Evaluation of rheumatoid arthritis-associated interstitial lung disease in patients treated with JAK inhibitors: a MAJIK-SFR cohort study.

Objective: To examine the course of interstitial lung disease associated with rheumatoid arthritis (RA-ILD) in France on treatment with Janus kinase inhibitors (JAKis) using the MAJIK-SFR registry.

Methods: Prospective national multicentre observational study identifying patients with RA-ILD from the MAJIK-SFR registry. Pulmonary assessment data were collected at JAKi initiation and follow-up visits (6 months, 12 months and a median of 21 months postinclusion), including chest high-resolution CT (HRCT), pulmonary function tests (forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO)), acute exacerbations of ILD, respiratory infections and lung cancers.

Results: We enrolled 42 patients (26 women, 62%) with RA-ILD with a mean age of 61±13 years and a mean disease duration of 16±10 years. Compared with the 778 RA patients without ILD from the MAJIK registry, RA-ILD patients were older, displayed more severe and active disease and had more prevalent comorbidities. Non-specific interstitial pneumonia and usual interstitial pneumonia accounted for 46% and 43% of the chest HRCT ILD patterns, respectively. No significant changes in FVC and DLCO were observed during the follow-up period. Chest HRCT lesions remained stable in 69% of patients. Progressive ILD was identified in 8 patients (19%). 16 (38%) respiratory tract infections were observed. Only one acute regressive exacerbation of ILD was noted, and no lung cancer was diagnosed. No deaths occurred. JAKi was discontinued in 17 patients including 8 for inefficacy on joint involvement and 5 for intolerance.

Conclusion: The analysis indicates stability of RA-ILD in patients treated with JAKi. The tolerance profile of JAKi in this higher risk population did not reveal new safety signal.