Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023380 (lethargy)
 5,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acivicin (AT-125) is a glutamine antagonist with dose-limiting, schedule-dependent CNS toxicity and predictable CSF penetration after intravenous administration. Because of these properties, a trial in CNS malignancies was initiated. Thirty-two patients with recurrent or residual malignant astrocytomas were treated with AT-125. The majority of patients had glioblastoma multiforme (24) and had received prior nitrosoureas (21). The median age was 50 years, and Southwest Oncology Group (SWOG) performance status was 2. The major determinant of response was based upon radiologic criteria using computed tomographic (CT) scanning and/or magnetic resonance imaging (MRI) scans. The tumor mass was measured in two perpendicular planes, which yielded the largest cross-sectional area. Standard solid tumor criteria for response were used. All responding patients also had a stable or tapered dose of corticosteroids with stable or improved performance status and neurologic examination. There were four objective responses (12%): one complete remission (3 1/2+ years) and three partial remissions (57, 86, and 322 days). Two patients had improvement in disease that did not meet requirements for a partial remission. Toxicity was mild and primarily consisted of nausea, vomiting, and lethargy. Two patients were removed from study due to neurotoxicity (depression and hallucinations). The strict response criteria used in this trial were not those that have been used in testing other active agents such as carmustine (BCNU). We conclude that AT-125 has objective antitumor activity in malignant astrocytomas and warrants further study.
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PMID:Objective antitumor activity of acivicin in patients with recurrent CNS malignancies: a Southwest Oncology Group trial. 164 69

Acivicin, an L-glutamine antagonist, was administered to 37 evaluable patients with refractory advanced solid tumors in a phase I trial. A total of 67 evaluable 72-hr iv infusions were given at 3- to 4-week intervals. Doses ranged from 3.0 to 90 mg/m2/course. Reversible CNS toxicity was dose-limiting and included lethargy, somnolence, anxiety, hallucinations, and paranoid psychoses. Four of five patients experienced unacceptable CNS toxicity at 90 mg/m2. Three of eight patients experienced reversible diaphoresis and chills without fever at 75 mg/m2, and two had dizziness and ataxia. Hematopoietic toxicity, nausea, emesis, and diarrhea were mild and dose-related. One patient developed a blue-green discoloration of the infusion arm. Serial plasma and urine specimens from 13 patients were assayed for acivicin using a microbiologic method. Peak plasma levels at the end of the 72-hr infusions correlated with dose and ranged from 0.09 to 1.10 microgram/ml. When data from six patients were fitted to a two-compartment open model, alpha-half-life ranged from 1.1 to 63 mins, while beta-half-life ranged fro 338 to 629 mins. Renal clearance ranged from 6 to 24 mL/min, and nonrenal clearance accounted for 58%-83% of the total drug clearance. CNS toxicity correlated with plasma acivicin levels which exceeded 0.9 microgram/ml for greater than 16 hrs, but not with peak plasma levels or with the integrals of the concentration x time curves. Minor responses were seen in one patient with melanoma, in one with epidermoid pulmonary carcinoma, and in two with colon carcinoma. A starting dose of 60 mg/m2/course was recommended for phase II trials, with possible escalation to 75 mg/m2 in the second course if the drug was well-tolerated.
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PMID:Phase I trial and pharmacokinetics of acivicin administered by 72-hour infusion. 687 83

Acivicin is a glutamine analogue antimetabolite that inhibits several glutamate-dependent synthetic enzymes. Previous studies of this agent administered on a 72-h continuous i.v. infusion schedule every 3 weeks demonstrated a high rate of severe, albeit reversible, central nervous system (CNS) toxicity at the 30 mg/m2/day dose level. Animal studies have shown that the CNS toxicity of acivicin can be prevented by a concomitant infusion of amino acids postulated to block drug uptake in the CNS by a saturable transport system that is common to endogenous amino acids. This study evaluated the feasibility of escalating acivicin doses in cancer patients by administering acivicin with a concomitant 96-h i.v. infusion of a mixture of 16 amino acids (Aminosyn, 10%). Twenty-three patients with advanced malignancies were treated with acivicin on a 72-h continuous infusion schedule at doses ranging from 25 to 60 mg/m2/day every 3 weeks. Reversible, dose-limiting CNS toxicity, characterized by lethargy, confusion, and decreased mental status, occurred in the two patients enrolled at the 60 mg/m2/day dose level, precluding further dose escalation. The maximum tolerated dose (MTD) and recommended dose for additional evaluation of acivicin on this schedule is 50 mg/m2/day. Other toxicities observed were dose-related neutropenia that was grade 4 in four patients (four courses), complicated with fever in three of those patients, and grade 3-4 thrombocytopenia in three patients (three courses). Pharmacokinetics studies performed in 15 patients revealed that the acivicin plasma Css increased from 0.44 microg/ml (range, 0.28-0.59 microg/ml) at the 25 mg/m2/day to 1.06 microg/ml (0.64-1.5 microg/ml) at the 50 mg/m2/dose level. Acivicin Css at the MTD was not significantly higher than previously reported values with single-agent acivicin on the same schedule of administration at the MTD of 25 mg/m2/day dose level (0.60 microg/ml; range, 0.43-0.81 microg/ml). Neurotoxicity did not correlate with acivicin Css, but relationships between exposure to acivicin and the occurrence of both neutropenia and thrombocytopenia were well described by a sigmoidal Emax model. This trial demonstrated that concomitant infusions of amino acid can prevent acivicin-induced CNS toxicity, which allows the dose of acivicin to be escalated 2-fold above previously tolerable doses; however, this effect did not translate in a significant increment in acivicin Css.
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PMID:A Phase I and pharmacological study of the glutamine antagonist acivicin with the amino acid solution aminosyn in patients with advanced solid malignancies. 982 40