The Adalimumab (Humira) and Biosimilar Market
Patent thickets, delayed biosimilars and PBM private labels
Adalimumab, sold by AbbVie as Humira, treats rheumatoid arthritis, Crohn's disease, psoriasis and other autoimmune conditions. It was for years the world's best-selling drug. Its market is controversial on two fronts: how AbbVie delayed US biosimilar competition until 2023, and how, once biosimilars arrived, PBM formulary decisions shaped which versions patients actually receive. It is widely regarded as the key test case for the US biosimilar system.
Questions
Why is the adalimumab market so important?
Humira peaked at ~$21 billion in global sales and has generated $200 billion+ cumulatively — with ten FDA-approved biosimilars now competing, how this market plays out is shaping the entire next wave of biologic patent expiries.
Humira was the best-selling drug in the world, peaking at roughly $21 billion in global sales before US biosimilar competition arrived in 2023, and generating more than $200 billion cumulatively. Biosimilars are near-copies of biologic drugs, meant to play the role generics play for pills by introducing price competition. Because Humira was so large, its loss of exclusivity was the most-watched biosimilar event in the industry, and the field of competitors is now the deepest for any biologic, with ten FDA-approved adalimumab biosimilars. How this market has played out, including how long biosimilars took to arrive and how slowly they gained share, is shaping policy for the next wave of biologic patent expiries, such as Stelara.
Q2Why did US biosimilars arrive five years after Europe's?
AbbVie filed ~250 patents — 90% post-approval — creating a 'patent thicket' that made litigation impractical; all eight challenger companies settled for 2023 US launch dates, while European biosimilars launched in 2018 and cut AbbVie's European price by up to 80%.
Humira's core patent expired in the US in 2016, but AbbVie had filed some 250 patents, about 90% after approval, creating a "patent thicket." Rather than litigating dozens of patents, biosimilar makers settled. AbbVie reached settlements with eight companies, all agreeing to US launch dates in 2023, starting with Amgen's Amjevita on January 31. In Europe, where the patent landscape differed, biosimilars launched in October 2018. Within four months they had about 15% of the European market, and AbbVie cut its European price by up to 80%. Congressional proposals would cap the number of patents asserted against biosimilars; one would have cut AbbVie's assertable Humira patents from 105 to 24.
Q3How much did US Humira prices rise before biosimilars?
AbbVie raised the price 27 times from 2003 to 2021 — a 470% increase to $77,586/year — while Enbrel followed each increase almost exactly in 'shadow pricing' rounds; from 2003 to 2021 Humira generated $170 billion worldwide, $107 billion in the US.
According to the House Oversight Committee, AbbVie raised Humira's price 27 times from 2003 to 2021, reaching $77,586 a year, a 470% increase from launch. Even after rebates, the net price rose 110% between 2009 and 2018. The committee found that Humira's main competitor, Amgen's Enbrel, did not constrain prices; the two companies engaged in "shadow pricing," following each other's increases almost exactly over dozens of rounds. From 2003 to 2021 Humira generated $170 billion in worldwide net revenue, including $107 billion from the US. Axios estimated that because US biosimilars were delayed, Americans would pay far more than Europeans for the same drug during that period. This history is why many see the market as evidence of patent system failure.
Q4Why did biosimilars gain so little share at first?
When biosimilars launched through 2023 US uptake sat at ~2–3% — because PBMs earning rebates tied to list price had no incentive to favour low-list-price options, and AbbVie defended share with rebates and by moving patients to Skyrizi and Rinvoq.
When biosimilars launched through 2023, US uptake was flat at around 2% to 3%. A key reason was the rebate system. Some biosimilars launched in both high-list-price and low-list-price versions, because PBMs earning rebates tied to list price had little incentive to favour low-list options. Drug Channels noted the largest PBMs' 2024 formularies generally supported the gross-to-net bubble for Humira biosimilars. AbbVie also defended its position with rebates and by moving patients to newer drugs. The result was that for more than a year after biosimilars became available, most patients continued on branded Humira, and payers and patients saw little of the expected savings. For critics, this showed that approval of biosimilars does not guarantee competition when intermediaries control access.
Q5What changed when CVS Caremark dropped Humira?
Biosimilar share rose from ~2% to ~22% by October 2024 after Caremark removed branded Humira on April 1, 2024 — but it excluded most competitors and included two made by its own Cordavis subsidiary, raising conflicts-of-interest questions.
On April 1, 2024, CVS Caremark removed branded Humira from its major national commercial formularies, the first large PBM to do so. Biosimilar share rose to about 22% by October 2024. But CVS did not open the category to all competitors. According to Forbes, instead of allowing all marketed biosimilars, CVS excluded most and included two made by its own subsidiary, Cordavis, which were not the lowest-priced products. CVS's preferred products include a Cordavis private-label version of Sandoz's Hyrimoz, and Drug Channels lists a Cordavis "follow-on biologic" supplied by AbbVie itself. The move shifted volume quickly, but raised questions about whether PBMs were steering patients towards products that benefited their own corporate groups rather than the cheapest option.
Q6What are PBM private-label biosimilars and why are they controversial?
All three large PBMs shifted 2025 national formularies to their own brands — Caremark/Cordavis, Express Scripts/Quallent, Optum/Nuvaila — excluding nearly all independent biosimilars and raising conflict-of-interest concerns that could deter future biosimilar investment.
