Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Taxol (Paclitaxel) is a novel anti-cancer drug which has shown excellent clinical activity in a variety of solid tumors, particularly in metastatic breast and ovarian cancer. 70-80% of patients with metastatic non-seminomatous germ cell tumor (NSGCT) attain disease-free status with standard cisplatin-based combination chemotherapy but the emergence of drug resistance still prevents a small proportion of these patients from achieving long-term remission. Here we report the results of pre-clinical studies investigating whether taxol exhibits cross-resistance to cisplatin or ifosfamide in human NSGCT cell lines and in a cisplatin refractory xenograft model of human NSGCT. Following 96-h drug exposure in a 5-day sulphohodamine B (SRB) in vitro assay, taxol demonstrated potent cytotoxicity in cell lines which were cisplatin sensitive (577 LM, H32, H12.1; mean IC50s 1.5-3.0 nM) or those with acquired or intrinsic cisplatin resistance (H12DDP, H23.1; mean IC50s 2.5 nM). Compared to the drug-sensitive cell line, H12.1, the IC50 values of taxol were increased in cell line 1777NRp Cl-A with intermediate level resistance to cisplatin and ifosfamide (4.7 nM; p > 0.05) and significantly elevated in cell line 1411HP, with a high level of cisplatin resistance (6.9 nM; p < 0.01). The latter 2 cell lines may represent models corresponding to patients relapsing after high-dose platinum-based chemotherapy who seem to be resistant to taxol therapy. The IC50s of taxol in H32 and H12DDP were approximately 100-fold lower following drug exposure times exceeding 24 hours compared with short exposure times (1-6 h). Dose-dependent anti-tumor activity was observed with taxol in a cisplatin-refractory xenograft model of NSGCT (H23.1), with significant anti-tumor activity observed at a dose of 15 mg/kg/d injected intravenously on days 1 through 5. The results of this study are in accordance with the most recent clinical data which showed that taxol is a useful drug in relapsed or cisplatin-refractory testicular germ cell cancer, with significant anti-tumor activity being observed in 25% of patients, but poor activity in patients previously treated with high-dose therapy. Further pre-clinical research, especially using models such as 1411HP and 1777NRp Cl-A, on the combinations of taxol with other regimens are required to enable successful treatment of the most drug-resistant relapsed germ cell tumors.
 ...
PMID:Pre-clinical activity of taxol in non-seminomatous germ cell tumor cell lines and nude mouse xenografts. 922 Feb 87

The purpose of this study was to evaluate the diblock copolymer poly(DL-lactide)-block-methoxy polyethylene glycol as an i.v. delivery vehicle for paclitaxel. Nude mice were implanted s.c. with fragments of MV-522 lung carcinomas and treated with paclitaxel on a daily x 5 schedule when tumors were approximately 5 x 5 mm in size. Cremophor paclitaxel or polymeric micellar paclitaxel were given i.p. or i.v. at the maximum tolerated dose (Cremophor paclitaxel MTD: 20 mg/kg/day i.v. or i.p.; micellar paclitaxel MTD: 25 mg/kg/day i.v. or 100 mg/kg/day i.p.). The tumors were measured using callipers during the experiment and accurately weighted at the end. Two biodistribution studies were carried out. In one study, the nude mice were given micellar paclitaxel at a dose of 25 mg/kg i.v. or 100 mg/kg i.p. in another study, BDF-1 mice were given either micellar paclitaxel or Cremophor paclitaxel at a dose of 20 mg/kg i.v. The mice were sacrificed after a given time and the organs were harvested. Paclitaxel in the organs was extracted with acetonitrile and analyzed using HPLC. Tumor growth inhibitions of 98.5 and 98.7% were obtained from i.v. administered micellar paclitaxel and Cremophor paclitaxel at their MTDs, respectively. Micellar paclitaxel was more efficacious i.p. (98.7% tumor growth inhibition) than Cremophor paclitaxel i.p. (83.0% tumor growth inhibition) at their MTDs. The highest concentrations of paclitaxel were found in the liver after administration of paclitaxel formulations. Paclitaxel was also found in spleen, kidney, lung and blood, in order of decreasing concentration. The preliminary results indicate that polymeric micellar paclitaxel could be a clinically useful chemotherapeutic formulation.
 ...
PMID:Anti-tumor efficacy and biodistribution of intravenous polymeric micellar paclitaxel. 931 46

