indicine-n-oxide and Neoplasms

A phase I trial of indicine-N-oxide was carried out in 12 children with solid tumors and in 16 with leukemia. Doses of 5, 6, and 7.5 g/m2 were given parenterally as a 15-min infusion every 3 weeks. The maximum tolerated dose in patients with solid tumors was 7.5 g/m2 and the dose-limiting toxicity was myelosuppression. In leukemia, the maximum tolerated dose was 6.0 g/m2 and hepatotoxicity was dose-limiting. Half of the children with leukemia showed elevations in transaminase levels and one child died of massive hepatic necrosis. This hepatotoxicity limits the use of indicine-N-oxide in children with leukemia. Antineoplastic activity was limited to a transient reduction in the numbers of circulating leukemic cells.

Topics: Adolescent; Antineoplastic Agents, Phytogenic; Child; Child, Preschool; Drug Administration Schedule; Drug Evaluation; Humans; Infusions, Intravenous; Leukemia; Liver; Male; Neoplasms; Pyrrolizidine Alkaloids; Thrombocytopenia

Indicine-N-Oxide is the water soluble N-oxide of the pyrolizidine alkaloid indicine recently evaluated in Phase I trials. Initially in a weekly times four schedule, twenty-nine patients were treated with a dose range of 1.0 to 7.5 g/m2 per week. Fifteen of 40 of the courses of four doses were interrupted by myelosuppression which prohibited completion of the course. Therefore, an intermittent schedule was evaluated utilizing single doses repeated every 3-4 weeks. Twenty-six patients were treated at doses of 5 to 10 g/m2. Myelosuppression is the dose limiting toxicity of both schedules with thrombocytopenia being more severe than leukopenia. Myelosuppression is predictable and reversible on the intermittent schedule. It is more severe in patients with heavy prior treatment. Partial responses were seen in four patients, one with a mucoepidermoid carcinoma of the salivary gland and three with adenocarcinoma of the colon. Phase II studies are planned at a starting dose of 7.5 g/m2 every 3-4 weeks in patients with no prior treatment and 5 g/m2 in patients with prior treatment.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Drug Administration Schedule; Drug Evaluation; Humans; Leukopenia; Middle Aged; Neoplasms; Pyrrolizidine Alkaloids; Thrombocytopenia

Indicine N-oxide is a pyrrolizidine alkaloid isolated from Heliotropium indicum, one of the widely used herbs in Ayurvedic medicine. Thirty-seven patients with solid tumors received the drug: 15 men and 22 women (mean age, 53 years). All had had prior chemotherapy, and 25 had had prior radiotherapy. Eighty-four percent had a performance status of 0-3 (Cancer and Leukemia Group B criteria). The drug was given as a short infusion over 15 minutes and repeated with a median interval of 4 weeks. Doses were escalated from 1 to 9 g/m2. A total of 55 courses were evaluable. Dose-limiting toxic effects were leukopenia and thrombocytopenia, and the toxicity was cumulative with repeated doses. Other toxic effects included nausea and vomiting, anemia, and hepatic dysfunction. The hematologic toxicity tended to be more pronounced in patients with hepatic dysfunction, poor marrow reserve, and heavy prior chemotherapy and radiotherapy. There were no complete or partial responses. One patient with skin melanoma and another with ovarian carcinoma had improvement lasting 2 months. The maximally tolerated dose is 9 g/m2 in our population. A recommended dose for therapeutic study is 7 g/m2. High-risk patients should be started at a dose of 5 g/m2. The treatment may be repeated at 4-week intervals with close monitoring of wbc and platelet counts. Dose reductions may be necessary for repeated courses.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Cyclic N-Oxides; Drug Evaluation; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms; Pyrrolizidine Alkaloids

Pharmacokinetics of the experimental antitumor agent indicine N-oxide were investigated in a group of 23 pediatric cancer patients. Plasma elimination of indicine N-oxide was best described by a two-compartment open model. The mean plasma distribution phase half-life, plasma elimination phase half-life, and plasma clearance were 8 min, 84 min, and 62 ml/min/m2 (2.1 ml/min/kg), respectively. One patient with renal impairment had an abnormally long plasma elimination phase half-life (275 min) and reduced plasma clearance (17 ml/min/m2). Plasma elimination phase half-life values increased and plasma clearance values decreased with increasing age of the pediatric patients. Plasma elimination of indicine N-oxide was more rapid in this group of children than in adults who had previously received the drug.

Topics: Adolescent; Adult; Antineoplastic Agents, Phytogenic; Child; Child, Preschool; Female; Half-Life; Humans; Infusions, Parenteral; Kinetics; Male; Neoplasms; Pyrrolizidine Alkaloids

Indicine-N-oxide was analyzed quantitatively in biological samples using a direct partial purification method involving acetonitrite precipitation or methanol precipitation followed by ion exchange chromatography. Trimethylsilyl derivatization of the resultant provided either of two derivatives, depending on the reaction conditions used, both of which had good gas chromatographic qualities. Heliotrine-N-oxide was used as the internal standard for this work. Data are presented to show that this is a reliable and useful internal standard based on its behavior in the partial purification method and on the gas chromatographic characteristics of its two derivatives. In addition, both low and high resolution mass spectral data indicate that heliotrine-N-oxide produces two trimethylsilyl derivatives analogous to those produced by indicine-N-oxide under the same conditions. Application of this procedure to urine and blood samples from cancer patients in clinical trials indicates that over 95% of the drug is removed from the circulation and excreted in the urine over the course of 48 h.

Topics: Antineoplastic Agents, Phytogenic; Chemical Precipitation; Chromatography, Ion Exchange; Cyclic N-Oxides; Gas Chromatography-Mass Spectrometry; Humans; Infusions, Parenteral; Neoplasms; Pyrrolizidine Alkaloids; Time Factors; Trimethylsilyl Compounds