Disease Activity-Guided Stepwise Tapering but Not Discontinuation of Biologics Is a Feasible Therapeutic Strategy for Patients with Ankylosing Spondylitis: Real-World Evidence.

Abstract

To analyze the history of biologics usage in patients with ankylosing spondylitis (AS) in China and to evaluate the impact of drug reduction and withdrawal on disease activity. Drug administration intervals and disease activity indexes in patients with AS who regularly used etanercept (ETN) biosimilars for more than 1 year and those who withdrew the drugs during the same period in a single center were analyzed retrospectively. A total of 108 patients with AS who used ETN biosimilars for more than a year were recruited in this study for analysis. (1) Overall, 98.1% patients with AS increased the intervals between drug administrations, averaging from 4.57 ± 0.15days during 0-3months to 8.53 ± 0.43days during 3-6months, and to 10.49 ± 0.39days during 6-12months. Compared with the baseline parameters, after 3-month and 12-month treatments disease activities were improved significantly, including Patient Global Assessment (PTGA), overall back pain, nocturnal pain, fatigue, Ankylosing Spondylitis Disease Activity Score-C-Reactive Protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI). (2) Only 59.3% used ETN biosimilars with full dose (3.5days' interval) in the first 3months. At baseline, disease activities of these patients were higher than those with reduced dose (5.9days' interval). However, at 12months of drug administration there was no significant difference in the overall length of drug administration intervals and disease activities between the two groups. (3) Twenty patients with low disease activity (LDA) discontinued therapy spontaneously; after 3months, 55% of them experienced disease recurrence (∆ASDAS ≥ 0.9). Spontaneous dose reduction was a common phenomenon among patients with AS in China, which becomes more notable with increasing relief of symptoms. Most patients could maintain an LDA state after dose reduction. Compared with dose reduction, ETN biosimilar withdrawal was more likely to induce disease recurrence. Therefore, disease activity-guided individualized stepwise tapering may become one of the feasible therapeutic strategies for AS in the future.