Tocilizumab for the treatment of giant cell arteritisand polymyalgia rheumatica in patients with serious comorbidities: experience of two Russian centers

Aim

To evaluate the efficacy and safety of intravenous tocilizumab (TCZ) in patients with giant cell arteritis (PCA) and/or polymyalgia rheumatica (PMR) associated with comorbidities that increase the risk of side effects of glucocorticoids (GCs).

Material and methods

Twenty two patients (21 females,mean age 72.8±6.5 years) with GCA (n=6), PMR (n=13) orGCA/PMR (n=3) were enrolled into the prospective study. Mean disease duration was 3.5 (0.5-19) months. All patientshad active GCA/PMR with mean C-reactive protein level of30.3±32.7 mg/L. All patients had serious comorbidities (13of them presented with at least three concurrent diseases). TCZ was administered intravenously at a dose of 2.3-8.8mg/kg Q4W. Eleven patients were also treated with prednisone at a average dose of 20 (10-70) mg per day. The follow-up period was 24 (6-60) months.

Results

All patients responded to intravenous TCZ givenfor average of 4,5 (2-11) months and achieved remission ofGCA/PMR. Several patients showed a very rapid improvement after initiation of TCZ monotherapy. Prednisone dose was discontinued in 6 patients and reduced to 2.5 (2.5-10) mgin 5 patients. After TCZ discontinuation, one patient developed relapse of GCA. However, this patient regained the remission after reinstitution of intravenous TCZ 4 mg/kg. One patient developed septic olecranon bursitis one month following TCZ discontinuation, whereas another patient died of myocardial infarction 12 months following TCZ discontinuation. Three remaining complications included one case of peripheral artery disease (claudication).

Conclusion

Interleukin-6 inhibitors should be consideredas potentially effective and relatively safe treatment for GCA/PMR patients with serious comorbidities, intolerance or contraindications to standard therapy with GCs. More data isneeded to identify the optimal dosing regimen and duration ofTCZ therapy, as well as its cost-effect.

Key words

Giant cell arteritis, polymyalgia rheumatica, tocilizumab, interleukin-6 inhibitor