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Biomedical subjects

J Verweij

Publications and source records attributed to J Verweij.

At least 145 records · Page 8Linked to original sources
PubMed1999

The venotonic drug hydroxyethylrutosiden does not prevent or reduce docetaxel-induced fluid retention: results of a comparative study.

PURPOSE: Fluid retention, which includes peripheral edema, ascites, pleural or pericardial effusion, or a combination of these that is sometimes associated with significant weight gain, is one of the most troublesome cumulative side effects of docetaxel. A suggestive observation from the data base available at the manufacturer (Rhone-Poulenc Rorer) was that patients who received venotonic drugs appeared to tolerate more courses of docetaxel. This prompted a comparative study to investigate whether the venotonic drug hydroxyethylrutosiden could reduce or delay docetaxel-related fluid retention. METHODS: A total of 85 patients with metastatic breast cancer who were treated with docetaxel at a dose of 100 mg/m2 with corticoid comedication were allocated to receive either 300 mg hydroxyethylrutosiden given orally four times daily (group A) or no hydroxyethylrutosiden (group B). The end point for analysis was the development of fluid retention of > or = grade 2. RESULTS: Fluid retention of > or = grade 2 was reported in 14 of 42 patients (33%) in group A and in 15 of 43 patients (35%) in group B and occurred after a median of 4 cycles of docetaxel in both groups. Weight gain was similar in groups A and B. CONCLUSION: We conclude that hydroxyethylrutosiden does not reduce or delay the incidence and severity of docetaxel-related fluid retention.

Adult↗
PubMed1999

Clinical pharmacokinetics of encapsulated oral 9-aminocamptothecin in plasma and saliva.

OBJECTIVE: To study the pharmacokinetics and pharmacodynamics of the novel topoisomerase I inhibitor and antitumor agent 9-amino-20(S)-camptothecin in patients with solid tumors after repeated oral administration. METHODS: Thirty-two patients with cancer received oral 9-aminocamptothecin formulated in capsules with polyethylene glycol-1000 as excipient at doses that ranged from 0.25 to 1.5 mg/m2/day. Serial plasma and saliva samples were obtained on days 1 and 6 or days 1 and 8 of the first cycle and analyzed for the lactone and carboxylate forms of 9-aminocamptothecin by HPLC. RESULTS: 9-Aminocamptothecin showed linear and dose-independent pharmacokinetics, with extremely small intrapatient kinetic variability (coefficient of variation: <10%). However, interpatient variability in plasma pharmacokinetics was large (coefficient of variation: 99%). The relative extent of lactone to carboxylate interconversion was large (>90%) and predictable from individual pretreatment serum albumin values (P = .0099). The 9-aminocamptothecin concentration ratio in plasma and saliva was strongly patient dependent, and highly variable around a mean value of <0.8, suggesting that saliva is an unreliable matrix for kinetic monitoring. The area under the curve of the lactone form of 9-aminocamptothecin was significantly correlated with the dose-limiting hematologic toxicity (P < .001). CONCLUSION: Our data indicate that the large interindividual pharmacodynamic variability in response to 9-aminocamptothecin is caused mainly by a variability in kinetic characteristics, suggesting that a kinetic-dynamic guided study design is warranted in future clinical investigations.

Administration, Oral↗
PubMed1999

Sensitivity and dynamics of rod signals in H1 horizontal cells of the macaque monkey retina.

We measured the sensitivity, temporal frequency response, latency, and receptive field diameter of rod input to the H1 horizontal cell type in an in vitro preparation of the macaque retina. The H1 cell has both a cone-connected dendritic tree and a long axon-like process that terminates in a rod-connected arbor. We recorded from the H1 cell body where rod signals were distinguished by sensitivity to short wavelength light after dark adaptation. Receptive fields of rod vs. cone mediated responses were coextensive, indicating that the rod signal is transmitted via rod-cone gap junctions. Sensitivity of the H1 cell rod signal was approximately 1 log unit higher than that of the cone signal. Below cone threshold rod signals were temporally low-pass, with a cutoff frequency below 10 Hz. Rod signals became faster and more transient with increasing light levels. We conclude that the H1 cell rod signal is not sensitive in the low scotopic range and, by comparison with the rod signal recorded directly in cones (Schneeweis & Schnapf (1995) Science, 268, 1053-1056), signal transmission across the cone-H1 synapse does not significantly filter the temporal properties of the rod signal.

