Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of temozolomide combined with irinotecan (CPT-11) was evaluated against eight independent xenografts (four neuroblastomas, three rhabdomyosarcomas, and one glioblastoma). In all studies, temozolomide was administered p.o. daily for 5 consecutive days/cycle, found in preliminary studies to be the optimal schedule for administration. Irinotecan was administered i.v. for 5 days for 2 consecutive weeks/cycle. Treatment cycles were repeated every 21 days for a total of three cycles over 8 weeks. In combination, temozolomide and CPT-11 induced complete responses in four neuroblastomas, two rhabdomyosarcomas, and the glioblastoma line. The activity of the combination was significantly greater than the activity of either agent administered alone in four tumor lines. Of interest, the interaction appeared independent of tumor MGMT or mismatch repair phenotype, suggesting that the mechanism of synergy may be independent of O6-methylation by temozolomide. Pharmacokinetic studies indicated no detectable interaction between these two agents. Further, coadministration of CPT-11 appeared to reduce the toxicity of temozolomide in tumor-bearing mice.
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PMID:Antitumor activity of temozolomide combined with irinotecan is partly independent of O6-methylguanine-DNA methyltransferase and mismatch repair phenotypes in xenograft models. 1105 Dec 64

Overexpression of the MDM2 oncogene is one of the molecular characteristics of gliomas. In this study we determined the therapeutic effects of an antisense anti-MDM2 oligonucleotide administered alone or in combination with the clinically used chemotherapeutic agents Paclitaxel and Irinotecan. In cultured cells with various p53 status, U87-MG (p53wt/wt), A172 (p53wt/mt) and T98G (p53mt/mt), the antisense oligonucleotide, produced a dose- and sequence-dependent reduction in MDM2 expression and elevation in p53 (in U87-MG and A172 cells) and p21 levels (in all three cell lines), resulting in an increase in apoptosis and cytotoxicity. Synergistic effects on p53 and p21 levels between the oligonucleotide and chemotherapeutic agents were also observed in vitro. In in vivo studies with U87-MG xenografts, the oligonucleotide inhibited tumor growth and improved the therapeutic efficacy of paclitaxel and irinotecan 39- and 63-fold, respectively. In conclusion, inhibiting MDM2 expression could be a novel pharmacological approach to glioblastoma therapy.
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PMID:Antisense anti-MDM2 oligonucleotides as a novel approach to the treatment of glioblastoma multiforme. 1201 71

This phase I study was conducted to determine the dose-limiting toxicity, maximum tolerated doses, and recommended phase II doses of the combination of irinotecan (CPT-11, Camptosar) and temozolomide (Temodar). Patients have received irinotecan and temozolomide on one of three different dosing schedules: (1) oral temozolomide on days 1-14 plus a single i.v. dose of irinotecan on day 8 every 28 days (arm 1); (2) weekly i.v. irinotecan on days 1, 8, 15, and 22 plus oral temozolomide on days 1-7 and 15-21 every 42 days (arm 2); and (3) every-other-week i.v. irinotecan on days 1 and 15 plus oral temozolomide on days 1-7 and 15-21 every 28 days (arm 3). A total of 49 patients have received 112+ cycles of therapy on all three dosing schedules to date. Dose-limiting toxicity consisting of diarrhea, neutropenia, and thrombocytopenia was encountered at a temozolomide dose of 125 mg/m2/d and an irinotecan dose of 250 mg/m2 on treatment arm 1. As a result, the protocol has been amended to explore lower doses of temozolomide in combination with higher doses of irinotecan, and patient accrual is currently continuing. Dose-limiting grade 3 diarrhea, nausea, and vomiting were reported in 7/12 patients enrolled on the two dose levels explored on treatment arm 2, so this dosing regimen was considered intolerable. Patient accrual currently continues at dose level 1 of treatment arm 3, so it is too early to determine dose-limiting toxicities and recommended phase II doses for this treatment schedule. Two partial responses have been reported to date in patients with glioblastoma and head and neck cancer, respectively. One evaluable response has also been observed in a patient with metastatic colorectal cancer. Irinotecan weekly x 4 plus temozolomide on days 1-7 and 15-21 is intolerable due to the development of dose-limiting gastrointestinal toxicities. The recommended phase II doses of irinotecan and temozolomide on treatment arms 1 and 3 remain to be determined as patient accrual is currently ongoing.
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PMID:Phase I. Trial of irinotecan and temozolomide in patients with solid tumors. 1280 Jun 6

Irinotecan (CPT-11) is a chemotherapeutic drug used to treat tumors by acting on malignant cells through inhibition of DNA topoisomerase I and inducing premature apoptosis. Major toxic effects of Irinotecan are myelosuppression and gastrointestinal (GI) toxicity, which limits the dose of administration, particularly severe diarrhea with a delay of onset. However, according to the literature, serious GI side effects are uncommon, comprising 3% of the reported cases. The mechanism of Irinotecan-induced delayed diarrhea is unknown and unpredictable. To our knowledge, this is the first case of colitis associated with Irinotecan administration for temporal glioblastoma documented by biopsies. The histopathologic findings are described and the potential mechanisms inducing such lesions are discussed.
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PMID:Irinotecan-induced colitis. 1586 88

