epothilone-a and Neutropenia

Microtubules are vital and dynamic cellular organelles and many agents have been developed that target them. The cytotoxic effects of taxanes and epothilones are mediated by stabilization of microtubule dynamics. Taxanes are one of the most effective cytotoxic agents, and have a broad spectrum of antitumor activity. However, their efficacy is limited by the development of resistance to these effects. Epothilones have a similar mechanism of action to taxanes, but a decreased propensity for drug resistance. Epothilones are macrolides, and have in vitro and in vivo activity in taxane-resistant or taxane-insensitive human cancer cell lines. Several epothilones are in clinical development: ixabepilone, patupilone, BMS-310705, KOS-862, KOS-1584, and ZK-EPO. Multiple dosing schedules of ixabepilone and patupilone have been studied. The toxicity profiles of epothilones are quite diverse and depend on the compound and the administration schedule. The epothilones have demonstrated a wide range of clinical activity, including important antitumor effects, in advanced prostate cancer. Epothilones are particularly useful in patients with prostate cancer who have previously been treated with taxanes or who have taxane-refractory tumors. In the setting of castrate metastatic prostate cancer, ixabepilone and patupilone showed encouraging clinical activity in the phase II setting and further studies are needed to determine if they provide additional clinical benefit to patients with advanced disease.

Topics: Antineoplastic Agents; Cell Line, Tumor; Clinical Trials, Phase II as Topic; Epothilones; Humans; Inhibitory Concentration 50; Male; Molecular Structure; Neoplasm Metastasis; Neutropenia; Prostate-Specific Antigen; Prostatic Neoplasms; Randomized Controlled Trials as Topic; Tubulin

The epothilones are a new class of microtubule-stabilizing drugs that exert potent antitumor activity against taxane-resistant and multidrug resistant cell lines. The most clinically advanced member of this class is the semisynthetic epothilone B derivative ixabepilone.. This article reviews the preclinical and clinical data on ixabepilone in patients with locally advanced and metastatic breast cancer (MBC) and provides guidance for pharmacists on its optimal use.. PubMed and conference proceedings through August 2008.. In preclinical studies, ixabepilone has demonstrated potent antitumor activity and low susceptibility to mechanisms that confer tumor resistance. Clinically meaningful benefits have been achieved with ixabepilone monotherapy in phase 2 trials of patients with MBC who have failed previous chemotherapies (anthracyclines, taxanes, or capecitabine). In a randomized, phase 3 trial, the combination of ixabepilone and capecitabine proved more effective than capecitabine alone after the failure of taxane and anthracycline regimens. At the recommended dose and schedule, the therapeutic ratio of ixabepilone is generally favorable, and its adverse effects (notably neutropenia and peripheral neuropathy) are generally manageable and reversible.. Ixabepilone represents an advance in the treatment of anthracycline - and taxane-pretreated MBC. Future studies will define its efficacy in combination with other drugs used in the treatment of MBC, as well as in other types of cancer.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Capecitabine; Clinical Trials as Topic; Deoxycytidine; Epothilones; Female; Fluorouracil; Humans; Neoplasm Metastasis; Neutropenia; Peripheral Nervous System Diseases; Premedication; Tubulin Modulators

Microtubule-targeted anticancer drugs are effective in treating various cancers but are limited in use due to development of resistance and unacceptable toxicities. The epothilones are a novel class of microtubule-stabilizing anticancer drugs and may have a role in treating taxane-resistant cancers. Revised and updated data from several clinical studies for ixabepilone were recently published and subsequently resulted in ixabepilone becoming the first epothilone approved as monotherapy or in combination for treatment of locally advanced or metastatic breast cancer. BMS-310705, patupilone, KOS-862, KOS-1584 and ZK-EPO are epothilones that have been developed. Although peripheral sensory neuropathy and neutropenia are the dose-limiting toxicities for ixabepilone, these dose-limiting toxicities are ixabepilone specific. This review will discuss the current preclinical, clinical pharmacokinetic and pharmacodynamic, efficacy and toxicity data of the epothilones.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Clinical Trials as Topic; Dogs; Drug Screening Assays, Antitumor; Epothilones; Female; Humans; Male; Mice; Microtubules; Neoplasm Metastasis; Neutropenia; Peripheral Nervous System Diseases; Rats; Structure-Activity Relationship; Tubulin Modulators

