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Biomedical subjects

L Schacter

Publications and source records attributed to L Schacter.

16 recordsLinked to original sources
PubMed1996

Etoposide bioavailability after oral administration of the prodrug etoposide phosphate in cancer patients during a phase I study.

PURPOSE: The purpose of this study was to determine the bioavailability (F) of etoposide (E;VP-16) after oral administration of the water-soluble prodrug etoposide phosphate (EP;BMY-40481) during a phase I trial in cancer patients. PATIENTS AND METHODS: Twenty-nine patients received oral EP (capsules, 50 to 150 mg/m2/d of E equivalent) for 5 days in week 1 (course 1), followed every 3 weeks thereafter by a daily intravenous (i.v.) infusion for 5 days of E (80 mg/m2, 1-hour i.v. infusion; course 2); in three patients, the i.v. E course was given before oral EP. Plasma and urine E pharmacokinetics (high-performance liquid chromatography [HPLC]) were performed on the first day of oral EP administration and on the first day of i.v. E. RESULTS: Twenty-six of 29 patients completed two courses or more, whereas three patients received only one course due to toxicity. Myelosuppression was dose-dependent and dose-limiting, with grade 4 leukoneutropenia in four of 15 patients at 125 mg/m2 and in five of seven patients at 150 mg/m2. One patient died of meningeal hemorrhage related to grade 4 thrombocytopenia. Other toxicities were infrequent and/or manageable. No objective response was observed. The maximum-tolerated dose (MTD) is therefore 150 mg/m2, and the recommended oral dose of EP for phase II trials in this poor-risk patient population is 125 mg/m2. Twenty-six patients had pharmacokinetic data for both oral EP and i.v. E, whereas three had pharmacokinetic data on the i.v. E course only. After oral administration of EP, the pharmacokinetics of E were as follows: mean absorption rate constant (Ka), 1.7 +/- 1.7 h-1 (mean +/- SD); lag time, 0.3 +/- 0.2 hours; time of maximum concentration (t(max)), 1.6 +/- 0.8 hours; and mean half-lives (t1/2), 1.6 +/- 0.2 (first) and 10.3 +/- 5.8 hours (terminal); the increase in the area under the plasma concentration-versus-time curve (AUC) of E was proportional to the EP dose. After the 1-hour i.v. infusion of E, maximum concentration (C(max)) was 15 +/- 3 micrograms/mL; mean AUC, 88.0 +/- 22.0 micrograms.h/mL; mean total-body clearance (CL), 0.97 +/- 0.24 L/h/m2 (16.2 mL/min/m2); and mean t1/2, 0.9 +/- 0.6 (first) and 8.1 +/- 4.1 hours (terminal). The 24-hour urinary excretion of E after i.v. E was significantly higher (33%) compared with that of oral EP (17%) (P < .001). Significant correlation was observed between the neutropenia at nadir and the AUC of E after oral EP administration (r = .58, P < .01, sigmoid maximum effect [E(max)] model). The mean F of E after oral administration of EP in 26 patients was 68.0 +/- 17.9% (coefficient of variation [CV], 26.3%; F range, 35.5% to 111.8%). In this study, tumor type, as well as EP dose, did not significantly influence the F in E. There was no difference in F of E, whether oral EP was administered before or after i.v. E. Compared with literature data on oral E, the percent F in E after oral prodrug EP administration was 19% higher at either low ( < or = 100 mg/m2) or high ( > 100 mg/m2) doses. CONCLUSION: Similarly to E, the main toxicity of the prodrug EP is dose-dependent leukoneutropenia, which is dose-limiting at the oral MTD of 150 mg/m2/d for 5 days. The recommended oral dose of EP is 125 mg/m2/d for 5 days every 3 weeks in poor-risk patients. Compared with literature data, oral EP has a 19% higher F value compared with oral E either at low or high doses. This higher F in E from oral prodrug EP appears to be a pharmacologic advantage that could be of potential pharmacodynamic importance for this drug.

Administration, Oral↗
PubMed1996

Etoposide phosphate: what, why, where, and how?

