Description: PF-06250112 is a novel, potent, highly selective, orally bioavailable BTK inhibitor with an IC50 of 0.5 nM, shows inhibitory effect toward BMX nonreceptor tyrosine kinase and TEC with IC50s of 0.9 nM and 1.2 nM, respectively. PF-06250112 inhibits both BCR-mediated signaling and proliferation, as well as FcR-mediated activation. To assess the therapeutic impact of BTK inhibition, aged NZBxW_F1 mice were treated with PF-06250112 and demonstrate that PF-06250112 significantly limits the spontaneous accumulation of splenic germinal center B cells and plasma cells. Correspondingly, anti-dsDNA and autoantibody levels were reduced in a dose-dependent manner. Moreover, administration of PF-06250112 prevented the development of proteinuria and improved glomerular pathology scores in all treatment groups. Strikingly, this therapeutic effect could occur with only a modest reduction observed in anti-dsDNA titers, implying a critical role for BTK signaling in disease pathogenesis beyond inhibition of autoantibody production. PF-06250112 prevents proteinuria in an FcR-dependent, Ab-mediated model of glomerulonephritis. Importantly, these results highlight that BTK inhibition potently limits the development of glomerulonephritis by impacting both cell- and effector molecule-mediated pathways. These data provide support for evaluating the efficacy of BTK inhibition in systemic lupus erythematosus patients.