Adaptation, Ocular↗
PubMed1999

Temozolomide in adult patients with advanced soft tissue sarcoma: a phase II study of the EORTC Soft Tissue and Bone Sarcoma Group.

Temozolomide, an oral imidazotetrazine derivative, was given to 31 patients with advanced soft tissue sarcoma. The dose of 750 mg/m2 was divided over 5 consecutive days, and escalated to 1000 mg/m2 over 5 days at cycle 2 if myelosuppression no worse than common toxicity criteria grade 2 was noted in the first 28-day cycle. A total of 99 treatment cycles were given to 31 patients. The drug was well tolerated, with nausea and vomiting as the most common side-effects. Only one partial tumour response was documented, giving a response rate of 3.33%, 95% confidence interval, (CI) 0.1-17.2%. The median time to progression was 8 weeks and the median survival was 27 weeks. These results indicate that temozolomide in this schedule is not active as second-line treatment in advanced soft tissue sarcoma.

Adult↗
PubMed1999

The reason for confining the use of adjuvant chemotherapy in soft tissue sarcoma to the investigational setting.

Adjuvant chemotherapy for soft tissue sarcoma has been the subject of many studies. Most studies have been nonrandomized and therefore by definition inconclusive. In addition, most of the 14 performed randomized studies have had small sample sizes. A meta-analysis on the data of these 14 studies suggested a possible survival improvement, albeit not significant. The outcome of the meta-analysis should be interpreted with caution in view of the fact that in 18% of patients, histology data were lacking; ineligibility rates in included studies were high; central pathology was not uniformly performed; and in 6% of patients, sarcomas other than soft tissue sarcomas were included. Because it is generally recommended that meta-analyses of small randomized trials are used only to generate hypotheses for more reliable randomized trials, it is argued that adjuvant chemotherapy in soft tissue sarcomas should remain confined to the investigational setting.

Antineoplastic Agents↗
PubMed1999

Phase II study of weekly dose-intensified cisplatin chemotherapy with oral etoposide in recurrent glioma.

BACKGROUND: In most patients with recurrent glioma chemotherapy is the only remaining treatment option. In general results of chemotherapy in these patients are poor, and trials on new regimens are indicated. Because relatively good results have been achieved with combinations of platin compounds and etoposide, we investigated a dose-intensified cisplatin regimen with oral etoposide. METHODS: Eligible patients, with recurrent glioma after surgery and radiation therapy were treated with two four week-cycles with cisplatin 70 mg/m2 on days 1, 8 and 15, combined with oral etoposide 50 mg daily on days 1-15. In responding or stabilized patients, treatment was continued with six four week-cycles of oral etoposide 50 mg/m2 on days 1-21. Toxicity was assessed using the NCI Common Toxicity Criteria, a 50% decrease in contrast enhancing area on MRI scan was considered a partial response. Time to progression was measured from the start of chemotherapy. RESULTS: Sixteen patients were included, 11 were progressive during or immediately after the induction cycles. Two patients achieved a partial response with a time to progression of 42 and 58 weeks. Three patients were stable for 11, 14 and 15 weeks respectively. Toxicity was modest. DISCUSSION: This dose-intensified cisplatin regimen did not result in a significant number of objective responses and even the number of 'stable disease' was small. Given the low response rate of this intensive treatment, we consider this intensive regimen inappropriate for these patients.

Adult↗
PubMed1999

Oral topoisomerase 1 inhibitors in adult patients: present and future.

