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Biomedical subjects

L Siu

Publications and source records attributed to L Siu.

7 recordsLinked to original sources

Phase I study to determine the safety and pharmacokinetics of the novel Raf kinase and VEGFR inhibitor BAY 43-9006, administered for 28 days on/7 days off in patients with advanced, refractory solid tumors.

BACKGROUND: BAY 43--9006, an oral multi-kinase inhibitor, targets serine-threonine kinases and receptor tyrosine kinases, and affects the tumor and vasculature in preclinical models. Based on its pharmacologic effect, it may be a useful cancer treatment. This study determined the maximum tolerated dose (MTD) of BAY 43-9006 in 42 patients with advanced, refractory metastatic or recurrent solid tumors. Dose-limiting toxicities (DLTs), safety, pharmacokinetics and tumor response were also evaluated. PATIENTS AND METHODS: In this open-label, phase I, dose-escalation study, BAY 43--9,006 was administered orally in repeated cycles of 35 days (28 days on/7 days off). Eight doses were investigated: from 50 mg every fourth day to 600 mg twice daily. Treatment continued until unacceptable toxicity, tumor progression or death. RESULTS: The MTD was 400 mg twice daily. BAY 43-9006 was well tolerated, with mild to moderate toxicities; only six patients discontinued study therapy due to adverse events. DLTs consisted of hand-foot skin reaction in three of seven patients receiving 600 mg twice daily. Stable disease was achieved in 22% of patients; median duration of stable disease was 7.2 months. Consistent with its observed half-life of approximately 27 h, BAY 43-9, 006 accumulated on multiple dosing. Increases in exposure were less than proportional to the increases in dose. CONCLUSIONS: Results indicate that further clinical investigation of BAY 43--9006 is warranted, and suggest it could be a promising future therapy for patients with cancer.

Administration, Oral↗

A National Cancer Institute of Canada clinical trials group phase II study of eniluracil (776C85) and oral 5-fluorouracil in patients with advanced squamous cell head and neck cancer.

UNLABELLED: BACKGROUND/PATIENTS AND METHODS: Thirty-two patients with recurrent head and neck cancer (HNC) following radiotherapy and/or surgery were treated with eniluracil (10 mg/m2) and 5-fluorouracil (5-FU) (1 mg/m2) (E5F) orally twice daily for 28 days followed by a seven-day treatment free period. Thirty-five-day cycles were repeated until disease progression, unacceptable toxicity or patient refusal. Doses were modified for toxicity. Standard toxicity and response criteria were used. RESULTS: Thirty-two patients were accrued; thirty-two and twenty-eight patients were evaluable for toxicity and response, respectively. Twelve patients received three or more cycles of E5F. Drug related toxicities were usually grade 1-2 intensity and included lethargy, nausea or diarrhea (> or = 25% of patients), and anorexia, rash or itch, stomatitis or vomiting (12%-24% of patients). Hematologic toxicity was generally mild; two patients experienced grade 3-5 leukopenia or thrombocytopenia. No significant biochemical toxicity was seen. One patient was withdrawn (severe nausea and vomiting) and one patient died because of drug related toxicity (thrombocytopenia). In the final analysis there were one complete and four partial responses for a 15.6% overall response. CONCLUSIONS: E5F demonstrates activity in chemotherapy naïve patients with advanced HNC cancer with acceptable toxicity profile. Further investigation of E5F with other active agents is warranted in HNC.

Adult↗

Phase I and pharmacokinetic study of irofulven, a novel mushroom-derived cytotoxin, administered for five consecutive days every four weeks in patients with advanced solid malignancies.

PURPOSE: To evaluate the toxicity and pharmacologic behavior of the novel mushroom-derived cytotoxin irofulven administered as a 5-minute intravenous (IV) infusion daily for 5 days every 4 weeks to patients with advanced solid malignancies. PATIENTS AND METHODS: In this phase I trial, 46 patients were treated with irofulven doses ranging from 1.0 to 17.69 mg/m(2) as a 5-minute IV infusion (two patients received a 1-hour infusion) daily for 5 days every 4 weeks. The modified continual reassessment method was used for dose escalation. Pharmacokinetic studies were performed on days 1 and 5 to characterize the plasma disposition of irofulven. RESULTS: Forty-six patients were treated with 92 courses of irofulven. The dose-limiting toxicities on this schedule were myelosuppression and renal dysfunction. At the 14.15-mg/m(2) dose level, renal dysfunction resembling renal tubular acidosis occurred in four of 10 patients and was ameliorated by prophylactic IV hydration. The 17.69-mg/m(2) dose level was not tolerated because of grade 4 neutropenia and renal toxicity, whereas the 14.15-mg/m(2) dose level was not tolerable with repetitive dosing because of persistent thrombocytopenia. Other common toxicities included mild to moderate nausea, vomiting, facial erythema, and fatigue. One partial response occurred in a patient with advanced, refractory metastatic pancreatic cancer lasting 7 months. Pharmacokinetic studies of irofulven revealed dose-proportional increases in both maximum plasma concentrations and area under the concentration-time curve, while the agent exhibited a rapid elimination half-life of 2 to 10 minutes. CONCLUSION: Given the results of this study, the recommended dose of irofulven is 10.64 mg/m(2) as a 5-minute IV infusion daily for 5 days every 4 weeks. The preliminary antitumor activity documented in a patient with advanced pancreatic cancer and the striking preclinical antitumor effects of irofulven observed on intermittent dosing schedules support further disease-directed evaluations of this agent on the schedule evaluated in this study.

Adult↗

Rapid troponin T measurement in whole blood for detection of myocardial damage.

A dry chemistry system for rapid qualitative measurement of cardiac troponin T in whole blood, serum, EDTA and lithium heparin plasma was studied in 197 admissions to the coronary care unit and general wards of a typical district general hospital for whom troponin T was requested. This included patients with unexplained collapse, acute dysrythmia or elevated creatine kinase of unknown origin. EDTA whole blood and plasma proved the most satisfactory sample matrices. Lithium heparin whole blood was equally appropriate but lithium heparin plasma gave a false negative result. Serum was an unsatisfactory sample material. Comparison with the conventional wet chemistry quantitative enzyme-linked immunosorbent assay showed a positive bias for EDTA plasma, particularly in the range 0-1 microgram/L and a significant negative bias for lithium heparin plasma. There was no difference between serum from plain or gel separator tubes. The whole blood method allows troponin T measurement to be performed rapidly and simply in the laboratory, either as an emergency test to alter patient management, or for those laboratories that wish to offer troponin T for selected cases but do not have the ability to measure troponin T quantitatively.

Adult↗