Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Topoisomerase I represents a unique new target that can be exploited for development of new antineoplastic agents. There are now two new topoisomerase I inhibitors that are in early clinical trials that have generated a tremendous amount of interest. Topotecan (SKF 104864-A) is a topoisomerase I inhibitor that has been explored in phase I trials using a variety of dosages and schedules. The dose-limiting toxicity of the agent is neutropenia. Other toxicities include alopecia, very mild nausea and vomiting, anemia, and occasional fever. Responses have already been noted in patients with advanced, refractory ovarian cancer and non--small-cell lung cancer. The drug is currently undergoing intense phase II testing. Irinotecan (CPT-11) is also a topoisomerase I inhibitor, which has already undergone extensive phase I and early phase II clinical testing in both Japan and the United States. Dose-limiting toxicities of the agent have included neutropenia and diarrhea. Responses have been noted in patients with refractory colorectal cancer, non--small-cell lung cancer, lymphoma, ovarian cancer, head and neck cancer, pancreatic cancer, and breast cancer. There is no doubt both of these agents will be important additions to our chemotherapy armamentarium.
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PMID:Clinical trials with the topoisomerase I inhibitors. 133 79

CPT-11 is a semisynthesized derivative of camptothecin that has a potent antitumor activity by inhibiting DNA topoisomerase I. Leukopenia (mainly neutropenia) is DLF (dose limiting factor) and MTD (maximum tolerated dose) is higher than 250 mg/m2 in CPT-11 from the results of clinical phase I study. Now we are going on phase II study of CPT-11. We are seeing the cases responded to the drug in cancer of the lung, ovary, uterus, stomach, colorectum, pancreas, breast, malignant lymphoma etc.
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PMID:[DNA topoisomerase inhibitor as chemotherapeutic drug--clinical point of view]. 165 85

Topoisomerase I inhibitors are a new therapeutic class whose clinical evaluation began a few years ago; Irinotecan (CPT-11) gave interesting results in colon cancer; side effects were neutropenia, diarrhea, vomiting and a cholinergic syndrome. Topotecan was useful in lung and ovarian cancer; side effects were mostly hematologic. Undergoing studies concern dose optimization, mode of administration and therapeutic associations.
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PMID:[Topoisomerase I inhibitors. Review of phase II trials with irinotecan (CPT-11) and topotecan]. 749 18

The camptothecin analogues topotecan and irinotecan (CPT-11) are active anticancer drugs. This article reviews the accumulated results of clinical and laboratory studies performed with these agents at The Johns Hopkins Oncology Center. In a phase I clinical and pharmacology trial of topotecan given as a 30-min infusion daily for 5 days every 3 weeks, profound neutropenia precluded dose escalation above 1.5-2.0 mg/m2 per day, the maximum tolerated dose (MTD). The daily x5 schedule has been developed further with dose escalation using granulocyte-colony-stimulating factor support in patients who have kidney or liver dysfunction and given in combination with cisplatin. In addition, a phase I trial of topotecan given as a 5-day continuous intravenous infusion to patients with refractory leukemia has had promising antileukemic responses. A separate series of in vitro studies indicates that a modest degree of resistance to the cytotoxicity of topotecan can be mediated by P-glycoprotein. A phase I and pharmacology study of irinotecan given as a 90-min infusion every 3 weeks has defined an MTD of 240 mg/m2, with dose escalation being limited by several toxicities. These included an acute treatment-related syndrome of flushing, warmth, nausea, vomiting, and diarrhea; a subacute combination of nausea, diarrhea, anorexia, and weight loss; and/or neutropenia. Antitumor activity has been observed with topotecan and irinotecan in patients with a variety of solid tumors and refractory leukemia in our studies, which supports the widespread enthusiasm for this group of compounds.
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PMID:Camptothecin analogues: studies from the Johns Hopkins Oncology Center. 752 Aug 44

