The monopoly protecting the worlds best-selling medicine is at an end. On Tuesday, Amgen is launching a copycat version of AbbVies autoimmune disease drug Humira in the U.S., giving physicians and people with conditions like arthritis, psoriasis and Crohns disease a lower-cost option to a treatment now priced at nearly $90,000 a year.Amgens drug, a so-called biosimilar named Amjevita, is the first of nine lookalike versions of Humira that are set to launch this year, which will help end Humiras reign as one of the pharmaceutical industrys most lucrative products. Worldwide sales totaled $20.7 billion in 2021 and another $15.7 billion over the first nine months of 2022. The bulk of those sales are in the U.S., following entry of biosimilar competitors in Europe four years ago.Amjevita will price its biosimilar55% lower than Humiraswholesale acquisition cost, which is $6,923 for a four-week supply. Due to discounts and rebates, insurers seldom pay that price, however.According to Amgen, a second list price 5% below Humiras will also be available to some payers to account for rebating and discounting practices by pharmacy benefits managers. For some entities in the system, the financial considerations mean a higher list price may allow for broader access for patients, a spokesperson wrote in an email to BioPharma Dive.The arrival of Humira biosimilars in the U.S. could carry consequences beyond AbbVie, Amgen and its other rivals, too. Their impact might be felt by other drugmakers that market products for the diseases Humira treats, while their success or failure will represent the latest test of biosimilars promise to reduce healthcare spending.Unlike small molecule pills or tablets made through a chemical process, biologic drugs like Humira are produced in living systems such as cell lines and are therefore harder to characterize and replicate. Until passage of a federal law in 2010, there was no regulatory pathway for approval of a generic biologic in the U.S. It took another five years after that law until the Food and Drug Administration approved the first biosimilar, Novartis Zarxio.However, uptake of many of the first biosimilars approved in the U.S. was slow, as the relatively small numbers of competitors and insurer contracting practices helped makers of brand-name drugs preserve their sales. While thats begun to change, Humira is seen as the most significant opportunity yet, given its high sales and breadth of approved indications. It faces many more biosimilar rivals than other biologic drugs that have lost patent protection in recent years and, as a result, the market might evolve differently.Furthermore, among the biosimilars set to launch this year is an interchangeable version of Humira that pharmacists could directly substitute for the branded version. Other biosimilars, while still considered equivalent to branded versions, have to be specifically prescribed by a doctor.David Risinger, an analyst at SVB Securities, wrote in a recent note to clients that insurers have already agreed to continue purchasing Humira in 2023. While they could add biosimilars to their covered drugs lists, they will likely not make biosimilars the preferred option over Humira this year, which would deny them a cost-sharing advantage. The equal status between biosimilars and branded Humira would also mean that patients wouldnt need prior authorization to keep using Humira.There are limited incentives for physicians to choose biosimilars, Risinger wrote.AbbVie also recently raised Humiras list price by 8%, leading Risinger to increase his forecast for 2023 U.S. sales of Humira to $11.7 billion, from $10.3 billion previously. In 2024, he is predicting only $6.2 billion in branded sales, however.A healthcare consultant and company creator called Goodroot, meanwhile, said in a report that they expect biosimilars to win 5%of the Humira market share this year and between 20% to 25% in 2026.For its part, AbbVie is telling investors that 2023 will represent an earnings floor for the company, and that sales will return to growth in 2024 as its successor inflammatory disease drugs, Skyrizi and Rinvoq, begin to supplant Humira. The company bumped up its combined revenue guidance for the two autoimmune disease drugs to $17.5 billion in 2025, 17% higher than its forecast of $15 billion about a year ago.AbbVie could try to use those two newer drugs in its negotiations with insurers to keep Humira in a preferred position, likely via discounting and rebating, according to the Goodroot report.Since Humiras 2003 launch by Abbott Laboratories, which later spun out AbbVie into a pure-play drugmaker, the medicine has become a standard treatment option for nine autoimmune conditions, including rheumatoid arthritis, plaque psoriasis and ulcerative colitis. AbbVies steady expansion of its use helped drive the blockbuster sales for which it is now known.But AbbVies lawyers have contributed, too, filing hundreds of patent applications on different features and improvements that have staved off competition for six years after Humiras main patent expired in 2016. In 2017 and 2018, AbbVie inked settlements with Amgen and the other biosimilar manufacturers that set entry for 2023.Editors note: This story has been updated to include Amgens comments on the second list price for Amjevitaand clarify the description of Goodroot. '