Towards streamlined product information: reporting of transporter-mediated drug interactions.

Purpose: The purpose of this study is to investigate the reporting of risks associated with transporter-mediated drug-drug interactions (DDIs) in medicinal product information and to identify suitable wording for future standardisation of summaries of product characteristics (SmPCs).

Methods: The SmPCs of medicinal products approved in the European Union from 2012 to 2023 were screened for warnings on Organic Anion Transporting Polypeptide 1B1 and 1B3 (OATP1B1 and OATP1B3), and Breast Cancer Resistance Protein (BCRP). An in-house search engine for product information was used.

Screening for cytotoxic compounds in poor-prognostic chronic lymphocytic leukemia.

Background/aim: For chronic lymphocytic leukemia (CLL) patients with poor-prognostic genomic aberrations the therapeutic options are limited. We used the Spectrum Collection library to identify compounds with anti-leukemia activity in high-risk CLL.

Materials And Methods: We identified substances with equal high cytotoxic activity in vitro in samples from poor-prognostic CLL (11q-/17p-, n=3) as compared to those from favourable-prognostic CLL (13q-, n=3).

In vitro evaluation of clinical activity and toxicity of anticancer drugs using tumor cells from patients and cells representing normal tissues.

Purpose: The aim of this study was to evaluate a phenotypic cell panel with tumor cells from various patients and normal cells for preclinical profiles of antitumor efficacy and toxicity of anticancer drugs.

Methods: The antitumor activity of fourteen anticancer drugs was tested in over one hundred tumor samples from patients with solid or hematological malignancies. Drug activity against four normal cell types was used for the assessment of normal tissue toxicity.

Identification of AKN-032, a novel 2-aminopyrazine tyrosine kinase inhibitor, with significant preclinical activity in acute myeloid leukemia.

Aberrant signal transduction by mutant or overexpressed protein kinases has emerged as a promising target for treatment of acute myeloid leukemia (AML). We here present a novel low molecular weight kinase inhibitor, AKN-032, targeting the FMS-like tyrosine kinase 3 (FLT3) and discovered in a new type of screening funnel combining the target therapy approach with sequential cellular screens. AKN-032 was identified among 150 selected hits from three different high throughput kinase screens.

The FMCA-GM assays, high throughput non-clonogenic alternatives to CFU-GM in preclinical hematotoxicity testing.

One of the most common dose limiting adverse effects in cancer treatment is myelotoxicity. The aim of this study was to develop an in vitro method for measuring potential myelotoxic properties of a drug candidate in a high throughput setting. Human CD34(+) progenitor cells from umbilical cord blood were plated in 384-well microplates with drugs in liquid culture, supplemented with specific cytokines for the granulocytopoietic-macrophage lineage.

Regression of orthotopic neuroblastoma in mice by targeting the endothelial and tumor cell compartments.

Background: High-risk neuroblastoma has an overall five-year survival of less than 40%, indicating a need for new treatment strategies such as angiogenesis inhibition. Recent studies have shown that chemotherapeutic drugs can inhibit angiogenesis if administered in a continuous schedule. The aim of this study was primarily to characterize tumor spread in an orthotopic, metastatic model for aggressive, MYCN-amplified neuroblastoma and secondarily to study the effects of daily administration of the chemotherapeutic agent CHS 828 on tumor angiogenesis, tumor growth, and spread.

In vitro activity of 20 agents in different prognostic subgroups of chronic lymphocytic leukemia--rolipram and prednisolone active in cells from patients with poor prognosis.

Background: There is a need for development of new drugs for treatment of B-cell chronic lymphocytic leukemia (CLL), especially for poor-prognostic subgroups resistant to conventional therapy.

Objective: The in vitro antileukemic activity of 20 different anticancer agents was characterized in tumor cells from CLL, aiming at identifying agents active in poor-prognostic subgroups.

Design And Methods: In tumor cells from 40 CLL patients and in peripheral blood mononuclear cells (PBMC) from three healthy controls, the activity of 20 substances was assessed using a non-clonogenic assay.

Rapamycin shows anticancer activity in primary chronic lymphocytic leukemia cells in vitro, as single agent and in drug combination.

The mammalian target of rapamycin inhibitor rapamycin and its analogues show promising anticancer activity in various experimental tumor models and are presently evaluated in clinical trials. We, here, evaluated the in vitro activity of rapamycin with regard to tumor-type specificity and possible mechanisms of drug resistance in 97 tumor cell samples from patients and in a resistance-based cell line panel, using the fluorometric microculture cytotoxicity assay. Rapamycin was dose-dependently cytotoxic in patient tumor cells and in cell lines.

In vitro activity of bortezomib in cultures of patient tumour cells--potential utility in haematological malignancies.

Bortezomib represents a new class of anti-cancer drugs, the proteasome inhibitors. We evaluated the in vitro activity of bortezomib with regard to tumour-type specificity and possible mechanisms of drug resistance in 115 samples of tumour cells from patients and in a cell-line panel, using the short-term fluorometric microculture cytotoxicity assay. Bortezomib generally showed dose-response curves with a steep slope.

