ABSTRACT
The discovery, synthesis and preliminary structure-activity relationships (SARs) of a novel class of CB1 antagonists is described. Initial optimization of benzimidazole-based screening hit 4 led to the identification of 'inverted' indole-based lead compound 18c with improved properties versus compound 4 including reduced AlogP, improved microsomal stability and improved aqueous solubility. Compound 18c demonstrates in vivo CB1 antagonist efficacy (CB1 agonist induced hypothermia model) and is orally bioavailable in rat.
Subject(s)
Benzimidazoles/chemistry , Benzimidazoles/pharmacology , Indoles/chemistry , Indoles/pharmacology , Receptor, Cannabinoid, CB1/antagonists & inhibitors , Receptor, Cannabinoid, CB1/metabolism , Animals , Benzimidazoles/metabolism , Benzimidazoles/pharmacokinetics , Humans , Hypothermia/chemically induced , Hypothermia/drug therapy , Indoles/metabolism , Indoles/pharmacokinetics , Male , Mice , Microsomes, Liver/metabolism , Obesity/drug therapy , Rats , Rats, Wistar , Solubility , Structure-Activity RelationshipABSTRACT
Tissue factor (TF) plays an important, physiological role in hemostasis. Recent studies have demonstrated the over-expression of TF in a number of solid tumor types and its pathological roles in angiogenesis and tumor metastasis. In this study, we report the development and characterization of a panel of murine MAbs that are specific for human TF, but do not inhibit TF-mediated blood coagulation. By using a modified repetitive immunizations at multiple sites (RIMMS) protocol in conjunction with an efficient hybridoma cloning procedure, anti-TF MAbs were generated within a relatively short time frame of 5-6 weeks. Following primary screening by ELISA, the binding of the MAbs to the native form of human TF was demonstrated in flow cytometry using a stable cell line expressing human TF. Several of these TF-specific MAbs did not inhibit blood coagulation in a blood coagulation assay and bound with high affinity (0.5-2 nM) to human TF in BIAcore analyses. Importantly, this study represents an independent evaluation of the RIMMS strategy for MAb generation and demonstrates that class-switched, high-affinity MAbs can be generated rapidly and reliably using RIMMS.
