At week 12, 70% of white and 63% of nonwhite participants treated with ustekinumab achieved a Psoriasis Area and Severity Index (PASI) 75. At the same time, 86% of white and 88% of nonwhite patients treated with brodalumab achieved the same outcome. Similarly, PASI 90 and PASI 100 scores did not differ significantly between the 1,667 white and 182 skin of color participants.
The two biologics act on different aspects of the molecular pathway involved in psoriasis. Brodalumab (Siliq) specifically blocks the interleukin-17 receptor, whereas other biologics used to treat psoriasis, including ustekinumab (Stelara), an IL-12 and -23 antagonist, target upstream molecules in the inflammatory pathway. Dr. McMichael said, “The superior skin clearance rates seen in patients treated with brodalumab may be due to its target being a receptor as opposed to a ligand.”
Treatment-emergent adverse event rates were similar between the white and nonwhite patients. Treatment-emergent adverse events were reported in 58% and 57% of the white brodalumab and ustekinumab groups, respectively, and in 53% and 47% of the nonwhite brodalumab and ustekinumab groups, respectively. Serious adverse events occurred in 1.2% and 1.1% of the white brodalumab and ustekinumab cohorts, respectively, and in 1.7% and 0% of the nonwhite participants, respectively.
The investigators also assessed health-related quality of life and again found outcomes were similar between white and nonwhite participants. For example, among those treated with brodalumab, 80% of white and 78% of nonwhite patients achieved a score improvement of 5 or greater on the Dermatology Life Quality Index. Of those randomized to ustekinumab, 76% of white patients and 73% of nonwhite patients achieved the same outcome.
