Over the next five years, 88 biologics—including several blockbuster agents like Eliquis, Keytruda, Opdivo, and Darzalex—are facing a loss of exclusivity, representing an estimated market of more than $100 billion. After the fierce competition between Humira (adalimumab) biosimilars, manufacturers are keeping a close eye on adoption dynamics for biosimilars of Johnson & Johnson’s autoimmune drug, Stelara (ustekinumab).
While Stelara is used in fewer indications than Humira, it commands a large market share in its therapeutic areas, most notably in plaque psoriasis, Crohn’s disease and ulcerative colitis. For the past few years, Stelara has been J&J’s top seller, earning $10.4 billion in 2024.
Now that seven ustekinumab biosimilars are commercially available, manufacturers will be paying close attention to how the market responds—and how this biosimilar race differs from last year’s. What is the impact of vertical integration, the IRA, and other factors on biosimilar adoption?
A Dearth of Differentiators
Back in 2023, several Humira biosimilars launched with a unique dual pricing strategy, featuring both high-WAC and low-WAC products. This strategy appealed to PBMs, as higher-priced biosimilars allowed them to maximize the rebates they offered clients.
For the most part, Stelara biosimilars have not followed this trend. Although Amgen launched its ustekinumab biosimilar, Wezlana, with both high- and low-WAC options, the remaining biosimilars debuted with list prices ranging from 80% to 90% below Stelara’s pricing. So how will these low-cost biosimilars distinguish themselves from one another?
In the Humira biosimilars competition, achieving FDA-approved interchangeability was a huge boon, as it meant that the biosimilar could be substituted for the originator drug at the pharmacy level, unlike its peers. This is not true for the Stelara biosimilar landscape, as only one (Accord BioPharma’s Imuldosa) lacks interchangeability status. In any case, interchangeability will likely become a non-issue for future biosimilar launches, as the FDA is currently seeking to amend the Public Health Service Act to deem all approved biosimilars interchangeable with their respective reference products.
As more ustekinumab biosimilars come to market—such as Bio-Thera Solutions and Hikma Pharmaceuticals’ Starjemza, the eighth to be approved by the FDA—it remains to be seen if any one factor will set a biosimilar apart. Right now, all the available ustekinumab biosimilars are approved for each of Stelara’s indications. And as every Stelara biosimilar thus far is available in both subcutaneous and intravenous formulations, the route of administration will not help differentiate between them.
So what will?
Net Cost Drives Formulary Decisions
According to MMIT research conducted in May 2025, net cost is far and away the most important factor for payers deciding which ustekinumab biosimilars to add to formularies. Payers also value biosimilars that have a similar formulation to Stelara, as well as interchangeability status and label breadth.
In our MMIT Index report on immunology, the majority of surveyed payers and PBMs—representing 83% of commercial lives—indicated they were very or extremely likely to remove Stelara from their formularies by Q2 2026. They noted that biosimilars offer lower list prices, more favorable contracting and greater cost savings for patients.
Read the full article in BioPharma Dive. For actionable insights from unblinded payer and provider field research, learn about our Biologics & Injectables Index.
