When will the IMULDOSA patents expire, and when will biosimilar IMULDOSA enter the market?

Last updated: August 31, 2026

IMULDOSA is Fresenius Kabi’s U.S. brand for ustekinumab-srlf, a biosimilar to Johnson & Johnson’s STELARA. The FDA approved IMULDOSA in November 2024 for the same principal indications as STELARA: plaque psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis.[1] Its commercial trajectory depends on three variables: the timing of U.S. biosimilar entry, discounts against STELARA, and the number of competing ustekinumab biosimilars.

IMULDOSA has a large addressable market but limited pricing power. STELARA generated approximately $10.4 billion in global sales in 2023 and remained one of Johnson & Johnson’s largest products before biosimilar erosion began.[2] IMULDOSA does not have publicly disclosed standalone revenue, and Fresenius Kabi reports it within broader pharmaceutical results. Its likely financial profile is a volume-driven, lower-margin product competing in a rapidly expanding U.S. ustekinumab biosimilar market.

What is IMULDOSA and who manufactures it?

IMULDOSA is ustekinumab-srlf, a monoclonal antibody biosimilar to STELARA, or ustekinumab. Fresenius Kabi is the sponsor and commercial manufacturer for the U.S. product.[1]

IMULDOSA product profile

Attribute	IMULDOSA
Active ingredient	Ustekinumab-srlf
Reference product	STELARA, ustekinumab
Sponsor	Fresenius Kabi USA, LLC
FDA pathway	351(k) biosimilar application
FDA approval	November 2024
Approved indications	Plaque psoriasis, psoriatic arthritis, Crohn’s disease, ulcerative colitis
Dosage forms	Subcutaneous injection and intravenous infusion, depending on indication
Reference-product class	Interleukin-12/23 monoclonal antibody
Biosimilar interchangeability	FDA approval status should be checked separately from biosimilarity; biosimilar approval alone does not establish pharmacy-level substitution

IMULDOSA’s label covers adult and pediatric plaque psoriasis, adult psoriatic arthritis, adult Crohn’s disease, and adult ulcerative colitis. The product uses the same core mechanism as STELARA by binding the p40 subunit shared by interleukin-12 and interleukin-23.[1]

When did IMULDOSA receive FDA approval?

The FDA approved IMULDOSA in November 2024. Approval followed analytical, nonclinical, pharmacokinetic, immunogenicity, and comparative clinical evidence supporting biosimilarity to STELARA.[1]

The approval did not create a new therapeutic market. It gave Fresenius Kabi access to an established market in which prescribers, payers, specialty pharmacies, and hospitals already understand ustekinumab treatment pathways.

How does IMULDOSA compare with STELARA?

Factor	IMULDOSA	STELARA
Regulatory status	FDA-approved biosimilar	Reference biologic
Sponsor	Fresenius Kabi	Johnson & Johnson / Janssen
Mechanism	IL-12/23 p40 inhibition	IL-12/23 p40 inhibition
Main markets	Dermatology and gastroenterology	Dermatology, rheumatology, gastroenterology
Pricing position	Expected to be discounted	Branded reference price
Substitution	Depends on interchangeability and state law	Reference product
Commercial strategy	Contracting, access, supply reliability	Brand retention, contracting, patient support

The central commercial difference is that STELARA retains clinical familiarity and established support programs, while IMULDOSA must win formulary access and prescribing volume through price, supply, and contracting.

How large is the IMULDOSA market opportunity?

The opportunity is substantial because STELARA is used in both dermatology and gastroenterology. The highest-value segments are Crohn’s disease and ulcerative colitis, where biologic treatment often continues for years and annual treatment costs are high.

Johnson & Johnson reported STELARA sales of approximately $10.4 billion in 2023, including about $6.4 billion in the United States.[2] The U.S. market is the principal near-term opportunity for IMULDOSA, although international markets may contribute through Fresenius Kabi’s established biosimilar infrastructure.

Market segments

Dermatology

Plaque psoriasis and psoriatic arthritis provide a large patient base and multiple competing biologics, including tumor necrosis factor inhibitors, IL-17 inhibitors, IL-23 inhibitors, and oral therapies. Dermatology adoption may be sensitive to payer formularies and site-of-care economics.

