eapb0203 and Melanoma

In spite of the development of new anticancer drugs by the pharmaceutical industry, melanoma and T lymphomas are diseases for which medical advances remain limited. Thus, there was an urgent need of new therapeutics with an original mechanism of action. Since several years, our group develops quinoxalinic compounds. In this paper, the first preclinical results concerning one lead compound, EAPB0203, are presented. This compound exhibits in vitro cytotoxic activity on A375 and M4Be human melanoma cell lines superior to that of imiquimod and fotemustine. A liquid chromatography-mass spectrometry method was first validated to simultaneously quantify EAPB0203 and its metabolite, EAPB0202, in rat plasma. Thereafter, the pharmacokinetic profiles of EAPB0203 were studied in rat after intravenous and intraperitoneal administrations. After intraperitoneal administration the absolute bioavailability remains limited (22.7%). In xenografted mouse, after intraperitoneal administration of 5 and 20mg/kg, EAPB0203 is more potent than fotemustine. The survival time was increased up to 4 and 2 weeks compared to control mice and mice treated by fotemustine, respectively. The results of this study demonstrate the relationship between the dose of EAPB0203 and its effects on tumor growth. Thus, promising efficacy, tolerance and pharmacokinetic data of EAPB0203 encourage the development towards patient benefit.

Topics: Aminoquinolines; Animals; Antineoplastic Agents; Cell Line, Tumor; Dose-Response Relationship, Drug; Humans; Imidazoles; Imiquimod; Injections, Intraperitoneal; Injections, Intravenous; Male; Melanoma; Mice; Mice, Nude; Nitrosourea Compounds; Organophosphorus Compounds; Quinoxalines; Rats; Skin Neoplasms; Xenograft Model Antitumor Assays

For several years, our group has been developing quinoxalinic compounds. Two of them, N-methyl-1-(2-phenethyl)imidazo[1,2-a]quinoxalin-4-amine (EAPB0203) and 1-(3-methoxyphenyl)-N-methylimidazo[1,2-a]quinoxalin-4-amine (EAPB0503), have emerged as the most promising anticancer drugs. In the present work, we determined metabolism pathways using liver microsomes from four mammalian species including human. We identified the cytochrome P450 isoform(s) involved in the metabolism and then investigated the pharmacokinetics and metabolism of EAPB0203 and EAPB0503 in rat after intravenous and intraperitoneal administration. Biotransformation of the compounds involved demethylation and hydroxylation reactions. Rat and dog metabolized the compounds at a higher rate than mouse and human. In all species, CYP1A1/2 and CYP3A isoforms were the predominant enzymes responsible for the metabolism. From human liver microsomes, unbound intrinsic clearances were approximately 56 ml/(min · g) protein. EAPB0203 and EAPB0503 were extensively bound to human plasma proteins, mainly human serum albumin (HSA) (∼98-99.5%). Thus, HSA could act as carrier of these compounds in human plasma. Scatchard plots showed patterns in which the plots yielded upwardly convex hyperbolic curves. On the basis of the Hill coefficients, there appears to be interaction between the binding sites of HSA, suggesting positive cooperativity. The main in vitro metabolites were identified in vivo. Total clearances of EAPB0203 and EAPB0503 [3.2 and 2.2 l/(h · kg), respectively] were notably lower than the typical cardiac plasma output in rat. The large volumes of distribution of these compounds (4.3 l/kg for EAPB0203 and 2.5 l/kg for EAPB0503) were consistent with extensive tissue binding. After intraperitoneal administration, bioavailability was 22.7% for EAPB0203 and 35% for EAPB0503 and a significant hepatic first-pass effect occurred.

Topics: Animals; Antineoplastic Agents; Biotransformation; Blood Proteins; Dogs; Humans; Lymphoma, T-Cell; Melanoma; Mice; Microsomes, Liver; Molecular Structure; Protein Binding; Quinoxalines; Rats; Rats, Sprague-Dawley; Species Specificity; Spectrometry, Mass, Electrospray Ionization; Tissue Distribution

New imidazo[1,2-a]quinoxaline analogues have been synthesized in good yields via a bimolecular condensation of 2-imidazole carboxylic acid, followed by a coupling with ortho-fluoroaniline and subsequent substitution on the imidazole ring by Suzuki Cross-coupling reaction using microwave assistance. Antitumor activities of these derivatives were evaluated by growth inhibition of A375 cells in vitro. All compounds exhibited high activities compared to imiquimod and fotemustine used as references.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Drug Screening Assays, Antitumor; Humans; Imidazoles; Melanoma; Quinoxalines; Structure-Activity Relationship