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Background The safety, pharmacokinetics (PK) and pharmacodynamics of CEP-18770, a new peptide boronic acid proteasome inhibitor, have been investigated after intravenous administration on days 1, 4, 8 and 11 of every 21 d cycle in patients with solid tumours and multiple myeloma (MM). Patients and methods Thirty-eight patients were treated with CEP-18770 at escalating doses from 0.1 to 1.8 mg/m 2 where 2 out of 5 patients showed dose limiting toxicities. The maximum tolerated/recommended dose (MTD/RD) of 1.5 mg/m 2 was tested in 12 additional patients. Skin rash was dose-limiting and occurred in 53% of patients; other frequent toxicities were asthenia (29%), stomatitis (21%) and pyrexia (16%). No significant peripheral neuropathy was observed. PK in plasma was linear with a half-life of the elimination phase of 62.0 ± 43.5 h. Proteasome inhibition in peripheral blood mononuclear cells was dose related in MM patients; it was of 45.4 ± 11.5% at the RD. Conclusions CEP-18770 showed a favourable safety profile with lack of neurotoxicity and linear plasma PK. The definition of the optimal biological dose and schedule of treatment is actively pursued because of the high incidence of skin toxicity of the twice a week schedule.

To determine the pharmacokinetics of gimatecan, a camptothecin with a lipophilic substitution in position 7, given orally to patients participating in the phase I study.Pharmacokinetics was evaluated in 78 patients after oral daily dose for 5 days a week for 1, 2 or 3 weeks by HPLC with a fluorescence detector.Gimatecan was mainly present in plasma as lactone (85%), the active form as DNA-topoisomerase I poison. The AUC(0-24) on the first day of treatment normalised per daily dose (mg/m(2)), ranged from 194 to 2909 ng h/mL/mg/m(2). The half-life was 77.1+/-29.6h, consequently C(max) and AUC rose 3-6-fold after multiple dosing. Multivariate analysis indicated the daily dose (p0.0001) and the alpha(1)-acid glycoprotein (AGP) plasma levels (p0.0001) as main predictors of gimatecan AUC(0-24). In the overall analysis, daily dose and AGP plasma levels explained 85% of the deviance. The hydroxy metabolite ST1698 was present in plasma at low levels with AUC values of 5-15% of gimatecan. In mice, orally treated with gimatecan, plasma and tissue levels were 2-fold higher after treatment with a pro-inflammatory agent causing AGP induction.Gimatecan is orally absorbed and its variable plasma levels seem to be related to AGP plasma concentrations. Data obtained in mice, together with the fact that AGP levels largely exceeded gimatecan plasma concentrations, suggest that the increased gimatecan levels in patients with high AGP levels are not related to the binding of the drug to AGP with consequent reduced tissue drug distribution, but possibly to other mechanism associated with inflammation being AGP simply a marker of the inflammation process.

This report reviews published information on the clinical pharmacokinetics of antitumour agents in patients with liver dysfunction, associated with primary liver disease or liver metastases. Information was available for anthracyclines and their related compounds, antimetabolites, cyclophosphamide, vinca alkaloids, taxanes and epipodophyllotoxins. Changes in the pharmacokinetic profile or metabolism in patients with mild or severe hepatobiliary dysfunction are described and the relationships between serum levels, parameters employed for measuring hepatic function and toxic or therapeutic effects are examined. Current knowledge of the pharmacokinetics of antineoplastic agents in liver disease is far from complete, mostly obtained in small numbers of non-homogeneous patients often presenting only moderate liver dysfunction, and empirical guidelines for dose assessment are still largely applied in clinical practice. Because of the complex pathophysiological mechanisms of liver insufficiency in cancer patients, there is still doubt whether endogenous markers are useful. Although caution in treating cancer patients with liver insufficiency is compulsory, for most compounds there seems no need to recommend dose reductions for moderate impairment. However, for the tubulin acting agents, vincristine, vinblastine and possibly for paclitaxel and docetaxel, there is strong evidence that dose adjustment is mandatory in order to avoid excessive neutropenia and neurotoxicity.