Biosimilars are large complex molecules that are highly similar in structure and function to the approved brand-name molecules known as biologics. Biosimilars currently approved in the United States that could be used by dermatologists include those for rituximab, etanercept, adalimumab, and infliximab. Other approved biosimilars include those for pegfilgrastim, bevacizumab, trastuzumab, filgrastim, and epoetin alpha.
This issue of JAMA Dermatology includes 2 articles assessing biosimilars of tumor necrosis factor blockers that are used to treat a number of dermatologic and nondermatologic conditions. Loft et al1 describe a nationwide switch for patients with psoriasis in Denmark from originator adalimumab to adalimumab biosimilars and report that the 1-year drug retention for patients making that switch was the same between those switching to the biosimilar and those receiving the originator drug. The study by Westerkam et al2 compares originator infliximab with biosimilar infliximab for treatment of patients with hidradenitis suppurativa, again reporting no significant difference between the 2 treatment groups.