Baricitinib

Baricitinib is a Janus kinase (JAK) inhibitor. JAKs are tyrosine protein kinases that play an important role in pro-inflammatory signaling pathways. Overactive JAKs have been implicated in autoimmune disorders, such as rheumatoid arthritis. By inhibiting the actions of JAK1 and JAK2, baricitinib attenuates JAK-mediated inflammation and immune responses.

Baricitinib was first approved by the European Commission (EC) in February 2017 for the treatment of rheumatoid arthritis in adults and was later approved by the FDA in 2018. The EC later approved baricitinib for the treatment of atopic dermatitis, making it the first JAK inhibitor used for this indication in Europe. While baricitinib was granted emergency use as a treatment for COVID-19 in combination with remdesivir under the Emergency Use Authorization (EUA) in November 2020, the FDA fully approved the use of baricitinib for the treatment of COVID-19 in May 2022.

In the US and Europe, baricitinib is indicated for the treatment of adult patients with moderately to severely active rheumatoid arthritis who have had an inadequate response to one or more TNF blockers. Baricitinib may be used as monotherapy or in combination with methotrexate or other DMARDs.

In Europe, baricitinib is indicated for the treatment of moderate to severe atopic dermatitis in adult patients who are candidates for systemic therapy.

In the US, baricitinib is also indicated for the treatment of coronavirus disease 2019 (COVID-19) in hospitalized adults requiring supplemental oxygen, non-invasive or invasive mechanical ventilation, or extracorporeal membrane oxygenation. Recently, it is also approved as the treatment for severe alopecia areata in adults.