Background Polymyalgia rheumatic (PMR) is a chronic inflammatory rheumatic disease in the elderly people. Glucocorticoid (GC) is still definitely a mainstay for the treatment of PMR, but long-term GC therapy is a major risk factor of osteoporotic fractures, diabetes, hyperlipidemia, cardio-cerebral vascular events, glaucoma, etc. So GC-free treatment strategies for PMR are necessary for some patients with PMR. IL-6 is involved in the pathogenesis of PMR and quite a few case reports have already shown the efficacy of tocilizumab (TCZ) in PMR patients and some of them received TCZ monotherapy without GC.

Objectives To assess the efficacy and safety of TCZ monotherapy for PMR

Methods Thirteen PMR patients (male 3, female 10) who had been diagnosed by 2012 ACR/EULAR classification criteria from Jan 2013 to Feb 2015 were enrolled in our study (IRB application No. 638, UMIN registration No. 000008812) after obtaining the written informed consent. TCZ (8 mg/kg) was administered biweekly for the first 2 months (5 infusions) and every 4 weeks thereafter for 40 weeks (total 48 weeks). ESR, CRP, patient's global health assessed by visual analog scale (VAS), PMR activity score were evaluated every 4 week prospectively and were evaluated at week 52. Remission was defined as PMR activity score less than 1.5.

Results Baseline patients' characteristics revealed various kinds of comorbidities in 11 patients; hypertension in 7, hyperlipidemia in 5, diabetes mellitus in 3, osteoporotic vertebral fractures in 2, history of angina pectoris in 1, history of brain infarction in 1, history of hematemesis due to NSAID ulcer in 1 and glaucoma in one patient. Nine patients could complete this 52-week trial and could achieve remission at week 52. Two patients discontinued TCZ because of no response at week 6 (No.1) and week 16 (No. 8) respectively. One patient (No.2), who were in clinical remission of PMR, dropped out from this study due to pemphigoid at week 50 and received GC therapy. Patient No. 12 abandoned TCZ at week 12 because of lung infiltrates although she was treated successfully with TCZ monotherapy, and she had been in remission without any treatment until week 52. The other 3 drop-out patients could obtain remission with GC therapy at week 52. There were no serious adverse events during 52-week treatment period.

Conclusions TCZ mono-therapy was effective in most (9 out of 13) PMR patients although response was not so rapid as compared to GC. TCZ mono-therapy may be a good alternative therapy instead of GC for elderly patients with various comorbidities.

References

1. Unizony S, et al.: Arthritis Care Res 2012; 64(11):1720–1729.

2. Macchioni P, et al.: Aemin Arthritis Rheum 2013; 43(1): 113–118.

3. Toussirot E, et al.: J Rheumatol 2016 43(1): 249–251.

4. Leeb BF, et al.: Arthritis Rheum 2007; 57(5): 810–815.

References

Acknowledgements We will thank Izumi Oshima, Takashi Kukita for data collection and management of this study.

Disclosure of Interest K. Amano Grant/research support from: Chugai Pharnmaceutical Co.Ltd., K. Chino: None declared, Y. Okada: None declared, A. Shibata: None declared, A. Okuyama: None declared, T. Kurasawa: None declared, H. Takei: None declared, T. Kondo: None declared