The renewed interest in topoisomerase 1 inhibitors, based on new insights on the mechanism of action and the development of semi-synthetic derivates of camptothecin with a more favourable toxicity profile, has led to extensive preclinical and clinical research. Significant levels of anti-tumor activity in human tumor xenografts were seen especially with prolonged duration of exposure. Since oral drug delivery is a more convenient method for prolonged drug administration, and preferred by patients, further development of oral formulations seems attractive. Common concerns in the development of oral formulations are their sometimes low oral bioavailability and the frequently large intra- and interpatient variation in systemic exposure. Efforts to improve absorption and minimize intestinal metabolism/efflux of the oral chemotherapeutic agent using new formulas might lead to better bioavailability. Pharmacokinetic and pharmacodynamic evaluations have enabled guidance in recommendations of schedules. Given the interpatient variation in exposure it is interesting to note that flat dosing of topotecan resulted in the same systemic exposure compared with the more complex dosing per body surface area. In order to diminish the interpatient variation in exposure to 9-AC a limited sampling model for oral 9-AC was developed, enabling prediction of the systemic exposure for 9-AC and optimizing treatment for any given patient. Drug sequencing plays a key role in the combination topotecan/cisplatin and might be important for combination with other classes of drugs. Therefore, forthcoming phase 1 trials on combination therapy with oral topoisomerase 1 inhibitors should include studies on sequence dependence and pharmacokinetic analyses to evaluate any mutual interaction.

Animals↗
PubMed1999

Randomized study of a short course of weekly cisplatin with or without amifostine in advanced head and neck cancer. EORTC Head and Neck Cooperative Group.

BACKGROUND: Cisplatin is one of the most active cytotoxic agents available for the treatment of patients with head and neck cancer. In a previous phase II study with weekly administration of cisplatin, a response rate of 51% was achieved. However, only in a minority of the patients the planned high dose intensity of 80 mg/m2/week could be reached because of toxicity, mainly thrombocytopenia and ototoxicity. Amifostine is a cytoprotective drug that can diminish the toxicity of alkylating agents and platinum compounds. Therefore the effect of amifostine on toxicity and activity of weekly cisplatin was investigated in a randomized study. PATIENTS AND METHODS: Patients with locally advanced, recurrent or metastatic head and neck cancer were eligible. Patients were randomized to weekly cisplatin 70 mg/m2 for six cycles preceded by amifostine 740 mg/m2, or cisplatin only. Cisplatin was administered in hypertonic saline (3% NaCl) as a one-hour infusion; amifostine was administered as a 15-minute infusion directly before the administration of cisplatin. RESULTS: Seventy-four patients were entered in the study. The median number of cisplatin administrations was 6 (range 2-6), equal in both arms. In both treatment arms the median dose intensity of cisplatin achieved was the planned 70 mg/m2/week. In the cisplatin only arm 6 out of 206 cycles were complicated by thrombocytopenia grade 3 or 4 versus 1 of 184 cycles in the amifostine arm (P = 0.035). Hypomagnesaemia grade 2 + 3 was significantly less observed in the amifostine arm (P = 0.04). Neurotoxicity analyzed by serial vibration perception thresholds (VPT) showed a diminished incidence of subclinical neurotoxicity in the amifostine arm (P = 0.03). No protective effect on renal and ototoxicity could be shown. Hypotension was the main side effect of amifostine but only of relevance in one patient. The antitumor activity of cisplatin was preserved as 63% of the evaluable patients in the amifostine arm responded compared to 50% of the evaluable patients in the cisplatin alone arm. CONCLUSION: Our study indicated that in combination with weekly administered cisplatin amifostine reduced the risk of thrombocytopenia, hypomagnesemia as well as subclinical neurotoxicity, but did not result in a higher dose intensity of cisplatin. Addition of amifostine did not compromise the antitumor effect of cisplatin.

Adult↗
PubMed1999

Docetaxel and cisplatin: an active regimen in patients with locally advanced, recurrent or metastatic squamous cell carcinoma of the head and neck. Results of a phase II study of the EORTC Early Clinical Studies Group.

