Tocilizumab Discontinuation Versus Dose Reduction for Patients With Well-Controlled Giant Cell Arteritis

This is a multi-center, randomized, open label study that will assess the efficacy and safety of ACTEMRA(R) or one of its FDA-approved biosimilars Tocilizumab (TCZ) maintenance versus withdrawal in Giant cell arteritis (GCA) patients who are in remission after at least 12 months of high dose TCZ treatment. Eligible participants will also have discontinued glucocorticoids (e.g., prednisone (or equivalent)) entirely at least three months before randomization. High dose TCZ treatment includes 6-8 mg/kg intravenously (IV) monthly or 162 mg subcutaneously (SC) weekly, which are two forms of administration that are commonly used in clinical practice and are equally efficacious in controlling GCA This research study has three parts: 1. The screening phase (up to 42 days) consists of collecting information about your health and your GCA, a physical exam, and blood tests to see If you qualify to enroll in the study 2. The study treatment phase (withdrawal/step down dosing phase study months 0 - 18) consists of you either completely stopping or decreasing your current dose of tocilizumab while collecting information about your health and your GCA as well as blood samples every two months at clinic visits 3. The safety follow-up phase (months 19-30) consists of collecting information about your health and your GCA as well as blood samples every three months The primary objective is to determine the rate of disease relapse at 18 months in participants with GCA who receive low-dose TCZ compared to those who discontinue TCZ