Stelara biosimilars compared: FDA status, interchangeability, payer coverage, and switching

Stelara (ustekinumab, Janssen/Johnson & Johnson) is an interleukin-12/23 antagonist approved for plaque psoriasis, psoriatic arthritis, Crohn's disease, and ulcerative colitis. US biosimilar entry began in early 2025 after Stelara's loss of exclusivity, and eight biosimilars are now FDA-approved. All eight carry the interchangeable designation — the highest interchangeable-biosimilar ratio for any reference product on the US market. Payers and PBMs have moved faster on Stelara exclusions than they did with Humira, with several major formularies excluding the branded product within the first year.

This reference-product dossier is for prescribers, access teams, pharmacists, and payer professionals who need to track which biosimilars are available, how payers are covering them, and what switching rules apply.

FDA-approved biosimilars

As of May 2026, eight biosimilars referencing Stelara have been approved by the FDA:

In addition, Janssen markets an unbranded version of ustekinumab (approved April 2025) under the Stelara BLA.

Interchangeability

All eight biosimilars carry the FDA interchangeable designation. After Wezlana's interchangeable exclusivity expired on April 30, 2025, subsequent biosimilars were able to receive interchangeable designation: Selarsdi (May 2025), Pyzchiva (April 2025), Imuldosa (2025), Otulfi (May 2025), Steqeyma (2025), Yesintek (June 2025), and Starjemza (2025). Wezlana was the first interchangeable biosimilar to Stelara, approved October 2023.

All eight interchangeable biosimilars may be substituted for Stelara at the pharmacy counter without prescriber intervention, subject to state pharmacy practice laws.

Indications

All eight biosimilars share the same FDA-approved indications as Stelara: plaque psoriasis, psoriatic arthritis, Crohn's disease, and ulcerative colitis. Dosing and administration routes (subcutaneous injection and intravenous infusion) match the reference product.

Formulations and devices

Biosimilars are available in both subcutaneous (prefilled syringe and single-dose vial) and intravenous (single-dose vial) presentations:

Device availability is expanding. Check individual product prescribing information for the most current device options.

Payer and PBM coverage

The Stelara biosimilar market is moving faster than Humira's did. Payers learned from the Humira experience and have accelerated formulary exclusion timelines. Key payer moves:

CVS Caremark

CVS Caremark initially kept branded Stelara on its formularies even as biosimilars launched, citing "supply chain instability" and ongoing litigation concerns. However, on May 5, 2026, CVS Health announced that effective July 1, 2026, its most common commercial template formularies will transition from Stelara to preferring lower-cost interchangeable biosimilars — specifically Pyzchiva (Sandoz) and Yesintek (Biocon Biologics). Most members will pay $0 out-of-pocket.

This is notable because CVS was the first PBM to remove Humira in April 2024, more than a year before other PBMs followed. Its more cautious approach with Stelara reflected the faster-than-expected biosimilar entry and the need to ensure supply stability.

Express Scripts (Cigna)

Express Scripts' 2026 National Preferred Formulary excludes branded Stelara. Preferred ustekinumab products include deeply discounted biosimilars from Teva (Selarsdi/unbranded ustekinumab-aekn) and Biocon (Yesintek), plus a higher-priced Quallent Pharmaceuticals private-label version of ustekinumab-ttwe (via Samsung Bioepis). The exclusion document lists Otulfi SC, Pyzchiva SC, Starjemza SC, Steqeyma SC, and Wezlana SC as excluded, along with unbranded ustekinumab and ustekinumab-aauz SC, while preferring the Quallent, Teva, and Biocon products.

The private-label Quallent product is affiliated with Express Scripts' parent company (Cigna), reprising the same dynamic seen with Humira where PBMs prefer their own vertically integrated products alongside deeply discounted biosimilars.

Optum Rx (UnitedHealth Group)

Optum Rx excluded branded Stelara from commercial and exchange formularies effective July 1, 2025, as part of a broader biosimilar formulary strategy that also excluded Humira. The Optum Rx Provider Biosimilars eToolkit guides prescribers through the transition to preferred biosimilar alternatives.

Horizon Blue Cross Blue Shield of New Jersey

Effective July 1, 2025, Horizon BCBSNJ moved Stelara to non-formulary or non-preferred status across its formularies. Preferred biosimilars (Tier 2) include Steqeyma (Celltrion) and Yesintek (Biocon). Other Stelara biosimilars were placed at Tier 3 or non-formulary. Horizon pre-entered prior authorizations for biosimilars for all impacted members before the transition date.

Health Alliance (U of IL)

Stelara became nonformulary effective April 1, 2025. Covered biosimilar alternatives include select NDCs of Wezlana, Otulfi, Selarsdi, Yesintek, Steqeyma, and Pyzchiva. No new prior authorizations were required for patients with an active Stelara PA on file.

Blue Cross Blue Shield (Florida Blue)

Florida Blue's medical coverage guideline for ustekinumab products lists Stelara, Steqeyma, unbranded ustekinumab, and Yesintek as preferred subcutaneous products when specific medical necessity criteria are met. Other biosimilars may require step therapy or are non-preferred.

Highmark (PA, WV, DE, NY)

Highmark lists Stelara and Yesintek as preferred products for all individuals and all indications, effective January 1, 2026. Both IV and subcutaneous formulations are included. Other biosimilars may require step therapy through a preferred product first.

Blue Shield of California (Medicare)

Blue Shield of California Medicare (PPO) uses Yesintek as the preferred step drug for ustekinumab products. Members newly initiating Wezlana, Stelara, Otulfi, Selarsdi, Steqeyma, Pyzchiva, Starjemza, or Imuldosa must try Yesintek first. Requests for non-preferred products require documentation of intolerable side effects or contraindication with Yesintek.