BACKGROUND: Docetaxel and cisplatin are among the most active antitumor agents in head and neck cancer, and phase I studies found the combination of the two drugs to be feasible. The EORTC ECSG performed a multicenter phase II study in patients with locally advanced, recurrent or metastatic squamous cell carcinoma of the head and neck to evaluate the antitumor efficacy and toxicity of this combination. PATIENTS AND METHODS: Eligibility criteria included written informed consent, a WHO performance status < 2, life expectancy of > 12 weeks, and adequate bone marrow, liver and renal function. Neoadjuvant pretreatment with cisplatin-based chemotherapy or prior radiotherapy were allowed. Patients were ineligible if pretreated with taxoids, had CNS involvement, concurrent malignancy, peripheral neuropathy, or no measurable disease. Treatment consisted of docetaxel 100 mg/m2 (one-hour i.v. infusion), followed by cisplatin 75 mg/m2 (three-hour i.v. infusion), repeated every three weeks. Supportive care included hydration, 5HT3-antagonists, and corticosteroids. RESULTS: Forty-four patients (median age 55 years, range 35-76) entered the trial; 41 patients were eligible, 164 cycles of treatment were evaluable for toxicity, and 31 patients for response. Fourteen patients had undergone prior surgery, 15 had received radiotherapy, and five had had chemotherapy. A median number of four treatment cycles (range 1-6) was given. Hematologic and non-hematologic toxicities were common, but hypersensitivity reactions and fluid retention were very infrequent due to corticosteroid prophylaxis. Four patients were taken off the study due to toxicity, and one toxic death occurred due to pneumonia. Among 41 eligible patients, objective responses as confirmed by independent review included six complete remissions and 16 partial remissions, resulting in an overall response rate of 53.7% (95% confidence interval: 37.4%-69.3%). Responses occurred in locally advanced, recurrent and metastatic disease, both in pre- and non-pretreated patients. Of 22 evaluable, non-pretreated patients with locally advanced or metastatic disease, five achieved complete responses, and 14 partial responses. Observed among nine evaluable pretreated patients with locally advanced or metastatic head and neck cancer were one complete response and two partial responses. CONCLUSION: The combination of docetaxel and cisplatin is feasible and active in locally advanced, recurrent, and metastatic squamous cell carcinoma of the head and neck.

Adult↗
PubMed1999

Phase I study of Carzelesin (U-80,244) given (4-weekly) by intravenous bolus schedule.

Carzelesin is a cyclopropylpyrroloindole analogue which acts as a DNA-sequence-specific alkylating agent. In this phase I study, Carzelesin was given as a 4-weekly 10 min i.v. infusion to 51 patients with advanced solid tumours. Patients received a median of two courses (range 1-5) at one of nine dose levels: 24, 48, 96, 130, 150, 170, 210, 250 and 300 microg m(-2). According to NCI-CTC criteria, non-haematological toxicities (grade 1/2) included fever, nausea and vomiting, mucositis and anorexia, none of which was clearly dose related. The dose-limiting toxicity was haematological and consisted mainly of neutropenia and to a lesser extent thrombocytopenia. From the dose level 150 microg m(-2), the haematological toxicity (particularly thrombocytopenia) was delayed in onset, prolonged and cumulative in some patients. In several courses, double WBC nadirs occurred. The maximum tolerated dose for a single course was 300 microg m(-2). From the dose level 170 microg m(-2), the intended dose intensity could not be delivered to most patients receiving > 2 courses owing to cumulative haematological toxicity. The dose level with the best dose intensity for multiple courses was 150 microg m(-2). The pharmacokinetics of Carzelesin and its metabolites (U-76,073; U-76,074) have been established in 31 patients during the first course of treatment using a HPLC method. Carzelesin exhibited linear pharmacokinetics. The concentration of U-76,074 (active metabolite) extended above the lower limit of quantitation (1 ng ml(-1)) for short periods of time and only at the higher dose levels. There was no relationship between neutropenia and the AUC of the prodrug Carzelesin, but the presence of detectable plasma levels of the active metabolite U-76,074 was usually associated with a substantial decrease in ANC values.

Adult↗
PubMed1999

A phase I/II study of combined weekly systemic cisplatin and locoregional hyperthermia in patients with previously irradiated recurrent carcinoma of the uterine cervix.

