Slow recruitment

This is a 6-week randomized, double-blind trial of 4 different non-steroidal anti-inflammatory drugs in patients with axial spondyloarthritis to compare the change of pain score from baseline at 4 weeks to the change of pain score from baseline at 6 weeks.

Patients with ankylosing spondylitis or axial spondyloarthritis who fulfills the inclusion and exclusion criteria will be randomized into one of the four arms after an initial one week washout period, including: 1) indomethacin 75mg every 12 hours (Q12H); 2) diclofenac 75mg Q12H; 3) meloxicam 7.5mg Q12H; 4) celecoxib 200mg Q12H. The treatment length will be 6 weeks. Primary outcome is the change of pain score from baseline to week 4 and to week 6.

Inclusion Criteria:

• A clinical diagnosis of ankylosing spondylitis (AS) by treating rheumatologists, or a diagnosis of axial spondyloarthritis (axSpA) with a pelvis MRI with significant bone marrow edema on STIR sequences;
• Minimum of 18 years old;
• Are taking NSAIDs on a regular basis for AS or axSpA (defined as more than 20 days in the past month) and willing to withhold medication for one week; or having active symptoms that require initiation of NSAIDs;
• Concomitant anti-rheumatic drugs are allowed, if the dose has been stable for the past three months;
• Have active disease after initial washout period, defined by BASDAI >=4/10, or back pain numerical rating scale (NRS)>=4/10

Exclusion Criteria:

• Patients who have concurrent rheumatic diseases other than AS or axSpA;
• Patients who have oral corticosteroid in the past two weeks; patients who have acute peripheral arthritis;
• Patients with a fibromyalgia score >= 13;
• Patient with extensive cardiac history, history of gastrointestinal bleeding that required blood transfusion, chronic kidney diseases, abnormal liver function tests; or female patients who are pregnant.

Use of low-dose of aspirin (<100mg daily) is allowed in the study.

This is a self-controlled study, the objective of the study is to compare the change at week 4 vs. week 6. The participants were randomized into 4 groups getting different drugs, but this is considered as one variable. The study does not intend to compare drug efficacy between arms.

6 weeks

The participants were randomized into 4 groups getting different drugs, but this is considered as one variable. The study does not intend to compare drug efficacy between arms.