Biologic Treatment Withdrawal in Takayasu Arteritis Patients in Sustained Remission

Takayasu arteritis (TAK) is a chronic granulomatous large-vessel vasculitis that primarily affects the aorta and its major branches. Despite advances in treatment, many patients require long-term immunosuppressive therapy to maintain disease control. Biologic agents, particularly tumor necrosis factor inhibitors and interleukin-6 receptor inhibitors such as tocilizumab, have demonstrated efficacy in refractory or relapsing disease. However, there is limited evidence regarding the optimal duration of biologic therapy and the safety of treatment discontinuation in patients who achieve sustained remission.

This prospective interventional study is designed to evaluate the outcomes of planned biologic treatment withdrawal in patients with Takayasu arteritis who have achieved long-standing clinical and radiologic remission and have received biologic therapy for at least three years. Eligible patients will undergo a predefined dose tapering protocol over a 3-month period. Patients who do not experience relapse during this phase will discontinue biologic therapy completely at the end of the tapering period.

Following treatment discontinuation, patients will be followed for 12 months. Clinical and laboratory evaluations will be performed at 1 month after discontinuation and every 3 months thereafter. Imaging studies will be performed as clinically indicated.

The primary outcome of the study is the proportion of patients maintaining remission at 12 months after biologic treatment withdrawal. Secondary outcomes include the rate and timing of major and minor relapses during the tapering phase and the post-withdrawal follow-up period. Additional analyses will explore potential predictors of relapse and differences according to biologic agent type and concomitant therapies.

Inclusion criteria

• Diagnosis of Takayasu arteritis according to the 2022 American College of Rheumatology/EULAR classification criteria
• Treatment with biologic therapy (TNF inhibitors or tocilizumab) for at least 3 years
• Sustained clinical, laboratory, and radiologic remission
• No change in treatment during the previous 12 months
• No glucocorticoid use within the previous 6 months
• Ability and willingness to provide written informed consent

Exclusion criteria

• Presence of other active inflammatory diseases requiring biologic therapy (e.g., inflammatory bowel disease, ankylosing spondylitis)
• Inability to attend scheduled follow-up visits after treatment tapering and discontinuation
• Pregnancy or planning pregnancy during the study period