The fluorometric microculture cytotoxicity assay.

The fluorometric microculture cytotoxicity assay (FMCA) is a nonclonogenic microplate-based cell viability assay used for measurement of the cytotoxic and/or cytostatic effect of different compounds in vitro. The assay is based on hydrolysis of the probe, fluorescein diacetate (FDA) by esterases in cells with intact plasma membranes. The assay is available as both a semiautomated 96-well plate setup and a 384-well plate version fully adaptable to robotics.

Significant cytotoxic activity in vitro of the EGFR tyrosine kinase inhibitor gefitinib in acute myeloblastic leukaemia.

Objectives: Gefitinib inhibits epidermal growth factor receptor (EGFR) signalling, but may also act by non-EGFR dependent mechanisms. We have investigated the activity of gefitinib in haematological tumour cells, in particular acute myeloblastic leukaemia (AML).

Methods: Cytotoxic activity of gefitinib, alone or in combination with standard anti-leukaemic drugs, was assessed by the short-term fluorometric microculture cytotoxicity assay in tumour cells from 117 patients representing five haematological and five non-haematological malignancies.

Modeling of in vitro drug activity and prediction of clinical outcome in acute myeloid leukemia.

The objectives of this study were to develop a population pharmacodynamic model describing the in vitro drug sensitivity of tumor cells and to relate in vitro parameters to clinical outcome. Cell samples from 179 patients with acute myelocytic leukemia were exposed to cytosine arabinoside and daunorubicin, and cytotoxicity was analyzed using the fluorometric microculture cytotoxicity assay. A sigmoid E(max)-model for daunorubicin and an E(max)-model for cytosine arabinoside described the data.

Pharmacological profiling of novel non-COX-inhibiting indole-pyran analogues of etodolac reveals high solid tumour activity of SDX-308 in vitro.

SDX-308 and SDX-309 are potent indole-pyran analogues of SDX-101 (R-etodolac) which has anti-tumour activity unrelated to cyclooxygenase-2 inhibition. Their cytotoxic activity was further studied herein using a well-characterized human tumour cell-line panel containing ten cell lines, as well as in 58 primary tumour cell samples from a variety of diagnoses. The indole-pyran analogues of SDX-101 were in general considerably more active in both cancer cell lines and primary tumour samples.

CHS 828 kill tumour cells by inhibiting the nuclear factor-kappaB translocation but unlikely through down-regulation of proteasome.

CHS 828 (N-(6-chlorophenoxyhexyl)-N'cyano-N"-4-pyridylguanidine) has shown promising activity in many preclinical systems and in phase I/II clinical trials. The nuclear transcription factor kappa B (NF-kappaB) has been identified as a target for CHS 828. The aim of this study was to confirm the inhibitory effect of CHS 828 on NF-kappaB translocation and to explore its possible effect on the proteasome using 7 cell lines.

R-etodolac (SDX-101) and the related indole-pyran analogues SDX-308 and SDX-309 potentiate the antileukemic activity of standard cytotoxic agents in primary chronic lymphocytic leukaemia cells.

Objective: SDX-101 is the non-cyclooxygenase 2-inhibiting R-enantiomer of the non-steroid anti-inflammatory drug etodolac, and has anti-tumour activity in chronic lymphocytic leukaemia (CLL). SDX-308 and SDX-309 are more potent, structurally related indole-pyran analogues of SDX-101. The current study was performed to investigate and quantify the cytotoxic potentiating effects resulting from a combination of either SDX-101, SDX-308 or SDX-309 with standard cytotoxic agents used in the CLL treatment today.

Imatinib activity in vitro in tumor cells from patients with chronic myeloid leukemia in chronic phase and blast crisis.

The aims of this study were to evaluate the feasibility of using the non-clonogenic fluorometric microculture cytotoxicity assay in drug sensitivity testing of tumor cells from patients with chronic myeloid leukemia. In nine samples (six chronic phase, three blast crisis), the drug sensitivities in tumor cells from blood versus from bone marrow and fresh tumor cells versus cryopreserved were compared. In 26 samples obtained in chronic phase (pretreatment), in six samples from patients in blast crisis and in the K 562 cell line, the activity of imatinib alone and in combination with cytarabine, vincristine, daunorubicin, interferon, arsenic trioxide and homoharringtonine was evaluated.

In vitro activity of the flt3-inhibitor su5614 and standard cytotoxic agents in tumour cells from patients with wild type and mutated flt3 acute myeloid leukaemia.

The correlation between drug sensitivity in vitro and the mutation status of the FLT3 receptor gene was evaluated in tumour cells from 17 previously untreated AML patients. Tumour cells with internal tandem duplication (ITD) in the FLT3 receptor gene were significantly more sensitive to the FLT3 inhibitor SU5614 than tumour cells with wild type FLT3. Combinations of SU5614 with etoposide and amsacrine showed better effect (p<0.

In vitro activity of imatinib in cells from patients with adult acute lymphoblastic leukemia.