The goal of this National Cancer Institute-sponsored phase I trial is to determine the feasibility, toxicity, and pharmacokinetics of continuous-infusion (24 hr/d, 7 d/wk, 7 weeks total) intravenous paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) when combined with standard, curative-intent radiation therapy (RT) for previously untreated, locally advanced non-small cell lung cancers. Eligible patients have locally advanced (T4NXM0 or TXN2-3M0) non-small cell cancer ineligible for potentially curative surgical resection, a good performance status, adequate hematologic, hepatic, and renal functions, and no distant metastases. All patients receive a total tumor dose of 64.8 Gy megavoltage RT in 7 weeks at 1.8 Gy once daily, 5 d/wk. Paclitaxel is delivered by continuous intravenous infusion starting 48 hours before RT and continuing for its duration. The dose of paclitaxel is escalated in cohorts of three patients in a standard phase I design. To date, 16 patients have entered the trial, and 15 are evaluable for toxicity in this ongoing study. Paclitaxel dose is currently at a 6.5 mg/m2/d dose level, with no dose-limiting toxicity recorded thus far. One patient at the highest dose level has had grade 2 pneumonitis. With the exception of anemia, toxicities are those that would be expected from RT alone. A slowly progressive normocytic anemia with no renal dysfunction was found to be associated with an acquired hypoerythropoietin state. These findings indicate that this therapy is feasible and well tolerated through current dose levels, with no dose-limiting toxicity. Dose escalation is ongoing.
 ...
PMID:Seven-week continuous-infusion paclitaxel plus concurrent radiation therapy for locally advanced non-small cell lung cancer: a phase I study. 933 Nov 30

The goal of this National Cancer Institute-sponsored phase I trial is to determine the feasibility, toxicity, and pharmacokinetics of continuous-infusion (24 hr/d, 7 d/wk, 7-week total) intravenous paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) combined with standard curative radiotherapy (RT) for previously untreated, locally advanced head and neck squamous cell cancers. Eligible patients have squamous cell cancers of the head and neck with expected 5-year survival rates of < or =25%; a good performance status; adequate hematologic, hepatic, and renal functions; and no distant metastases. All patients receive 70 Gy megavoltage RT in 7 weeks (2 Gy/d x 5 d/wk). Paclitaxel is delivered by protracted venous infusion starting 48 hours before RT and continuing for its duration. Biopsies for cell-cycle distribution analyses and paclitaxel tissue levels are obtained, if possible, before beginning paclitaxel and after 48 hours just before RT begins. The dose of paclitaxel is escalated in cohorts of three patients. Eighteen patients are evaluable for toxicity. Treatment has been completed through the 6.5 mg/m2/d dose level and is ongoing at 10.5 mg/m2/d. There has been no dose-limiting toxicity thus far. With the exception of anemia, toxicity is commensurate with what would be expected from RT alone. A slowly progressive normocytic anemia with no renal dysfunction was found to be associated with an acquired hypoerythropoietin state. Tumor biopsies have suggested the possibility of paclitaxel-induced mitotic arrest. This therapy is feasible and has been well tolerated through current dose levels with no dose-limiting toxicity. There is a suggestion of biologic activity evidenced by the anemia and the possibility of alteration in cell-cycle distributions. Dose escalation is ongoing.
 ...
PMID:Seven-week continuous-infusion paclitaxel with concurrent radiotherapy for locally advanced head and neck squamous cell cancer: a phase I study. 942 70

