alvocidib and Neutropenia

To review preclinical and clinical information on flavopiridol, an inhibitor of cyclin-dependent kinases (CDKs), tested as an antitumor agent.. Primary and review articles were identified by MEDLINE search (1990-June 2001). Abstracts from recent meetings were also used as source materials.. Flavopiridol was reviewed with regard to its mechanisms, preclinical and clinical results, pharmacokinetics, and metabolism.. Flavopiridol is an inhibitor of several CDKs and displays unique anticancer properties. In addition to direct CDK inhibition, flavopiridol also exhibited other features such as inducing apoptosis in many cancer cell lines, decreasing cyclin D1 concentration, and inhibiting angiogenesis. Preclinical xenograft models showed significant antitumor activity for flavopiridol. The regimen using 72-hour continuous infusion every 2 weeks has been most extensively applied in clinical trials, with a 1-hour infusion currently being explored to achieve higher peak concentrations. Several Phase I and II trials have been reported, with some evidence of antitumor activity noted. Further Phase I and II trials using flavopiridol as a single agent and in combination with standard chemotherapeutic regimens and various tumor types are ongoing.. Flavopiridol is the first CDK inhibitor to enter clinical trials. Several Phase I and Phase II clinical trials with different regimens (72-h or 1-h infusion) have been completed. Initial clinical trials have been intriguing, but many questions remain: What is the best regimen (< or =72-h infusion)? Does optimal future development of this drug depend on the combination with other chemotherapy? What is the best combination of flavopiridol with other chemotherapy?

Topics: Antineoplastic Agents; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Colonic Neoplasms; Cyclin-Dependent Kinases; Diarrhea; Drug Evaluation, Preclinical; Drug Therapy, Combination; Fatigue; Flavonoids; Humans; Infusion Pumps; Kidney Neoplasms; Lymphoma, Non-Hodgkin; Neoplasms; Neutropenia; Piperidines

Flavopiridol has in vitro activity in chronic lymphocytic leukemia (CLL) and promotes apoptosis independent of p53 function or prior fludarabine exposure. We sought to determine if flavopiridol has activity in previously treated CLL using two schedules of administration.. Patients with previously treated CLL were enrolled in two sequentially done phase II studies. Patients in the first trial received flavopiridol (50 mg/m(2)/d) as a continuous infusion (CI) for 72 hours every 2 weeks. Patients in the second trial received flavopiridol 50 mg/m(2) as a 1-hour bolus (IVB) daily for 3 days repeated every 3 weeks. Patients received up to 12 (CI cohort) or 8 (IVB cohort) cycles of therapy.. Fifteen patients were enrolled in the 72-hour CI phase II trial; 6 (40%) had intermediate-risk (Rai stage I or II) and 9 (60%) had high-risk (Rai stage III and IV) stages. No responses were noted in this group; 27% had stable disease and 73% had progressive disease. Thirty-six patients were enrolled in the second IVB trial, with 13 (36%) having intermediate and 23 (64%) having high-risk disease. Four patients (11%) had partial responses, 19 (53%) had stable disease, and 13 (36%) had progressive disease. The progression-free survival for responders in the IVB trial was 3, 3, 9, and 19 months. The median progression-free survival was 2 months [95% confidence interval (95% CI), 1.8-3.8] for patients in the CI trial and 3 months (95% CI, 2.5-7.4) for the IVB trial. The median overall survival was 27 months (95% CI, 20-42) for the CI trial and 24 months (95% CI, 18-31) for the IVB trial. Toxicity was manageable and included mainly myelosuppression, infections, diarrhea, and fatigue.. Flavopiridol has modest, schedule-dependent clinical activity in relapsed CLL and warrants future investigation utilizing alternative schedules of administration.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Drug Administration Schedule; Female; Flavonoids; Humans; Infusion Pumps; Leukemia, Lymphocytic, Chronic, B-Cell; Male; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Neutropenia; Piperidines; Survival Analysis; Thrombocytopenia; Treatment Outcome

To determine the dose-limiting toxicities, maximum-tolerated dose, and pharmacokinetics of the cyclin-dependent kinase inhibitor flavopiridol (NSC 649890) when administered as a 1-hour infusion over 3 consecutive days to children with recurrent or refractory solid tumors.. Flavopiridol was administered as a 1-hour intravenous infusion daily for 3 consecutive days every 21 days, or when hematologic toxicity or any grade 2 or greater nonhematologic toxicity resolved. The starting dose was 37.5 mg/m2/d. Dose escalation was in cohorts of three patients in a standard fashion until dose-limiting toxicity and the maximum-tolerated dose were determined. Flavopiridol levels were measured on days 1, 2, and 3.. Twenty-five children received flavopiridol at doses of 37.5 to 80 mg/m2/day over 3 consecutive days. The maximum-tolerated dose was 62.5 mg/m2/d. The primary dose-limiting toxicities were neutropenia and diarrhea. No antitumor effect was observed in this population. Mean peak plasma concentrations of 3.71 and 9.11 micromol/L were achieved at the end of the 1-hour infusion, following dose escalation from 37.5 mg/m2 to 80 mg/m2, respectively. The median flavopiridol plasma clearance was 8.0 L/h/m2 (range, 2.6 to 17.1 L/h/m2).. The maximum-tolerated dose of flavopiridol in children, and the recommended phase II dose for pediatric studies, was 62.5 mg/m2/day when administered as a 1-hour infusion for 3 consecutive days. Dose-limiting toxicities of neutropenia and diarrhea were similar to those in adult studies.

Topics: Adolescent; Adult; Antineoplastic Agents; Child; Child, Preschool; Diarrhea; Female; Flavonoids; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Neoplasms; Neutropenia; Piperidines

To define the maximum-tolerated dose (MTD), dose-limiting toxicity, and pharmacokinetics of the cyclin-dependent kinase inhibitor flavopiridol administered as a daily 1-hour infusion every 3 weeks.. Fifty-five patients with advanced neoplasms were treated with flavopiridol at doses of 12, 17, 24, 30, 37.5, and 52.5 mg/m(2)/d for 5 days; doses of 50 and 62.5 mg/m(2)/d for 3 days; and doses of 62.5 and 78 mg/m(2)/d for 1 day. Plasma sampling was performed to characterize the pharmacokinetics of flavopiridol with these schedules.. Dose-limiting neutropenia developed at doses >/= 52.5 mg/m(2)/d. Nonhematologic toxicities included nausea, vomiting, diarrhea, hypotension, and a proinflammatory syndrome characterized by anorexia, fatigue, fever, and tumor pain. The median peak concentrations of flavopiridol achieved at the MTDs on the 5-day, 3-day, and 1-day schedule were 1.7 micro mol/L (range, 1.3 to 4.2 micro mol/L), 3.2 micro mol/L (range, 1.7 to 4.8 micro mol/L), and 3.9 micro mol/L (1.8 to 5.1 micro mol/L), respectively. Twelve patients had stable disease for >/= 3 months, with a median duration of 6 months (range, 3 to 11 months).. The recommended phase II doses of flavopiridol as a 1-hour infusion are 37.5 mg/m(2)/d for 5 days, 50 mg/m(2)/d for 3 days, and 62.5 mg/m(2)/d for 1 day. Flavopiridol as a daily 1-hour infusion can be safely administered and can achieve concentrations in the micromolar range, sufficient to inhibit cyclin-dependent kinases in preclinical models. Further studies to determine the optimal schedule of flavopiridol as a single agent and in combination with chemotherapeutic agents are underway.

Topics: Adult; Aged; Antineoplastic Agents; Area Under Curve; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Flavonoids; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Piperidines; Treatment Outcome