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Biomedical subjects

F A Eskens

Publications and source records attributed to F A Eskens.

14 recordsLinked to original sources

[Developments in chemotherapy; cytostatic agents with an increased specificity and other forms of administering cytotoxic antineoplastic agents].

In recent years developments in molecular biology have greatly increased our knowledge about the cellular processes which govern the development of cancer. This has led to the development of anticancer agents that specifically target one of these cellular processes, for example, farnesyl transferase inhibitors, receptor tyrosine kinase inhibitors, matrix metalloproteinase inhibitors and anti-angiogenic agents. In addition to this, new chemotherapeutic agents with increased target specificity have been developed. Finally, in recent years there has been an emphasis on developing new forms of administration so that optimal use can be made of existing chemotherapeutic agents.

Alkyl and Aryl Transferases↗

Temozolomide chemotherapy in recurrent oligodendroglioma.

The authors determined the tolerance, response rate, and duration of recurrent anaplastic oligodendroglioma in 30 patients to temozolomide given orally at 150 to 200 mg/m2 on days 1 through 5 in cycles of 28 days. Nine patients responded: 7 of 27 patients (26%) treated with temozolomide after prior PCV chemotherapy and 2 of 3 chemotherapy-naive patients (both complete response). Median time to progression in responding patients was 13 months. Temozolomide shows promise and has an acceptable safety profile in recurrent anaplastic oligodendroglial tumors. Patients not responding to PCV may respond to temozolomide.

Adult↗

Phase I and pharmacokinetic study of the oral farnesyl transferase inhibitor SCH 66336 given twice daily to patients with advanced solid tumors.

PURPOSE: A single-agent dose-escalating phase I and pharmacokinetic study on the farnesyl transferase inhibitor SCH 66336 was performed to determine the safety profile, maximum-tolerated dose, and recommended dose for phase II studies. Plasma and urine pharmacokinetics were determined. PATIENTS AND METHODS: SCH 66336 was given orally bid without interruption to patients with histologically or cytologically confirmed solid tumors. Routine antiemetics were not prescribed. RESULTS: Twenty-four patients were enrolled onto the study. Dose levels studied were 25, 50, 100, 200, 400, and 300 mg bid. Pharmacokinetic sampling was performed on days 1 and 15. At 400 mg bid, the dose-limiting toxicity (DLT) consisted of grade 4 vomiting, grade 4 neutropenia and thrombocytopenia, and the combination of grade 3 anorexia and diarrhea with reversible grade 3 plasma creatinine elevation. After dose reduction, at 300 mg bid, the DLTs consisted of grade 4 neutropenia, grade 3 neurocortical toxicity, and the combination of grade 3 fatigue with grade 2 nausea and diarrhea. The recommended dose for phase II studies is 200 mg bid, which was found feasible for prolonged periods of time. Pharmacokinetic analysis showed a greater than dose-proportional increase in drug exposure and peak plasma concentrations, with increased parameters at day 15 compared with day 1, indicating some accumulation on multiple dosing. Plasma half-life ranged from 4 to 11 hours and seemed to increase with increasing doses. Steady-state plasma concentrations were attained at days 7 through 14. A large volume of distribution at steady-state indicated extensive distribution outside the plasma compartment. CONCLUSION: SCH 66336 can be administered safely using a continuous oral bid dosing regimen. The recommended dose for phase II studies using this regimen is 200 mg bid.

Administration, Oral↗

Matrix metalloproteinase inhibitors: current developments and future perspectives.

Malignant tumors are characterized by invasive growth and metastasis. To facilitate this invasive behavior, the enzymatic breakdown of the extracellular matrix (ECM) is a prerequisite. Many human tumors are characterized by locally increased concentrations of matrix metalloproteinases (MMPs), enzymes that are able to degrade this ECM. A vast number of matrix metalloproteinase inhibitors (MMPIs) have been developed in recent years and after extensive preclinical testing, the results of the first clinical studies with several of these compounds have recently been presented. In this review we will describe some of the basic concepts of the degradation of the ECM, with special emphasis on the role of MMPs in the progression of cancer. Furthermore we will review the results of preclinical and clinical studies with MMPIs and discuss their future perspective.

Clinical Trials as Topic↗

Phase I and pharmacological study of the oral matrix metalloproteinase inhibitor, MMI270 (CGS27023A), in patients with advanced solid cancer.

This Phase I study of MMI270, an p.o. administered matrix metalloproteinase inhibitor, assessed toxicity, pharmacokinetics, and tumor response data and investigated markers of biological activity to recommend a dose for Phase II studies. MMI270 was administered continuously at seven dose levels (50 mg once daily to 600 mg three times/day). Patients were evaluated for toxicity and tumor response, and blood and urine samples were taken for pharmacokinetics, bone resorption markers, direct targets of the inhibitor [matrix metalloproteinase-2 (MMP-2), MMP-8, and MMP-9], indirect targets [tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, basic fibroblast growth factor, vascular endothelial growth factor, vascular cell adhesion molecule-1, soluble urokinase plasminogen activator receptor, and cathepsins B and H] and for a tumor necrosis factor-alpha cytokine release assay. Ninety-two patients were entered. There was no myelotoxicity. Eighteen patients developed a widespread maculopapular rash, which increased in frequency and severity at doses > or = 300 mg bid. Thirty nine patients developed musculoskeletal side effects, which were related to duration of treatment, not to dose level. Pharmacokinetics were linear, and MMI270 was rapidly absorbed and eliminated with minimal accumulation on chronic dosing. Sustained plasma concentrations in excess of 4 x mean IC(50) for the target enzymes were observed at dose levels > or = 150 mg bid. There were no tumor regressions; however, 19 patients had stable disease for > or = 90 days. There was a dose-response increase of MMP-2 and TIMP-1 with MMI270. Transient effects on the bone resorption markers were detected. MMI270 was generally well tolerated, with adequate plasma levels for target enzyme inhibition. The two main toxicities were rash, resulting in a maximum tolerated dose of 300 mg bid and musculoskeletal side effects. Biological marker data indicate drug effects. The rise in TIMP-1 suggests that a reflex rise in inhibitors could modify the effects of MMI270. The recommended Phase II dose is 300 mg bid.

