Discovery and Optimization of Orally Bioavailable Phthalazone and Cinnolone Carboxylic Acid Derivatives as S1P2 Antagonists against Fibrotic Diseases
Oscar Mammoliti, Koen Jansen, Sandy El Bkassiny, Adeline Palisse, Nicolas Triballeau, Denis Bucher, Brigitte Allart, Alex Jaunet, Giovanni Tricarico, Maxim De Wachter, Christel Menet, Javier Blanc, Vatroslav Letfus, Renata Rupčić, Mario Šmehil, Tanja Poljak, Beatrice Coornaert, Kathleen Sonck, Inge Duys, Ludovic Waeckel, Lola Lecru, Florence Marsais, Catherine Jagerschmidt, Marielle Auberval, Philippe Pujuguet, Line Oste, Monica Borgonovi, Emanuelle Wakselman, Thierry Christophe, Nicolas Houvenaghel, Mia Jans, Bertrand Heckmann, Laurent Sanière, Reginald Brys
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease. Current treatments only slow down disease progression, making new therapeutic strategies compelling. Increasing evidence suggests that S1P2 antagonists could be effective agents against fibrotic diseases. Our compound collection was mined for molecules possessing substructure features associated with S1P2 activity. The weakly potent indole hit 6 evolved into a potent phthalazone series, bearing a carboxylic acid, with the aid of a homology model. Suboptimal pharmacokinetics of a benzimidazole subseries were improved by modifications targeting potential interactions with transporters, based on concepts deriving from the extended clearance classification system (ECCS). Scaffold hopping, as a part of a chemical enablement strategy, permitted the rapid exploration of the position adjacent to the carboxylic acid. Compound 38, with good pharmacokinetics and in vitro potency, was efficacious at 10 mg/kg BID in three different in vivo mouse models of fibrotic diseases in a therapeutic setting.