Gastroenterology

Crohn’s disease and ulcerative colitis generate higher strategic value because patients may remain on therapy for extended periods. Gastroenterology adoption can be slower than dermatology adoption because physicians may be cautious when switching stable patients from STELARA to a biosimilar.

Hospital and infusion channels

Intravenous induction for Crohn’s disease and ulcerative colitis creates a hospital, outpatient infusion, and specialty-provider opportunity. The commercial economics differ from retail pharmacy products because contracting often involves providers, distributors, group purchasing organizations, and payers.

What is the expected financial trajectory for IMULDOSA?

IMULDOSA is likely to follow a three-stage financial trajectory.

Stage	Timing	Financial characteristics
Launch formation	2024-2025	Low initial revenue, high contracting and market-access costs
Share expansion	2025-2027	Rapid volume growth if payer coverage and supply are competitive
Mature competition	2027 onward	Lower net prices, share fragmentation, margin pressure

Fresenius Kabi has not disclosed a standalone IMULDOSA revenue forecast. The product is part of a broader portfolio that includes injectable medicines, biosimilars, and hospital products. Revenue analysis therefore requires market-share and price assumptions rather than direct company guidance.

Revenue scenarios

A simple U.S. revenue framework illustrates the opportunity:

Scenario	Assumed share of $6.4 billion U.S. STELARA sales base	Gross sales equivalent
Conservative	1%	$64 million
Moderate	5%	$320 million
High adoption	10%	$640 million

These figures are not forecasts. They show the scale of revenue available before accounting for biosimilar discounts, rebates, channel deductions, switching rates, and market growth or contraction.

A biosimilar may obtain a meaningful share of prescriptions while producing much less revenue than the reference product because net prices are discounted. If IMULDOSA captured 5% of the historical U.S. STELARA sales base at a 30% net-price discount, the implied net revenue would be approximately $224 million before distribution and other deductions. At a 50% discount, the implied revenue would be approximately $160 million.

The actual outcome will depend more on net contract price and persistence than on prescription share alone.

What pricing pressure will IMULDOSA face?

IMULDOSA is entering a crowded ustekinumab biosimilar market. Competing U.S. products include:

SELARSDI, ustekinumab-aekn, from Sandoz.
WEZLANA, ustekinumab-auub, from Amgen.
PYZCHIVA, ustekinumab-ttwe, from Samsung Bioepis.
STEQEYMA, ustekinumab-stba, from Celltrion.
IMULDOSA, ustekinumab-srlf, from Fresenius Kabi.

The number of approved competitors increases the probability of aggressive payer contracting. The market may not resemble a single-biosimilar launch in which the first entrant retains a large price premium. Multiple suppliers can produce rapid price compression, especially in infusion and hospital channels.

What determines IMULDOSA’s net price?

The principal variables are:

Whether the product is designated interchangeable.
Whether major pharmacy benefit managers place it on preferred formularies.
Whether health systems use it as a preferred infusion product.
Whether Fresenius Kabi offers bundled contracting across its biosimilar portfolio.
Whether the product has reliable manufacturing and distribution.
Whether physicians initiate new patients on IMULDOSA or switch stable patients.

List-price comparisons will provide limited insight. Biosimilar net prices are usually shaped by confidential rebates and contracting arrangements.

What patents and exclusivity protect IMULDOSA?

IMULDOSA is protected primarily by the regulatory approval and commercial position of the biosimilar sponsor, not by a new composition-of-matter patent. The relevant patent risk historically centered on STELARA’s patent estate and the BPCIA patent-litigation process.

STELARA’s principal U.S. composition patent expired in 2023, but secondary patents covering formulations, dosing, manufacturing, and other aspects extended the reference product’s practical exclusivity. Johnson & Johnson disclosed multiple patent settlements with biosimilar developers that permitted launches before the expiration of all asserted patents.[2]

Does IMULDOSA have an Orange Book listing?

