Bimekizumab versus Adalimumab in Plaque Psoriasis

Background: Bimekizumab is a monoclonal IgG1 antibody that selectively inhibits interleukin-17A and interleukin-17F. The efficacy and safety of bimekizumab as compared with the tumor necrosis factor inhibitor adalimumab in patients with moderate-to-severe plaque psoriasis have not been extensively examined.

Methods: We randomly assigned patients with moderate-to-severe plaque psoriasis in a 1:1:1 ratio to receive subcutaneous bimekizumab at a dose of 320 mg every 4 weeks for 56 weeks; bimekizumab at a dose of 320 mg every 4 weeks for 16 weeks, then every 8 weeks for weeks 16 to 56; or subcutaneous adalimumab at a dose of 40 mg every 2 weeks for 24 weeks, followed by bimekizumab at a dose of 320 mg every 4 weeks to week 56. The primary end points were a 90% or greater reduction from baseline in the Psoriasis Area and Severity Index (PASI) score (PASI 90 response; PASI scores range from 0 to 72, with higher scores indicating worse disease) and an Investigator's Global Assessment (IGA) score of 0 or 1, signifying clear or almost clear skin (scores range from 0 [clear skin] to 4 [severe disease]), at week 16. The analysis of the primary end points tested noninferiority at a margin of -10 percentage points and then tested for superiority.

Results: A total of 614 patients were screened, and 478 were enrolled; 158 patients were assigned to receive bimekizumab every 4 weeks, 161 to receive bimekizumab every 4 weeks and then every 8 weeks, and 159 to receive adalimumab. The mean age of the patients was 44.9 years; the mean PASI score at baseline was 19.8. At week 16, a total of 275 of 319 patients (86.2%) who received bimekizumab (both dose groups combined) and 75 of 159 (47.2%) who received adalimumab had a PASI 90 response (adjusted risk difference, 39.3 percentage points; 95% confidence interval [CI], 30.9 to 47.7; P<0.001 for noninferiority and superiority). A total of 272 of 319 patients (85.3%) who received bimekizumab and 91 of 159 (57.2%) who received adalimumab had an IGA score of 0 or 1 (adjusted risk difference, 28.2 percentage points; 95% CI, 19.7 to 36.7; P<0.001 for noninferiority and superiority). The most common adverse events with bimekizumab were upper respiratory tract infections, oral candidiasis (predominantly mild or moderate as recorded by the investigator), hypertension, and diarrhea.

Conclusions: In this 56-week trial, bimekizumab was noninferior and superior to adalimumab through 16 weeks in reducing symptoms and signs of plaque psoriasis but was associated with a higher frequency of oral candidiasis and diarrhea. Longer and larger trials are required to determine the efficacy and safety of bimekizumab as compared with other agents in the treatment of plaque psoriasis. (Funded by UCB Pharma; BE SURE ClinicalTrials.gov number, NCT03412747.).