A feasible treatment strategy for tapering subcutaneous tocilizumab in giant cell arteritis: a 24-month multi-center retrospective study.

To examine whether extending tocilizumab (TCZ) intervals is a feasible treatment strategy in giant cell arteritis (GCA). This multicenter retrospective study included patients with GCA who started subcutaneous TCZ at five Japanese hospitals between January 2008 and July 2021. We collected clinical data and monitored relapses for up to 24 months following the initiation of TCZ. The treatment regimen, including TCZ intervals and glucocorticoid (GC) dosage, was evaluated every 6 months. Of 56 eligible patients, 44 (79%) initiated TCZ weekly, and 12 (21%) every two weeks. The GC dosage consistently decreased after initiating TCZ; GC discontinuation was achieved in 87.5% at month 24. The number of patients extending TCZ intervals increased over time. Among the 32 patients who were followed at month 24, 5 (15.6%) continued weekly TCZ; the TCZ interval was every two weeks in 13 (40.6%), every three weeks in 7 (21.9%), and every four weeks or longer in 5 (15.6%), and 2 (6.3%) discontinued TCZ due to well-controlled disease. During 24-month follow-up, 10 (31.3%) extended TCZ intervals by two weeks or more from the starting dose. Three patients experienced relapses after extending TCZ intervals for well-controlled GCA, and all improved by shortening TCZ intervals. Gradually extending TCZ intervals by one week each is a feasible treatment strategy for well-controlled GCA patients after achieving GC-free status. While some patients may experience relapses following the extension of TCZ intervals, these relapses might be potentially managed by adjusting only the TCZ intervals.