This was expected to be the year that Humira, AbbVie‘s blockbuster $90,000-a-year arthritis treatment and the best-selling biopharmaceutical in history, loses its chokehold on the healthcare system.

After more than 20 years, the patents protecting AbbVie’s (ticker: ABBV) cash cow expired at the beginning of 2023. That opened the door for a host of competitors known as biosimilars, drugs that function as the generic equivalent of complex treatments like Humira. The first, Amjevita from Amgen (AMGN), was launched in January; as many as seven more could arrive later this year.