We investigated the feasibility and the anti-tumour activity of weekly cisplatin and the simultaneous application of local hyperthermia in patients with a pelvic recurrence of cervical cancer in previously irradiated area. Dose levels of cisplatin 60 mg m(-2), 70 mg m(-2) and 80 mg m(-2) were studied. Treatment objective of hyperthermia was the achievement of a tumour temperature of > or = 42 degrees for 60 min, during cisplatin administration. The protocol advised six weekly cycles of combined treatment. Nineteen patients, median age 47 years (range 26-71), were treated. A total of 89 cycles of combined treatment were administered. Even at the highest dose level of cisplatin, 80 mg m(-2) weekly, no dose-limiting toxicity was observed. Leucocytopenia at scheduled retreatment resulted in 1 or 2 weeks postponement in five cases. Neurotoxicity and renal toxicity were mild or absent. Maximum tumour temperatures achieved ranged 39.7-43.6 degrees C, mean 41.6+/-0.7 degrees C. All 19 patients were evaluable for response. One patient achieved a complete response that lasted 20 months, and nine patients achieved a partial response for a median duration of 6 months (range 4-50+ months), for an overall response rate of 53%. One patient subsequently underwent salvage surgery and currently remains free of disease at 4 years. We found that this combined hyperthermia-dose-intensive cisplatin regimen was well-tolerated. The true impact of the combination of cisplatin and locoregional hyperthermia can only be answered in a randomized study. Nonetheless, based on existing data on the poor efficacy of cisplatin in pelvic recurrent cervical cancer, we believe that the combined modality approach of weekly hyperthermia plus dose-intensive cisplatin is an attractive regimen, particularly if subsequent salvage surgery is available.

Adult↗
PubMed1999

Sparse-data set analysis for irinotecan and SN-38 pharmacokinetics in cancer patients co-treated with cisplatin.

The clinical pharmacokinetics of the antineoplastic agent irinotecan (CPT-11) are associated with substantial interpatient variability. The degree to which this variability in CPT-11 exposure impacts upon the response and toxicity of the drug has not yet been properly determined. In general, the area under the plasma concentration-time curve (AUC) is an appropriate indicator of exposure, but requires collection of up to 17 timed blood samples. This presents difficulties if large-scale population samplings are required. The present study involved the development and validation of a strategy to estimate the AUCs of the lactone and total (i.e. lactone plus carboxylate) forms of CPT-11 and its active metabolite SN-38 from a limited number of blood samples in patients co-treated with cisplatin. Using data from 24 patients, univariate and multivariate regression analyses were employed to generate the models. The best predictive models for simultaneous estimation of CPT-11 and SN-38 AUCs were obtained with three time points at 0.5, 1.67 and 5.50 h after start of the 90 min i.v. infusion of CPT-11. The models were tested separately in another group of 24 patients receiving the same combination treatment. This validation set demonstrated that CPT-11 and SN-38 AUCs after standard dose administration could be predicted sufficiently unbiased and precisely with three timed samples to warrant clinical application.

Adult↗
PubMed1999

Phase I and pharmacologic study of the arotinoid Ro 40-8757 in combination with cisplatin and etoposide in patients with non-small cell lung cancer.

This phase I study was performed to assess the feasibility of combining cisplatin/etoposide (VP-16) with the arotinoid Ro 40-8757 and to determine the dose-limiting toxicity (DLT) of Ro 40-8757 in this combination. Patients with non-small cell lung cancer were eligible. Treatment consisted of Ro 40-8757 p.o. day 1-21, cisplatin 100 mg/m2 i.v. on day 2 and VP-16 100 mg/m2 i.v. on day 2-4, repeated every 3 weeks. Eighteen patients were evaluable for toxicity and response. The doses of Ro 40-8757 ranged from 84 mg/m2 once daily to 42 mg/m2 thrice daily (tid). DLT consisting of delayed nausea/vomiting was reached at 42 mg/m2 tid. Consequently, the maximum tolerated dose was set at one dose level below the DLT, i.e. 28 mg/m2 tid. Skin toxicity occurred but was well manageable. Pharmacological analyses showed a small increase in the volume of distribution of cisplatin and VP-16 between the first and third course. However, no relationship with side effects was found. A response was achieved in 50% of patients. The combination of cisplatin/VP-16 with Ro 40-8757 appears to be feasible at a dose schedule of 28 mg/m2 tid. The response rate was at the upper rate of what can be expected with cisplatin and VP-16.

