AMAGINE-3 is a multi-arm trial that assessed the safety and efficacy of two doses of brodalumab compared with placebo and Stelara (ustekinumab; Janssen Biotech) in patients with moderate-to-severe plaque psoriasis. Initially patients were randomized 2:2:1:1 ratio to receive brodalumab 140mg or 210mg, Stelara, or placebo in a 12-week, double-blind, active comparator- and placebo-controlled induction phase. At week 12, patients originally randomized to either brodalumab arm were re-randomized 2:2:2:1 into the maintenance phase to receive brodalumab 140mg or 210mg at four different maintenance regimens. Patients originally randomized to Stelara continued to receive the same treatment, and those originally randomized to receive placebo began 210mg of brodalumab every two weeks. At week 52, patients entered the long-term extension portion of the study. Patients may be enrolled in the study for up to 271 weeks.
The primary endpoint comparing brodalumab with Stelara was the proportion of patients achieving total clearance of skin disease, as measured by Psoriasis Area Severity Index (PASI 100) at week 12. When comparing brodalumab with placebo, the primary endpoints included the proportion of patients achieving at least a 75% improvement from baseline in disease severity (PASI 75) at week 12, and the achievement of clear or almost clear skin, according to the static Physician Global Assessment (sPGA 0 or 1) at week 12.
Results demonstrated that brodalumab is superior to Stelara on the primary endpoint of achieving total clearance of skin disease, as measured by the PASI 100. Data shows that 36.7% of patients in the brodalumab 210mg group, 27.0% in the brodalumab 140mg group, 18.5% in the Stelara group and 0.3% in the placebo group achieved total clearance of skin disease (PASI 100). A significantly greater proportion of patients treated with brodalumab achieved at least a 75% improvement from baseline in disease severity at week 12 compared to placebo, as measured by the PASI 75. At week 12, 85.1% of patients in the brodalumab 210mg group, 69.2% in the brodalumab 140mg group, 69.3% in the Stelara group, and 6.0% in the placebo group achieved PASI 75. A significantly greater proportion of patients treated with brodalumab also achieved clear or almost clear skin at week 12 compared with placebo, according to the sPGA 0 or 1.