Oxidative stress is an underlying component of acute and chronic kidney disease. Apoptosis signal-regulating kinase 1 (ASK1) is a widely expressed redox-sensitive serine threonine kinase that activates p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase kinases, and induces apoptotic, inflammatory, and fibrotic signaling in settings of oxidative stress. We describe the discovery and characterization of a potent and selective small-molecule inhibitor of ASK1, GS-444217, and demonstrate the therapeutic potential of ASK1 inhibition to reduce kidney injury and fibrosis. Activation of the ASK1 pathway in glomerular and tubular compartments was confirmed in renal biopsies from patients with diabetic kidney disease (DKD) and was decreased by GS-444217 in several rodent models of kidney injury and fibrosis that collectively represented the hallmarks of DKD pathology. Treatment with GS-444217 reduced progressive inflammation and fibrosis in the kidney and halted glomerular filtration rate decline. Combination of GS-444217 with enalapril, an angiotensin-converting enzyme inhibitor, led to a greater reduction in proteinuria and regression of glomerulosclerosis. These results identify ASK1 as an important target for renal disease and support the clinical development of an ASK1 inhibitor for the treatment of DKD.

Drug advertisement brochures (DABs) contain claims that are often supplemented by references in medical literature. Several studies have evaluated the DABs as they are commonly distributed by drug companies to practicing physicians. The objective of this study is to assess the consistency between the claims and references referred to in the DABs in Saudi Arabia. DABs were collected from medical practitioners in Riyadh, Saudi Arabia. Authors developed a protocol to be followed for quality assessment of the DABs. The vast majority of cited scientific papers were indexed in PubMed. Consequently, each reference was categorized as: justifiable, false, exaggerated or ambiguous. A total of 89 DABs were collected; 48 (53.9%) brochures were excluded from further analysis and the remaining 41 brochures (46.1%) contained 240 references with an approximate average of 5.9 references per DAB. A total of 201 cited papers were traced (83.8%). The majority of references (93.0%) supported the claims for which they were cited. However, 1.5%, 4.0% and 1.5% of claims were deemed inaccurate/false, exaggerated, and ambiguous, respectively. This study supports that the majority of the claims made in the DABs of pharmaceutical companies in Saudi Arabia were unreferenced. However, most of the evidence presented to substantiate claims made was considered true.