Objective: To evaluate the efficacy and safety profile of a loading regimen of the anti-TNFalpha antibody infliximab in ankylosing spondylitis (AS).
Methods: This was an open-labeled trial. Subjects eligible for this study were adults with a diagnosis of definite AS. Active disease was a Bath AS disease activity index (BASDAI) > or = 4 and spinal pain VAS > or = 4. Concurrent stable treatment with nonsteroidal anti-inflammatory drugs was permitted during the study. Subjects were not permitted to be on methotrexate, systemic corticosteroids, cytotoxic drugs or disease-modifying anti-rheumatic drugs for various time periods before screening. Infliximab 5 mg/kg was infused at weeks 0, 2, 6. All patients were followed up to 10 weeks. The primary endpoint was proportion of ASAS 20 responders at week 10. The secondary endpoints were the proportion of subjects achieving an ASAS partial remission, the change from baseline in bath AS functional index and in the physical component summary score of the short form-36 in health survey questionnaire at week 10. Other secondary endpoints, related to reducing signs and symptoms of AS and improving range of motion and physical function, were evaluated.
Results: 63 patients (79% males, 90% HLA-B(27)(+), median age 32 yr, median disease duration 10 yr) completed the treatment. The proportion of ASAS 20 responders at 2, 6, 10 week was 75%, 84%, 84% respectively. The proportion of ASAS partial remission patients at 2, 6, 10 week was 10%, 21%, 30% respectively. Results for other secondary efficacy endpoints showed that infliximab could provide substantial benefits to patients with AS by reducing clinical signs and symptoms and improving range of motion, physical function, and quality of life. Sixty-five percent of subjects reported treatment-related adverse events. The most frequently occurred were upper respiratory tract infection and skin and appendages. Secondary was elevation of liver enzymes. Most treatment-related adverse events were mild to moderate in severity. Two patients had serious dermatitis and one stopped treatment owing to an infusion reaction. Short-term follow up indicated that effect of Remicade lasted for about 2 to 8 months without any new side effect.
Conclusion: A loading regimen of infliximab demonstrated consistent evidence of efficacy and was well tolerated in the treatment of active AS.