Hydroxychloroquine, sulfasalazine and gold were of marginal value. In the late 1980s, methotrexate (MTX) became widely accepted as a highly effective DMARD and largely superseded these prior therapies. Over the years, MTX has repeatedly been shown to reduce the signs and symptoms of RA, slow structural disease progression and improve functional capacity in patients with RA. MTX remains an important first line DMARD, and often forms the foundation of an RA

treatment protocol.[4, 5] In the late 1990s, a new class of DMARDs was introduced: biologicals. These macromolecular proteins are potent immunomodulatory agents that have revolutionized RA disease management, prognosis, and outcomes. Some biologics antagonize inflammatory cytokines like tumor necrosis factor alpha (TNF-α) (adalimumab, certolizumab, etanercept, golimumab and infliximab), interleukin-1 (IL-1) (anakinra) or selleck screening library IL-6 (tocilizumab). In addition, abatacept impairs T cell co-stimulation and rituximab depletes B cell numbers and antagonizes B cell function. In most instances, traditional synthetic DMARDs, such as MTX, can be used safely and effectively in combination

with a biologic agent. Indeed, this combination approach has repeatedly demonstrated reduced RA symptoms and joint see more damage in patients unresponsive to MTX alone.[6, 7] The current standard of care for RA is to initiate DMARD therapy soon after diagnosis and escalate treatment in an attempt to control inflammatory disease. Ideally, this will achieve disease remission by completely suppressing Pomalidomide in vivo inflammatory joint disease, preventing progressive joint damage and improving function. All biologics are either subcutaneously or intravenously administered. The most important adverse effect of biological therapies is immunosuppression, leading to an increased risk of infection. Despite their general safety and effectiveness, wider adoption of biologics has been limited by high drug costs which may affect medication adherence.[8] Furthermore, up

to 30% of patients show a primary or secondary non-response to biologic therapies, and an American College of Rheumatology (ACR) criteria response of ACR50 is achieved in approximately 50% or less of participants in most clinical trials of biologic agents.[9-12] Thus, despite all of the advances in disease management, patients with RA continue to experience relapses, unresponsiveness to therapies, unaffordable treatment costs and intolerable medication toxicities.[13] These concerns have paved the way for the development of new, oral, small molecule DMARDs. The most widely studied and developed agents target various kinase pathways. Many kinases play a key role in immune activation and inflammation. Kinases and pharmacologic inhibitors of these pathways will be the topic of this review. Through protein phosphorylation, kinases regulate multiple essential cellular activities, including signaling, metabolism, transcription and cycle progression.