Study on the safety and efficacy of tocilizumab, an anti-IL-6 receptor antibody, in patients with rheumatoid arthritis complicated with AA amyloidosis

Abstract

Objectives: Although treatment of rheumatoid arthritis (RA) has progressed by the use of biologics, amyloid A (AA) amyloidosis is still an intractable complication in patients with RA. In the present study, safety and efficacy of 1-year treatment with an anti-IL-6 receptor antibody tocilizumab (TCZ) on RA and AA amyloidosis were estimated.

Methods: TCZ (8 mg/kg every 4 weeks) was administered to five RA patients complicated with AA amyloidosis. The primary end point was improvement in renal dysfunction and the secondary end point was CDAI at 1 year after the treatment.

Results: An improvement in the renal dysfunction, including urinary protein secretion, was found, in four patients including two patients who were refractory to etanercept, with a remarkable decrease of SAA concentration, and the progression of organ dysfunction was prevented at 1 year in all patients treated with TCZ. The mean clinical disease activity index decreased from 33.9 to 4.7 (p = 0.012) in five patients treated with TCZ for 1 year. Three non-serious adverse events were observed in two patients.

Conclusions: TCZ ameliorates renal dysfunction in RA patients complicated with AA amyloidosis who are refractory to conventional therapies, thereby suggesting that TCZ has a potential to regulate AA amyloidosis.

Keywords:

• AA Amyloidosis
• Tocilizumab
• Rheumatoid Arthritis
• Treatment

Acknowledgements

The authors thank all medical staff members at the associated institutions for providing the data.

Funding

This work was supported in part by a Research Grant-In-Aid for Scientific Research by the Ministry of Health, Labor and Welfare of Japan, the Ministry of Education, Culture, Sports, Science and Technology of Japan, and the University of Occupational and Environmental Health, Japan.

Conflict of interest

Y Tanaka has received consulting fees, speaking fees, and/or honoraria from Mitsubishi-Tanabe Pharma, Chugai Pharma, Eisai Pharma, Pfizer, Abbott Immunology Pharma, Daiichi-Sankyo, Janssen Pharma, Astra-Zeneca, Takeda Industrial Pharma, Astellas Pharma, Asahi-kasei Pharma and GlaxoSmithKline and has received research grant support from Mitsubishi-Tanabe Pharma, Bristol-Myers Squibb, Takeda Industrial Pharma, MSD, Astellas Pharma, Eisai Pharma, Chugai Pharma, Pfizer and Daiichi-Sankyo.