PF-1355, a mechanism-based myeloperoxidase inhibitor, prevents immune complex vasculitis and anti-glomerular basement membrane glomerulonephritis.

Small vessel vasculitis is a life-threatening condition and patients typically present with renal and pulmonary injury. Disease pathogenesis is associated with neutrophil accumulation, activation, and oxidative damage, the latter being driven in large part by myeloperoxidase (MPO), which generates hypochlorous acid among other oxidants. MPO has been associated with vasculitis, disseminated vascular inflammation typically involving pulmonary and renal microvasculature and often resulting in critical consequences. MPO contributes to vascular injury by 1) catabolizing nitric oxide, impairing vasomotor function; 2) causing oxidative damage to lipoproteins and endothelial cells, leading to atherosclerosis; and 3) stimulating formation of neutrophil extracellular traps, resulting in vessel occlusion and thrombosis. Here we report a selective 2-thiouracil mechanism-based MPO inhibitor (PF-1355 [2-(6-(2,5-dimethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide) and demonstrate that MPO is a critical mediator of vasculitis in mouse disease models. A pharmacokinetic/pharmacodynamic response model of PF-1355 exposure in relation with MPO activity was derived from mouse peritonitis. The contribution of MPO activity to vasculitis was then examined in an immune complex model of pulmonary disease. Oral administration of PF-1355 reduced plasma MPO activity, vascular edema, neutrophil recruitment, and elevated circulating cytokines. In a model of anti-glomerular basement membrane disease, formerly known as Goodpasture disease, albuminuria and chronic renal dysfunction were completely suppressed by PF-1355 treatment. This study shows that MPO activity is critical in driving immune complex vasculitis and provides confidence in testing the hypothesis that MPO inhibition will provide benefit in treating human vasculitic diseases.

Strategies for Accelerated Drug Development: An Industry Perspective Based on an IQ Consortium Survey of CMC Considerations.

Over the past decade, there has been an increase in accelerated drug development with successful regulatory approval that has provided rapid access of novel medicines to patients world-wide. This has created the opportunity for the pharmaceutical industry to continuously improve the process of quickly bringing new medicines to patients with unmet medical needs. This can be accomplished through sharing the learnings and advancements in drug development, enhancing regulatory interactions, and collaborating with academics on developing the underlying science to reduce drug development timelines. In this paper, the IQ Consortium - Accelerated Drug Development working group members intend to share recommendations for optimizing strategies that build efficiencies in accelerated pathways for regulatory approval. Information was obtained by surveying member pharmaceutical companies with respect to recent expedited submissions within the past 5 years to gain insights as to which development strategies were successful. The learnings from this analysis are provided, which includes shared learnings in formulation development, stability, analytical methods, manufacturing, and importation testing as well as regulatory considerations. Each of these sections provide a summary illustrating the key data collected as well as a discussion that is aimed to guide pharmaceutical companies on strategies to consider streamlining development activities and expedite the drug to market.