Tildrakizumab (MK-3222), an anti-interleukin-23p19 monoclonal antibody, improves psoriasis in a phase IIb randomized placebo-controlled trial

Background Tildrakizumab is a high-affinity, humanized, IgG1/kappa, anti-interleukin (IL)-23p19 monoclonal antibody that does not bind human IL-12 or p40 is being developed for the treatment of chronic plaque psoriasis. Objectives To evaluate the safety and efficacy of subcutaneous tildrakizumab in patients with moderate-to-severe chronic plaque psoriasis. Methods A three-part, randomized, double-blind, phase IIb trial was conducted in 355 adults with chronic plaque psoriasis. Participants were randomized to receive subcutaneous tildrakizumab (5, 25, 100, 200 mg) or placebo at weeks 0 and 4 (part I) and every 12 weeks thereafter until week 52 (part II). Study drug was discontinued at week 52 and participants were followed through week 72 (part III). Primary efficacy end point was Psoriasis Area and Severity Index (PASI) 75 response at week 16. Adverse events (AEs) and vital signs were monitored throughout the study. Results At week 16, PASI 75 responses were 33.3% (n = 14), 64.4% (n = 58), 66.3% (n = 59), 74.4% (n = 64) and 4.4% (n = 2) in the 5-, 25-, 100- and 200-mg tildrakizumab and placebo groups, respectively (P <= 0.001 for each tildrakizumab dose vs. placebo). PASI 75 response was generally maintained through week 52; only eight of 222 participants who achieved PASI 75 response at week 52 and continued to part III relapsed following discontinuation up to week 72. Possible drug-related serious AEs included bacterial arthritis and lymphoedema (part I), and melanoma, stroke, epiglottitis and knee infection (part II). Conclusions Tildrakizumab had treatment effects that were superior to placebo, maintained for 52 weeks of treatment, and persisted for 20 weeks after cessation. Tildrakizumab was generally safe and well tolerated. These results suggest that IL-23p19 is a key target for suppressing psoriasis.