Upadacitinib for the treatment of rheumatoid arthritis

Introduction: Tofacitinib and baricitinib have recently been approved as second-line treatments for Rheumatoid arthritis (RA) though their maximum expected efficacy may be limited by dose-related toxicities. Upadacitinib selectively inhibits Janus Kinase 1 (JAK1) which could potentially reduce JAK2 and JAK3-related side effects. Areas covered: In this paper, we review a newly developed oral selective JAK inhibitor, upadacitinib for the treatment of RA. The doses of upadacitinib extended-release 15 and 30 mg daily selected in phase III RA studies have shown a near-maximum efficacy in phase II studies. Upadacitinib inhibited radiographic progression and displayed rapid and sustained clinical and functional efficacy in RA when in combination with methotrexate (MTX), upadacitinib was superior to placebo in MTX-Inadequate Responders (IRs) and biologic disease modifying antirheumatic drugs-IRs while as monotherapy, it was superior to MTX in MTX-IRs and MTX-naïve patients. Upadacitinib was superior to adalimumab using ACR70, reduction of pain-VAS and improvement of HAQ-DI. The comparison with abatacept is still ongoing. Expert commentary: Upadacitinib has displayed a rapid and favorable efficacy profile in RA but despite being a selective JAK1 inhibitor appears to have a similar safety profile to less-selective Jakinibs. Longer term safety data are awaited.