Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:5.99.1.2 (topoisomerase)
9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pharmacokinetically guided phase I study of topotecan and etoposide phosphate was conducted in recurrent ovarian cancer. The scheduling of the topoisomerase I and II inhibitors was determined using in vitro activity data. All patients had recurrent disease following prior platinum-containing chemotherapy. Patients had a World Health Organisation performance status of 0-2 and adequate bone marrow, renal and hepatic function. Treatment was with topotecan intravenously for 5 days followed immediately by a 5-day intravenous infusion of etoposide phosphate (EP), with pharmacokinetically guided dose adjustment. Plasma etoposide levels were measured on days 2 and 4 of the infusion. A total of 21 patients entered the study. In all, 48% were platinum resistant and 71% had received prior paclitaxel. The main toxicities were haematological, short lived and reversible. A total of 29% of patients experienced grade 4 thrombocytopenia and 66% grade 4 neutropenia after the first cycle. Neutropenia and thrombocytopenia was dose limiting. The maximum-tolerated dose was topotecan 0.85 mg m(-2) day(-1) days 1-5 followed immediately by a 5-day infusion of EP at a plasma concentration of 1 mug ml(-1). The response rate (RR) was 28% in 18 evaluable patients. There was marked interpatient variability in topoisomerase IIalpha levels measured from peripheral lymphocytes, with no observed increase following topotecan. This regimen of topotecan followed by EP demonstrated good activity in recurrent ovarian cancer and was noncrossresistant with paclitaxel. Both the toxicity and RR was higher than would be expected from the single agent data, in keeping with synergy of action.
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PMID:Pharmacokinetically guided phase I trial of topotecan and etoposide phosphate in recurrent ovarian cancer. 1595 76

The goal of this phase I study was to develop a novel schedule using oral etoposide and infusional topotecan as a continually alternating schedule with potentially optimal reciprocal induction of the nontarget topoisomerase. The initial etoposide dose was 15 mg m(-2) b.i.d. days (D)1-5 weeks 1,3,5,7,9 and 11, escalated 5 mg per dose per dose level (DL). Topotecan in weeks 2,4,6,8,10 and 12 was administered by 96 h infusion at an initial dose of 0.2 mg m(-2) day(-1) with a dose escalation of 0.1, then at 0.05 mg m(-2) day(-1). Eligibility criteria required no organ dysfunction. Two dose reductions or delays were allowed. A total of 36 patients with a median age of 57 (22-78) years, received a median 8 (2-19) weeks of chemotherapy. At DL 6, dose-limiting toxicities consisted of grade 3 nausea, vomiting and intolerable fatigue. Three patients developed a line-related thrombosis or infection and one subsequently developed AML. There was no febrile neutropenia. There were six radiologically confirmed responses (18%) and 56% of patients demonstrated a response or stable disease, typically with only modest toxicity. Oral etoposide 35 mg m(-2) b.i.d. D1-5 and 1.8 mg m(-2) 96 h (total dose) infusional topotecan D8-11 can be administered on an alternating continual weekly schedule for at least 12 weeks, with promising clinical activity.
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PMID:A phase I clinical trial of continual alternating etoposide and topotecan in refractory solid tumours. 1598 34

Irinotecan is a topoisomerase I inhibitor that is highly active against small cell lung cancer (SCLC). Etoposide is another drug that is effective for SCLC. Since combination of these two topoisomerase inhibitors revealed a synergistic effect in vitro and showed a safety in phase I study, we conducted a phase II study in patients with previously un-treated extensive disease (ED) SCLC to evaluate the efficacy and toxicity of this combination. Fifty patients with previously untreated ED-SCLC were enrolled. Irinotecan was administered intravenously at 60mg/m(2) on days 1, 8, and 15, while etoposide was given at 80mg/m(2) on days 2-4. Treatment was repeated every 4 weeks for four cycles. The overall response rate was 66.0%, with a complete response rate of 10.0%. The median survival time was 11.5 months and the 1- and 2-year survival rates were 43.2 and 14.4%, respectively. The major toxicity of this regimen was myelosuppression, including grade 3 or 4 neutropenia (62.9%), leukopenia (28.0%), and anemia (14%). The other grade 3 toxicity was diarrhea (2%). This irinotecan and etoposide regimen is active against ED-SCLC with relatively mild toxicity.
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PMID:Irinotecan and etoposide for previously untreated extensive-disease small cell lung cancer: a phase II trial of West Japan Thoracic Oncology Group. 1602 21