Administration, Oral↗

Clinical studies in the development of new anticancer agents exhibiting growth inhibition in models: facing the challenge of a proper study design.

Various new specifically targeted anticancer agents such as matrixmetalloproteinase inhibitors, angiogenesis inhibitors, farnesyl transferase inhibitors, and tyrosine kinase inhibitors have been developed in recent years. These agents exert antitumor activity through specific target inhibition, and preclinical studies showed dose-dependent tumor growth inhibition and only sporadic tumor regressions. Toxicity of these new agents was often strikingly mild or did not occur at all. Clinical studies are now being performed. Because these new agents might have a different toxicity profile and exert their antitumor activity in a way that is completely different from that of cytotoxic agents, the design of clinical studies will have to be adapted in several ways, and new endpoints for phase I, II, and III studies must be defined.

Animals↗

Farnesyl transferase inhibitors: current developments and future perspectives.

Ras oncogenes play an important role in carcinogenesis and are frequently found in various human tumour types. Cellular activity of Ras oncoprotein, regulated through the enzyme farnesyl transferase, is crucial in the process of ras -dependent carcinogenesis, and therefore, specific inhibition of this enzyme is an attractive goal in anticancer treatment. Specific inhibitors of farnesyl transferase have been developed in recent years, many of them showing in vitro and in vivo growth inhibitory or cytostatic activity. Recently, results of the first clinical studies with various farnesyl transferase inhibitors have been presented. In the design of phase I and II studies, either single-agent or combination studies, new endpoints have to be defined in order to properly assess feasibility, antitumour activity and clinical valuability.

Alkyl and Aryl Transferases↗

Effect of food on the pharmacokinetics of oral MMI270B (CGS 27023A), a novel matrix metalloproteinase inhibitor.

MMI270B is a matrix metalloproteinase inhibitor (MMPI) with in vitro and in vivo activity. To exert optimal target inhibition, MMPI must be given chronically, and therefore, oral bioavailability is important. We analyzed the effect of food intake on AUC0-8 h, Cmax, and Tmax. Seventeen patients were entered into the study. Doses of MMI270B were 150, 400, and 600 mg. The first day, patients ingested the drug in a fasted state and were not allowed to eat for 2 h. The second day, patients ingested the drug 30 min after a light breakfast. Mean AUC0-8 h was not significantly influenced by food intake. Plasma concentrations were well above the IC50 of several MMPs at all doses tested. Mean Cmax was significantly decreased after food intake. Mean Tmax was significantly delayed after food intake. Food intake did not result in a significant change in exposure to MMI270B (AUC0-8 h) but did result in a significant, although not clinically relevant, decrease in peak plasma levels and time to reach peak plasma levels. No specific guidelines concerning the ingestion of MMI270B in either a fed or a fasted state are recommended.

Administration, Oral↗

Phase I and pharmacological study of weekly administration of the polyamine synthesis inhibitor SAM 486A (CGP 48 664) in patients with solid tumors. European Organization for Research and Treatment of Cancer Early Clinical Studies Group.

A single-agent dose-escalating Phase I and pharmacological study of the polyamine synthesis inhibitor SAM 486A was performed. A dosing regimen of four weekly infusions followed by 2 weeks off therapy was studied. Fifty patients were entered into the study. Dose levels studied were 1.25, 2.5, 5, 8, 16, 32, 48, 70, 110, 170, 270, and 325 mg/m2/week. Pharmacokinetic sampling was done on day 1, and trough samples were taken weekly during the first treatment cycle. Pharmacodynamic sampling was done on days 1 and 22. At 325 mg/m2/week, dose-limiting toxicity was seen (one patient each with grade 4 febrile neutropenia, grade 3 neurotoxicity, and grade 3 hypotension with syncope and T-wave inversions on electrocardiogram). The recommended dose for further testing was set at 270 mg/m2/week. Infusion time was increased from 10 to 180 min due to facial paresthesias and flushing and somnolence. Drug exposure increased linearly with dose. Mean +/- SD t1,2 at 70-325 mg/m2 doses was 61.4+/-26.2 h, with a large volume of distribution at steady state. In peripheral blood leukocytes, a clear relationship between dose and inhibitory effect on S-adenosylmethionine decarboxylase or changes in intracellular polyamine pools was not recorded. SAM 486A can be administered safely using a dosing regimen of four weekly infusions followed by 2 weeks off therapy. The recommended dose for Phase II studies using this regimen is 270 mg/m2/week.

Adult↗

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↗

Pancreatic islet cell tumor producing vasoactive intestinal polypeptide and calcitonin.

A patient with a pancreatic islet cell tumor concurrently producing vasoactive intestinal polypeptide (VIP) and calcitonin with related symptoms is presented. The patient was given palliative treatment consisting of octreotide, streptozotocin and 5-fluorouracil, and survival now exceeds 72 months. The concurrent production of VIP and calcitonin by a pancreatic islet cell tumor has not been described before.

Antineoplastic Combined Chemotherapy Protocols↗