VIENNA — Results from the phase 3 SELECT-GCA study showed that the Janus kinase (JAK) inhibitor upadacitinib (Rinvoq) induces significant and sustained remission in people with new-onset or relapsing giant cell arteritis (GCA).
The primary endpoint of sustained remission — the absence of GCA signs or symptoms from weeks 12 to 52 together with adherence to a steroid-tapering regimen — occurred in 46% of 210 individuals randomly assigned to treatment treated with a once-daily 15-mg dose of upadacitinib and 29% of 105 randomly assigned to placebo (P = .0019).
Nine of the 11 secondary endpoints were also positive for upadacitinib 15 mg vs placebo, and no new safety concerns were identified in a late-breaking abstract presented at the at the annual European Congress of Rheumatology.
First JAK Trial in GCA
This is the first trial to look at the use of a JAK inhibitor for the treatment of GCA, and it is addressing a real unmet need, the presenting study investigator Daniel Blockmans, MD, PhD, of University Hospitals Leuven in Belgium, told this news organization.
Glucocorticoids remain the mainstay of treatment, and tocilizumab has been licensed for use, but people don’t always get better or can relapse, he explained.
“I have the impression that these only suppress the disease but do not cure it,” Dr. Blockmans said, adding that “patients get very well soon after these treatments are started, but there are more and more reports that there is a kind of smoldering vasculitis that exists, and this can lead to dilatation of the aorta.”
Upadacitinib inhibits two JAK-dependent cytokines, interleukin 6 and interferon gamma, which have been implicated in the pathogenesis of GCA. The latter could be particularly important, Dr. Blockmans suggested.
Study Details
SELECT-GCA is an ongoing multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the safety and efficacy of upadacitinib vs placebo in patients with GCA.
A total of 428 patients have been included: 210 were randomly allocated to treatment with upadacitinib 15 mg, 105 to upadacitinib 7.5 mg, and 105 to placebo. The inclusion of the lower “minimally effective” upadacitinib dose was a requirement of the regulatory authorities, Dr. Blockmans said; the licensed dose in rheumatoid arthritis (RA) is 15 mg.
Dr. Blockmans reported data from the first 52 weeks of the trial during which all patients underwent glucocorticoid tapering — 26 weeks for upadacitinib and 52 weeks for placebo.
No imaging was done in this trial, which Dr. Blockmans said should be considered for future studies.
Secondary Endpoints
One of the key secondary endpoints was sustained complete remission, defined as sustained remission plus a normalized erythrocyte sedimentation rate to ≤ 30 mm/h and reducing high-sensitivity C-reactive protein to < 1 mg/dL.
Sustained complete remission occurred in 37% and 16% of patients treated with upadacitinib 15 mg and placebo, respectively (P < .0001).
Additionally, a significantly lower proportion of upadacitinib 15 mg- than placebo-treated patients experienced at least one disease flare through week 52 (34% vs 56%, P = .0014).
Other positive secondary endpoints for upadacitinib 15 mg vs placebo out to week 52 were the number of disease flares per patient, cumulative glucocorticoid exposure, and complete remission (also at week 24).
And significant changes in SF-36 and FACIT-Fatigue from baseline to week 52 were seen for upadacitinib 15 mg.
The only secondary endpoints not showing a clear benefit for upadacitinib 15 mg were the changes in the Treatment Satisfaction Questionnaire for Medication at 52 weeks and the rate of glucocorticoid-related adverse events through week 52.
As for the 7.5-mg dose of upadacitinib, neither the primary nor secondary endpoints were significantly better vs placebo.