Pazopanib is a tyrosine kinase inhibitor predominantly acting on tumor endothelium, and ixabepilone is a semisynthetic analog of epothilone B that promotes microtubule stabilization inducing tumor and tumor endothelial cell apoptosis. The purpose of this study was to determine the optimal tolerated dose (OTD) of the combination of pazopanib and ixabepilone for the treatment of metastatic previously treated solid tumors.. Dose escalation started at 32 mg/m of ixabepilone and increased to 40 mg/m. Pazopanib was administered initially at 400 mg and escalated at 200 mg increments up to 800 mg. Pharmacokinetic analysis assessed effect of ixabepilone on pazopanib metabolism. Correlative studies evaluated changes in angiogenic cytokines.. Thirty-one patients (20 male and 11 female; median age, 58 y) with ECOG PS of 0 or 1 were enrolled. Three patients had dose-limiting toxicities (fatigue and neutropenia) at dose level 2 (ixabepilone 40 mg/m and pazopanib 400 mg), and therefore the ixabepilone dose was decreased (32 mg/m) before escalating pazopanib to levels 3 and 4. One patient had a dose-limiting toxicity (thrombocytopenia) at dose level 4 (ixabepilone 32 mg/m and pazopanib 800 mg). Dose level 3 was determined to be the OTD (pazopanib 600 mg and ixabepilone 32 mg/m). The most common toxicities were cytopenias. A significant decrease in the level of sE-selectin was associated with improvement in progression free survival.. The OTD for combination of pazopanib and ixabepilone was established. There was no impact of ixabepilone on pazopanib pharmacokinetics. The relationship between sE-selectin and progression free survival warrants further investigation.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Cytokines; Disease-Free Survival; E-Selectin; Epothilones; Fatigue; Female; Humans; Indazoles; Male; Middle Aged; Neoplasms; Neutropenia; Pyrimidines; Retreatment; Sulfonamides; Survival Rate; Thrombocytopenia

This multicenter, open-label, randomized phase II trial compared the efficacy and tolerability of weekly ixabepilone versus the standard 3 weekly dosing regimen. Patients with human epidermal growth factor receptor 2-negative, metastatic breast cancer (MBC) were randomly assigned to receive either ixabepilone 16 mg/m(2) as a 1-h intravenous (IV) infusion weekly on days 1, 8, and 15 of a 28-day cycle (1 week off therapy; n = 85), or 40 mg/m(2) as a 3-h IV infusion on day 1 of a 21-day cycle (n = 91), until disease progression or unacceptable toxicity. Randomization was stratified by (i) measurable versus nonmeasurable (evaluable) disease, (ii) ≤two versus >two prior chemotherapy regimens for MBC, and (iii) hormone receptor (HR)-positive versus HR-negative breast cancer. The primary endpoint was rate of progression-free survival (PFS) at 6 months. Of 176 randomized patients, 171 were treated. The 6-month PFS rate was significantly higher in patients treated with ixabepilone every 3 weeks (42.7, 95 % confidence interval [CI] 31.5-53.5) compared with those who received ixabepilone weekly (28.6, 95 % CI 18.9-38.9; log-rank P = 0.03). Every-3-week dosing significantly prolonged median PFS versus weekly dosing (5.3 vs. 2.9 months; log-rank P = 0.05). The every-3-week regimen was associated with higher rates of grade 3/4 toxicities, particularly neutropenia (38.2 vs. 6.1 %) and a higher rate of patient withdrawal due to adverse events. These results suggest that every-3-week ixabepilone is more effective than weekly treatment in MBC, albeit with more toxicity.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Breast Neoplasms; Drug Administration Schedule; Epothilones; Female; Humans; Middle Aged; Neutropenia; Peripheral Nervous System Diseases; Treatment Outcome

We previously demonstrated that peak microtubule bundle formation (MBF) in peripheral blood mononuclear cells (PBMCs) occurs at the end of drug infusion and correlates with drug pharmacokinetics (PK). In the current study, a new expanded evaluation of drug target effect was undertaken.. Patients with advanced solid malignancies were treated with ixabepilone 40 mg/m2 administered as a 1-h i.v. infusion every 3 weeks. Blood, plasma, and tumor tissue sampling was carried out to characterize pharmacodynamics and PK.. Forty-seven patients were treated with 141 cycles of ixabepilone. In both PBMCs (n=27) and tumor cells (n=9), peak MBF occurred at the end of infusion; however, at 24-72 h after drug infusion, the number of cells with MBF was significantly greater in tumor cells, relative to PBMCs. A Hill model (EC50=109.65 ng/ml; r2=0.94) was fitted, which demonstrated a relationship between percentage of PBMCs with MBF and plasma ixabepilone concentration. The percentage of PBMCs with MBF at the end of infusion also correlated with severity of neutropenia (P=0.050).. Plasma ixabepilone concentration and severity of neutropenia correlate with the level of MBF in PBMCs. Therefore, this technically straightforward assay should be considered as a complement to the clinical development of novel microtubule-binding agents.

