Filgotinib (GLPG0634/GS-6034), an oral selective JAK1 inhibitor, is effective as monotherapy in patients with active rheumatoid arthritis: results from a randomised, dose-finding study (DARWIN 2).

Objectives: To evaluate the efficacy and safety of different doses of filgotinib, an oral Janus kinase 1 inhibitor, as monotherapy in patients with active rheumatoid arthritis (RA) and previous inadequate response to methotrexate (MTX).

Methods: In this 24-week phase IIb study, patients with moderately to severely active RA were randomised (1:1:1:1) to receive 50, 100 or 200 mg filgotinib once daily, or placebo, after a ≥4-week washout from MTX. The primary end point was the percentage of patients achieving an American College of Rheumatology (ACR)20 response at week 12.

The inhibition of NK cell function by azathioprine during the treatment of patients with rheumatoid arthritis.

Treatment with azathioprine of patients with rheumatoid arthritis leads to a dramatic reduction in the 4 h NK cytotoxicity against K562 cells. The 24 h cytotoxicity against K562 and U937 cells, however, remains intact. The generation of cell-free supernatant cytotoxic factor(s) after incubating non-adherent mononuclear cells with U937 cells for 24 h is similar in the azathioprine patients and the controls.