Successful treatment of rheumatoid arthritis‐associated interstitial lung disease with filgotinib: A case report on janus kinase 1 inhibition

Abstract

AbstractFilgotinib, a janus kinase 1 (JAK1) inhibitor, is used in the treatment of rheumatoid arthritis (RA). RA‐associated interstitial lung disease (RA‐ILD) is a severe RA complication with no established effective treatment. We report the case of a patient with RA‐ILD successfully treated with filgotinib. A 46‐year‐old woman with RA and RA‐ILD, presenting with a non‐specific interstitial pneumonia pattern, was refractory to abatacept and prednisolone but responded to filgotinib. Both arthritis and RA‐ILD improved significantly, and the patient remained in remission for over 12 months. Basic research indicates that JAK1 plays a role in the cytokine signal transduction in ILD; however, there are no clinical reports on the efficacy of filgotinib in RA‐ILD. This case suggests filgotinib as a potential treatment for patients with RA‐ILD, particularly in the early stages of this disease.