Ixekizumab significantly improves enthesitis, dactylitis in PsA
Among patients with psoriatic arthritis with pre-existing enthesitis or dactylitis, 90-mg treatments of ixekizumab, administered either every 2 or 4 weeks, significantly improved both conditions, according to data published in Arthritis Research & Therapy.
“Biologic therapy for patients with active enthesitis and/or dactylitis is effective and is now recommended for patients who have not responded well to nonsteroidal anti-inflammatories or corticosteroid injections,” Dafna D. Gladman, MD, of the Center for Prognosis Studies in the Rheumatic Diseases at the University of Toronto, and colleagues wrote. “Ixekizumab is an anti-interleukin-17A (IL-17A) antagonist that has recently been approved for the treatment of active PsA.”
To offer an integrated analysis of the baseline disease burden and subsequent outcomes among patients with PsA and either enthesitis or dactylitis who were treated with ixekizumab (Taltz, Eli Lilly), Gladman and colleagues obtained and presented data from the SPIRIT-P1 and SPIRIT-P2 cohorts. Both studies were randomized, double-blind, placebo-controlled, phase 3 trials of patients with PsA. Patients were randomly assigned to receive 80-mg treatments of ixekizumab either every 2 or 4 weeks following a 160-mg starting dose, or placebo. Participants with inadequate responses at week 16 received rescue therapy.
The researchers included 679 patients in the integrated analysis. Those with baseline enthesitis or dactylitis were evaluated for characteristics and disease burden, with Leeds Enthesitis Index or Leeds Dactylitis Index-Basic assessed at week 24. They then used pooled treatment groups to determine the impact of either enthesitis or dactylitis resolution on health-related quality of life, physical function and pain.
According to the researchers, 403 patients in the integrated analysis had baseline enthesitis while 155 had baseline dactylitis. By week 24, 39% of patients with baseline enthesitis who were treated with ixekizumab every 4 weeks achieved resolution, compared with 35% of those treated every 2 weeks and 21% of those who received placebo. Among patients with baseline dactylitis, 78% of those treated with ixekizumab every 4 weeks experienced resolution, compared with 65% of those treated every 2 weeks and 24% of those in the placebo group.
In addition, among all patients treated with placebo and ixekizumab, resolution of enthesitis at week 24 was associated with improvements in physical function and health-related quality of life. Resolution of dactylitis was associated with more limited improvements, the researchers wrote. The least squares mean Health Assessment Questionnaire-Disability Index improvements from baseline were –0.44 for patients with resolved enthesitis, and –0.25 for patients who did not resolve enthesitis. Such figures for patients with dactylitis were –0.41 for those with resolution and –0.31 for those without.
Improvements in patients’ EuroQol-5 Dimensions Visual Analogue Scale were 12.3 for those who resolved their enthesitis and 5.8 for those who did not. Among patients with dactylitis, improvements were 10.8 in those with resolution and 9.8 those without.
“Treatment with ixekizumab every 2 weeks and every 4 weeks resulted in significant improvements in enthesitis and dactylitis in patients with pre-existing enthesitis or dactylitis,” Gladman and colleagues wrote. “Resolution of enthesitis symptoms was associated with improvements in patients’ function, pain and [health-related quality of life], irrespective of treatment.” – by Jason Laday
Disclosure: Gladman reports consulting fees from AbbVie, Amgen, BMS, Celgene, Eli Lilly and Company, Janssen, Novartis, Pfizer and UCB, as well as grant or research support from AbbVie, Amgen, Celgene, Eli Lilly and Company, Janssen, Novartis, Pfizer and UCB. Please see the study for all other relevant financial disclosures.