To assess the efficacy and safety of loxoprofen sodium hydrogel patch (LX-P) versus loxoprofen sodium tablet (LX-T) in patients with active ankylosing spondylitis(AS). The trial includes 70 patients who are randomly assigned to either the LX-P group (LX-P 100 mg per day) or LX-T group (LX-T 60 mg t.i.d.) for 4 weeks.

This is a 4-week randomized, open-label trial to investigate the efficacy and safety of loxoprofen sodium hydrogel patch (LX-P) versus loxoprofen sodium tablet (LX-T) in patients with active ankylosing spondylitis(AS). The trial includes 70 patients who are randomly assigned to either the LX-P group (LX-P 100 mg per day) or LX-T group (LX-T 60 mg t.i.d.) for 4 weeks.

Inclusion Criteria:

• 18 to 65 years
• Meet 1984 modified New York criteria for AS
• The Bath AS Disease Activity Index (BASDAI) ≥4 on a 0-10-cm visual analog scale or the Ankylosing Spondylitis Disease Activity Score using the C-reactive protein level (ASDAS-CRP) ≥1.3
• NSAIDs washout period of at least 5 days prior to randomization
• DMARDs washout period of at least 4 weeks prior to randomization
• Corticosteroids washout period of at least 4 weeks prior to randomization
• Biological agents washout period of at least 3 months prior to randomization.

Exclusion Criteria:

• Peptic ulcer
• Unstable cardiac diseases
• Abnormal hepatic function with an elevation of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ 2.5 times of upper normal limits
• Abnormal renal function with creatinine more than upper normal limit
• Hematologic disorders
• Psychosis
• Malignancy
• Allergic to LX drug.