Activin receptor-like kinase 5 (ALK5) inhibitors: a patent review (2013-present)

INTRODUCTION: Activin receptor-like kinase 5 (ALK5) is a pivotal component of the transforming growth factor β (TGF-β) signaling pathway. Currently, 10 ALK5 inhibitors are under clinical investigation, with numerous others in preclinical stages, demonstrating broad therapeutic potential. However, no systematic review of ALK5 inhibitor-related patents has been conducted to date. Therefore, this study systematically reviews patents related to ALK5 inhibitors from 2013 to the present, providing a theoretical basis for discovering structurally novel, safe, and effective ALK5 inhibitors. AREAS COVERED: This paper briefly outlines ALK5 inhibitors currently in clinical development and ALK5-related patents published since 2013, retrieved through databases such as Google Patents, CAS SciFinder and PatSnap. EXPERT OPINION: ALK5 inhibitors have garnered significant interest in recent years for the treatment of TGF-β-related diseases, with encouraging outcomes observed in clinical trials. However, certain structural classes have been associated with adverse effects such as cardiotoxicity and bone toxicity. This review consolidates patent literature on ALK5 inhibitors, offering insights to support the development of novel, highly efficient, and low-toxicity inhibitors with improved pharmacokinetic profiles.