TNFα inhibitor biosimilars associated with alopecia areata. Case-based review

Alopecia areata (AA) is a common non-scaring hair loss associated with many inflammatory and autoimmune disorders. Anti-tumor necrosis factor alpha (TNFα) therapy is used to treat many chronic inflammatory disorders and has been proven to be effective and relatively safe. However, several immune-mediated skin reactions have been described with the use of TNFα inhibitors, among them AA. In this report, we describe two patients, a 32-year-old woman with ankylosing spondylitis and a 48-year-old man with rheumatoid arthritis who were both treated with SB4 (Benepali®), an etanercept biosimilar, and developed AA, 6 and 12 months respectively after the initiation of TNFα blocker biosimilar. These, are the first two cases of AA development during TNFα inhibitors biosimilar. Thus, physicians when dealing with patients treated with these agents, should be aware of possible immune skin reactions, among them AA. To this end, a close follow-up and monitoring is mandatory.