The podophyllotoxin derivatives etoposide and teniposide are active in the treatment of a variety of malignant conditions. Both represent chemical modifications of podophyllin, an extract of Podophyllum peltatum (May apple, mandrake, Indian apple, wild lemon, or duck's foot), a plant long used as a folk remedy and recognized in the 19th century to be effective in the treatment of cancer. While etoposide is active in the treatment of many cancers and is widely used, it has a number of limitations due to its lack of water solubility. Etoposide phosphate (Etopophos; Bristol-Myers Squibb Company, Princeton, NJ) is a water-soluble prodrug of etoposide that is rapidly and completely converted to the parent compound after intravenous dosing. The pharmacokinetic profile of etoposide after treatment with either etoposide or etoposide phosphate is identical. Toxicity and clinical activity also are the same. Because etoposide phosphate is water soluble and can be made up to a concentration of 20 mg/mL, however, it can be given as a 5-minute bolus, in high doses in small volumes, and as a continuous infusion. Furthermore, it is not formulated with polyethylene glycol, polysorbate 80 (Tween; ICI Americas, Wilmington, DE), and ethanol, and does not cause acidosis when given at high doses. The easier-to-use etoposide phosphate represents an improved formulation of etoposide.

Antineoplastic Agents↗
PubMed1995

Phase I and pharmacokinetic study of etoposide phosphate.

Etoposide phosphate (EP) is a water-soluble derivative of etoposide (VP-16), a semisynthetic podophyllotoxin which is useful in the treatment of a wide variety of hematological malignancies and solid tumors. Because etoposide is poorly water soluble, it must be dissolved in a variety of organic solvents and given in relatively large volumes of saline. EP is rapidly converted to the parent drug in vivo and has been shown to be active in animal studies. We performed a phase I pharmacokinetic study in 27 patients. Three patients each received an etoposide-equivalent dose of 50 or 75 mg/m2 each day by i.v. bolus (5 min) daily for 5 days and 21 patients received a dose equivalent to 100 mg/m2 of etoposide each day for 5 days. Non-compartmental pharmacokinetic data were obtained for 22 of the patients. As with previous studies, EP behaves as a prodrug of etoposide. The Cmax (25.3-42.5 micrograms/ml) increased linearly, while AUCinf (75.8-156 h micrograms/ml) of etoposide increased proportionately with dose (50-100 mg/m2 of etoposide equivalents). Time to achieve Cmax corresponded to the end of the 5 min injection, indicating a rapid formation of etoposide from EP. Mean etoposide phosphate/etoposide Cmax and AUCinf ratios were 0.08 or less and 0.003, respectively, indicating that the major circulating moiety in plasma was etoposide. Parameters such as MRT, T1/2, CL/F, CLR, VSS/F and %UR were dose independent. The toxicities of EP were virtually identical to those seen with etoposide, with dose-related myelosuppression, alopecia and stomatitis. Severe neutropenia was the dose-limiting toxicity. No significant problems with hypotension or allergic reactions were observed. No problems, difficulties or complications were observed as a result of bolus (5 min) administration. On the basis of phase I toxicity data, we recommend an etoposide equivalent starting dose of 100 mg/m2/day for 5 days in previously untreated patients who have an excellent performance status. In patients who have had one or more prior chemotherapy regimens, extensive prior radiation therapy or moderately impaired performance status, we recommend an etoposide phosphate starting dose of 75 mg/m2/day for 5 days with courses repeated at 3 week intervals.

Adult↗
PubMed1994

Phase II study of elsamitrucin in non-small cell lung cancer.

Elsamitrucin (BMY-28090) a novel fermentation product has demonstrated pre-clinical anti-tumour activity against a number of cell lines. The dose limiting toxicity in phase I studies was a reversible increase in hepatic transaminase. This study was initiated to determine the activity of elsamitrucin in patients with previously untreated, bi-dimensionally measurable, cytologically or histologically proven, non-small cell lung cancer who were not curable by surgery. Elsamitrucin at a dose of 25 mg/m2 was administered intravenously over 5-10 min weekly for a minimum of 6 weeks. Seventeen patients were entered on study, 15 were evaluable for toxicity and 14 evaluable for response. No responses were documented in the 14 patients evaluable for response. Both hematological and non-hematological toxicities were mild to moderate in severity. The commonest being nausea, vomiting, lethargy and local skin reactions at the site of the infusion. These results indicate that elsamitrucin when given in this dose and schedule to patients with surgically incurable non-small cell lung cancer has no activity.

Aged↗
PubMed1992

A phase III randomized study comparing cisplatin and fluorouracil as single agents and in combination for advanced squamous cell carcinoma of the head and neck.