No conventional Orange Book listing should be expected for IMULDOSA because it is a biologic licensed under the Public Health Service Act, not a small-molecule drug approved under section 505 of the Federal Food, Drug, and Cosmetic Act. The FDA’s Purple Book is the primary database for licensed biological products and biosimilar relationships.[3]

Patent information affecting biologics may appear through litigation records, FDA regulatory documents, company disclosures, and BPCIA exchanges rather than through a standard Orange Book patent table.

What formulation patents affect ustekinumab biosimilars?

Relevant STELARA patent categories have included:

Liquid formulations and stabilizers.
Subcutaneous delivery.
Dosing regimens.
Manufacturing and cell-culture processes.
Treatment methods for psoriasis and inflammatory bowel disease.
Device and presentation claims.

The commercial effect of these patents depends on claim scope, validity, enforceability, and settlement terms. A biosimilar sponsor can launch under a license, after patent expiry, after settlement, or following a non-infringement and invalidity challenge.

Which companies are challenging the STELARA market?

The competitive challenge is broad rather than concentrated. The main participants include Amgen, Sandoz, Samsung Bioepis, Celltrion, and Fresenius Kabi. Each has regulatory approval or a commercial pathway for an ustekinumab biosimilar in the United States.

This creates two forms of competition:

Reference-product competition, in which biosimilars take share from STELARA.
Biosimilar-on-biosimilar competition, in which suppliers compete for preferred formulary status and lower net prices.

Fresenius Kabi’s advantage is its experience with hospital medicines, injectable products, and biosimilars. Its disadvantage is that IMULDOSA entered after several other ustekinumab biosimilars had already established commercial relationships or received market attention.

What generic or biosimilar launch risks exist for IMULDOSA?

IMULDOSA faces several launch risks.

Payer exclusion

A product can be FDA-approved but commercially restricted if a payer gives preferred status to a competing biosimilar. A lower list price may not overcome a weaker rebate position.

Physician switching resistance

Stable patients with controlled psoriasis or inflammatory bowel disease may remain on STELARA. New-patient starts are generally easier to convert than established patients.

Interchangeability limitations

Biosimilarity and interchangeability are separate regulatory concepts. Without interchangeable designation, pharmacy substitution is less automatic, and product selection depends more heavily on physician prescriptions, payer policies, and specialty-pharmacy protocols.

Manufacturing and supply risk

Monoclonal antibodies require complex cell-culture manufacturing, fill-finish capacity, cold-chain distribution, and consistent quality control. Any supply interruption can damage formulary position and physician confidence.

Price erosion

Five or more U.S. ustekinumab suppliers create a high risk of price competition. Revenue may rise through volume while gross margin declines.

How does IMULDOSA compare with competing ustekinumab biosimilars?

Product	Sponsor	U.S. regulatory position	Commercial implication
IMULDOSA	Fresenius Kabi	FDA-approved	Leverages Fresenius Kabi’s injectable and biosimilar infrastructure
Wezlana	Amgen	FDA-approved	Benefits from Amgen’s scale and payer relationships
Selarsdi	Sandoz	FDA-approved	Benefits from Sandoz’s established biosimilar platform
Pyzchiva	Samsung Bioepis	FDA-approved	Benefits from Samsung Bioepis development experience and partner network
Steqeyma	Celltrion	FDA-approved	Benefits from Celltrion’s biologics manufacturing base

No single product has an automatic commercial lead based only on FDA approval. Contracting, interchangeability, launch timing, supply, and physician support will determine share.

What litigation and settlement issues affect IMULDOSA?

The principal litigation issue is the STELARA patent estate and any BPCIA patent exchanges involving Fresenius Kabi. Public company disclosures and court filings are the controlling sources for launch dates and settlement obligations.[2]

Patent settlements can permit a biosimilar to enter before the final expiration of every asserted patent. They can also impose geographic, indication-specific, or timing restrictions. A settlement may allow a product to launch in the United States while delaying entry in other markets.

The key business question is not whether STELARA patents existed, but whether Fresenius Kabi obtained a legally permitted launch date and whether any remaining patents could support an injunction or damages claim.

What is the geographic coverage for IMULDOSA?