Adult↗
PubMed1999

Role of erythrocytes and serum proteins in the kinetic profile of total 9-amino-20(S)-camptothecin in humans.

9-Amino-20(S)-camptothecin (9-AC) is a water-insoluble topoisomerase I inhibitor with evident schedule-dependent antitumor activity in preclinical studies. The pharmacokinetic behavior of 9-AC given as a bolus i.v. infusion (1.0 mg/m2 over 5 min) was recently characterized in 12 patients in a bioavailability study. Remarkable rebound concentrations of 9-AC total drug (i.e. lactone plus carboxylate forms) were observed at about 2-3 h after dosing. In vitro experiments indicated that this phenomenon was associated with a substantial uptake of 9-AC lactone by erythrocytes immediately after dosing and its subsequent release followed by accumulation of 9-AC carboxylate in the plasma compartment mediated by a pH-dependent hydrolysis of the lactone form, which is unable to diffuse across cell membranes. The preferential binding of 9-AC carboxylate to human serum albumin shifts the equilibrium between the lactone and carboxylate forms of 9-AC to the pharmacological inactive carboxylate form.

Animals↗
PubMed1999

Clinical pharmacokinetics of doxorubicin in combination with GF120918, a potent inhibitor of MDR1 P-glycoprotein.

Previous clinical investigations with doxorubicin indicated that modulators of P-glycoprotein dramatically decrease the systemic clearance of the drug, which complicates the interpretation of toxicity and response data. In the present study, we examined the pharmacokinetics of doxorubicin and GF120918, a novel potent P-glycoprotein inhibitor, in cancer patients in a search for more selective modulation of multidrug resistance (MDR). Seven cohorts (46 patients) received sequential treatments with doxorubicin alone by a 5 min i.v. bolus (50-75 mg/m2), oral GF120918 alone (50 mg q.d.-400 mg b.i.d.), and the combination of doxorubicin and GF120918. Serial blood and urine samples were taken during both treatment courses and analyzed for doxorubicin and its metabolite doxorubicinol by a liquid chromatographic assay. The pharmacokinetic characteristics of doxorubicin in the presence or absence of GF120918 indicate a very minor overall effect of the modulator, except at the highest combined dose level (i.e. 75 mg/m2 plus 400 mg b.i.d.). A limited number of patients experienced significantly increased exposure to doxorubicinol upon combined treatment, which was associated with concomitantly higher plasma levels of GF120918. Sigmoidal maximum-effect models revealed significant correlations (p<0.02) between the area under the curve of doxorubicinol and the percent decrease in neutrophils and platelets. Sigmoidicity factors in the fitted Hill equation were similar between both treatment courses, suggesting no pharmacodynamic potentiation of doxorubicinol myelotoxicity by GF120918. Our data indicate that GF120918 at the tested doses of combination treatment achieves plasma concentrations that reverse MDR in experimental models and it lacks the significant kinetic interaction with doxorubicin observed previously with other modulators. Hence, it may be possible in future trials to assess the contribution of a potent inhibitor of P-glycoprotein activity to the toxicity and activity of doxorubicin with the knowledge that profound plasma pharmacokinetic interactions are unlikely.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Phase I and pharmacologic study of BMS-181174 given as a 6 h infusion every 4 weeks to patients with advanced solid tumors.

