Key clinical point: Prescriptions of the biosimilar infliximab-dyyb remain low compared with those for bio-originator infliximab and other tumor necrosis factor inhibitors.
Major finding: Prescriptions for the infliximab biosimilar known as infliximab-dyyb accounted for 3.5% of all prescriptions of tumor necrosis factor inhibitors between January 2017 and September 2018; patients remained on the biosimilar for approximately as long as those who were on the bio-originator.
Study details: The data come from 909 patients prescribed the biosimilar infliximab-dyyb and 4,413 patients with a new prescription for the bio-originator infliximab in the American College of Rheumatology’s RISE electronic health record registry, which at the a time of the study included data from 218 rheumatology practices and over 1 million rheumatology patients in the United States.
Disclosures: The study received no outside funding. Several authors disclosed relationships with multiple companies, including Bristol-Myers Squibb, Roche, UCB, AbbVie, Janssen, Radius, Regeneron, Amgen, Eli Lilly, and Pfizer.
"The advent of biosimilar medications for RA in the US was thought to be a path towards decreasing costs and increasing access to biologic medications. This study, an analysis of the ACR’s RISE registry from January 2017-September 2018, found that only one biosimilar medication, infliximab-dyyb, was prescribed (out of two available at the time), and while 909 new prescriptions were written for infliximab-dyyb compared to 4,413 for the originator infliximab, overall the biosimilar drug only accounted for 3.5% of all anti-TNF prescriptions. Rates of continuation of both infliximab and infliximab-dyyb were similar. This rate is lower than rates for biosimilar use in other countries, potentially due to a lack of significant savings over the originator drug."
Arundathi Jayatilleke, MD
Bansback N et al. ACR Open Rheumatol. 2020 Jan 6. doi: 10.1002/acr2.11106.