AB0379 BARICITINIB IN POLYMYALGIA RHEUMATICA AND GIANT CELL ARTERITIS: REPORT OF SIX CASES

Background: Glucocorticoids (GC) are the cornerstone of the treatment of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA), but they are associated with several adverse events (AEs). Moreover, a considerable proportion of patients relapse during GC tapering. Objectives: To describe the efficacy and safety of the JAK-inhibitor baricitinib (BARI) in a group of patients with PMR and/or GCA. Methods: Case series of patients with PMR and/or GCA with a refractory disease course, despite several lines of therapy, including methotrexate (MTX) and tocilizumab (TCZ), started treatment with BARI. All patients underwent periodic, standardised clinical and laboratory examinations, and also FDG-PET/CT. PMR-activity score (AS) was calculated at each visit except in patients with isolated large vessel vasculitis (LVV) or GCA. Results: A total of six patients (five females and one male, median age 64 years, range 50-83) were treated with BARI. Two of them had isolated PMR (patients #1 and #6), two had PMR with associated LVV (patients #2 and #5), and one (patient #3) had cranial-GCA. Demographic and clinical characteristics are provided in Table 1. At the time of starting BARI, patients were taking a median prednisone dose of 8.75 mg/day (range 0-25), and the 4 patients with PMR±LVV had a median PMR-activity score (PMR-AS) of 23.3 (indicating high disease activity), which decreased to 1.58 after 6 months of treatment with BARI. Two of them could stop GC and continued BARI monotherapy (in one case, BARI was tapered down to 2 mg/day after 12 months). After starting BARI, patient #3 (GCA) could gradually taper prednisone from 25 mg/day to 10 mg/day in six months, without reporting fever or headache. After one year of treatment, she feels well while taking prednisone 7.5 mg/day. Patient #4 (LVV) remained clinically stable during the treatment with BARI, but a follow-up FDG-PET/CT showed LVV, and we decided to stop BARI and restart TCZ. After 4 months of treatment with BARI, patient #5 suffered from pneumonia, while she was also taking prednisone 15 mg/day. BARI was therefore stopped. No other AEs attributable to BARI were detected. Conclusion: BARI appears as an appealing option for treating patients with PMR and/or GCA. Although these preliminary results should be confirmed by a RCT, BARI lowered rapidly disease activity and exerted a significant steroid-sparing effect, allowing GC withdrawal in 2 out of 6 patients. Disclosure of Interests: Dario Camellino Speakers bureau: Medac, Eli Lilly, Paid instructor for: Mylan, Consultant of: Accord, Celgene, Novartis, Sanofi, Christian Dejaco Speakers bureau: Eli Lilly (