuronal damage, and anatomic alterations of neuronal input pathways. Levetiracetam (LEV) is a new AED with a novel mechanism of action, which includes reducing the Ca++ current through neuron-specific, high voltage activated Ca++ channels (n-type). ⋯ Overall, the seizure frequency was reduced in 90% of patients (P<0.0001; Sign test). The most common toxicity was somnolence, noted in 37% of patients. LEV was very effective and well tolerated in brain tumor patients with seizures, and should be considered for add-on therapy to current AEDs, or as a substitute anti-convulsant for monotherapy.
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Journal of neuro-oncology · May 2006
Comparative StudyImmunotoxin pharmacokinetics: a comparison of the anti-glioblastoma bi-specific fusion protein (DTAT13) to DTAT and DTIL13.
DTAT13, a novel recombinant bispecific immunotoxin (IT) consisting of truncated diphtheria toxin, an amino-terminal (AT) fragment of the urokinase-type plasminogen activator (uPa), and a fragment of human IL-13 was assembled in order to target receptors on glioblastoma multiforme (GBM) and its associated neovasculature. Previous in vitro studies confirmed the efficacy of DTAT13 against various GBM cell lines expressing both IL-13 receptor or uPA receptor, and previous in vivo testing demonstrated the efficacy of DTAT13 in significantly inhibiting a range of xenograft tumors and showed that DTAT13 was 160- and 8-fold less toxic to the parental fusion IT, DTAT and DTIL13, respectively. To further understand the properties of DTAT13, pharmacokinetic/biodistribution experiments were performed. ⋯ The rate of protein synthesis inhibition of DTAT13 was identical to that of DTIL13 in U373 MG cells. Intracranial biodistribution studies revealed that DTAT13 was able to cross to the contralateral hemisphere unlike DTIL13 but similar to DTAT. These studies show that DTAT13 has properties encompassing those of both DTIL13 and DTAT and warrants further consideration for clinical development.
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Journal of neuro-oncology · May 2006
Lactacystin exhibits potent anti-tumor activity in an animal model of malignant glioma when administered via controlled-release polymers.
Lactacystin, a proteasome-inhibitor, has been shown to induce apoptosis of experimental gliomas in vitro. However, its systemic toxicity prevents further clinical use. To circumvent this problem, lactacystin can be delivered intratumorally. ⋯ Polymers released lactacystin for 21 days and intracranial implantation in rats neither generate local nor systemic toxicity at doses lower than 2%. Treatment with lactacystin/pCPP : SA polymers with loading concentrations of 1.0, 1.3, and 1.5% prolonged survival of animals intracranially challenged with 9L when polymers where inserted in the day of tumor implantation. In conclusion, lactacystin exhibits potent cytotoxic-activity against 9L and F98 in vitro, it can be efficiently incorporated and delivered using controlled-release polymers, and at the proposed concentrations lactacystin polymers are safe for CNS delivery and prolong survival in the 9L model.