O'Reilly T.,Novartis |
McSheehy P.M.J.,Novartis |
Wartmann M.,Novartis |
Lassota P.,Novartis |
And 3 more authors.
Anti-Cancer Drugs | Year: 2011
The aim was to determine the potential of the allosteric mammalian target of rapamycin inhibitor, everolimus, to act in combination with cytotoxic anticancer compounds in vitro and in vivo. A concomitant combination in vitro showed no evidence of antagonism, but enhanced the antiproliferative effects (additive to synergistic) with cisplatin, doxorubicin, 5-fluorouracil, gemcitabine, paclitaxel, and patupilone. Everolimus (1-5 mg/kg/d orally) was evaluated for antitumor activity in vivo alone or in combination with suboptimal cytotoxic doses using athymic nude mice bearing subcutaneous human H-596 lung, KB-31 cervical, or HCT-116 colon tumor xenografts. Everolimus monotherapy was very well tolerated and caused inhibition of tumor growth, rather than regression, and this was associated with a dose-dependent decline in tumor pS6 levels, a key downstream protein of mammalian target of rapamycin. At the doses used, the cytotoxics inhibited tumor growth and caused tolerable body-weight loss. Concomitant combinations of cisplatin, doxorubicin, paclitaxel, or patupilone with everolimus produced cooperative antitumor effects, in some cases producing regressions without clinically significant increases in toxicity. In contrast, combinations with gemcitabine and 5-fluorouracil were less well tolerated. Alternative administration schedules were tested for cisplatin, gemcitabine, or paclitaxel combined with everolimus: these did not dramatically affect cisplatin or gemcitabine activity or tolerability but were antagonistic for paclitaxel. Everolimus showed promising maintenance activity after treatment with doxorubicin or paclitaxel ceased. Overall, the results confirm that everolimus is an effective, well-tolerated suppressor of experimental human tumor growth, and although it did not show strong potentiation of efficacy, antitumor activity in vivo was increased without marked increases in toxicity, supporting clinical use of everolimus as a partner for conventional cytotoxics. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Yamazaki T.,Chugai Pharmaceutical Co. |
Inagaki Y.,Chugai Pharmaceutical Co. |
Fujii T.,Chugai Pharmaceutical Co. |
Ohwada J.,Chugai Pharmaceutical Co. |
And 6 more authors.
International Journal of Antimicrobial Agents | Year: 2010
The in vitro susceptibilities of 140 laboratory reference strains of fungi, including type strains, and 165 clinical yeast isolates from Japan towards isavuconazole compared with fluconazole (FLC), itraconazole (ITC), voriconazole and amphotericin B were measured. Broth microdilution methods based on Clinical and Laboratory Standards Institute (CLSI) methods were used for yeasts, and RPMI-MOPS medium semi-solidified with 0.2% low-melting-point agarose based on CLSI guidelines was used for moulds. The range of isavuconazole minimum inhibitory concentrations (MICs) was 0.0004-0.21. mg/L for Candida albicans, 0.0036-0.4. mg/L for Candida glabrata, 0.023-0.058. mg/L for Candida krusei, 0.0026-0.032. mg/L for Cryptococcus neoformans, 0.1-0.39. mg/L for Aspergillus fumigatus and 0.2-0.39. mg/L for Aspergillus terreus. Isavuconazole was as active as ITC against the dimorphic true pathogenic fungi, with a range of MICs from <0.0004. mg/L to 0.0063. mg/L for Blastomyces dermatitidis and Histoplasma capsulatum. It was also active against uncommon dematiaceous fungi such as Exophiala spp. and Phialophora spp. as well as against dermatophytic species. Isavuconazole showed very good in vitro antifungal activity with a broad spectrum, including against FLC-resistant Candida spp., Aspergillus spp. and uncommon opportunistic fungal species. This is the first report of the in vitro susceptibility of Japanese clinical yeast isolates to isavuconazole. No cross-resistance was found to isavuconazole amongst FLC-resistant strains. © 2010 Elsevier B.V. and the International Society of Chemotherapy.
O'Reilly T.,Novartis |
McSheehy P.M.J.,Novartis |
Kawai R.,Novartis |
Kretz O.,Novartis |
And 7 more authors.
Cancer Chemotherapy and Pharmacology | Year: 2010
Purpose: Comparative pharmacokinetic (PK) analysis of the mTOR inhibitor RAD001 (everolimus) in rats and mice. Methods: Blood cell partitioning, plasma protein binding and PK parameters of RAD001 in blood and tissues (including brain) of both mice and rats were determined. PK modeling predicted plasma/blood and tumor levels from a variety of regimens and these were compared with the known human PK profile. DCE-MRI was used to compare tumor vascularity between mice and rats. Estimation of IC50 values in vitro and ED50 values in vivo were used to provide an indication of anti-tumor activity. Results: The PK properties of RAD001 differed between mice and rats, including erythrocyte partitioning, plasma protein binding, plasma/blood t 1/2, oral bioavailability, volume of distribution, tissue/tumor penetration and elimination. Modeling of tumor and blood/plasma PK suggested that in mice, multiple daily administrations result in a ~2-fold increase in tumor levels of RAD001 at steady state, whereas in rats, a ~7.9-fold increase would occur. Weekly high-dose regimens were predicted not to facilitate tumor accumulation in either species. Total tumor levels of RAD001 were four- to eight-fold greater in rats than in mice. Rat tumors had a >2-fold greater plasma content and permeability compared to mouse tumors, which could contribute to differences in tumor drug uptake. Maximal antitumor effects (T/C of 0.04-0.35) were observed in both species after daily administration with similar C max and AUC values of unbound (free) RAD001. These free levels of RAD001 are exceeded in serum from cancer patients receiving clinically beneficial daily regimens. In rodents, brain penetration of RAD001 was poor, but was dose-dependent and showed over-proportional uptake in rats with a longer t 1/2 compared to the systemic circulation. Conclusions: The PK of RAD001 differed between mice and rats, with rats having a PK profile closer to that of humans. High intermittent doses of RAD001 may be more appropriate for treatment of brain tumors. © 2009 Springer-Verlag.
Grunwald H.,Basilea Pharmaceutica International AG |
Hargreaves P.,Basilea Pharmaceutica International AG |
Gebhardt K.,Basilea Pharmaceutica International AG |
Klauer D.,Basilea Pharmaceutica International AG |
And 5 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013
A systematic comparison between two labeling approaches for the investigation of the in vitro metabolic pattern of pharmaceutical drugs was performed by examining the use of (i) radiolabeled drugs analyzed with LC-MS-offline radiodetection and (ii) stable-isotope labeled drugs, used in a defined mixture with the unlabeled drug and analyzed by LC-MS with recognition of the specific isotopic pattern. 14C was used for the radioisotope-approach and deuterium for the stable-isotope approach. Olanzapine, diclofenac and ketoconazole were chosen as model drugs, as they are commercially available in their non-, radio- and stable-isotope labeled forms. For all three model drugs, liver microsome- and hepatocyte-incubations (both from rat) were performed with various concentrations and incubation times for both, the radio- and the stable-isotope approaches. The metabolic pattern, including structure elucidation of all detected metabolites, was performed independently for all individual compounds and incubations. Subsequently, the metabolic patterns of the radio-, and the stable-isotope approaches were compared. In conclusion, all metabolites found with the radioisotope approach could also be found with the stable-isotope approach. Although the stable-isotope approach does not provide a quantitative result, it can be considered to be a highly suited analytical alternative for early in vitro metabolism investigations, especially when radiolabeled drug analogues are not yet available and quantitative results are not yet necessary. © 2013 Elsevier B.V.