Safety of Ixekizumab in Patients With Psoriatic Arthritis: Results From a Pooled Analysis of Three Clinical Trials

Objective: To evaluate ixekizumab safety in adults with psoriatic arthritis (PsA). Methods: Safety data from 2 integrated data sets are presented: 1) 24-week, double-blind, placebo-controlled period of SPIRIT-P1 and SPIRIT-P2; and 2) all ixekizumab-treated patients of SPIRIT-P1 and SPIRIT-P2 plus SPIRIT-P3 open-label period. We report adverse event (AE) frequency and exposure-adjusted incidence rates per 100 patient-years at 12-week intervals to week 96. Results: The placebo-controlled period had 678 patients (safety population): 224 placebo, 229 ixekizumab every 4 weeks, and 225 ixekizumab every 2 weeks. Overall, 1,118 patients received ixekizumab (total exposure 1,373.4 patient-years). In the placebo-controlled period, the frequencies of ixekizumab-treated patients experiencing ≥1 treatment-emergent AE (TEAE) and those experiencing serious AEs were 68.1% (56.7% placebo) and 4.4% (2.7% placebo), respectively. Injection site reactions (ISRs) were very common (21.4% ixekizumab [4.5% placebo]), with ISR discontinuation rates of 1.1% (ixekizumab) and 0.4% (placebo). Through week 96, the incidence rates of ISRs decreased with increasing ixekizumab exposure. The frequencies of AEs of special interest were 32.8% (ixekizumab) and 27.7% (placebo); for serious infections, the frequencies were 1.3% and 0%, respectively; Candida infections, 2.6% and 0.4%; confirmed major adverse cardiac events, 0% and 0%; malignancy, 0.4% and 0%; hypersensitivities, 5.3% and 1.8%; and depression-related, 1.8% and 1.3%. The frequency of Crohn's disease and ulcerative colitis (investigator-reported) was 0% in both groups, and the frequencies of sponsor-determined inflammatory bowel disease were 0.2% in the ixekizumab group and 0% in the placebo group. Overall, no active tuberculosis, invasive Candida infections, anaphylaxis, or suicide/self-injury behaviors were reported. Conclusion: The PsA ixekizumab safety integrated data set reached 1,373.4 patient-years total exposure. Ixekizumab-treated patients had higher rates of overall TEAEs, serious infections, mucocutaneous Candida, hypersensitivities (non-anaphylactic), and ISRs than placebo-treated patients. No unexpected safety outcomes were reported.