For 2025, all three of the largest PBMs shifted national formularies to favour their own private-label biosimilars: Caremark with Cordavis, Express Scripts with Quallent and Optum with Nuvaila. Nearly all other marketed Humira biosimilars were excluded from the largest PBMs' 2025 formularies. Drug Channels argued that PBMs' benefits from private labels can align with those of plan sponsors and patients, since private labels generally carry low net costs. Critics counter that when a PBM owns or co-brands a product, it faces a conflict of interest, and independent biosimilar makers are shut out, which could deter future investment in biosimilars. One analysis warned plan sponsors to watch for pushback and regulatory scrutiny of the private-label models. There are now eight distinct adalimumab brands causing confusion at pharmacies.
Q7What is product hopping, and how does it apply to Humira?
Critics say AbbVie offered Humira patients Skyrizi coupons just as biosimilars launched — preserving immunology share while keeping overall adalimumab volume trending down, limiting biosimilars' cost-containment impact. A House bill would restrict this practice.
Product hopping describes a company moving patients from an older drug about to face competition to a newer, still-protected drug. In adalimumab, critics say AbbVie encouraged patients and prescribers to switch to its newer immunology drugs Skyrizi and Rinvoq. One pharmacy-cost analyst described the tactic as offering patients on Humira a coupon to Skyrizi just as biosimilars launched, and said it allowed AbbVie to preserve substantial immunology market share despite ten biosimilars. The same analysis noted overall adalimumab volume was trending down, limiting biosimilars' impact on cost containment. A House bill would limit product hopping and abuse of the "patent dance" provisions for biosimilars. AbbVie argues its newer drugs offer superior efficacy and that switching reflects clinical choices by doctors and patients.
Q8Did AbbVie face allegations over how it marketed Humira?
In 2020 AbbVie paid $24 million to settle allegations it deployed nurse 'ambassadors' to encourage refills and paid doctors cash, meals and trips — while the House report found AbbVie had obstructed its investigation for two years until threatened with a subpoena.
Yes. In 2020 AbbVie paid $24 million to settle a lawsuit brought by California's insurance commissioner and a whistleblower. The suit alleged AbbVie used nurse "ambassadors," who visited patients or called them, to ensure prescriptions were refilled, blurring the line between caregiver and marketer, and offered doctors cash, meals, gifts and trips to encourage Humira prescribing. The settlement required marketing reforms, and AbbVie did not admit wrongdoing. The House report also found AbbVie had obstructed the committee's investigation for more than two years until threatened with a subpoena. Separately, a Senate Finance report found the IP rights for US Humira sales were held by a Bermuda subsidiary, a lawful but criticised tax structure.
Q9How are hospitals and 340B affecting the adalimumab market?
340B pricing may still favour branded Humira in the medical-benefit channel, and interchangeability designations vary by biosimilar and formulation — pharmacists now report that a prescription accepted by one PBM may be rejected by another for non-covered brand selection.
Adalimumab is dispensed through both pharmacy and medical benefit channels, and hospitals participating in the federal 340B drug discount programme can buy it at steep discounts. One market analysis noted that 340B pricing for Humira may continue to favour the branded product, creating a split incentive between pharmacy and medical channels. This illustrates how multiple, overlapping discount systems can undermine the simple expectation that cheaper biosimilars will win. Interchangeability designations, which let pharmacists substitute biosimilars without a new prescription, also vary by product and formulation, adding to complexity. Pharmacists now report that a prescription accepted by one PBM may be rejected by another because of non-covered brand selection, requiring them to check each patient's plan-preferred product before dispensing.
Q10How much has Humira cost the US health system?
AbbVie earned $16.1 billion from US Humira in 2020 versus $3.7 billion from Europe; more than 77% of its worldwide 2021 sales were in the US; four-plus additional years of exclusivity vs Europe cost American patients, employers and taxpayers tens of billions.
A great deal, particularly compared with other countries. The House Oversight Committee found Humira generated about $170 billion in worldwide net revenue from 2003 to 2021, including $107 billion from the US. In 2020, AbbVie earned $16.1 billion from US Humira sales compared with $3.7 billion from Europe. A Senate Finance Committee report found AbbVie had sold $62 billion of Humira in the United States over four years, and that more than 77% of AbbVie's worldwide sales in 2021 were made in the US. The House committee said AbbVie's internal data showed US price increases far outpaced discounts and rebates. Critics argue that the four-plus years of additional US exclusivity compared with Europe cost American patients, employers and taxpayers tens of billions of dollars.
Q11What does the Humira experience mean for future biosimilar markets?
The Humira playbook — patent thickets, PBM private labels, formulary control, list-price cuts and patient switching — is now the template for the next biologics facing the patent cliff, with the key open question being whether reforms produce genuine price competition or merely transfer profits from manufacturers to PBMs.
The Humira market has become the template for what happens when a blockbuster biologic loses exclusivity in the US. Its lessons are that patent thickets and settlements can delay competition for years; that rebate-driven formularies can keep biosimilar uptake near zero until a PBM acts; and that when PBMs do act, they may favour their own private labels. As one analysis put it, the "Humira playbook", comprising PBM private label, formulation matching and aggressive list-price cuts, is the template for the next biologics facing the patent cliff. Policymakers are considering patent reform, FDA streamlining of biosimilar approvals, and PBM reforms such as those in the FTC's insulin settlements. Whether these produce genuine price competition, rather than a transfer of profits from manufacturers to PBMs, is the key open question.