Camptothecin is a natural product derived from the Oriental tree Camptotheca acuminata which has shown activity in a number of experimental tumors. Its clinical development was halted in the early-70s owing to its unpredictable and formidable toxicities. Two water-soluble camptothecin analogs have been synthesized recently and are currently in clinical trials: topotecan and CPT-11. Camptothecin and its derivatives are unique in that they represent the only family of topoisomerase I inhibitors. Topoisomerase I is a nuclear enzyme which modulates the topological structure of DNA by making transient single-stranded breaks. Pre-clinical studies have shown that CPT-11 and topotecan possess high and broad antitumor activity against a variety of experimental tumors including both non-small cell lung cancer (NSCLC) and small cell lung cancer. Lack of cross-resistance with most classical anticancer agents has been also demonstrated. Phase I studies have identified neutropenia to be the dose-limiting toxicity for topotecan while, for CPT-11, either neutropenia or diarrhoea were dose-limiting. Maximum Tolerated Doses (MTD) of both agents are greatly dependent upon the schedule used. A Phase II Japanese study of CPT-11 in advanced untreated NSCLC has been recently published. Given at the dose of 100 mg/m2 as a 90-min infusion, CPT-11 produced a 32% objective response rate out of 72 assessable untreated patients. Similar studies are in progress with topotecan. The same Japanese group has completed Phase I-II studies on the combination of CPT-11 with cisplatin. The optimal dose of CPT-11, which can be safely combined with cisplatin 80 mg/m2, was found to be 60 mg/m2.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Camptothecin analogues in the treatment of non-small cell lung cancer. 755 27

A total of three topoisomerase I inhibitors, including topotecan, CPT-11 (irinotecan), and intoplicine, have been studied in both preclinical and clinical/clinical pharmacology studies. In in vitro testing against human tumor colony-forming units, all three compounds were significantly more effective when tested as a continuous exposure as compared with a 1-h exposure. The dose-limiting toxicities were different for all three of the agents, with neutropenia and thrombocytopenia being dose-limiting for topotecan; diarrhea, for CPT-11; and hepatotoxicity, for intoplicine. In these phase I studies a number of marginal responses were noted with topotecan; partial and marginal responses, with CPT-11 (particularly in patients with colon cancer); and no response, with intoplicine. The detailed pharmacology of all three agents documented a very short half-life for topotecan, an intermediate half-life for CPT-11, and a prolonged half-life for intoplicine. Based on our experience to date, these compounds (particularly CPT-11) have promise as useful additions to our tremendous therapeutic armamentarium.
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PMID:Preclinical and phase I trials of topoisomerase I inhibitors. 807 26

An early phase II study of irinotecan (CPT-11) in patients with advanced or recurrent breast cancer was undertaken by a cooperative study group of 15 institutes in Japan. CPT-11 was administered by intravenous drip-infusion. The administration schedules were 100 mg/m2 weekly (regimen A), 150 mg/m2 biweekly (regimen B), and 200 mg/m2 every 3-4 weeks (regimen C). There were 4 partial responses (PRs), 12 cases with no changes (1 minor response) and 9 cases of progressive diseases with a response rate of 16% (4/25). One out of 7 patients on regimen A and 3 patients out of 15 patients on regimen C achieved PR with a response rate of 14% and 20%, respectively. In three out of 4 PRs, prior chemotherapy, endocrinotherapy or radiotherapy had failed. Major adverse reactions were leukopenia 28/33 (85%), neutropenia 19/25 (76%), anemia 15/33 (46%), nausea/vomiting 28/33 (85%), anorexia 25/33 (76%), diarrhea 22/33 (67%) and alopecia 20/33 (61%). The incidence of leukopenia and thrombocytopenia seemed to be higher in regimen C than regimen A, and diarrhea was also more severe in regimen C than regimen A. The recovery of leukopenia was delayed in some patients on regimen C. The results suggested that CPT-11 was effective against advanced or recurrent breast cancer. The recommended administration schedule for a late phase II study was thought to be 100 mg/m2 weekly, considering efficacy and safety.
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PMID:[An early phase II study of CPT-11 (irinotecan hydrochloride) in patients with advanced breast cancer]. 829 19

The nuclear enzyme topoisomerase I (topo I) has been recently recognized as the target for the anticancer drug camptothecin (CPT) and its derivatives. Two of the agents that target this enzyme--topotecan (TPT) and CPT-11--appear to be active against a broad range of human tumors. In the following presentation, we review 1) the role of topo I in normal cells, 2) the chemistry and proposed mechanism of action of CPT and its analogues, 3) the results of preclinical and clinical testing of TPT and CPT-11, and 4) mechanisms of resistance to these agents. In normal cells, topo I is thought to be involved in gene transcription and DNA replication. During the course of its normal catalytic cycle, topo I transiently forms a covalent bond with DNA. CPT and its derivatives slow the religation step of the enzyme and stabilize the covalent adduct between topo I and DNA. In S-phase cells, advancing replication forks convert these topo I-DNA adducts into double-strand breaks that appear to be responsible for the cytotoxicity of these agents. Preclinical studies demonstrate antineoplastic activity for TPT and CPT-11 in a variety of tumor models. Phase I studies have identified neutropenia as the dose-limiting toxicity for both drugs. Gastrointestinal effects might also be dose-limiting for CPT-11 administered on some schedules. CPT-11 has shown antitumor activity in phase II trials for patients with carcinomas of lung, cervix, ovary, colon, and rectum and for patients with non-Hodgkin's lymphoma. Phase II studies of TPT are in progress. Resistance to the cytotoxic effects of these agents might result from decreased production of topo I or from production of a mutated form of topo I. In addition, decreased metabolic activation of CPT-11 (which is a pro-drug) and active efflux of TPT by P-glycoprotein-mediated transport might contribute to resistance. As agents with a novel mechanism of action, tolerable toxicity, and encouraging antitumor activity in early clinical trials, TPT and CPT-11 are undergoing further clinical development. If these agents can be successfully combined with other active chemotherapy agents, the topo I-directed agents offer the potential for significant advances in the treatment of patients with a variety of malignancies.
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PMID:The current status of camptothecin analogues as antitumor agents. 838 Nov 86

