The JAK1 inhibitor filgotinib improves outcomes in patients with active rheumatoid arthritis refractory to disease-modifying anti-rheumatic drug (DMARD) therapy, a clinical trial shows.

Stanford-led researchers evaluated the effects of filgotinib (100mg or 200mg once daily) versus placebo in their study of 448 patients at 114 international sites with moderate to severely active RA and inadequate response or intolerance to one or more prior biologic DMARDs in the phase 3 trial called FINCH-2.

Significantly more patients randomised to filgotinib (66% on 200mg and 58% on 100mg) than to placebo (31%) achieved the primary endpoint of at least a 20% improvement, according to American College of Rheumatology criteria (ACR20) at week 12.

This was also true among patients with three or more prior biologic DMARDs: ACR20 response rates at week 12 in this subgroup were 70% with filgotinib 200mg, 59% with filgotinib 100mg, and 18% with placebo.