Camptothecins represent an established class of effective agents that selectively target topoisomerase I by trapping the catalytic intermediate of the topoisomerase I-DNA reaction, the cleavage complex. The water-soluble salt camptothecin-sodium - introduced in early trials in the 1960s - was highly toxic in animals, whereas the semisynthetic derivatives irinotecan and topotecan did not cause haemorrhagic cystitis because of their higher physicochemical stability and solubility at lower pH values. Myelosuppression, neutropenia and, to a lesser extent, thrombocytopenia are dose-limiting toxic effects of topotecan. In contrast to the structurally-related topotecan, irinotecan is a prodrug which has to be converted to SN-38, its active form. SN-38 is inactivated by conjugation, thus patients with Gilbert's syndrome and other forms of genetic glucuronidation deficiency are at an increased risk of irinotecan-induced adverse effects, such as neutropenia and diarrhoea. The cytotoxic mechanism of podophyllotoxin is the inhibition of topoisomerase II. Common adverse effects of etoposide include dose-limiting myelosuppression. Hypersensitivity reactions are more common with etoposide and teniposide than with etoposide phosphate because the formulations of the former contain sensitising solubilisers. Leukopenia and thrombocytopenia occur in 65% and 80%, respectively, of patients after administration of conventional doses of teniposide. Anorexia, vomiting and diarrhoea are generally of mild severity after administration of conventional doses of topoisomerase II inhibitors. Clinical pharmacokinetic studies have revealed substantial interindividual variabilities regarding the area under the concentration-time curve values and steady-state concentrations for all drugs reviewed in this article. Irinotecan, etoposide and teniposide are degraded via complex metabolic pathways. In contrast, topotecan primarily undergoes renal excretion. Regarding etoposide and teniposide, the extent of catechol formation over time during drug metabolism may be associated with a higher risk for secondary malignancies.
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PMID:Camptothecin and podophyllotoxin derivatives: inhibitors of topoisomerase I and II - mechanisms of action, pharmacokinetics and toxicity profile. 1652 21

Rebeccamycin analog (NSC 655649) is a synthetic antibiotic cytotoxic agent thought to inhibit topoisomerase function. We sought to determine the response rate to rebeccamycin analog among patients with refractory advanced breast cancer using two different treatment schedules. Eligible patients had measurable disease, central venous access, and one or two prior chemotherapy regimens for advanced cancer, or recurrence within 12 months of adjuvant chemotherapy. Patients were randomized to rebeccamycin analog on one of two treatment schedules: arm 1, 500 mg/m2 IV bolus every 21 days; arm 2, 140 mg/m2 IV bolus daily x 5 days, every 21 days. The primary study endpoint was response rate; a two stage accrual design evaluated each schedule separately. Forty-two women entered the trial, 21 on each arm. Prior chemotherapy regimens for metastatic breast cancer were: 0, n=4; 1, n=21; 2, n=17. Prior treatments (including adjuvant therapy) anthracyclines: 88%, taxanes 67%, 5FU-based therapy, 50%. There were 5 partial responses (overall response rate 12%), two in arm 1 and 3 in arm 2, all in patients with prior anthracycline-based adjuvant chemotherapy. Median time to progression was 2.1 months (range 1-14+ months). An additional 9 patients had stable disease as best response. Grade 3 or 4 toxicity rates were: anemia 5%, neutropenia 33%, thrombocytopenia 12%, RBC transfusion 14%, nausea/vomiting 10%. Toxicity profiles were similar between the treatment arms. Rebeccamycin analog is reasonably well tolerated on two different treatment schedules for advanced breast cancer, with modest clinical activity in this heavily pretreated population.
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PMID:Rebeccamycin analog for refractory breast cancer: a randomized phase II trial of dosing schedules. 1696 7

