Another JAK1 Inhibitor Looks Promising for Treatment of Rheumatoid Arthritis
by Dr. C.H. Weaver M.D. 10/10/2018
Filgotinib is an investigational, selective JAK1 inhibitor and results from recently reported clinical trials have demonstrated that treatment of rheumatoid arthritis patients with filgotinib led to a significantly higher proportion of patients achieving American College of Rheumatology 20% (ACR20) response when compared with placebo.
Janus-associated kinase 1 (JAK1) inhibitors mediate the signaling of cytokines and growth factors important for blood cell production and immune function. Jakafi® (ruxolitinib) was the first JAK 1 inhibitor approved for the treatment of some Myleoproliferative Neoplasms. Blocking the JAK pathway also appears important for treating the immune response in RA and investigators have begun to report results. Oluminant (baricitnib) was recently approved by the US Food and Drug Administration for the treatment of RA and the investigational agent (Upadacitinib) ABT-494, another JAK-1 inhibitor has been reported to be effective for the management of refractory moderate-to-severe RA in two clinical studies.
In the current study patients with moderate-to-severely active RA and a prior inadequate response or intolerance to biologic agents were treated with once-daily filgotinib 100mg, 200mg, or placebo for 24 weeks and directly compared. Overall approximately twice as many patients treated with filgotinb responded to treatment. The proportion of patients who achieved a clinical remission was also significantly higher in the filgotinib groups. Filgotinib which is currently being investigated in 2 other trials, FINCH 1 and 3, has been reported to be well tolerated.
Jak inhibitors appear quite effective for the treatment of rheumatoid arthritis and provide patients with another way to treat the disease. The final results of the filgoitnib trials will be presented at an upcoming medical meeting and if they remain positive the drug manufacturer will apply for US Food and Drug Administration approval for use in the management of rheumatoid arthritis.