We evaluated the in vitro activity of imatinib on BCR-ABL-positive and -negative tumor cells from patients with adult acute lymphoblastic leukemia (ALL), and investigated in vitro interactions between imatinib and conventional agents. A non-clonogenic cytotoxicity assay was used to analyze p190 BCR-ABL-positive (n = 4), p210 BCR-ABL-positive (n = 2) and BCR-ABL-negative (n = 9) tumor cells from adult ALL patients. The in vitro cytotoxic effect of imatinib was studied alone, and in combination with the cytotoxic agents cytarabine, prednisolone, vincristine, daunorubicin, asparaginase and mercaptopurine.

Pharmacokinetic-pharmacodynamic modelling of the schedule-dependent effect of the anti-cancer agent CHS 828 in a rat hollow fibre model.

N-(6-Chlorophenoxyhexyl)-N'-cyano-N''-4-pyridylguanidine (CHS 828) is a novel anticancer agent that shows schedule-dependent effects in vitro and in vivo, as well as in Phase I clinical trials. A rat hollow fibre model was used to investigate whether this dependency is due to pharmacokinetic and/or pharmacodynamic factors. The effect on two cell lines, MDA-MB-231 (breast cancer) and CCRF-CEM (leukaemia) were studied after CHS 828 was administered orally as a single dose or in a 5-day schedule, at different total dose levels.

In vitro drug resistance in B cell chronic lymphocytic leukemia: a comparison with acute myelocytic and acute lymphocytic leukemia.

The aim of the study was to evaluate cellular drug resistance in B cell chronic lymphocytic leukemia (B-CLL) in vitro, and compare it with that in acute myelocytic leukemia (AML) and acute lymphocytic leukemia (ALL). In vitro drug resistance was analyzed by the fluorometric microculture cytotoxicity assay (FMCA) in all samples from patients with leukemia sent to our laboratory between 1992 and 2001. Up to 14 standard drugs were evaluated in samples from 66 patients with B-CLL, 212 patients with AML and 80 patients with ALL.

Cytotoxic activity of a new paclitaxel formulation, Pacliex, in vitro and in vivo.

Background: The paclitaxel formulation, Taxol (Bristol-Myers Squibb), is one of the most effective anticancer agents used today. However; it is associated with serious side effects believed to be caused by the Cremophor EL used for its formulation.

Aim: To evaluate the cytotoxic activity of a new paclitaxel formulation, Pacliex (developed by Oasmia Pharmaceutical, Uppsala, Sweden), a mixed micelles preparation in which an amphiphilic synthetic derivative of retinoic acid replaced Cremophor EL/ethanol vehicle.

VH gene mutation status and cellular drug resistance in chronic lymphocytic leukaemia.

Objective: B-cell chronic lymphocytic leukaemia (B-CLL) can be divided into two clinical entities based on the immunoglobulin variable heavy chain (VH) gene mutation status, as cases with unmutated VH genes display a more aggressive disease with shorter survival time than mutated cases. The aim of this study was to investigate whether differences in cellular drug resistance could give an explanation for these divergent clinical courses.

Methods: The VH gene mutation status was analysed in patients with previously untreated B-CLL using VH gene family-specific PCR amplification and nucleotide sequencing.

Antitumor efficacy and acute toxicity of the novel dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) in vivo.

The novel alkylating dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) was evaluated for acute toxicity and antitumor activity in mice, with melphalan as a reference. To determine a safe and tolerable dose for efficacy studies the acute toxicity following intravenous injection in the tail vein was monitored using a 14-day schedule with up to four doses. The highest tested dose, 25 micromoles/kg, was considered close to this level, with minor effects on body weight gain but significant effects on hematological parameters.

Cytotoxic effect in vivo and in vitro of CHS 828 on human myeloma cell lines.

CHS 828 is a pyridyl cyanoguanidine with promising antitumor activity both in vitro and in vivo, and has previously been found especially active against tumor cells obtained from patients with B cell chronic lymphocytic leukemia. In the present study the cytotoxic effect in vitro of CHS 828 was investigated on a panel of 10 human myeloma cell lines using the fluorometric microculture cytotoxicity assay. CHS 828 induced a concentration-dependent, but variable decrease in tumor cell survival in the cell line panel with inhibitory concentrations 50% (IC50) in the range 0.

Cytotoxic activity of a new lipid formulation of doxorubicin in cell lines and primary tumor cells.

Background: Liposomal formulations of the anthracyclines are being developed to circumvent toxicity and prolong effect. The current study investigates the in vitro activity of a novel doxorubicin micelle formulation, containing a vehicle designed to release pharmacologically active subcomponents.

Materials And Methods: The cytotoxicity of doxorubicin formulated in a vehicle containing C4 (N-docosahexaenoyl-O-phospho-2-aminoethanol) and C11 (N-all trans-retinoyl-O-phospho-L-tyrosine) was measured in a panel of human tumor cell lines, 19 primary cultures of human tumor cells and 5 lymphocyte preparations.