Table 1.

Open questions about treatment of axSpA to be addressed in the future

Treatment	Question	Potential solution
NSAIDs	Effect on objective signs of inflammation, specifically on MRI inflammation	Controlled study with NSAIDs vs analgesics without anti-inflammatory properties
	Effect of NSAIDs in general and of COX-2-selective inhibitors specifically on radiographic spinal progression	Controlled clinical trial, at least 2 years duration with conventional X-rays, potentially shorter with a low-dose computed tomography
	Long-term safety of NSAIDs in axSpA	Long-term registry data
b- und tsDMARDs	Comparative efficacy of TNFi, IL17i and JAK	Head-to-head studies
	The optimal first- and second-line treatment, potential for combination, optimized individual treatment strategy, selective predictors of response	Strategy trials, trials with cross-over design
	Short- and long-term advantages of a treat-to-target strategy, optimal time points and criteria for the escalation of treatment	Trials with the treat-to-target approach
	Optimal strategy for the treatment de-escalation, predictors of sustained drug-free remission	Trials with treatment de-escalation strategies
	Effects of b-and tsDMARDs on radiographic spinal progression, alone or in combination with NSAIDs	Controlled trials, at least 2 years duration with conventional X-rays, potentially shorter with a low-dose computed tomography
Potential novel treatment options	Targeting microbiota, restoration of immune tolerance, targeting disease-relevant T cells, dietary intervention	Identification of the appropriate targets and conduction of trials