Topics: Adult; Aged; Aged, 80 and over; Epothilones; Female; Humans; Infusions, Intravenous; Leukocytes, Mononuclear; Male; Microtubules; Middle Aged; Neoplasms; Neutropenia; Tubulin Modulators

To establish the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), safety, pharmacokinetics, and pharmacodynamics of ixabepilone when administered as a 1-hour infusion every 3 weeks to patients with advanced solid tumors or relapsed/refractory non-Hodgkin's lymphoma. Dosing schedules of 40 mg/m2 and 50 mg/m2 over 3 hours were also evaluated.. Sixty-one patients were enrolled using an initial accelerated dose-escalation phase followed by a standard dose-escalation phase, with doses of ixabepilone ranging from 7.4 to 65 mg/m2. The pharmacokinetics of ixabepilone and two of its chemical degradation products were evaluated. Plasma pharmacodynamics were evaluated for both 1- and 3-hour infusions using an assay that measures the amount of endogenous tubulin in peripheral-blood mononuclear cells that exists in the polymerized versus the unpolymerized state. Response evaluation was performed every 6 weeks.. The most common DLTs were neutropenia, stomatitis/pharyngitis, myalgia, and arthralgia. The MTD of ixabepilone as a 1-hour infusion every 3 weeks was established as 50 mg/m2. The maximum plasma concentration and area under the plasma concentration time curve appeared to increase less than proportionally to dose. Durable objective responses were seen in eight patients, including two complete responses. Five of the responders had experienced treatment failure with a taxane.. The recommended dose of ixabepilone for the initiation of phase II studies on the basis of these results is 50 mg/m2 over 1 hour every 3 weeks. The promising efficacy and tolerability results demonstrated by ixabepilone in this study warrant its continued development.

Topics: Adult; Aged; Antineoplastic Agents; Cohort Studies; Drug Administration Schedule; Drug Hypersensitivity; Epothilones; Female; Humans; Infusions, Intravenous; Lymphoma, Non-Hodgkin; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Neoplasms; Neutropenia; Peripheral Nervous System Diseases; Practice Guidelines as Topic; Survival Analysis; Thrombocytopenia; Time Factors; Treatment Failure; Treatment Outcome; Tubulin Modulators; United States

Paclitaxel and docetaxel are active agents in advanced urothelial cancer. BMS-247550 (ixabepilone) has activity in preclinical models in paclitaxel resistant models. A phase 2 trial of this epothilone was performed to determine the activity and toxicity of this agent in a multi-institutional setting in patients previously treated with 1 prior chemotherapy regimen.. Forty-five patients with advanced urothelial carcinoma were treated with BMS-247550 40 mg/m(2) over 3 hours intravenously on Day 1 of a 21-day cycle and continued therapy until progression or unacceptable toxicity.. Five patients obtained an objective partial response (PR) among the 42 eligible patients for an overall response rate of 11.9% (90% confidence interval [5.3%, 26.5%]). Median overall survival of the group was 8 months. Toxicity was moderate with granulocytopenia, fatigue, and sensory neuropathy being the most common side effects noted.. BMS-247550 (ixabepilone) has very modest activity as a second-line therapy for advanced urothelial cancer. Responses in visceral, nodal, and soft tissues sites were observed. Granulocytopenia without fever, fatigue, and sensory neuropathy was common.

Topics: Adult; Aged; Aged, 80 and over; Agranulocytosis; Carcinoma, Transitional Cell; Epothilones; Female; Fever; Humans; Male; Middle Aged; Neutropenia; Prognosis; Survival Analysis; Treatment Outcome; Urinary Bladder Neoplasms

BMS-310705, a water-soluble semi-synthetic analogue of epothilone B, was selected for clinical development because of its in vivo anti-tumour activity and toxicity profile similar to that of ixabepilone, currently the most extensively evaluated and promising epothilone B analogue. The improved solubility of BMS-310705 allowed a cremophore-free formulation that avoided the need for pre-medication.. Two schedules were tested, one with drug administrations on days (D) 1, 8 and 15 followed by 1-week's rest, the other with administrations on D1 and 8 (D1&8 schedule) followed by 1-week's rest. Treatment was given as a 15-min infusion without pre-medication against hypersensitivity. The plasma pharmacokinetics of BMS-310705 was studied in 30 patients. An accelerated titration design 2B was applied for dose escalations. Twenty-seven patients were accrued in the D1, 8, 15 and 32 in the D1&8 schedule.. The dose was escalated from 5-30 mg/m(2)/week with diarrhoea as dose-limiting toxicity; 15 and 20 mg/m(2) were the recommended doses in the D1, 8, 15 and D1&8 schedule, respectively. Other frequent non-haematological toxicities were neurotoxicity, mainly paraesthesia, asthenia and myalgia. Preliminary results showed linear pharmacokinetics along the range of doses tested with a short half-life. Five objective responses were reported.. Further clinical development of BMS-310705 might be worthwhile in solid tumours where ixabepilone or other epothilones are not indicated.

