Brodalumab is a fully human monoclonal antibody that binds to the interleukin 17 receptor A. The AMAGINE I, II and III are randomized, double blind, placebo-controlled, phase III clinical trials testing brodalumab for moderate to severe plaque psoriasis. The AMAGINE trial demonstrated that brodalumab is superior with regards to skin clearance at week 12 in comparison to placebo and ustekinumab.
It is well established that patients with skin of color experience differences in psoriasis related symptoms. Furthermore, African Americans and Latinos report worse psoriasis quality of life outcomes in comparison with their Caucasian peers. Researchers at the Department of Dermatology at Wake Forest Baptist Medical Center, led by Dr. Amy McMichael, performed a post-hoc analysis of the use of AMAGINE trial highlighting results in people with skin of of color.
In their study published recently in the American Journal of Clinical Dermatology, they analyzed the efficacy, safety and health related quality of life outcomes in patients with skin of color receiving brodalumab over 52 weeks. The patients were self-categorized as Black, Asian, Hispanic/Latino.
Of the 3712 patients that underwent randomization in the AMAGINE study 56 were self-described as Black, 63 as Asian, and 200 as Hispanic/Latino. In the analysis this subgroup, patients who received brodalumab achieved higher PASI scores and sPGA scores at week 12 and 52 in comparison with ustekinumab. The rate of adverse reactions were similar across racial/ethnic backgrounds. The exposure-adjusted event rate per patient year in the Black, Asian and Hispanic/Latino subgroups were 222, 301, and 268 respectively.
Patient reported outcomes were similar across all subgroups. The PSI response rate among the Black, Asian and Hispanic/Latino subgroups were 67%, 80% and 55% respectively. Health related quality of life outcomes were similar in all subgroups with patients who received a 5 point improvement in the DLQI similar across subgroups.
This research suggests that brodalumab demonstrates efficacy in Black, Asian and Hispanic/Latino subgroups. This study also suggests that brodalumab may be superior to ustekinumab in these subgroups. The authors admit that the study has several limitations. First, it is limited by a small sample size of non-white patients. Second, there is no clear biologic basis for the advantage of brodalumab. The authors suggest that genetic polymorphisms may play a role in differences in psoriasis manifestations and pathogenesis. This may in turn provide a biologic foundation for differences in medication efficacy.
The AMAGINE trial represents one of the largest randomized clinical trials in psoriasis. The large cohort allows for subgroup analysis supporting the efficacy and safety of brodalumab in patients that are Black, Asian and Hispanic/Latino.
McMichael, Amy, et al. "Efficacy and safety of brodalumab in patients with moderate-to-severe plaque psoriasis and skin of color: results from the pooled amagine-2/-3 randomized trials." American Journal of Clinical Dermatology 20.2 (2019): 267-276.