The U.S. Food and Drug Administration approved four biosimilar drugs in 2021 under the provisions of the Biologics Price Competition and Innovation Act (BPCIA, codified at 42 U.S.C. § 262) as part of the Affordable Care Act of 2010 (colloquially known as "Obamacare").  This brings to 33 the total number of approved biosimilars, although the effects of the pandemic has been felt in the last two years.  From 2015 (when there was only a single approved biosimilar, Sandoz’s Zarxio®, see chart below), the rate of approvals rose every year (3 in 2016, 5 in 2017, 7 in 2018, and 10 in 2019), but 2020 saw only 3 approvals.  The roster of approved drugs is in this table:

One bright spot in the approval trend is denoted by asterisks in the table, where this year, the FDA approved the first interchangeable biosimilar, Mylan Pharmaceutical’s Semglee® (insulin glargine-yfgn) followed by the FDA granting interchangeability to an earlier-approved biosimilar drug, Cyltezo® (adalimumab-adbm), produced by Boehringer Ingelheim.  The two most recent approvals include Eli Lilly & Co.'s Rezvoglar®, an injectable insulin glargine and the Coherus Bioscience's Yusimry®, a Humira® biosimilar.

In contrast, the FDA approved fifty new drugs in 2021, including New Molecular Entities (NME) and biologic products regulated under the FDA's Center for Drug Evaluation and Research (CDER), as well as thirteen approvals for vaccines, allergenic products, blood and blood products, plasma derivatives, cellular and gene therapy products approved by FDA's Center for Biologics Evaluation and Research (CBER).

While encouraging, only one of these products, Semglee®, is yet on the market, and Byooviz®, approved earlier this year, will not enter the market place until June 2022.  These occurrences exacerbate a trend set forth in the following table:

As this table shows, almost one third of approved biosimilar products are not yet on the market and the ones that are cluster among seven reference products.  There are many reasons for these delays, some relating to disputes arising under the BPCIA involving patent litigation.  While legislators (see "Senators Ask FTC to Investigate Biosimilar Litigation Settlement Agreement") and legislation (see "A Solution in Search of a Problem") concerning the relatively slow pace of approval (and the pandemic hasn't helped) it is most likely the case simply that the complexity of the process, patient and physician resistance to change, and other factors are responsible and can be expect to ameliorate over time.