ABSTRACT
Constitutive activation of the canonical Wnt signaling pathway, in most cases driven by inactivation of the tumor suppressor APC, is a hallmark of colorectal cancer. Tankyrases are druggable key regulators in these malignancies and are considered as attractive targets for therapeutic interventions, although no inhibitor has been progressed to clinical development yet. We continued our efforts to develop tankyrase inhibitors targeting the nicotinamide pocket with suitable drug-like properties for investigating effects of Wnt pathway inhibition on tumor growth. Herein, the identification of a screening hit series and its optimization through scaffold hopping and SAR exploration is described. The systematic assessment delivered M2912, a compound with an optimal balance between excellent TNKS potency, exquisite PARP selectivity, and a predicted human PK compatible with once daily oral dosing. Modulation of cellular Wnt pathway activity and significant tumor growth inhibition was demonstrated with this compound in colorectal xenograft models in vivo.
Subject(s)
Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Enzyme Inhibitors/pharmacology , Tankyrases/antagonists & inhibitors , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Female , Humans , Mice , Mice, SCID , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Structure-Activity Relationship , Tankyrases/metabolismABSTRACT
Tankyrases 1 and 2 (TNKS1/2) are promising pharmacological targets that recently gained interest for anticancer therapy in Wnt pathway dependent tumors. 2-Aryl-quinazolinones were identified and optimized into potent tankyrase inhibitors through SAR exploration around the quinazolinone core and the 4'-position of the phenyl residue. These efforts were supported by analysis of TNKS X-ray and WaterMap structures and resulted in compound 5k, a potent, selective tankyrase inhibitor with favorable pharmacokinetic properties. The X-ray structure of 5k in complex with TNKS1 was solved and confirmed the design hypothesis. Modulation of Wnt pathway activity was demonstrated with this compound in a colorectal xenograft model in vivo.
