Ixekizumab Shows Strength Against Adalimumab in SPIRIT-H2H

Philip Mease, MD

Results from the SPIRIT-H2H study indicate that in patients with active psoriatic arthritis, ixekizumab (Talz) is superior to adalimumab (Humira) in the proportion of patients who simultaneously reduced disease activity by ≥50% and achieved complete skin clearance.

The research was presented at a late-breaking session at the European Congress of Rheumatology (EULAR 2019) in Madrid, Spain, by Philip Mease, MD, Swedish Medical Center/Providence St. Joseph Health and University of Washington.

“In the SPIRIT-H2H trial, Taltz demonstrated effectiveness in improving the signs and symptoms of active psoriatic arthritis,” said Mease. “Head-to-head data like these are significant and help inform treatment decisions. This study underscores that Taltz is an important option for healthcare providers to consider for their patients.”

The assessor-blinded SPIRIT-H2H study included 566 patients who were naïve to biologic disease-modifying anti-rheumatic drugs (bDMARDs) and inadequately responded to conventional synthetic DMARDs. Of those, 465 participants had active psoriatic arthritis and were randomized to either ixekizumab (n = 234) or adalimumab (n = 231) at the FDA-approved doses for those treatments for 52 weeks. The study also included 101 patients with moderate to severe plaque psoriasis who were randomized to ixekizumab (n = 49) or adalimumab (n = 52) at the approved dose for psoriasis.

Meeting the primary endpoint, at 24 weeks, 36% of patients receiving ixekizumab had achieved both disease activity reduction of ≥50% according to the American College of Rheumatology (ACR50) and complete skin clearance as measured by the Psoriasis Area and Severity Index (PASI 100) compared to 28% for adalimumab (P <.05).

“For patients with active psoriatic arthritis, it’s important to find a treatment that is effective and consistent in alleviating the debilitating joint symptoms, while also improving skin clearance,” said Christi Shaw, president of Lilly Bio-Medicines.

However, ixekizumab was not superior for both ACR50 and PASI 100, when the endpoints were analyzed separately. Patients taking ixekizumab were significantly more likely than those taking adalimumab to achieve PASI 100 (60% vs 47%; P <.01) at 24 weeks, while the difference in ACR50 was not significant between groups (51% vs 47%).

Ixekizumab was found statistically significantly superior to adalimumab for several secondary endpoints at week 24 including, PASI 75 (80% vs 69%), PASI 90 (72% vs 56%), minimal disease activity (48% vs 35%), and Psoriatic Arthritis Disease Activity Score very low disease activity (PASDAS VLDA <1.9; 29% vs 19%)(P <.01 for all these measures).

The safety results for ixekizumab were similar to previous studies with no new signals observed. The most frequent adverse reactions for ixekizumab and adalimumab were infections (36.0% vs 30.7%, respectively), injection site reactions (9.5% vs 3.2%), allergic/hypersensitivity reactions (2.5% vs 3.9%) and cerebrocardiovascular events (1.1% vs 1.8%).

The US Food and Drug Administration (FDA) approved ixekizumab for the treatment of psoriatic arthritis in December 2017. Adalimumab was first approved in 2002 for rheumatoid arthritis and the label has since been expanded to include indications for juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, adult and pediatric Crohn’s disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurative, and uveitis.

The abstract, “Multicentre, Randomised, Open-Label, Assessor-Blinded, Parallel-Group Head-to-Head Comparison of the Efficacy and Safety of Ixekizumab Versus Adalimumab in Patients with Psoriatic Arthritis Naive to Biologic Disease-Modifying Anti-Rheumatic Drugs: 24-Week,” was presented on June 14 at EULAR 2019.