Tocilizumab for polymyalgia rheumatica: report of two cases and review of the literature

Background: Glucocorticoids (GC) are the mainstay of treatment of polymyalgia rheumatica (PMR). However GC-related adverse events occur frequently, particularly in patients with relapsing disease. Several studies have demonstrated that IL-6 is a key player in the pathogenesis of PMR.

Objectives: To report 2 patients with PMR treated with the anti-IL-6 receptor monoclonal antibody tocilizumab (TCZ) and to review the published evidence on the efficacy and safety of TCZ in patients with PMR.

Methods: We treated 2 GC-naive patients with newly diagnosed pure PMR with monthly TCZ infusions (8mg/kg body weight) for 6 months. Disease activity and drug tolerability were assessed clinically, by laboratory tests, and bilateral shoulder ultrasonography before starting the treatment and subsequently every month during TCZ therapy. We performed a systematic literature search (PubMed until July 2012) using the terms "tocilizumab," "anti-IL-6-receptor," "polymyalgia rheumatica," "giant cell arteritis", and "large-vessel vasculitis" to identify published reports of patients with PMR treated with TCZ.

Results: One of our patients responded well to TCZ, while the other patient required GC therapy after the 2nd TCZ infusion because of lack of appreciable clinical response. Both patients tolerated TCZ well. The review of the literature revealed 4 reports with a total of 9 patients who received TCZ for PMR. In 7 of these 9 patients, PMR was associated with giant cell arteritis. Including our patients, 5 patients received TCZ alone and 6 TCZ plus GC. A good response to TCZ treatment was observed in all patients reported in the literature without any major adverse events.

Conclusions: TCZ both as monotherapy and in association with GC appears to be mostly effective and safe to treat patients with PMR. However, larger controlled studies are required to confirm these favorable data.