rpr-109881a and Neoplasms

Larotaxel (XRP9881, RPR109881), a novel semi-synthetic taxoid that shares a mode of action with the taxanes docetaxel and paclitaxel, was active in preclinical studies against a broad spectrum of tumour cells and tumour models refractory/resistant to taxanes, and have demonstrated clinical activity in taxane pre-treated/resistant metastatic breast cancer (MBC) patients. The current phase I dose-escalation study sought to define in Japanese patients with advanced solid tumours the maximum tolerated dose (MTD) and recommended dose (RD) of larotaxel administered as a 1-h intravenous infusion every 3 weeks. Eighteen patients were treated in total with 11 of those (61%) having previously received a docetaxel- or paclitaxel-based regimen. The MTD was defined as 90 mg/m(2) following the occurrence of dose-limiting toxicities (DLTs) in two of five patients treated at this dose level including grade 4 neutropenia lasting >7 days or febrile neutropenia. The RD for phase II was consequently 75 mg/m(2) q3w, with no DLTs in the six patients treated. The principal toxicity and DLT was neutropenia, with or without neutropenic complications. Partial responses were reported for 2 of 18 (11%) treated patients and a further 8 achieved stable disease (44%). The clearance 19.1-31.9 L/h was similar to that observed in Caucasian subjects with value of 33.0 +/- 10.7 L/h. In conclusion, larotaxel 75 mg/m(2), administered as a 1-h infusion every 3 weeks, appeared to be clinically tolerable in this Japanese patient population and showed early indications of activity.

Topics: Adult; Aged; Antineoplastic Agents; Asian People; Dose-Response Relationship, Drug; Female; Fever; Humans; Infusions, Intravenous; Japan; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Taxoids; Treatment Outcome

To define the maximum tolerated dose (MTD), the recommended phase II dose, the optimal infusion duration and pharmacokinetics of the semisynthetic taxoid derivative RPR 109881A, given as a 1-h or 3-h infusion every 3 weeks.. RPR109881A was administered as a 1-h i.v. infusion to 34 patients (study 1) with oral steroids as pre-medication. In a subsequent study, 29 patients were treated at the recommended dose or at the dose immediately below (study 2); the first 14 patients received RPR 109881A as a 3-h infusion, while the subsequent 15 were randomized to receive the drug as a 1-h or 3-h infusion. The pharmacokinetics of RPR109881A was studied in plasma and urine and for selected patients in some biological fluids (cerebrospinal fluid, pleural effusion, ascitis).. In study 1, the dose was escalated from 15 to 105 mg/m(2), at which dose two of five patients presented dose-limiting toxicities with febrile neutropenia (FN) after the first cycle, thus defining the MTD. The dose of 90 mg/m(2), at which grade 3/4 neutropenia was almost universal with FN in 18%, was recommended for phase II. At 90 mg/m(2) the incidence of diarrhea, fatigue and alopecia were 59, 29 and 70%, respectively. The results of study 2 were comparable to those of study 1, thus recommending the 1-h infusion duration for phase II evaluation. RPR 109881A exhibited a high total body clearance, a large distribution volume and long terminal half-life of 20 h. RPR 109881A was detected in cerebrospinal fluid shortly after the end of 1-h infusion. Three objective responses were observed in non-small-cell lung cancer (NSCLC) patients, including a patient with brain metastases.. The antitumor activity in NSCLC, the reproducible profile of toxicity and above all the ability to cross the blood-brain barrier make RPR 109881A worthy of further disease-oriented clinical development.

Topics: Adolescent; Adult; Aged; Biological Availability; Biopsy, Needle; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Neoplasms; Paclitaxel; Risk Assessment; Sensitivity and Specificity; Survival Analysis; Taxoids; Treatment Outcome

To define the maximum-tolerated dose, recommended phase II dose (RD), dose-limiting toxicity (DLT), and pharmacokinetics of a novel taxane, RPR 109881A, administered on days 1 and 8 of a 21-day cycle.. Twenty-nine patients were enrolled and treated according to a modified continual reassessment method from a starting dose of 7.5 mg/m(2) to 52.5 mg/m(2). Detailed pharmacokinetic analyses of blood and urine were performed on days 1 and 8 of the first cycle. Toxicity was monitored weekly.. DLT consisting of grade 3 or 4 diarrhea was seen in three of six patients at 52.5 mg/m(2). Grade 3 or 4 granulocytopenia was also seen in five of six patients treated at this dose (four of six in the first cycle). At the next lower dose level, 45 mg/m(2) toxicity was moderate, with only one of 12 patients experiencing severe diarrhea and grade 4 granulocytopenia with associated infection. Drug concentrations were consistent with a three-compartment open model. The total-body clearance suggests a linear dose-concentration relationship. RPR 109881A has a high clearance (mean, 42.6 L/h/m(2)), a large volume of distribution (mean, 952 L/m(2)), and a long terminal half-life (mean, 24 hours). There was no drug accumulation between days 1 and 8. One partial response was seen in a patient with renal cell carcinoma.. The RD of RPR 109881A given as a 1-hour infusion on days 1 and 8 of a 21-day cycle is 45 mg/m(2). At this dose the drug is well tolerated and should be further studied.

Topics: Adult; Aged; Agranulocytosis; Antineoplastic Agents, Phytogenic; Diarrhea; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Neoplasms; Paclitaxel; Taxoids

RPR 109881A is a new semisynthetic taxoid compound that has a similar mechanism of action to docetaxel. The purpose of this phase I study was to characterize the maximum-tolerated dose (MTD), toxicity profile, pharmacokinetic profile, and antitumor effects of this agent.. Nineteen eligible patients with advanced solid tumors were enrolled. RPR 109881A was administered as a 1-hour intravenous infusion every 3 weeks at doses ranging from 15 to 75 mg/m(2). Pharmacokinetic evaluation was performed at the first cycle.. Neutropenia (febrile neutropenia) and fatigue were dose-limiting toxicities at doses of 60 and 75 mg/m(2) and seemed to be dose-related. Both thrombocytopenia and anemia were infrequent. Nonhematologic toxicities were generally mild. Pharmacokinetic studies indicated that RPR 109881A plasma disposition was bi- or triphasic, with a high total plasma clearance, a large volume of distribution, and a long terminal half-life. The area under the concentration-time curve (AUC) and the peak concentration of RPR 109881A seemed to increase with increasing dose proportionally, suggesting linear pharmacokinetics. Urinary excretion over 48 hours was low, with a mean of 0.8 +/- 0.36% of the administered dose. A significant relationship existed between the percentage decrease of neutrophil counts and the AUC of RPR 109881A. Among 18 assessable patients, two partial and two minor responses were documented.. RPR 109881A was found to be a well-tolerated and promising taxoid agent. The MTD was 75 mg/m(2), and the recommended dose for phase II study was 60 mg/m(2) as a 1-hour infusion every 3 weeks.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Neoplasms; Paclitaxel; Taxoids