Are Abatacept and Leflunomide safe in RA patients with ILD?

Patients with ILD and RA pose a unique challenge for rheumatologists in clinical practice: balancing effective RA treatment while limiting adverse ILD outcomes. It only takes one patient to have worsening ILD on therapy to make anyone skittish.

Two posters at this year’s ACR shed some light on this issue. The first study (poster #477) was a meta-analysis of leflunomide including over 4,500 patients. This study concluded that, "Leflunomide was not associated with an increased risk of total adverse respiratory events." The drawback of this study is that nobody in the meta-analysis had pre-existing ILD. Furthermore, if ILD associated with leflunomide is rare (i.e. 1 in 10,000), with only 4,500 patients the denominator may have been too small to detect any cases.

The second study (poster #472) looked at 16 Japanese patients with RA and pre-existing ILD. These patients all received IV Abatacept. At week 52 there was no worsening of ILD in any patient and RA signs and symptoms improved significantly. The authors concluded that Abatacept may be safe for patients with RA and pre-existing ILD.

More reports from ACR 2014