Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The severe combined immunodeficient (SCID) mouse model of human acute myelogenous leukemia (AML) is a unique system for preclinical in vivo evaluation of the activity and toxicity of new agents. The topoisomerase I (topo I) inhibitor topotecan is active in patients with AML and myelodysplastic syndromes. DX-8951f is a novel topo I inhibitor with more potent antitumor effects than topotecan or CPT-11 in vitro. To study the in vivo activity of DX-8951f, 6-week-old female SCID mice received injections into the tail vein with 2 x 10(7) exponentially growing KBM-3 cells. In each experiment, three to five sets of five mice were treated with DX-8951f doses ranging from 7.5 to 80 mg/kg and at schedules of 1, 3, and 5 days; a control set of five mice was treated with the drug vehicle alone. One group received DX-8951f on day 7 of the inoculation with KBM-3 (early-treatment group). To study the activity of DX-8951f in advanced disease, a second group was treated 1 month after the inoculation, when the animals were developing symptoms (late-treatment group). The study end point was the duration of survival until death from leukemia, which was assessed clinically and by the presence of the human DQ alpha gene in tissue samples by PCR. Six experiments were conducted with 170 animals. Survival was higher in both the early- and late-treatment groups than in untreated controls, and the treated groups had significantly less central nervous system disease. Significantly improved survival was observed in animals treated early with 60 and 80 mg/kg as a single injection, with 15 and 20 mg/kg over 3 days, and with 7.5 and 10 mg/kg over 5 days. In the late-disease model (treatment starting on days 28-35), improved survival was observed with a single dose of 80 or 20 mg/kg over 5 days. Dose escalation was limited by dilution problems at the 1-day schedule and by toxicity (mainly gastrointestinal) of the prolonged schedules. Both efficacy and toxicity were dose schedule dependent, increasing with higher doses and prolonged exposure. By establishing the antileukemic activity of DX-8951f against human AML transplanted into SCID mice at doses below the LD10, our data provide a rationale for clinical evaluation of the drug in patients with AML and favor the use of prolonged administration.
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PMID:The topoisomerase I inhibitor DX-8951f is active in a severe combined immunodeficient mouse model of human acute myelogenous leukemia. 1069 May 60

CPT-11 is an antineoplastic agent which acts as a specific inhibitor of DNA topisomerase 1 and has a broad spectrum of activity in solid tumors. Very few studies have evaluated the activity of CPT-11 in hematological malignancies. We conducted a phase II trial of CPT-11 in 26 patients with high-risk MDS (RAEB 1: n = 4; RAEB 2: n = 9; MDS having progressed to AML: n = 10; CMML: n = 3) who could not receive anthracycline/cytarabine intensive chemotherapy. Induction therapy consisted of four courses of CPT-11 given intravenously at 200 mg/m(2) every 2 weeks. Patient characteristics were: median age, 71 (range 51-77); sex, (M/F), 21/5, median % marrow blasts cells, 13.5 (range 7-52). Cytogenetics according to IPSS were: low-risk n = 13, intermediate-risk n = 6, high-risk n = 3, failure or not done n = 4. Six patients stopped treatment after only one or two courses of CPT-11 due to severe infection (n = 2), progressive disease (n = 3), acute lysis syndrome with renal failure (n = 1). In the 20 patients who received at least three cycles of CPT-11, complete remission was achieved in one case, partial remission in four cases, and hematological improvement in three cases with an overall response rate of 33% in the 26 patients. Duration of response was short (median 4 months, range 1-6 months) and median survival was 8 months (range 1-23 months). Digestive toxicity (diarrhea) occurred in 26/89 (29%) courses, but was mild (grade 1, 20% courses; grade 2 or 3, 9% courses). Hematological toxicity was difficult to assess in non-responders because of initial pancytopenia, but all the patients who responded had grade 3/4 hematological toxicity associated with grade >/=2 infection requiring hospitalization in 18% of the courses. No other major toxicity was observed. Thus CPT-11 has an interesting activity in MDS with excess of blasts; toxicity is easily managed and most patients can be treated in the out-clinic setting. These results suggest that further evaluation of CPT-11 in MDS is warranted.
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PMID:Phase II trial of CPT-11 in myelodysplastic syndromes with excess of marrow blasts. 1259 29