Baricitinib is a medication that helps an overactive immune system adjust itself, leading to improvements in the inflammatory condition atopic dermatitis. Baricitinib is approved for patients with moderate-to-severe atopic dermatitis in 40 countries. Because it works with the immune system, it is important to understand the safety of baricitinib. Safety information was collected from eight studies and analyzed in two datasets. The first dataset compared the safety of baricitinib 2 mg with placebo in six 16-week studies in which neither patient nor physician knew whether they were taking baricitinib or placebo. The second dataset included an additional two extension studies and examined the safety of baricitinib in all patients receiving at least one dose of baricitinib 2 mg. Patients took baricitinib 2 mg for a maximum of 2.4 years, with a median time of 330 days. In the first dataset, adverse events were higher for baricitinib 2 mg (57.9%) than placebo (51.6%). Serious adverse events, serious infections, and opportunistic infections were low in number and similar for patients taking baricitinib 2 mg or placebo. Herpes simplex infections were more frequent in patients taking baricitinib 2 mg (3.8%) than in those taking placebo (2.8%), but rates in those taking baricitinib 2 mg decreased with a longer treatment duration. There were no occurrences of cancer, gastrointestinal perforations, or major adverse cardiovascular events. In the second dataset, there were five reports of cancer other than non-melanoma skin cancer, two major adverse cardiovascular events, one peripheral venous thrombosis, one arterial thrombosis, and no pulmonary embolisms, deep vein thromboses, or deaths. Longer treatment with baricitinib is required to better understand the risks of developing cancer or major adverse cardiovascular events. This analysis of safety in patients with moderate-to-severe atopic dermatitis is consistent with the safety reported previously for baricitinib 2 mg. Extended Safety Analysis of Baricitinib 2 mg in Adult Patients with Atopic Dermatitis: An Integrated Analysis from Eight Randomized Clinical Trials (MP4 87244 kb).