MELBOURNE, Australia — Two-year data from the SELECT-GCA trial of the JAK inhibitor upadacitinib in patients with giant cell arteritis (GCA) suggest the drug can maintain remission for the longer period, according to data presented at the 22^nd International Vasculitis Workshop (IVW) 2026.

The SELECT-GCA trial initially randomly assigned 428 adults with new-onset or relapsing GCA to receive either 7.5 mg or 15 mg of oral upadacitinib daily plus a 26-week glucocorticoid taper or placebo plus a 52-week glucocorticoid taper, for 52 weeks.

That study, published in April 2025, showed that 46.4% of the 15-mg group achieved sustained remission, compared to 29% of the placebo group, and also had significantly lower cumulative glucocorticoid exposure, which led to the drug being approved in both the US and EU.

At the 1-year point, the investigators then began a second randomization of patients who had achieved remission for ≥ 24 weeks, randomly assigning 181 participants to remain on placebo or their original dose of upadacitinib, while others switched to placebo or the active treatment. As with the first phase of the study, the primary endpoint was remission, defined as the absence of signs and symptoms of GCA and no requirement for glucocorticoids.

At week 104, 149 patients remained on their assigned treatment: 28 had been on continuous placebo, 59 had been on a continuous 15-mg dose of upadacitinib, 28 had been on a continuous 7.5-mg dose, and 34 had switched from upadacitinib to placebo at week 52.

Among those who transitioned to placebo at week 52 from the 15-mg dose, 59% experienced at least one disease flare, defined as signs or symptoms of GCA and reinitiation of glucocorticoids, between weeks 52-104, compared to 7.4% of patients who remained on the 15-mg dose throughout the 2 years.

Of the group who remained on the 15-mg dose of upadacitinib, 76.3% achieved complete remission by week 104, compared to 20% of those who switched from 15 mg of upadacitinib to placebo at week 52.

The mean cumulative glucocorticoid exposure at week 104 was 1532.6 mg in those who switched from 15 mg of upadacitinib to placebo at week 52, and 139.2 mg in those who remained on 15 mg of upadacitinib through week 104. 

Study presenter Wolfgang Schmidt, MD, a rheumatologist at Immanuel Krankenhaus Berlin, Medical Center for Rheumatology Berlin-Buch in Berlin, noted that the data on the risk of flare presented at IVW 2026 showed a lower rate of flare in the upadacitinib group compared to what was presented at the American College of Rheumatology (ACR) 2025 Annual Meeting. “The data in the ACR abstract actually showed 104 weeks plus 30 days – this was necessary for safety reasons but not for the efficacy results,” Schmidt told the conference. “At week 104, the study drug was stopped, and some patients flared again.”

He commented that those who did flare after stopping the drug flared fairly early, with more than half the flares occurring within the first 8 weeks after treatment cessation. This was faster than what was observed after stopping treatment with tocilizumab, which is also approved to treat GCA.

The longer-term data from this study showed no new safety signals. There were around twice as many incidents of serious infection in the continuous placebo group, compared to the continuous 15-mg upadacitinib group, but twice as many cases of herpes zoster occurred in the continuous 15-mg upadacitinib group, compared to the continuous placebo group.

Schmidt told Medscape Medical News that upadacitinib should be considered in patients with GCA who are at higher risk of glucocorticoid side effects. “Maybe a woman with osteoporosis already and glaucoma or cataract or diabetes, or they develop diabetes once you start the steroids. This would be a clear patient to treat from the beginning” with upadacitinib, he said. 

Commenting on the presentation, rheumatologist Joanna Tieu, MD, of the Queen Elizabeth Hospital in Adelaide, Australia, said it was interesting that the longer-term follow-up of the 15-mg upadacitinib group showed that the drug remained relatively effective without any new safety concerns. She noted that there was a question from the audience about whether the drug should be continued longer than 2 years, given the rapid rate of flare soon after treatment cessation. “That’s probably the thought process, although we don’t have that data,” she said to Medscape Medical News. 

The SELECT-GCA study was funded by AbbVie, which markets upadacitinib. Schmidt declared advisory and review panel roles, grant and research support, and honoraria from AbbVie, as well as other pharmaceutical companies.