Ixekizumab outperforms adalimumab for joint, skin improvement in PsA
Ixekizumab demonstrated significantly greater joint and skin improvement, through week 52, than adalimumab among patients with psoriatic arthritis, according to data published in the Annals of the Rheumatic Diseases.
“Initial treatment traditionally involves non-steroidal anti-inflammatory drugs, glucocorticoids and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs),” Josef S. Smolen, MD, of the Medical University of Vienna, in Austria, and colleagues wrote. “When csDMARDs are ineffective, biological (b)-DMARDs such as tumor necrosis factor (TNF)-inhibitors, anti-interleukin (IL)-12/23, anti-IL-17A inhibitors or targeted synthetic DMARD are recommended, with TNF-inhibitors being frequently the first-line bDMARD therapy.
“bDMARDs can be used as monotherapy or in combination with csDMARDs, most commonly methotrexate (MTX),” they added. “Ixekizumab (IXE) is an immunoglobulin G4 monoclonal antibody that selectively inhibits IL-17A and its efficacy across multiple PsA domains was previously established. Despite the approval of numerous bDMARDs for the treatment of PsA, no direct comparisons are available to enable evidence-based treatment decisions.”
To examine the efficacy and safety of ixekizumab (Taltz, Eli Lilly & Co.) compared with adalimumab (Humira, AbbVie) among patients with PsA, Smolen and colleagues conducted the SPIRIT head-to-head trial. According to the researchers, SPIRIT was a 52-week, multicenter, open-label, blinded-assessor study of 566 adults with PsA who had not yet been treated with a biological DMARD. Participants were randomized to receive either ixekizumab or adalimumab, with stratification by concomitant csDMARD use and presence of moderate-to-severe plaque psoriasis.
Endpoints included musculoskeletal and subgroup analyses, psoriasis, quality of life outcomes and safety at weeks 24 and 52. The researchers also compared simultaneous American College of Rheumatology (ACR)50 and Psoriasis Area and Severity Index (PASI)100 responses between the two treatment groups.
According to Smolen and colleagues, 39% of patients in the ixekizumab group simultaneously achieved ACR50 and PASI100 responses, compared with 26% in the adalimumab group (P < .001) at week 52. In all, 64% of participants in the ixekizumab achieved the PASI100 response by week 52, compared with 41% of those in the adalimumab group (P < .001). Efficacy was similar between the two groups for ACR50 alone, treat-to-target outcomes, enthesitis and dactylitis resolution. In the ixekizumab group, response to treatment was consistent regardless of concomitant use of conventional, synthetic DMARDs.
The researchers also found that 38% of patients who received ixekizumab monotherapy demonstrated simultaneous ACR50 and PASI100 at week 52, compared with 19% among those treated with adalimumab monotherapy. In addition, 66% of participants who received ixekizumab monotherapy achieved the PASI100 response alone, compared with 35% for adalimumab monotherapy. Neither treatment group demonstrated any new safety findings.
“IXE treatment resulted in significantly greater simultaneous ACR50 and PASI100 responses versus ADA through 1year of the study,” Smolen and colleagues wrote. “IXE performed as well as ADA across musculoskeletal PsA domains with a faster onset of action and showed significantly greater efficacy on the skin and nails through Wk52. Concomitant csDMARD use had a response-modifying effect in the ADA group, but not the IXE group; responses to IXE were consistent in monotherapy and combination with csDMARDs. The results of this study are informative for the management of patients with PsA in routine clinical practice.”