Background It has been defined that ADA monotherapy has only limited effectiveness compared to combination therapy with Methotrexate (MTX). On the other hand, MTX cannot be administered in some patients because of tolerability concern or their complications. It is inadequate to clarify the efficacy of ADA treatment concomitant with disease-modifying antirheumatic drugs (DMARDs) other than MTX in patients in whom MTX cannot be administered.
Objectives The objective of this study was to investigate the effectiveness of ADA concomitant with DMARDs other than MTX in Japanese patients with RA.
Methods All patients (n=175) who underwent ADA treatment between August 2008 and October 2009 at Tsurumai Biologics Communication Study Group’s institutes were enrolled. Patients were divided into three groups: (1) concomitant MTX (MTX group) (2) concomitant DMARDs other than MTX (DMARDs group) (3) monotherapy (mono group). Effectiveness end point was DAS28-ESR at 52 weeks. Kaplan-Meier analysis was used to estimate drug survival rates during first 52 weeks.
Results In total, 136 (77,4%) were in MTX group, 20 (11.4%) were in DMARDs group and 19 (10.9%) were in mono group. The mean age was 58±14 years in MTX group, 61±13 in DMARDs group, 65±9 in mono group. The mean duration of disease was 12.9±10.9 years, 13.0±11.3, 17.2±11.1, respectively. In MTX group, mean dosage of MTX was 7.0±1.9 mg/weeks. In DMARDs group, the number of DMARDs types was 7 (Fig A). DAS28-ESR scores decreased from 4.84±1.18 at baseline to 3.27±1.29 at week 52 in MTX group (p<0.001 vs baseline), from 5.18±1.10 to 4.09±1.12 in DMARDs group (p<0.001 vs baseline) and from 6.06±0.95 to 5.21±1.61 in mono group (not significant vs baseline) (Fig B). Mean DAS28-ESR scores of patients in MTX and DMARDs groups were significantly greater than those of patients in mono group (MTX vs mono: p=0.002 DMARDs vs mono: p=0.04). Figure C shows the proportion of patients who achieved different disease statuses at 52 weeks in each group. The proportions of patients who still remains high disease activity in MTX and DMARDs group were less than that in mono group (MTX vs mono: p=0.001 DMARDs vs mono: p=0.004). The drug survival rates in MTX and DMARDs group were significantly higher than that in mono group (MTX vs mono: p=0.041 DMARDs vs mono: p=0.020) (Fig D). In the present study, effectiveness and drug survival rate were not significant difference between use of concomitant MTX with other DMARDs. We speculate that these results were caused from low dosage of MTX because the approved dosage of MTX is ≤8 mg/week according to the Japanese labeling at the time of the present study.
Conclusions This study clearly confirmed the superior effectiveness of combination therapy with MTX and otherDMARDs over ADA monotherapy.
Disclosure of Interest K. Terabe: None Declared, T. Kojima Speakers Bureau: Abbott Japan, Chugai Pharmaceutical, Daiichi Sankyo Pharmaceutical, Eisai, Mitsubishi Tanabe Parma, Pfizer Japan, Takeda Pharmaceutical, A. Kaneko: None Declared, Y. Hirano: None Declared, T. Fujibayashi: None Declared, Y. Hattori: None Declared, N. Ishiguro Speakers Bureau: Abbott Japan, Chugai Pharmaceutical, Daiichi Sankyo Pharmaceutical, Eisai, Mitsubishi Tanabe Parma, Pfizer Japan, Takeda Pharmaceutical