Recent patent landscape of ASK1 inhibitors: spotlight on 2-(1-isopropyl-4H-1,2,4-triazole-3-yl) pyridine as a privileged scaffold.

Apoptosis signal-regulating kinase 1 (ASK1) is an important stress-responsive kinase involved in multiple pathological conditions including fibrosis, cancer, cardiovascular disorders, inflammatory diseases, and neurodegenerative disorders. Owing to its central role in JNK/p38 signaling, ASK1 has emerged as an attractive therapeutic target for drug discovery. This review summarizes the recent patent landscape of ASK1 inhibitors with particular emphasis on the privileged 2-(1-isopropyl-4H-1,2,4-triazole-3-yl)pyridine scaffold. Literature and patent data were collected through comprehensive searches of WIPO Patentscope, USPTO, Espacenet, SciFinder, and Google Scholar. Patents reporting novel ASK1 inhibitors, synthetic methodologies, biological evaluation, and structure-activity relationship (SAR) studies were included, while unrelated or structurally insufficient patents were excluded. The reported compounds are classified according to linker architecture, including amide-linked derivatives, cyclic urea scaffolds, and other heterocyclic variations. Comparative SAR analysis highlights the importance of hinge-binding interactions, hydrophobic substituents, and conformational rigidity in improving ASK1 inhibitory potency and selectivity. The 2-(1-isopropyl-4H-1,2,4-triazole-3-yl)pyridine scaffold remains one of the most promising pharmacophores for ASK1 inhibition. Incorporating ASK1 inhibitors into treatment strategies will likely require a shift toward combination therapies and others. Future development of ASK1 inhibitors should focus on improving selectivity, pharmacokinetic properties, and multi-target therapeutic strategies to overcome current clinical limitations.