We demonstrated in an earlier trial that paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has substantial antineoplastic activity, with acceptable toxicity, in patients with advanced metastatic esophageal cancer. Preclinical and clinical data from studies in other tumors indicate substantial additive or even synergistic activity for paclitaxel/cisplatin combination chemotherapy. We encountered substantial toxicity with a cisplatin/paclitaxel/5-fluorouracil combination. To maximize paclitaxel dose, we initiated a phase II trial using cisplatin and paclitaxel alone. This report summarizes preliminary data from that trial. Paclitaxel 200 mg/m2 is given as a continuous, 24-hour infusion on day 1. On day 2, cisplatin 75 mg/m2 is given. Courses are repeated every 21 days. Dose adjustments are based on myelosuppression, neurotoxicity, and (for cisplatin) renal or auditory toxicity. All patients receive recombinant human granulocyte colony-stimulating factor to minimize the risk of neutropenic fever. The primary end point of the study is tumor regression. Secondary end points include duration of response and toxicity. Two groups of patients are being studied. Those with advanced metastatic disease receive chemotherapy alone as palliative treatment. The second group has locoregional disease that is potentially resectable. These patients receive combined-modality therapy involving induction paclitaxel/cisplatin chemotherapy followed by surgery. To date, 37 evaluable patients have been treated. Twenty had advanced metastatic disease and 17 were treated before planned surgery. Twenty-seven patients had adenocarcinoma and 10 had epidermoid carcinoma. Major objective responses were seen in 49% of all patients, with similar response rates for patients with metastatic and locoregional disease. The median duration of response for patients with metastases is 4+ months. Among 14 patients treated before surgery, one experienced a complete pathologic response, and the neoplasms of 43% were downstaged. Primary toxicity was neutropenia, which was tolerable. Surgical morbidity or mortality did not increase. Cisplatin plus paclitaxel is an active combination in the treatment of patients with advanced or locoregional esophageal cancer. Further studies with this combination both in metastatic and locally advanced disease are indicated.
 ...
PMID:A phase II trial of paclitaxel and cisplatin in patients with locally advanced metastatic esophageal cancer: a preliminary report. 942 72

The current phase II study evaluates the safety and efficacy of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and 5-fluorouracil (5-FU) plus folinic acid in patients with advanced gastric cancer. Paclitaxel 175 mg/m2 was given intravenously over 3 hours on days 1 and 22; folinic acid 500 mg/m2 given intravenously over 2 hours followed by 5-FU 2,000 mg/m2 given intravenously over 24 hours was administered on days 1, 8, 15, 22, 29, and 36. Six weeks of treatment were considered one cycle, and each cycle was followed by 2 weeks off treatment. Twenty-two patients (six women and 16 men) with advanced/metastatic gastric cancer were entered on trial. All patients are evaluable for response and toxicity. None had received prior chemotherapy. Radiologically metastatic sites included gastric lymph nodes (64%), liver (36%), lungs (18%), peritoneum (18%), bone (9%), and skin (5%). No complete responses were observed. Seven patients (32%; 95% confidence interval, 12% to 52%) had a partial response. Sites of partial responses included the lungs, skin, lymph nodes, and locally advanced tumor. Twelve patients (55%) had stable disease and three (14%) had disease progression. At a median follow-up of 12 months (range, 1 to 17+ months), the median overall survival for all patients was 11 months (range, 1 to 17+ months; 95% confidence interval, 6.8 to 18.2) and the median progression-free interval was 8 months (range, 1 to 13+ months; 95% confidence interval, 4.7 to 9.8). Severe nonhematologic toxicities were alopecia (45%), fever/infection (9%), diarrhea (5%), and nausea/vomiting (5%). Grade 3/4 neutropenia occurred in three patients (14%). In summary, paclitaxel given every 3 weeks in combination with once-weekly, 24-hour continuous infusions of 5-FU/folinic acid is active in advanced gastric cancer and appears to achieve response rates comparable to regimens like etoposide/folinic acid/5-FU or 5-FU/doxorubicin/methotrexate. The toxicity of this new combination is moderate and allows treatment in an outpatient setting. Ongoing studies are evaluating the activity of paclitaxel combined with weekly continuous infusions of 5-FU/folinic acid with or without cisplatin.
 ...
PMID:Paclitaxel and weekly 24-hour infusion of 5-fluorouracil/folinic acid in advanced gastric cancer. 942 77

We examined paclitaxel for anti-tumor activity against human lung cancer xenografts in nude mice and compared its efficacy with that of cisplatin, currently a key drug for lung cancer chemotherapy. Five non-small cell lung cancers (A549, NCI-H23, NCI-H226, NCI-H460 and NCI-H522) and 2 small cell lung cancers (DMS114 and DMS273) were chosen for this study, since these cell lines have been well characterized as regards in vitro and in vivo drug sensitivity. These cells were exposed to graded concentrations of paclitaxel (0.1 to 1000 nM) for 48 h. The 50% growth-inhibitory concentrations (GI50) for the cell lines ranged from 4 to 24 nM, which are much lower than the achievable peak plasma concentration of paclitaxel. In the in vivo study, 4 cell lines (A549, NCI-H23, NCI-H460, DMS-273) were grown as subcutaneous tumors xenografts in nude mice. Paclitaxel was given intravenously as consecutive daily injections for 5 days at the doses of 24 and 12 mg/kg/day. Against every xenograft, paclitaxel produced a statistically significant tumor growth inhibition compared to the saline control. Paclitaxel at 24 mg/kg/day was more effective than cisplatin at 3 mg/kg/day with the same dosing schedule as above, although the toxicity of paclitaxel was similar to or rather lower than that of cisplatin, in terms of body weight loss. In addition, paclitaxel showed potent activity against 2 other lung cancer xenografts (NCI-H226 and DMS114). Therefore, paclitaxel showed more effective, wider-spectrum anti-tumor activity than cisplatin in this panel of 6 lung cancer xenografts. These findings support the potential utility of paclitaxel in the treatment of human lung cancer.
 ...
PMID:Anti-tumor efficacy of paclitaxel against human lung cancer xenografts. 947 39

