The FDA has approved Simlandi (adalimumab-ryvk), which joins Pfizer’s Abrilada (adalimumab-afzb) and Boehringer Ingelheim’s Cyltezo (adalimumab-adbm) as interchangeable with AbbVie’s Humira’s (adalimumab), the reference brand-name product that has set all kinds of sales records, for some uses.

Interchangeability means the biosimilar can be substituted for the reference product or another biosimilar at the pharmacy level, although state-level pharmacy regulations can complicate matters. Interchangeability is widely seen as important for gaining market share in the increasingly crowded market for Humira biosimilars and for pharmacy benefit managers (PBMs) steering prescriptions to their preferred products.

A total of nine Humira biosimilars are on the market in the U.S., so Alvotechn's Simlandi will be the 10th.

Biosimilars are replicas of brand-name biologics that are supposed to help bring down healthcare cost by creating price competition. The market for biosimilars has been slow to develop in the U.S. for a number of reasons, including PBMs having a business interest in keeping higher priced brand-name products on their lists of covered lists (formularies). Biosimilar trade groups say, though, that more biosimilars are being prescribed and one group said biosimilars collectively led to $9.4 billion in savings in 2022, a year before the Humira biosimilars starting to come on the market. AbbVie has reported sharp decreases in Humira as result of biosimilar competition. First approved in late 2002 as a treatment for rheumatoid arthritis, Humira has piled up additional approvals for other autoimmune conditions. The drug, which inhibits tumor necrosis factor, has powerful anti-inflammatory effects.

Alvotech, which is headquartered and has manufacturing facilities has in Iceland, is a late comer to the U.S. Humira biosimilar market because the FDA identifying problems with its manufacturing processes, which lead to two complete response letters, which is an official FDA notification that tells a manufacturer that their application will not be approved in its current form. Although not a rejection, complete response letters delay approvals and sometimes led to drugmakers abandoning a product that that has bene development.

Alvotech and Teva Pharmaceuticals announced the FDA approval in a news release issued last night at 8:15 p.m. EST. Teva, a major generic medication manufacturer and marketer, will commercialize and market Simlandi in the U.S. European drug regulators approved the biosimilar in 2021 and it is marketed in Europe under a different name, Hukyndra

The news release touts as the Simlandi as the first high-concentration, citrate-free biosimilar to Humira that is interchangeable. Citrate is a buffer that stabilizes medications, but it causes burning and pain at the injection. Other buffers have been identified, and all of the nine Humira biosimilars on the U.S. market are citrate-free formulations. However, Simlandi is also a high-concentration version of adalimumab. Most of Humira prescriptions are for high-concentration formulations. The other two Humira biosimilars with the interchangeable designation, Abrilada and Cyltezo, are low-concentration formulations, so at the moment, Simlandi has the high-concentration, citrate-free and interchangeable Humira biosimilar market to itself.