Secukinumab for Giant Cell Arteritis.

Glucocorticoids (GCs) are standard treatment for giant cell arteritis (GCA). Many patients experience relapses or GC-related toxicity. Secukinumab, a fully human monoclonal antibody that selectively inhibits interleukin-17A, is being studied as additional therapy for GCA. GCAptAIN was a randomized, parallel-group, double-blind, placebo-controlled, multicenter phase 3 trial. Patients with new-onset or relapsing GCA were initially randomly assigned (2:1) to either 300 mg of secukinumab (SEC-300) or placebo for 52 weeks. After a protocol amendment, patients were randomly assigned (1:1:1) to either SEC-300, 150 mg of secukinumab (SEC-150), or placebo. Patients in the SEC-300 and SEC-150 groups received a 26-week GC taper. Patients in the placebo group received a 52-week GC taper. The primary outcome was the proportion of patients experiencing sustained remission in the SEC-300 versus placebo groups at week 52. Sustained remission in patients in the SEC-150 group versus patients in the placebo group enrolled after the protocol amendment was a secondary outcome. Adverse events (AEs) and serious AEs (SAEs) were assessed. A total of 140 patients in the SEC-300 group, 98 in the SEC-150 group, and 115 in the placebo group (19 patients were enrolled in the placebo group before and 96 after the protocol amendment) were analyzed for efficacy and safety. The proportion of patients achieving sustained remission at week 52 was 25.6% for SEC-300 versus 16.9% for placebo (marginal difference: 8.7 percentage points; 95% confidence interval [CI], -1.3 to 18.8; P=0.09) and 19.4% for SEC-150 versus 17.7% for placebo (marginal difference, 1.6 percentage points; 95% CI, -9.2 to 12.4). AEs occurred in 92.9%, 95.9%, and 97.4% of patients in the SEC-300, SEC-150, and placebo groups, respectively. SAEs occurred in 20.0%, 27.6%, and 32.2% of patients in the SEC-300, SEC-150, and placebo groups, respectively. Serious infections occurred in 5.0%, 9.2%, and 6.1% of patients in the SEC-300, SEC-150, and placebo groups, respectively. Sustained remission at week 52 did not differ significantly between patients with GCA randomly assigned to receive SEC-300 with a 26-week GC taper versus placebo with a 52-week GC taper. (Funded by Novartis Pharma; EudraCT number, 2020-004809-31; ClinicalTrials.gov number, NCT04930094.).