reduced dose of tnfi in patients with ankylosing spondylitis (recast)

Conditions: Ankylosing Spondylitis; Axial Spondyloarthritis

Summary: participants maintaining stable disease activity of ankylosing spondylitis (as) with standard-dose tumor necrosis factor inhibitor (tnfi) treatment will randomly split into two groups: maintaining standard-dose tnfi, versus reduced-dose tnfi. the proportion of participants not underwent flare between the two groups will be analyzed.


Eligibility criteria:
inclusion criteria: * documented diagnosis of ankylosing spondylitis (as) and meet the modified new york classification criteria for as. * subjects maintaining stable disease (bath ankylosing spondylitis disease activity index \[basdai\] \< 4) with standard-dose subcutaneous tumor-necrosis factor inhibitor (tnfi) treatment during previous 6 months from screening. * ankylosing spondylitis disease activity score (asdas) \< 2.1 at screening and 12 weeks prior to screening * in subjects treated with methotrexate or sulfasalazine, the dose should be maintained (methotrexate≤ 25mg/day, sulfasalazine ≤ 3 g/day) during previous 4 weeks before screening. * in subjects treated with systemic glucocorticoids, the dose should be less than 10mg/day of predinisolone or equivalent during at least 2 weeks from the screening * subjects with stable dose of concomitant nsaid (including cox2 inhibitors) during the 2 weeks from the randomization exclusion criteria: * exposure to more than 1 tnfi * history of hypersensitivity reaction to any tnfis * subjects with concomitant fibromyalgia, as determined by the investigator * subjects who have received any tnfis with reduced dosage * presence of total spinal ankylosis ('bamboo spine') * female subjects who are breastfeeding, pregnant, or plan to become pregnant during the study * subjects with a history of malignancies and lymphoproliferative disorder including lymphoma within 5 years (basal cell carcinoma treated within previous 3 months and showing no evidence of recurrence, actinic keratosis, and treated cervical/colon carcinoma in situ were allowed.) * subjects with current or history of severe, progressive, and/or uncontrolled renal, hepatic, hematological, endocrine, pulmonary, cardiac or neurological disease, as determined by the investigator * subjects with significant laboratory abnormalities included but not limited to: 1. ast/alt \> 3.0 x uln 2. white blood cell (wbc) \< 3000/μl and/or absolute neutrophil count (anc) \< 1500/μl 3. platelet count \<100,000/μl and/or hemoglobin level \<8.5 g/dl 4. serum creatinine ≥ 1.5 x uln * subjected with any high-potency opioids (ex. methadone, hydromorphone, morphine, oxycodone, oxymorphone, fentanyl, levorphanol, buprenorphine, meperidine) * subjects with current acute or chronic viral hepatitis b or c or with human immunodeficiency virus (hiv) infection * subjects planning to receive any live attenuated vaccinations after screening * subjects has history of chronic alcohol abuse or drug abuse within 6 months from screening * subjects concomitantly treated with systemic glucocorticoid (\>10mg/day of prednisolone or equivalent doses) * subjects with any other condition that, in the investigator's judgment, would make the subject unsuitable for inclusion in the study