The add-on effectiveness and safety of iguratimod in patients with rheumatoid arthritis who showed an inadequate response to tocilizumab

Abstract

Objectives: To evaluate the effectiveness of add-on iguratimod (IGU) in patients with rheumatoid arthritis (RA) who showed an inadequate response to tocilizumab (TCZ), especially patients who were intolerant of an effective dose of methotrexate (MTX).

Methods: Thirty-one patients with RA (22 women, age 62.4 years, disease duration 13.8 years, prior TCZ duration 35.7 months, 25 intravenous [8 mg/kg/4 weeks] and 6 subcutaneous [162 mg/2 weeks] TCZ treatments, concomitant MTX 8.5 mg/week [35.5%], and prednisolone (PSL) 4.3 mg/day [25.8%]) who showed an inadequate response to TCZ (disease activity score assessing 28 joints with C-reactive protein [DAS28-CRP] 2.9, clinical disease activity index [CDAI] 15.0, 28 secondary inadequate responders) were treated with additional IGU (final dose 41.7 mg/day) and enrolled in this 24-week, multicenter, retrospective study.

Results: Twenty-nine patients (93.5%) continued the treatment for 24 weeks (one dropped out for pneumonia and one for digestive symptoms). The TCZ and the concomitant dose and rate of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) (MTX, salazosulfapyridine [SASP], and tacrolimus [TAC]) were not significantly changed during this period. Outcome measures improved significantly, as follows: DAS28-CRP from 2.9 to 1.7 (p < .001); CDAI from 15.0 to 6.0 (p < .001); modified Health Assessment Questionnaire (mHAQ) from 0.8 to 0.6 (p < .05); and rheumatoid factor (RF) from 382.1 to 240.3 IU/mL (p < .001). Using the EULAR criteria, 64.5% achieved a moderate response, and 51.6% achieved ACR 20 at 24 weeks.

Conclusion: Adding IGU to inadequate responders to TCZ may be a promising and safe complementary treatment option.

Keywords:

• Iguratimod
• inadequate response
• rheumatoid arthritis
• tocilizumab

Conflict of interest

K.E., M.H., and H.Y. received research grants from Astellas, Daiichi Sankyo, Eisai, and Mitsubishi Tanabe. K.E. received speaker fees from AbbVie, Astellas, Asahi Kasei, Chugai, Daiichi Sankyo, Eli Lily, Eisai, Mitsubishi Tanabe, Ono Pharmaceutical, and UCB Japan. H.T. received speaker fees from Chugai, Mitsubishi Tanabe, Bristol-Myers Squibb, and Eisai, and received research grants from Chugai and Ayumi. S.K. received speaker fees from Bristol-Myers Squibb, Chugai, Otsuka, and Takeda. M.N. received travel fees from Abbie. H.O. received speaker fees from Bristol-Meyers, Ayumi, and Chugai, and moderator fees from Astellas, Pfizer, AbbVie, Mitsubishi Tanabe, Bristol-Meyers, and Eisai. S.T. received speaker fees from AbbVie, Asahi Kasei, Chugai, Daiichi Sankyo, Eli Lilly, Eisai, Mitsubishi Tanabe, Celgene, and Novartis Pharma K.K. M.H. received speaker fees from Astellas, Bristol-Meyers, Pfizer, Ono Pharmaceutical, and UCB Japan. J.H. received speaker fees from Astellas, Asahi Kasei, Ayumi, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eli Lily, Eisai, Hisamitsu, Mitsubishi Tanabe, MSD, Taisho-Toyama, and Teijin Pharmaceuticals. A.M., Y.E., and A.G. declare they have no conflict of interest.