Background/Purpose: Roughly 10-30% of rheumatoid arthritis (RA) patients reportedly develop pulmonary complications. These patients are at increased risk of MTX or biologics-induced damage, which often becomes problematic for RA treatment. Abatacept (ABT) has been reported to have relatively few adverse events, and is often used in clinical settings in patients with pulmonary complications. Given the paucity of studies on the safety of ABT, however, accumulation of safety data under actual clinical settings is warranted. In the present study, we examined the persistence rates and treatment effects of ABT in patients with pulmonary complications.

Methods: We divided 250 RA patients registered in the Tsurumai Biologics Communication Registry who used ABT for ≥52 weeks according to whether they had pulmonary complications (L group: n=32) or not (N group: n=218). We then compared the persistence rates, incidence of adverse events, and disease activity between the two groups.

Results: No significant differences were found between groups with regard to mean age (L group, 67.7±6.9; N group, 64.0±12.8), disease duration (L group, 12.6±9.8; N group, 11.8±8.8), concomitant use rates of steroid (L group, 62.5%; N group, 60.5%), CRP (L group, 2.6±2.9; N group, 2.1±2.8), DAS28-CRP (L group, 4.7±1.5; N group, 4.4±1.3), or SDAI (L group, 28.8±16.5; N group, 24.5±14.0) at the time ABT was initiated, but significant differences were found in the percentage of women (L group, 65.6%; N group, 83.5%) and concomitant use rates of MTX (L group, 25%; N group, 53.2%). The persistence rates for 52 weeks were 73.1% and 74.3% in the L and N groups, respectively (Figure 1a). Adverse events occurred in 1 (3.13%) and 7 (3.83%) patients in the L and N groups, respectively. No pulmonary complications occurred after ABT administration in the L group, but 2 patients in the N group had interstitial pneumonia. Treatment was discontinued due to insufficient response in 6 (18.8%) and 29 (15.9%) patients in the L and N groups, respectively. None of these were significantly different by group. Mean DAS28-CRP significantly improved in both groups (Figure 1b), from 4.7 at ABT initiation to 3.2 at 52 weeks in the L group (P<0.01), and from 4.4 to 3.1 in the N group (P=0.034). Achievement of those with low disease activity also increased, from 9.4% at ABT initiation to 53.3% at 52 weeks in the L group, and from 8.3% to 47.7% in the N group.

Conclusion: The safety, treatment effects, and persistence rates of ABT were similar among RA patients with and without pulmonary complications. Use of ABT is beneficial even in patients with pulmonary complications, under close consideration of the risks involved.