PURPOSE: To determine whether combination chemotherapy is superior to single agents for recurrent/metastatic head and neck cancer, we compared the efficacy and toxicity of cisplatin (CP) and fluorouracil (5-FU), alone and in combination in a phase III trial. PATIENTS AND METHODS: Two hundred forty-nine patients with recurrent head and neck cancer were randomized to one of three treatments: CP (100 mg/m2) and 5-FU (1 g/m2 x 4), CP, or 5-FU every 3 weeks. RESULTS: The overall response rate to the combination (32%) was superior to that of CP (17%) or 5-FU (13%) (P = .035). Response was associated with good performance status (PS) but not with primary site, site of recurrence, histology, prior irradiation, or relative dose intensity. Median time to progression was less than 2.5 months, and there was no significant difference in median survival (5.7 months) among the groups. By multivariate analysis, patients with better PS and poorly differentiated tumors had superior survival. Hematologic toxicity and alopecia were worse in the combination arm. CONCLUSION: Although the response rate to the combination of CP plus 5-FU was superior to that achieved with single agents, survival did not improve.

Analysis of Variance↗
PubMed1991

Randomized study of cisplatin dose intensity in poor-risk germ cell tumors: a Southeastern Cancer Study Group and Southwest Oncology Group protocol.

Between 1984 and 1989, 159 patients presenting with advanced germ cell cancer were entered on a randomized clinical trial comparing the efficacy and toxicity of etoposide and bleomycin and either standard-dose cisplatin (20 mg/m2 daily for 5 days) or high-dose cisplatin (40 mg/m2 daily for 5 days). Of the 159 patients, 153 were assessable for toxicity and response. As expected, patients receiving the high-dose cisplatin regimen experienced significantly more neurotoxicity, ototoxicity, nausea and vomiting, and myelo-suppression. Four patients (3%) died related to therapy. Despite the toxicity encountered, dose intensity was maintained. Overall, 84% of patients in the high-dose arm received 80% or more of the projected dose of cisplatin, etoposide, and bleomycin; and 90% of patients on the standard-dose arm received 80% or more of the projected dose. Of the 76 eligible patients randomized to receive the high-dose cisplatin regimen, 52 (68%) became disease-free with chemotherapy alone or with subsequent resection of residual teratoma or cancer. Of the 77 patients randomized to the standard-dose arm, 56 (73%) became disease-free with chemotherapy alone or with surgery. Median follow-up is now 24 months. Eleven patients (three high-dose and eight standard-dose) relapsed from disease-free status. Overall, 74% of patients receiving the high-dose cisplatin regimen are alive, and 63% are continuously free of disease. Of the patients receiving the standard-dose cisplatin regimen, 74% are alive, and 61% are continuously free of disease. This randomized prospective trial in advanced germ cell cancer achieved dose intensity of the most active single agent in this disease. This dose intensity did not translate into an improved survival or cure. We conclude that dose escalation of cisplatin beyond standard doses results in excess toxicity with no accompanying therapeutic benefit.

Adolescent↗
PubMed1991

Protracted infusion of 5-FU with weekly low-dose cisplatin as second-line therapy in patients with metastatic colorectal cancer who have failed 5-FU monotherapy.

Forty four patients who had documented progression of metastatic colorectal cancer while receiving 5-fluorouracil (5-FU) monotherapy were treated with continuous infusion 5-FU, 300 mg/mg2/day, plus weekly low-dose cisplatin, 20 mg/m2. Treatment was given in 12-week cycles, consisting of 8 weeks of chemotherapy followed by a 4-week rest period, and was well tolerated. Three of 23 patients (13%) who had failed bolus 5-FU but not been exposed previously to infusional 5-FU responded. Of 21 patients who had failed infusional 55-FU monotherapy, only one (5%) responded. Time to progression (5.7 vs. 1.8 months) and survival (12 vs. 5.5 months) were significantly longer for patients who had not previously received infusional 5-FU but who had failed bolus schedules, compared with patients who had previously failed infusional 5-FU (p less than .001).

Adult↗
PubMed1988

Altered amount and activity of superoxide dismutase in sickle cell anemia.

