A Phase 3 Trial of Upadacitinib for Giant-Cell Arteritis

Background Giant-cell arteritis is a systemic vasculitis with limited treatment options. The efficacy and safety of upadacitinib - a selective Janus kinase (JAK) inhibitor that blocks the signaling of several cytokines, including interleukin-6 and interferon-γ - are unknown in patients with giant-cell arteritis. Methods We randomly assigned patients with new-onset or relapsing giant-cell arteritis, in a 2:1:1 ratio, to receive upadacitinib at a dose of 15 mg or 7.5 mg orally once daily plus a 26-week glucocorticoid taper or placebo plus a 52-week glucocorticoid taper. The primary end point was sustained remission at week 52, defined by the absence of signs or symptoms of giant-cell arteritis from week 12 through week 52 and adherence to the protocol-specified glucocorticoid taper. Results A total of 209 patients received upadacitinib at a dose of 15 mg, 107 received upadacitinib at a dose of 7.5 mg, and 112 received placebo; 70% of the patients had new-onset giant-cell arteritis. Upadacitinib at a dose of 15 mg showed superiority over placebo with respect to the primary end point (46.4% [95% confidence interval {CI}, 39.6 to 53.2] vs. 29.0% [95% CI, 20.6 to 37.5]; P=0.002). Upadacitinib at a dose of 15 mg was superior to placebo in the analysis of the hierarchically prespecified and multiplicity-controlled key secondary end points of sustained complete remission, time to a disease flare, cumulative glucocorticoid exposure, and patient-reported outcomes. Upadacitinib at a dose of 7.5 mg was not superior to placebo with respect to the primary end point (41.1% [95% CI, 31.8 to 50.4]). Safety outcomes during the treatment period of 52 weeks were similar in the upadacitinib and placebo groups. Although cardiovascular risk is a potential concern with a JAK inhibitor, no major adverse cardiovascular events occurred in the upadacitinib groups. Conclusions In patients with giant-cell arteritis, upadacitinib at a dose of 15 mg - but not 7.5 mg - with a 26-week glucocorticoid taper showed efficacy superior to that of placebo with a 52-week glucocorticoid taper. (Funded by AbbVie; SELECT-GCA ClinicalTrials.gov number, NCT03725202.).