Filgotinib maleate is used in the treatment of autoimmune and inflammatory conditions, particularly rheumatoid arthritis. It functions by selectively inhibiting Janus kinase 1 (JAK1), which plays a key role in the signaling pathways of various pro-inflammatory cytokines. This inhibition helps reduce inflammation and modulate the overactive immune response seen in such diseases. It is especially beneficial for patients who have not responded adequately to other disease-modifying antirheumatic drugs (DMARDs), including biologics. The compound offers an oral treatment option, providing convenience compared to injectable therapies. It has also been explored for use in other inflammatory conditions such as psoriatic arthritis, ulcerative colitis, and Crohn’s disease, showing promise in improving clinical symptoms and achieving remission in some cases.