The inhibition of topoisomerase I by topotecan results in a compensatory increase in topoisomerase II associated with increased in vitro sensitivity of tumors to etoposide. Maximal synergy has been observed for the sequence of topotecan followed by etoposide. Carboplatin has clinical activity when combined with either of these two agents. These interactions were the pharmacologic rationale for topotecan p.o. days 1-5, carboplatin i.v. day 6, and etoposide p.o. days 6-10. Three successive dose levels were explored: (1) topotecan 2mg/day, carboplatin AUC 5, etoposide 150 mg/day; (2) topotecan 3mg/day, carboplatin AUC 5, etoposide 150 mg/day; and (3) topotecan 3mg/day, carboplatin AUC 5, etoposide 200mg/day. Filgrastim 5 microg/kg/day was injected s.c. days 11-18. Up to 6 cycles were administered every 21 days. Eligible patients had measurable or evaluable, extensive disease, small lung cell lung cancer, no prior chemotherapy, ECOG performance status 0-2, and adequate hematologic, renal, and hepatic function. Follow-up was weekly for CBC. Tumor response was assessed after 2 and 6 cycles. Dose limiting toxicity (DLT) was defined as any of the following in cycle 1: grade 3 or 4 non-hematologic toxicity other than nausea and vomiting, grade 4 neutropenia lasting more than 3 days, neutropenic fever or sepsis, grade 4 thrombocytopenia, or failure to recover neutrophils >or=1500/microl or platelets >or=100,000/microl by day 28. Ten patients were enrolled: median age 62 (range, 50-79); female/male 4/6; and performance status 0/1/2 in 2/7/1. Three patients each were treated on dose levels 1 and 2 without DLT. The first 2 patients entered on dose level 3 had no DLT. The third patient on dose level 3 developed grade 4 neutropenia lasting more than 3 days, neutropenic fever, and grade 4 thrombocytopenia on day 15 of cycle 1. The fourth patient on dose level 3 developed grade 4 thrombocytopenia on day 18 of cycle 1. One patient received only 1 cycle and was not evaluable for response. Seven patients completed 6 cycles: 1 had a complete response and 6 achieved a partial response. The third patient on dose level 3 received 2 cycles and had stable disease, but had to be removed from protocol treatment because of grade 4 neutropenia despite dose reduction in cycle 2. The fourth patient on dose level 3 achieved a partial response, but had to be removed from protocol therapy after cycle 5 because of recurrent grade 4 thrombocytopenia. In conclusion, neutropenia and thrombocytopenia were dose-limiting. The maximum tolerated dose (MTD) is topotecan 3mg/day p.o. days 1-5, carboplatin AUC 5i.v. day 6, and etoposide 150 mg/day p.o. days 6-10 with filgrastim.
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PMID:Phase I and pharmacologic study of sequential topotecan-carboplatin-etoposide in patients with extensive stage small cell lung cancer. 1704 3

The topoisomerase I agents are established as a therapy in recurrent ovarian cancer. Karenitecin, an analog of topotecan with solubility and pharmacologic advantages, was tested in a phase II trial in previously treated patients with recurrent or persistent ovarian cancer. The drug was administered intravenously over 1 h at a dose of 1.0 mg/m(2) daily for 5 days every 21 days. Patients were treated until disease progression, intolerable toxicity, or voluntary withdrawal. Response was evaluated according to modified RECIST criteria. Twenty-seven patients were entered into the study. One patient was inevaluable for not receiving any treatment. Of the 26 evaluable patients, there were two partial responses and one complete response for a total response rate of 12%. This response rate was insufficient to justify accrual to the second stage. The most common grade 3 or 4 toxicities were neutropenia (19%) and gastrointestinal (15%). Karenitecin is a well-tolerated topoisomerase compound but has minimal activity in extensively pretreated ovarian cancer with the dose-schedule employed.
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PMID:Phase II multicenter open-label study of karenitecin in previously treated epithelial ovarian and primary peritoneal cancer: a Gynecologic Oncology Group Study. 1785 32

