Defining the target: Clinical aims in axial spondyloarthritis

Treat-to-target (T2T) is an emerging treatment paradigm in axial spondyloarthritis (axSpA), originally based on evidence from other inflammatory conditions, which aims to direct therapy to a clear target such as disease remission or low disease activity, with the ultimate goal of maximizing quality of life in affected individuals. The 2016 update of the Assessment of Spondyloarthritis International Society/EULAR guidelines for axSpA have recommended that treatment should be guided according to a predefined target but controversy remains as to what this target should be. An international task force has recommended remission or inactive disease as the desired outcome; however, there are many disease outcome measures developed for use in clinical practice in axSpA and the question remains of which is the most appropriate to use. Another important consideration when discussing the T2T paradigm is when to intervene. Although evidence is limited in this respect, the available data suggest that therapy should be commenced at an early stage of the disease, when the process of bone repair expected to occur after an inflammatory phase has not yet started. It has also been argued that the success of the T2T paradigm may depend more on the treatment strategy than the individual therapies utilized. This article will explore the feasibility of using a T2T approach in axSpA clinical practice, the utilization of new composite outcome measures of disease activity such as the ASDAS, and the validity of different treatment strategies to allow for a T2T intervention in these patients.