On March 4, 2017, head-to-head trial results comparing the safety and efficacy of Eli Lilly’s Taltz (ixekizumab) to Johnson & Johnson’s Stelara (ustekinumab) at Week 24 in patients with psoriasis were presented at the 75th annual American Academy of Dermatology (AAD) conference. Taltz, a monoclonal antibody selectivity inhibiting interleukin 17A (IL-17A), has previously demonstrated superiority to Stelara, an IL-12/23 inhibitor, after 12 weeks of treatment.  Despite Taltz’s competition from two other biologic drug classes approved for psoriasis, anti-tumor necrosis factor therapies and IL-12/23 therapies, as well as biosimilars, GlobalData’s forecast shows that Taltz will gross an estimated $1.1 billion in total global drug sales in 2014 across the eight major pharmaceutical markets.  

In the IXORA-S trial, 302 patients with moderate-to-severe plaque psoriasis previously treated with systemic therapy were randomized 1:1 to receive a starting dose of 160mg of Taltz followed by 80mg every two weeks for 12 weeks and then 80mg every four weeks, or 45mg or 100mg of Stelara based on weight per the prescription label. At Week 24, patients receiving Taltz demonstrated significantly superior efficacy compared with Stelara according to the Psoriasis Area and Severity Index (PASI) 100 (Taltz: 49.3%, Stelara: 23.5%, p=0.001) and PASI 90 (Taltz: 83.1%, Stelara: 59.0%, p<0.001), while PASI 75 was 91.2% for patients treated with Taltz and 81.9% for patients treated with Stelara (p=0.015). Further, Taltz showed superiority compared with Stelara in static Physician Global Assessment (sPGA) of zero (Taltz: 53.7%, Stelara: 24.1%, p<0.001) and sPGA of zero or one (Taltz: 86.6%, Stelara: 69.3%, p<0.001). The continued superiority of Taltz not only marks a win for Eli Lilly, but also for additional IL-17 inhibitors approved for psoriasis, including Novartis’ Cosentyx (secukinumab) and Valeant’s Siliq (brodalumab).   
Although IL-17 inhibitors are newcomers to the psoriasis market, Cosentyx is already recommended as a first-line biologic for the treatment of psoriasis, given its improved efficacy over other approved biologics. Cosentyx and Taltz have already started to heavily impact the market and are on their way to gaining blockbuster status, with forecast sales of $1.3 billion and $1.1 billion, respectively, by 2024 across the 8MM. That being said, given Stelara’s established presence in the psoriasis market, it is expected to remain the best-selling psoriasis drug, with GlobalData’s forecast showing 2024 sales of $1.4 billion across the 8MM.