Irinotecan hydrochloride (CPT-11), topotecan, sobuzoxane, NC-190, and IST-622 are unique topoisomerase inhibitors and are investigational in Japan. CPT-11 is a water-soluble, semisynthetic derivative of camtothecin. CPT-11 shows its anticancer activity by inhibiting topoisomerase I activity, now a target of anticancer agents with major interest. Recent clinical trials reveal that CPT-11 is very effective in the treatment of cancer including lung cancer, cervical cancer, ovary cancer, stomach cancer, colon cancer, and non-Hodgkin's lymphoma. Major dose limiting toxicities are leukopenia and diarrhea, and are dose related. Topotecan is an another semisynthetic derivative of camtothecin and is also topoisomerase I inhibitor. Topotecan has undergone phase I clinical evaluations in USA, europe, and recently in Japan. DLF are leukopenia and neutropenia. Topotecan is more hydrophilic than its parent compound and shows lesser protein binding. Renal excretion appears to be the major route of elimination. Sobuzoxane (MST-16) is a unique derivative of dioxopiperazine, an inhibitor of topoisomerase II. In phase II studies, definite anticancer effects are observed in patients with non-Hodgkin's lymphoma and adult T-cell leukemia/lymphoma. Responses are seen even in pretreated cases. Leukopenia is also dose-limiting. Non-hematologic toxicities are mild and include alopecia and G.I. toxicities. NC-190 is a novel benzophenazine derivative with excellent antitumor activities against murine tumors. NC-190 also inhibits topoisomerase II. Now the drug is an early clinical phase II studies in Japan. Toxicities include bone marrow suppression, transient mild to moderate liver enzyme elevation, alopecia and mild G.I. toxicities. Tumor responses are occasionally encountered. IST-622 is a semisynthetic derivative of chartreusin. The drug is an inhibitor of topoisomerase II (and I in high concentration). IST-622 shows excellent, broad anticancer activity against murine tumors. The drug is well absorbed from small intestine. IST-622 is now in phase I clinical trial in Japan.
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PMID:[Topoisomerase inhibitors developing in Japan]. 842 86

Phase I studies of CPT-11 (irinotecan) have been conducted in Europe, the United States, and Japan to determine the maximum tolerated dose (MTD) and the most appropriate intravenous administration schedule for further evaluation in phase II investigations. Diarrhea and/or neutropenia were the major dose-limiting toxicities in all the phase I studies. In Japanese and US investigations, the CPT-11 MTD was defined as 240 to 250 mg/m2 using a once every 3 weeks schedule and 100 and 150 mg/m2 using a weekly schedule. The weekly intermittent schedule was associated with greater dose intensity and was thus chosen in Japan (100 mg/2 every week) and in the United States (150 mg/m2/wk for 4 weeks followed by 2 weeks rest) for further evaluation in phase II studies. Preliminary results of an ongoing US study showed that CPT-11 could be administered in doses of at least 175 mg/m2 on an every other week basis. In European studies, the MTD was 90 to 100 mg/m2/d with IV infusion over 3 consecutive days every 3 weeks and 100 to 115 mg/m2 with a weekly infusion for 3 weeks every 4 weeks. European experience with a single infusion every 3 weeks showed diarrhea to be dose limiting at 350 mg/m2, but concomitant administration of high-dose loperamide allowed administration of CPT-11 at doses of up to 600 mg/m2. This latter schedule was better tolerated, achieved the highest dose intensity, and was considered to confer greater convenience in an outpatient setting when compared with the other European regimens. European phase II studies were therefore commenced using a CPT-11 schedule comprising a single intravenous infusion every 3 weeks at a dose of 350 mg/m2.
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PMID:CPT-11: clinical experience in phase I studies. 863 50


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