Tumor necrosis factor-α (TNFα) inhibitors in the treatment of nonradiographic axial spondyloarthritis: current evidence and place in therapy

Nonradiographic axial spondyloarthritis (SpA) and radiographic SpA (also known as ankylosing spondylitis) are currently considered as two stages or forms of one disease (axial SpA). The treatment with tumor necrosis factor- (TNF) inhibitors has been authorized for years for ankylosing spondylitis. In recent years, most of the anti-TNF agents have also been approved for the treatment of nonradiographic axial SpA by the European Medicines Agency (EMA) and similar authorities in many countries around the world (but not in the US), increasing the number of possible therapies for this indication. Data from several clinical trials have demonstrated the good efficacy and safety profiles from those anti-TNF agents. Presently, a large number of patients achieve a satisfactory clinical control with the current therapies, however, there remains a percentage refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) and TNF inhibitors; therefore, several new drugs are currently under investigation. In 2015, the first representative of a new class of biologics [an interleukin (IL)-17 inhibitor] secukinumab, was approved for the treatment of ankylosing spondylitis; a clinical trial in nonradiographic axial SpA is currently underway. In this review, we discuss the recent data on efficacy and safety of TNF-inhibitors focusing on the treatment of nonradiographic axial SpA.