Baricitinib is a JAK1-2 inhibitor recently approved in Europe and Japan for the treatment of moderate-to-severe atopic dermatitis in adult patients at doses of 2 and 4 mg daily. The aim of this article is to discuss the safety profile of baricitinib in atopic dermatitis using data from clinical trials and the supporting literature, with a focus on infectious adverse events. An integrated analysis of safety data from eight clinical trials described infections as the most frequent treatment-emergent adverse events, mainly of mild-to-moderate severity, notably upper respiratory tract infections and herpes simplex exacerbations. Real-world data are still limited and will contribute to precisely profile the patients that might benefit from this treatment.
Keywords: JAK inhibitors; atopic dermatitis; baricitinib; clinical trials; infections; safety; systemic treatment.
Baricitinib is a drug taken by mouth, currently approved for the treatment of moderate-to-severe atopic dermatitis in adults who are candidates for systemic therapy, a medication that is designed to be absorbed into the bloodstream and work throughout the body. Baricitinib is available as 2- and 4-mg tablets and has been shown to improve the cutaneous manifestations, such as dry and cracked skin, redness and symptoms of atopic dermatitis, especially itchiness. Baricitinib is generally well tolerated. The most common adverse events that have emerged from clinical trials include headache, nausea and high cholesterol. Another reported side effect is an increased risk of infections, mainly of mild-to-moderate severity, especially upper respiratory tract infections such as nasopharyngitis (inflammation of the nose and throat) and reactivation of herpes zoster, a virus that causes a painful rash on one side of the body, and herpes simplex, which causes clustered blisters usually on the lips or genitals. There is still a lack of data from real-world experience, which will be important for the development of a more precise profile of patients who may benefit from this treatment.