Combination of platinum with topoisomerase-I inhibitors are synergistic. The objectives of this study were to determine MTD range and toxicity profile of combinations of oral 9-nitrocamptothecin (9NC) and intravenous cisplatin in patients with refractory solid tumors. Each course was 28 days starting on day 1 with cisplatin, and then 9NC daily for 5 days/week for three weeks. A new two arm crossing design was created: patients in arm 1 were treated with at the single agent recommended dose of cisplatin (50 mg/m(2)), and increasing doses of 9NC and in arm 2 with the single agent recommended dose of 9NC (1.5 mg/day) and increasing dose of cisplatin. Once a dose limiting toxicity was observed, the dose of the escalated drug was decreased by one level, and the fixed-dose drug was then escalated. A 3 + 3 design was used. Eligibility criteria were standard for a phase I trial. Pharmacokinetics was performed. Eighteen patients were treated on Arm 1, 3 at the crossing level, and 33 on Arm 2. Dose limiting toxicities were gastrointestinal at the crossing dose level. After crossing, prolonged grade 3 thrombocytopenia was the DLT in arm 1, and grade 4 neutropenia in Arm 2. Only one patient with ovarian cancer had a partial remission, and 12 patients had disease stabilization (24% of clinical benefit). A Bayesian optimal dose finding was tested post-facto. The recommended doses for phase II studies by the 3 + 3 design are cisplatin 60 mg/m(2) and 9NC 1.25 mg/day and cisplatin 40 mg/m(2) and 9NC 2.0 mg/day. The Bayesian optimal dose finding suggested a different solution, closest to that of the latter dosing which may be less toxic.
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PMID:Optimal modeling for phase I design of a two drug combination-results of a phase I study of cisplatin with 9-nitrocamptothecin. 1860 Mar 1

Belotecan (Camtobell, CKD602) is a new camptothecin derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this phase II study was to evaluate the efficacy and safety of single agent belotecan in patients with small cell lung cancer (SCLC). Patients with previously untreated extensive stage disease (ED) SCLC were entered into the study. Belotecan was given by daily intravenous infusion at 0.5mg/m(2)/day for 5 consecutive days, every 3 weeks. 62 patients were enrolled in this study. The overall response rate to chemotherapy on an intention-to-treat basis was 53.2%. The median overall survival was 10.4 months, the median time to progression 4.6 months, and the 1-year survival rate 49.9%. The most common toxicity was hematologic. Grade 3/4 neutropenia occurred in 71.0% of patients and grade 3/4 thrombocytopenia 12.9%. Non-hematologic toxicity of grade 3 or 4 was low. The results suggest that belotecan is relatively active and well tolerable as single agent in patients with ED SCLC. Further investigations with platinum or other active agents are needed.
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PMID:A multicenter phase II study of belotecan, new camptothecin analogue, in patients with previously untreated extensive stage disease small cell lung cancer. 1968 59

Belotecan (Camtobell, CKD602) is a new camptothecin derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this phase II study was to evaluate the efficacy and safety of single agent belotecan as a second-line therapy in patients with small cell lung cancer (SCLC). Patients who were previously treated for SCLC were entered into the study. Belotecan was given by daily intravenous infusion for five consecutive days, every three weeks. Twenty-five patients were enrolled in this study. On an intention-to-treat basis, belotecan induced an overall response rate of 24%, a median overall survival of 9.9 months, a median time to progression of 2.2 months, and a 1-year survival rate of 38.3%. Grade 3/4 neutropenia developed in 88.0% of patients and grade 3/4 thrombocytopenia in 40.0%. Nonhematologic toxicity of grade 3 or 4 was low. The results suggest that belotecan is relatively active and well tolerated as a second-line agent in patients with SCLC.
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PMID:A multicenter phase II study of belotecan, a new camptothecin analogue, as a second-line therapy in patients with small cell lung cancer. 2083 94


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