Topics: Adult; Aged; Antineoplastic Agents; Diarrhea; Drug Administration Schedule; Epothilones; Female; Humans; Male; Middle Aged; Neoplasms; Nervous System Diseases; Neutropenia; Tubulin Modulators

To evaluate the antitumor activity and safety of the epothilone B analog, ixabepilone, with or without estramustine phosphate (EMP), in chemotherapy-naive patients with progressive castrate metastatic prostate cancer.. Patients were randomly assigned to receive ixabepilone (35 mg/m(2)) by intravenous infusion every 3 weeks with or without EMP 280 mg orally three times daily on days 1 to 5.. Between December 2001 and October 2003, 92 patients were enrolled and randomly assigned to treatment with ixabepilone alone (45 patients) or in combination with EMP (47 patients). Grades 3 and 4 toxicities experienced by more than 5% of patients included neutropenia (22%), fatigue (9%), and neuropathy (13%) on the ixabepilone arm, and neutropenia (29%), febrile neutropenia (9%), fatigue (9%), neuropathy (7%), and thrombosis (6%) on the ixabepilone + EMP arm. Post-treatment declines in prostate-specific antigen of > or = 50% were achieved in 21 of 44 patients (48%; 95% CI, 33% to 64%) on the ixabepilone arm, and 31 of 45 patients (69%; 95% CI, 55% to 82%) on the ixabepilone + EMP arm. In patients with measurable disease, partial responses were observed in eight of 25 patients (32%; 95% CI, 14% to 50%) on the ixabepilone arm, and 11 of 23 (48%; 95% CI, 27% to 68%) on the ixabepilone + EMP arm. Time to prostate-specific antigen progression was 4.4 months (95% CI, 3.1 to 6.9 months) on the ixabepilone-alone arm and 5.2 months (95% CI, 4.5 to 6.8 months) on the combination arm.. Ixabepilone, with or without estramustine phosphate, is well tolerated and has antitumor activity in patients with castrate metastatic prostate cancer.

Topics: Aged; Aged, 80 and over; Antineoplastic Agents; Antineoplastic Agents, Alkylating; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Castration; Epothilones; Estramustine; Fatigue; Humans; Male; Middle Aged; Neoplasm Metastasis; Neutropenia; Peripheral Nervous System Diseases; Prostatic Neoplasms; Thrombosis

The epothilones are a novel class of nontaxane microtubule-stabilizing agents. BMS-247550 is a semisynthetic analog of the natural product epothilone B. We conducted a phase I study administering BMS-247550 as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days.. Twenty-one patients received BMS-247550 without filgrastim in the first cycle. An additional six patients were enrolled at a starting dose of 8 mg/m2/d with filgrastim support. Twenty-one of the 27 patients had received prior paclitaxel, docetaxel, or both.. One hundred seven cycles were administered to 27 patients. The maximum-tolerated dose was 6 mg/m2 of BMS-247550 administered as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. Dose-limiting toxicity at a dose of 8 mg/m2/d was neutropenia with or without filgrastim support. Nonhematologic grade 3 toxicities included fatigue (seven cycles), stomatitis (two cycles), and anorexia (one cycle). The mean terminal half-life of BMS-247550 was 16.8 +/- 6.0 hours, the volume of distribution at steady-state was 798 +/- 375 L, and the clearance was 712 +/- 247 mL/min. Objective responses were observed in patients with breast, cervical, and basal cell cancer. Reductions in CA-125 levels were noted in patients with ovarian cancer.. The recommended phase II dose of BMS-247550 on the daily schedule for 5 days is 6 mg/m2/d. Neutropenia was dose limiting, but higher doses were tolerated by a large fraction of patients with filgrastim support. Peripheral neuropathy was mild, even after multiple cycles of therapy, and was not dose limiting.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Drug Administration Schedule; Epothilones; Fatigue; Female; Filgrastim; Granulocyte Colony-Stimulating Factor; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Recombinant Proteins; Stomatitis