On October 5, 2023, Pfizer, Inc., announced that the FDA has designated Abrilada (adalimumab-afzb) as an interchangeable biosimilar to Humira (adalimumab). Initially, Abrilada was approved in November 2019 as a citrate-free biosimilar based on the review of a comprehensive data package, which confirmed biosimilarity of Abrilada to the reference product. This includes results from the REFLECTIONS B538-12 clinical comparative study, which discovered no clinically meaningful variances in efficacy, safety, or immunogenicity of Abrilada compared with the reference product, each administered in combination with methotrexate, in patients with moderately to severely active rheumatoid arthritis (RA).


Abrilada is the second adalimumab biosimilar to receive the designation and is also the fifth biosimilar overall to be considered interchangeable.

The interchangeable designation pertains to all approved indications of Abrilada, including certain patients with RA, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurativa, and uveitis.

An interchangeable biosimilar may be substituted at the pharmacy for the reference product without the involvement of the prescribing healthcare provider, depending on state pharmacy laws. Not all biosimilars are interchangeable. An interchangeable designation is granted by the FDA to only those biosimilars that meet additional data requirements demonstrating that patients who alternate between the reference product and the biosimilar will have the same clinical result as patients who are being treated with the reference product alone.

Roy Fleischmann, MD, clinical professor of medicine, University of Texas Southwestern Medical Center, stated, “With this designation, Abrilada is now both biosimilar to and interchangeable with Humira, reinforcing confidence among physicians and pharmacists that there is no decrease in effectiveness or increase in safety risk associated with switching between Abrilada and the reference product.”

The interchangeable designation was supported by data from the phase III REFLECTIONS B538-12 study. This study demonstrated comparable outcomes in terms of pharmacokinetics, safety, and immunogenicity in patients with moderately to severely active RA who switched multiple times between treatment with the 40 mg/0.8 mL concentration of Abrilada and the 40 mg/0.4 mL concentration of Humira compared with patients who received continuous Humira, each taken in combination with methotrexate.

The results from this study were recently published in The Lancet Rheumatology. Based on their findings, Dr. Fleischman and colleagues wrote, “We concluded that the biosimilar can be expected to produce the same clinical results as reference adalimumab in any given patient with respect to immunogenicity, safety, and efficacy.”

Angela Hwang, CCO, president of Global Biopharmaceuticals Business at Pfizer, stated, “Abrilada was developed with patients in mind, and having an interchangeable designation is a key step toward potentially increasing their access to this important treatment option. With 15 years of global in market experience in biosimilars and an industry-leading seven marketed biosimilar products in the U.S., Pfizer continues to expand options for patient care by introducing Abrilada.”

Abrilada will be available later this year at two price points, with the goal of achieving the broadest possible access for patients. Starting in late October 2023, Abrilada will be available at a list price (wholesale acquisition cost) 5% below the Humira list price. Later in 2023, Abrilada will be available at a second list price 60% below the Humira list price.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.