Resistance to radiation and chemotherapy remains an obstacle to the treatment of brain tumors. We have demonstrated that the replication-deficient adenovirus d1520, which lacks the E1A 13S protein, replicates efficiently and exhibits oncolytic potential in multidrug-resistant cells with nuclear localization of the human transcription factor YB-1. However, besides others, key factors regarding oncolytic virotherapy are limited tumor transduction rate and low replication efficiency. The objective of this study was to determine whether the chemotherapeutic agent irinotecan, by enhancing nuclear localization of YB-1, and the histone deacetylase inhibitor trichostatin A, by upregulating coxsackievirus-adenovirus receptor (CAR) expression, could augment replication of and cell lysis by adenovirus dl520 in glioblastomas in vitro. We found that trichostatin A upregulated CAR expression and that irinotecan caused increased nuclear localization of YB-1 in both glioblastoma cell lines. Irinotecan alone, and trichostatin A alone, enhanced replication of and cell lysis by dl520. Importantly, when combining both agents, the replication efficiency (maximum, 27-fold) and induction of cytopathic effect (maximum, 3.8-fold) of dl520 were further augmented significantly. These results support the hypothesis that the enhanced oncolytic effect of dl520, after incubation with chemotherapeutic agents, is mediated by an increased accumulation of YB-1 in the nucleus (due to irinotecan) and by upregulation of CAR (due to trichostatin A). Thus, therapy combining virotherapy, chemotherapy, and histone deacetylase inhibitor treatment is a novel approach to enhance the oncolytic efficacy of dl520.
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PMID:Novel three-pronged strategy to enhance cancer cell killing in glioblastoma cell lines: histone deacetylase inhibitor, chemotherapy, and oncolytic adenovirus dl520. 1640 25

Treatment of malignant glioma requires a multidisciplinary team. Treatment includes surgery, radiotherapy, and chemotherapy. Recently developed agents have demonstrated activity against recurrent malignant glioma and efficacy if given concurrently with radiotherapy in the upfront setting. Oligodendroglioma with 1p/19q deletions has been recognized as a distinct pathologic entity with particular sensitivity to radiotherapy and chemotherapy. Randomized trials have shown that early neoadjuvant or adjuvant administration of procarbazine, lomustine, and vincristine chemotherapy prolongs disease-free survival; however, it has no impact on overall survival. Temozolomide, a novel alkylating agent, has shown modest activity against recurrent glioma. In combination with radiotherapy in newly diagnosed patients with glioblastoma, temozolomide significantly prolongs survival. Molecular studies have demonstrated that the benefit is mainly observed in patients whose tumors have a methylated methylguanine methyltransferase gene promoter and are thus unable to repair some of the chemotherapy-induced DNA damage. For lower-grade glioma, the use of chemotherapy remains limited to recurrent disease, and first-line administration is the subject of ongoing clinical trials. Irinotecan and agents like gefitinib, erlotinib, and imatinib targeting the epidermal growth factor receptor and platelet-derived growth factor receptor have shown some promise in recurrent malignant glioma. This review summarizes recent developments, focusing on the clinical management of patients in daily neuro-oncology practice.
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PMID:Changing paradigms--an update on the multidisciplinary management of malignant glioma. 1647 37

Malignant glioma is the most commonly occurring primary malignant brain tumor. It is difficult to treat and is usually associated with an inexorable, rapidly fatal clinical course. Chemotherapy, radiotherapy, and surgical excision are core components in the management of malignant glioma. However, chemotherapy, even with the most active regimens currently available, achieves only modest improvement in overall survival. Novel agents and new approaches to therapy are required to improve clinical outcomes. Irinotecan, a first-line treatment for metastatic colorectal cancer and an agent with high activity against solid tumors of the gastrointestinal tract, is an inhibitor of topoisomerase I, a critical enzyme needed for DNA transcription. Irinotecan crosses the blood-brain barrier and, in preclinical investigations, has demonstrated cytotoxic activity against central nervous system tumor xenografts. Its antitumor activity has also been demonstrated against glioblastoma cells with multidrug resistance. Studies in adult and pediatric patients with recurrent, intractable malignant glioma have evaluated irinotecan as monotherapy and in combination with other agents, including temozolomide, carmustine, thalidomide, and bevacizumab. Studies of irinotecan in combination with other medications, particularly temozolomide and bevacizumab, have yielded promising results. Irinotecan monotherapy has demonstrated efficacy; however, its efficacy appears to be enhanced when used in combination with other chemotherapeutic agents. When administered concurrently with enzyme-inducing antiepileptic drugs, the dosage must be increased to compensate for enhanced cytochrome CY3A4/5 enzyme activity. Toxicities associated with irinotecan have been manageable; the most important dose-limiting toxicities are neutropenia and diarrhea. Irinotecan-based chemotherapy of malignant glioma merits further study.
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PMID:Experience with irinotecan for the treatment of malignant glioma. 1878 79