The United States is the highest-value market because STELARA had multibillion-dollar U.S. sales and the FDA approval covers major commercial indications. European and other international markets may offer earlier biosimilar access, but pricing is typically more regulated and country-specific.

Fresenius Kabi’s international commercial network can support expansion, although each jurisdiction applies separate rules on:

Biosimilar approval.
Interchangeability or substitution.
Reference-product exclusivity.
Tender procurement.
Pharmacovigilance.
Hospital reimbursement.
Naming and labeling.

The commercial value of international sales will depend on tender wins rather than on a single global price.

How strong is the IMULDOSA commercial position?

IMULDOSA has a strong market opportunity but a moderate competitive position.

Its strengths are FDA approval across four major indications, the size of the STELARA market, Fresenius Kabi’s hospital-product infrastructure, and the growing acceptance of biosimilars.

Its constraints are late entry relative to some competitors, likely price compression, lack of disclosed standalone revenue guidance, and dependence on payer and provider contracting.

The product can become a meaningful revenue contributor without approaching STELARA’s historical sales. A reasonable business expectation is rapid unit growth with constrained net pricing and declining incremental margins as competitors increase discounts.

Key Takeaways

IMULDOSA is Fresenius Kabi’s ustekinumab-srlf biosimilar to STELARA.
The FDA approved it in November 2024 for psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis.
STELARA generated approximately $10.4 billion globally and $6.4 billion in the United States in 2023.
IMULDOSA has no publicly disclosed standalone revenue forecast.
Five major U.S. ustekinumab biosimilar competitors create substantial pricing and formulary pressure.
Revenue potential is meaningful, but net sales will be reduced by rebates, discounts, and channel deductions.
The relevant FDA database is the Purple Book, not the conventional Orange Book.
The principal legal issues involve STELARA formulation, dosing, manufacturing, and method-of-use patents and any related BPCIA settlement terms.
The most likely financial trajectory is rapid volume growth, lower net prices, and increasing margin pressure.

FAQs About IMULDOSA

Is IMULDOSA interchangeable with STELARA?

FDA biosimilar approval does not by itself establish interchangeability. Pharmacy-level substitution depends on the product’s FDA interchangeability designation and applicable state law.

Will IMULDOSA reduce the cost of Crohn’s disease treatment?

It is expected to increase payer and provider negotiating leverage and may reduce net treatment costs. The size of the reduction will depend on formulary contracts and competing biosimilar discounts.

Does IMULDOSA compete with Skyrizi and Tremfya?

Yes, indirectly. Skyrizi and Tremfya compete with ustekinumab products in psoriasis and inflammatory bowel disease. Their presence may limit the share available to both STELARA and IMULDOSA.

Is IMULDOSA a generic drug?

No. IMULDOSA is a biologic biosimilar, not a conventional small-molecule generic. It was approved under the FDA’s 351(k) biosimilar pathway.

Can Fresenius Kabi report IMULDOSA as a separate revenue line?

Fresenius Kabi does not generally disclose standalone product revenue for IMULDOSA. Its financial contribution is reported within broader business segments and product categories.

References

U.S. Food and Drug Administration. (2024). IMULDOSA (ustekinumab-srlf) prescribing information and approval materials. https://www.fda.gov
Johnson & Johnson. (2024). 2023 annual report. https://www.jnj.com/investor-relations
U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products. https://purplebooksearch.fda.gov
Fresenius Kabi. (2024). Fresenius Kabi receives FDA approval for IMULDOSA, a biosimilar to STELARA. https://www.fresenius-kabi.com

Mechanism of Action	Interleukin-12 Antagonists Interleukin-23 Antagonists
Established Pharmacologic Class	Interleukin-12 Antagonist Interleukin-23 Antagonist

High Confidence Patents:	0
Applicants:	1
BLAs:	1

Summary for Tradename: IMULDOSA

Pharmacology for IMULDOSA

Note on Biologic Patents

1) High Certainty: US Patents for IMULDOSA Derived from Brand-Side Litigation

2) High Certainty: US Patents for IMULDOSA Derived from DrugPatentWatch Analysis and Company Disclosures

3) Low Certainty: US Patents for IMULDOSA Derived from Patent Text Search