Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1261473 (sarcoma)
 25,952 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty-seven patients with advanced soft tissue sarcoma were treated with merbarone utilizing a daily intravenous schedule for five days. Only one partial response was observed in the thirty-three evaluable patients. The major toxicities were renal, with elevation of creatinine and/or proteinuria, and gastrointestinal, with mild to moderate nausea and vomiting. Merbarone in this dose and schedule has minimal activity in soft tissue sarcoma.
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PMID:Phase II trial of merbarone in soft tissue sarcoma. A Southwest Oncology Group study. 148 11

Merbarone, a nonsedating derivative of thiobarbituric acid, has demonstrated excellent activity against certain murine tumors, including L1210 and P388 leukemias, B16 melanoma, and M5076 sarcoma. Preclinical studies suggested that the antitumor effects of this drug were schedule dependent, since repeated dosing increased killing of tumor cells when compared to intermittent injections. We have completed a Phase I clinical and pharmacological study of merbarone in which the drug was administered both as a 2-h infusion and as a continuous i.v. infusion over 24 h. In view of the increased toxicity observed in animals following bolus injections and the possibility of schedule-dependent anticancer activity, a schedule of drug administration daily for 5 days was selected. Fifty patients with advanced cancer were treated at dose levels that ranged from 100 to 1500 mg/m2/day. When the drug was administered by peripheral vein, phlebitis was observed at the infusion site at daily doses greater than or equal to 150 mg/m2. Therefore, all patients who received drug doses greater than or equal to 200 mg/m2 were treated by continuous i.v. infusion using central venous catheters. Renal insufficiency, initially observed at a dose of 1000 mg/m2/day, was the dose-limiting toxic reaction at 1500 mg/m2/day. Three of five patients treated at the highest dose level were unable to complete the infusion due to this effect. Marked hypouricemia was observed in all patients. Other toxic effects were mild and included nausea, fatigue, leukopenia, thrombocytopenia, and anorexia. Alopecia was noted in several patients who received doses greater than or equal to 1000 mg/m2/day. No major antitumor effects were observed. Dose-dependent, steady-state plasma concentrations of merbarone were reached within 24-48 h after beginning the continuous i.v. infusion. Elimination of drug from plasma followed a two-compartment model, with a t1/2 alpha of 4.2 h and a t1/2 beta of 15.3 h. Renal excretion of merbarone and its major metabolites accounted for less than 30% of the administered dose. We conclude that merbarone is relatively well tolerated with few constitutional symptoms. The current formulation of the drug causes phlebitis when administered by peripheral vein, and renal insufficiency is commonly observed at daily doses which exceed 1250 mg/m2. The recommended dose for extended Phase II evaluation is 1000 mg/m2/day daily for 5 days administered by central venous catheter.
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PMID:Phase I clinical and pharmacological study of merbarone. 229 63

Merbarone was developed to clinical trial stage on the basis of its 'curative' activity against P388 and L1210 leukemias and moderate activity against B16 melanoma and M5076 sarcoma. Its activity appears to be schedule-dependent favoring a longer duration of administration. The mechanism of action of merbarone is not yet established but it does induce single strand breaks in DNA apparently without binding to DNA. The pharmacokinetic data in the dog indicate that clearance mechanisms may be saturable. Merbarone is hydroxylated at the 4' position in the rat, mouse and dog, and glucuronidated in the dog. Parent drug and the hydroxy metabolite are excreted in the urine. If saturable clearance mechanisms also pertain to man, this will mean that infusion rate (and therefore steady state concentrations reached) may be a significant factor in determining acute toxicity. Preclinical toxicology studies revealed that major target tissues are in the lymphoid organs, bone marrow, gastrointestinal tract and kidney. Some behavioral signs of reversible central nervous system toxicity were observed. Phase I trials have commenced using only a 5-day continuous intravenous infusion schedule based on the preclinical data. The pharmacokinetic information from these trials will be crucial for further clinical development of the compound, including selection of the optimal schedule(s) for phase II/III evaluation.
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PMID:Merbarone: an antitumor agent entering clinical trials. 330 62

The standard treatment for patients with primary malignant glioma includes surgical resection, radiotherapy, and nitrosourea. Despite this multimodality approach, adults with newly diagnosed glioblastoma multiforme (GBM) and high-grade astrocytoma have a median survival duration of 50 weeks and 150 weeks respectively. Chemotherapy has had a limited impact on the survival of these patients. Merbarone (5-phenylcarboxamide-2-thiobarbituric acid) is a nonsedating derivative of barbituric acid that crosses the blood brain barrier. Antitumor activity of merbarone has been described against L1210, B16 melanoma cell line and the M5076 sarcoma cells in phase I studies. Merbarone inhibits DNA synthesis and tumor growth by inducing single strand breaks in DNA. It also inhibits RNA and protein synthesis. We evaluated merbarone in a phase II trial in patients (pts) with recurrent or refractory GBM (7 pts) and high grade anaplastic astrocytoma (7 pts). Fourteen patients (nine males, five females) were treated with merbarone at a dose of 1000 mg per m2 per day by continuous intravenous infusion for 5 days every 3 weeks. Every patient received at least two cycles of treatment. No complete or partial responses were observed, although one patient had stable disease lasting 20 weeks. Our conclusion is that merbarone is ineffective against GBM and high-grade anaplastic astrocytoma at the dose and schedule in which it was administered in this trial.
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PMID:Phase II trial of merbarone in patients with malignant brain tumors. 946 39