The amount and activity of superoxide dismutase (SOD) (EC 1.15.1.1) were measured in red cells collected from 50 white controls, 101 black controls, 50 patients with sickle hemoglobin (SS Hb), 12 with sickle trait, and 11 with other sickling hemoglobinopathies. Red cells from normal black subjects had more SOD amount and activity than normal whites (1.77 U/mg Hb and 2.96 micrograms/mg Hb vs. 1.47 U/mg Hb and 2.64 micrograms/mg Hb, respectively) or blacks with SS Hb or other sickling hemoglobinopathies. Patients with more severe manifestations of SS Hb had lower levels of SOD activity than those with milder symptoms but had the same amount of enzyme protein. Individuals with sickle trait had amounts and activities of SOD comparable to black controls. An alteration in defense to free radical oxygen may play a role in the severity of symptoms experienced by patients with homozygous sickle cell disease.

Anemia, Sickle Cell↗
PubMed1986

Fatal radiation hepatitis: a case report and review of the literature.

A case of fatal radiation hepatitis occurring after treatment with 2200 rad given by the moving strip technique is presented. This fatality occurred in a 28-year-old woman with persistent ovarian carcinoma despite prolonged chemotherapy. Scans of the liver using computerized tomography, 99mTc sulfur colloid, and 99mTc diisopropyl iminodiacetic acid showed abnormalities only in sulfur colloid uptake and these resolved late in the course. Death was caused by progressive hepatic and renal failure. Postmortem examination showed changes typical of radiation hepatitis. Only 32 cases of radiation hepatitis have been previously reported and they are reviewed. The possible role of prolonged prior chemotherapy in enhancing sensitivity to radiotherapy is considered.

Adult↗
PubMed1986

Sarcoidosis, Hodgkin's disease, and autoimmune hemolytic anemia.

Reported is the unique occurrence of sarcoidosis, Hodgkin's disease, and autoimmune hemolytic anemia in the same patient. Although the diagnosis of sarcoidosis preceded that of Hodgkin's disease by 29 years, massive splenomegaly had been present for 13 years before Hodgkin's disease was diagnosed following splenectomy. The known associations of sarcoidosis and Hodgkin's disease as well as each disease with autoimmune hemolytic anemia are reviewed.

Anemia, Hemolytic, Autoimmune↗
PubMedDate not supplied

Overview of phase I trials of 2',3'-dideoxyinosine (ddI) conducted on adult patients.

Ninety-two adult patients with AIDS or severe AIDS-related complex were treated with 2',3'-dideoxyinosine (didanosine; ddI) at dosages ranging from 0.8 to 66.0 mg/(kg.d) for at least 6 weeks in phase I trials. Potentially beneficial changes in weight (40% of patients), clinical signs or symptoms (40% of patients), CD4+ cell counts (25% of patients), and serum levels of HIV p24 antigen (50% of antigen-positive patients) were reported. Response rates tended to be higher among patients with AIDS-related complex and among those who had not received prior zidovudine therapy. A major response (improvement in at least one clinical parameter and in at least one laboratory marker) occurred in 29% of patients, and rates of major response tended to be higher in patients receiving higher dosages. The primary dose-limiting toxicity observed was peripheral neuropathy, which was observed with increasing frequency in patients receiving greater than 20 mg/(kg.d). Of the other adverse effects, pancreatitis was possibly dose-dependent and hyperuricemia (without clinical gout) occurred only at high doses. Dosages of 250 mg and 375 mg of ddI twice daily will be used in extended phase II/III studies.

AIDS-Related Complex↗
PubMedDate not supplied

Managing attribute--value clinical trials data using the ACT/DB client-server database system.

ACT/DB is a client-server database application for storing clinical trials and outcomes data, which is currently undergoing initial pilot use. It stores most of its data in entity-attribute-value form. Such data are segregated according to data type to allow indexing by value when possible, and binary large object data are managed in the same way as other data. ACT/DB lets an investigator design a study rapidly by defining the parameters (or attributes) that are to be gathered, as well as their logical grouping for purposes of display and data entry. ACT/DB generates customizable data entry. The data can be viewed through several standard reports as well as exported as text to external analysis programs. ACT/DB is designed to encourage reuse of parameters across multiple studies and has facilities for dictionary search and maintenance. It uses a Microsoft Access client running on Windows 95 machines, which communicates with an Oracle server running on a UNIX platform. ACT/DB is being used to manage the data for seven studies in its initial deployment.

Clinical Trials as Topic↗