High grade primary CNS gliomas hold some of the worst prognoses of any malignancy, with the vast majority of patients dying within two years of diagnosis, even with aggressive modern treatments. Surgical resection and radiotherapy are cornerstones of treatment when possible. In spite of many years of research, only recently has management with chemotherapy been able to prolong survival in patients with high grade gliomas, albeit only modestly at best. Topoisomerase I (TOP1) inhibitors target an enzyme critical for DNA replication and cell-cycle progression; they cross the blood-brain barrier and have antitumor activity against glioblastoma cells in vitro. The most frequently associated toxicities are neutropenia and diarrhea, but are often manageable. The two most used agents are irinotecan and topotecan. Due to enhanced cytochrome CY3A4/5 enzyme activity, irinotecan dose must be adjusted with concomitant enzyme-inducing antiepileptic drug usage; the data is less clear regarding the effects on topotecan. Clinical trials in patients with recurrent malignant glioma have evaluated TOP1 inhibitors as monotherapy and in combination with other agents. There is evidence for using topotecan with radiotherapy. Irinotecan has limited efficacy as monotherapy, but shows promise in combination with other agents, particularly temozolomide and bevacizumab. Newer generation TOP1 inhibitors are currently being evaluated in phase I trials. TOP1 inhibitors show promising activity in patients with primary CNS malignancies and warrant further study.
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PMID:Topoisomerase I inhibitors in the treatment of primary CNS malignancies: an update on recent trends. 2123 38

Antiangiogenic treatment has recently become an integral part of modern cancer therapy targeting the vasculature of numerous aggressive malignancies including glioblastoma. There is preclinical evidence that antiangiogenic therapies promote glioma cell invasiveness. In clinical series, upon progression on antiangiogenic therapy with the vascular endothelial growth factor-directed antibody bevacizumab (BEV), glioblastoma has been reported to display a more infiltrative pattern of recurrence. This distant spread at recurrence or progression and a gliomatosis cerebri-like growth pattern is best detectable on fluid-attenuated inversion recovery MRI. The frequency of up to 20% to 30% of such a pattern in BEV-treated patients is higher than expected to occur without BEV. Older reports and common clinical knowledge estimate the frequency of diffuse or distant spread in recurrent glioblastoma at 10%. This observation stimulated two streams of research. One is to overcome this often insidious adverse effect of antiangiogenic treatment, to optimize antiangiogenic therapies and to face this major challenge, integrating antiangiogenic with anti-invasive mechanisms into one combined treatment concept. The second is questioning a specific property of antiangiogenic therapy to induce diffuse or distant spread. Here, alternative hypotheses of increased awareness and better imaging as well as invasiveness being part of the natural course of the disease have been tested. Without doubt, migration and invasiveness are major obstacles to successful glioma therapy, notably local therapies, both in the natural course of the disease and in the concept of "evasive resistance." However, clinical analyses of case series, matched pairs analyses, and follow-up on the BRAIN trial (A Study to Evaluate Bevacizumab Alone or in Combination with Irinotecan for Treatment of Glioblastoma Multiforme), which led to accelerated approval of BEV for recurrent glioblastoma in the United States, have not supported a specific propensity of BEV to induce diffuse growth or distant spread at recurrence.
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PMID:Patterns of progression in malignant glioma following anti-VEGF therapy: perceptions and evidence. 2127 15

We determined the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of the oral vascular endothelial growth factor receptor (VEGFR) inhibitor, sunitinib, when administered with irinotecan among recurrent malignant glioma (MG) patients. For each 42-day cycle, sunitinib was administered once a day for four consecutive weeks followed by a 2 week rest. Irinotecan was administered intravenously every other week. Each agent was alternatively escalated among cohorts of 3-6 patients enrolled at each dose level. Patients on CYP3A-inducing anti-epileptic drugs were not eligible. Twenty-five patients with recurrent MG were enrolled, including 15 (60%) with glioblastoma (GBM) and 10 (40%) with grade 3 MG. Five patients progressed previously on bevacizumab and two had received prior VEGFR tyrosine kinase inhibitor therapy. The MTD was 50 mg of sunitinib combined with 75 mg/m(2) of irinotecan. DLT were primarily hematologic and included grade 4 neutropenia in 3 patients and one patient with grade 4 thrombocytopenia. Non-hematologic DLT included grade 3 mucositis (n = 1) and grade 3 dehydration (n = 1). Progression-free survival (PFS)-6 was 24% and only one patient achieved a radiographic response. The combination of sunitinib and irinotecan was associated with moderate toxicity and limited anti-tumor activity. Further studies with this regimen using the dosing schedules evaluated in this study are not warranted.
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PMID:Phase I study of sunitinib and irinotecan for patients with recurrent malignant glioma. 2174 79


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