Pfizer has announced top-line Phase III results for its investigational oral Janus kinase 1 (JAK1) inhibitor, abrocitinib, for patients ages 12 years and older with moderate to severe atopic dermatitis, a chronic skin disease characterised by inflammation and skin barrier defects that affects up to 10% of adults and up to 20% of children worldwide.
The study achieved all co-primary and key secondary endpoints and both doses of abrocitinib were found to be well-tolerated, which was broadly consistent with the results of a previous study of abrocitinib, JADE MONO-1.
This study, JADE MONO-2, was designed to evaluate the safety and efficacy of two-dose regimens of abocitinib monotherapy over a 12-week, randomised, placebo-controlled, parallel-group study that enrolled 387 adults. The study results showed that either dose of abrocitinib reduced pruritus by Week 2 in a statistically significant number of patients compared to the placebo control.
This reduction was measured as a four-point reduction in the itch severity numerical rating scale (NRS), the magnitude of decrease in the Pruritus and Symptoms Assessment of Atopic Dermatitis (PSAAD), and a 75% or greater change in the Eczema Area and Severity Index (EASI) score.
The frequency of serious treatment-emergent adverse events was 1.3%, 3.2%, and 1.3% for placebo, 100mg abocitinib, and 200mg abocitinib, respectively. The discontinuation rates due to adverse events were 12.8%, 3.8%, and 3.2% for placebo, 100mg abocitinib, and 200mg abocitinib, respectively. One subject with co-existing cardiovascular risk factors died from an unknown etiology three weeks after completing 100mg abrocitinib once daily, but the investigator ruled this as unrelated to the study drug.
This study has provided continued support for abrocitinib’s ability to provide relief from moderate to severe atopic dermatitis. Future results from a study using Sanofi/Regeneron’s Dupixent (dupilumab) as an active control for abrocitinib are expected in Spring 2020. In February 2018, abrocitinib received a breakthrough therapy designation from the US Food and Drug Administration (FDA) for the treatment of moderate to severe atopic dermatitis. GlobalData expects that abrocitinib could be a serious challenger to Dupixent, which had sales of about $553m in Q2 2019, as there will likely be space for multiple products in this market.