BMS-181174, a new mitomycin C (MMC) analog, showed more activity than the parent compound in tumor xenografts. In a phase I study with a 5-30 min slow bolus administration, hematologic and vascular toxicity were observed as major side effects. A prolonged infusion was suggested to circumvent the vascular toxicity. In this phase I study BMS-181174 was administered as a 6 h infusion every 4 weeks; the doses studied were 3.2, 6.4, 11.5, 19.0, 32.0, 50.0, 75.0 and 100 mg/m2. Twenty-eight patients were enrolled in the study, the majority with colorectal cancer. Hematologic side effects consisted of thrombocytopenia, and mild leuko- and granulocytopenia. The most distressing non-hematologic side effect was vascular toxicity consisting of phlebosclerosis and phlebitis, becoming dose limiting at 100 mg/m2. One patient developed a hemolytic uremic syndrome at a cumulative dose of 350 mg/m2. Pharmacokinetic data are available for 24 patients. The AUC ranged from 3.35 to 41.49 (microg x h/ml) and was highly correlated with the dose administered (r = 0.83). The kinetics appeared to be linear. One patient with metastatic colon cancer had a partial response of liver metastases. BMS-181174 is a MMC analog with a toxicity profile comparable to that of the parent compound. As doses above 50 mg/m2 are complicated by vascular toxicity precluding multiple administrations, further exploration of BMS-181174 will not be performed.

Adult↗
PubMed1999

Phase II study of raltitrexed ('Tomudex') for patients with advanced soft tissue sarcomas refractory to doxorubicin-containing regimens.

Advanced soft tissue sarcomas (ASTS) refractory to therapy with doxorubicin and/or ifosfamide are highly resistant to therapy with other cytotoxic agents. The efficacy and safety of raltitrexed ('Tomudex') was assessed in patients with ASTS refractory to one or two doxorubicin- and/or ifosfamide-containing regimens in eight centers of the EORTC STBSG group. Raltitrexed was given at 3 mg/m2 as a 15 min i.v. infusion once every 3 weeks. Among the 23 patients [mean age 54 (range 25-73) years] included, 22 patients (15 males and seven females) were eligible and evaluable for response to therapy and 21 were evaluable for toxicity. Patients had previously received chemotherapy in metastatic phase (n=16), as adjuvant treatment (n=5) or both (n=1). The primary tumor was located in the trunk (n=11), in the limbs (n=8) or in the head and neck (n=3). Most patients (n=13) received two courses of raltitrexed (range 1-8). The best response was stable disease in five (23%) patients, while disease progression was noted in 17 patients (77%); the median time to disease progression was 6 weeks. The treatment was well tolerated with only one patient experiencing grade 4 neutropenia and thrombocytopenia, one patient experiencing grade 3 nausea, one lethargy, one headache, and one asthenia. Only one patient experienced febrile neutropenia. Raltitrexed as monotherapy is not an effective treatment for patients with ASTS who failed conventional chemotherapy with doxorubicin and ifosfamide.

Adult↗
PubMed1999

Rational design of new tumoractivated cytotoxic agents.

5-Fluorouracil (5-FU) plays an important role in the treatment of several tumor types, particularly colorectal cancer and breast cancer. Xeloda (capecitabine; 5'-deoxy-5-fluoro-N-[(pentyloxy)carbonyl-cytidine]) is a new rationally designed fluoropyrimidine carbamate. It is administrated orally and after absorption it is first metabolized to 5'-deoxy-5-fluorocytidine (5'-DFCR) by carboxylesterase from the liver and then converted to 5'-deoxy-5-fluorouridine (5'-DFUR) by cytidine deaminase from the liver and tumor tissues. Finally, thymidine phosphorylase (TP) converts 5'-DFUR to 5-FU. TP is more active in tumor tissues than in normal tissue. This tissue localization pattern results in preferential metabolism and generates higher levels of 5-FU in malignant tissue, thus enhancing efficacy but minimizing side effects. The tumor tissue selectivity was confirmed in a study of 19 patients with colorectal cancer. After Xeloda administration, concentrations of 5-FU were 2.5 times higher in the primary tumor compared with adjacent healthy tissue. Xeloda was highly active in human tumor xenografts. It was more active than 5-FU, 5'-DFUR and tegafur plus uracil (UFT) and had a better therapeutic index. Xeloda also demonstrated synergistic or additive activity when used in combination with cyclophosphamide, methotrexate, doxorubicin, paclitaxel and docetaxel. This may be in part a result of up-regulation of TP by the cytotoxic agents. Phase I and II clinical trials have shown that Xeloda is active across a range of tumor types, and phase III studies are ongoing.

Animals↗