The taxanes paclitaxel and docetaxel represent a novel class of antineoplastic agents. A major problem of both drugs is their low aqueous solubility and the design of suitable formulations has been a difficult step in the process of therapeutic development. The formulations currently used are mixtures of Cremophor EL:ethanol for paclitaxel (Taxol) and Tween 80:ethanol for docetaxel (Taxotere), but many new approaches have been tested or are under investigation. Paclitaxel and docetaxel have a similar mechanism of action, which is based on promotion of tubulin assembly and inhibition of microtubule disassembly. Pharmacokinetic studies revealed a marked non-linearity of paclitaxel in mice, which appeared to result exclusively from Cremophor EL, the major component present in the pharmaceutical formulation. An almost linear pharmacokinetic behavior was observed in the case of docetaxel. The reported plasma protein binding of both compounds ranged from 76 to 97% in different animal species. Paclitaxel and docetaxel widely distribute into most tissues of mice and rats, including tumor tissue, but only low concentrations were detected in the central nervous system. Despite the great similarity in the chemical structures of paclitaxel and docetaxel, their metabolic profile is very distinct. Furthermore, whereas paclitaxel metabolism is largely species dependent, docetaxel metabolism is similar across species in both isolated hepatic microsomal fractions and in vivo models. For both taxanes, hepatobiliary excretion is the major pathway of elimination and a major fraction of the dose is excreted in feces as parent drug or hydroxylated metabolites.
 ...
PMID:Preclinical pharmacokinetics of paclitaxel and docetaxel. 949 87

Paclitaxel (Taxol) is a diterpene originally obtained from the bark of the Pacific Yew Tree, Taxus Brevifolia. Its mechanism of action is unique. It stabilizes microtubule polymerization, thus blocking cells in the G2/M phase of the cell cycle. In breast cancer, initial studies using paclitaxel demonstrated high activity. The first study was reported in 1991 by Holmes et al who gave paclitaxel as a 24-hour infusion at 250 mg/m2 to 25 patients with metastatic breast cancer following only one prior chemotherapy regimen--they achieved a 56% response rate. Since then, numerous studies have confirmed the effectiveness of paclitaxel in patients with metastatic disease. A second taxane, docetaxel (Taxotere), has also demonstrated excellent activity. Clinical research is now focused on integrating the taxanes into combination drug regimens and into neoadjuvant and adjuvant schedules for patients with early stage breast cancer, as well as looking at the biologic determinants of response and resistance to taxanes. This article will review developments in the use of taxanes in the adjuvant and neoadjuvant settings and it will review the information on possible molecular markers that may be useful in predicting tumor responsiveness to taxanes.
 ...
PMID:Taxanes in adjuvant and neoadjuvant therapies for breast cancer. 951 99

Paclitaxel (Taxol) is a new class of anti-tumor agents which act by promoting the assembly and inhibiting the disassembly of microtubules. Single-agent studies have shown its significant activity for advanced cancers in various organs including ovary, lung, breast, and head and neck. Combination therapies with other anticancer agents have been extensively investigated in these cancers. Paclitaxel combined with cisplatin is now considered to be the standard treatment for advanced ovarian cancer. In other cancers, promising results have been obtained in several studies of paclitaxel-based chemotherapy. Major toxicities of paclitaxel-monotherapy are hypersensitivity reaction, neutropenia, and peripheral neuropathy. Combination of other cytotoxic agents sometimes leads to severer toxicities such as neurotoxicity with cisplatin and cardiotoxicity with anthracycline. Although further evaluation is needed, paclitaxel will be a main agent in the treatment of advanced solid tumors.
 ...
PMID:[Paclitaxel (taxol): a review of its antitumor activity and toxicity in clinical studies]. 953 Mar 72


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>