CarelonRx

CarelonRx's medical drug clinical criteria cover all nine ustekinumab products (Stelara, unbranded ustekinumab, Selarsdi, Imuldosa, Pyzchiva, Otulfi, Steqeyma, Wezlana, Yesintek). HCPCS coding has been established for each product. Prior authorization criteria are aligned across all products with indication-specific requirements.

Pricing and formulary dynamics

The Stelara biosimilar market shows a faster progression to reference-product exclusion than Humira. Key differences:

• Time to formulary exclusion: Major PBMs excluded Stelara within 12–18 months of first biosimilar launch, compared to 15–20 months for Humira.
• Private-label products: All three major PBMs have introduced private-label ustekinumab products (Quallent for Express Scripts, Cordavis for CVS, Nuvaila for Optum Rx), replicating the Humira playbook.
• Price competition: The Stelara biosimilar market features the steepest discounting seen in any US biosimilar launch. WAC pricing as of early 2026:

Yesintek carries the deepest discount at approximately 90% below Stelara's WAC. This has made it the preferred product on multiple major formularies.

Drug Channels' analysis of the January 2026 formulary status showed that the Stelara market had 12 biosimilars plus the unbranded biologic from J&J, with WAC list prices spanning a range comparable to the Humira market.

Pharmacy substitution and switching

State law

All eight interchangeable biosimilars may be substituted for Stelara at the pharmacy level in states that permit automatic substitution. Prescribers can prevent substitution by writing "dispense as written" or "brand medically necessary." State requirements for prescriber notification and patient consent vary.

Medical benefit versus pharmacy benefit

Stelara is used in both subcutaneous (self-injected, pharmacy benefit) and intravenous (infused, medical benefit) settings:

• Subcutaneous: PBM formulary changes drive switching. When a plan excludes Stelara, the specialty pharmacy contacts the prescriber for a new prescription for a covered biosimilar.
• Intravenous: Hospital and infusion-center formularies may prefer specific biosimilars. Buy-and-bill reimbursement and 340B pricing can create different incentives compared to the pharmacy benefit channel.

Patient transition process

When a payer excludes Stelara, the transition follows a similar pattern to Humira:

1. Patient receives a letter 30–60 days before the formulary change.
2. Specialty pharmacy or payer contacts the prescriber for a new prescription.
3. Prior authorization for the biosimilar is submitted. Many payers auto-approve transitions for patients with an active Stelara PA.
4. Patient begins therapy with the new product.

Horizon BCBSNJ, for example, entered prior authorizations for all impacted members before the July 1, 2025, transition date, so prescribers did not need to initiate new PA requests until the existing authorization expired.

Practical implications for prescribers

When a patient is switched to a biosimilar

• The biosimilar will have the same route, frequency, and dosing as Stelara.
• For subcutaneous use, the device type (prefilled syringe versus auto-injector) may differ from what the patient is accustomed to. Patient education on the new device is recommended.
• Monitor for injection-site reactions during the first few doses, even though clinical trials showed no clinically meaningful differences in safety.

When a patient needs to stay on Stelara

If a prescriber determines that a patient must remain on branded Stelara (e.g., due to documented adverse reaction to a biosimilar), they should:

1. Contact the patient's plan to request a formulary exception.
2. Provide clinical documentation supporting medical necessity for the branded product.
3. Be prepared for the plan to require step therapy through a biosimilar first.

Record-keeping

Document the specific ustekinumab product (brand or biosimilar, including nonproprietary name and suffix) in the patient's medical record. This is important for tracking immunogenicity, lot numbers, and any future product-specific safety signals.

What to monitor

1. CVS Caremark July 2026 formulary change: The transition from Stelara to preferred biosimilars (Pyzchiva and Yesintek) will be one of the largest payer-driven biosimilar switches in 2026. Watch for implementation issues and member disruption data.
2. Additional biosimilar entrants: The ustekinumab market may see more products. Monitor the FDA Purple Book for new approvals.
3. Private-label pricing scrutiny: Congressional and regulatory attention to PBM-affiliated private-label biosimilars may affect formulary dynamics.
4. IRA negotiated price: Stelara was selected for IRA Medicare price negotiation. The maximum fair price (MFP) takes effect in 2026 and may interact with biosimilar pricing in ways that affect Part D formulary decisions.
5. Hospital and 340B channel dynamics: The medical benefit channel may retain different incentives than the pharmacy benefit channel, creating split utilization patterns.
6. Starjemza and newer entrant market uptake: Starjemza (Bio-Thera/Hikma) was the most recent approval as of May 2026. Monitor its formulary placement and adoption trajectory.

Sources

• FDA. Biosimilar Product Information. Updated May 2026. https://www.fda.gov/drugs/biosimilars/biosimilar-product-information
• FDA. Purple Book: Database of Licensed Biological Products. https://purplebooksearch.fda.gov/
• Drugs.com. What are the biosimilars for Stelara? Updated February 2026.
• Aetna. Ustekinumab — Medical Clinical Policy Bulletin 0912. Updated 2026.
• CVS Health. CVS Caremark Expands Biosimilar Adoption Through Formulary Updates. Press release. May 5, 2026.
• Drug Channels. The Stelara Biosimilar Price War: How PBM-Affiliated Private Labels Are Reshaping the Market. July 2025.
• Drug Channels. The Big Three PBMs' 2026 Formulary Exclusions. January 2026.
• Optum Business. Provider Biosimilars eToolkit. July 1, 2025.
• Horizon Blue Cross Blue Shield of New Jersey. Effective July 1, 2025: New biosimilars to replace Humira and Stelara.
• Health Alliance. Flash: Stelara will be a nonformulary medication effective 4/1/25.
• Pearce IP BioBlast. Ustekinumab Biosimilar Updates. May 5, 2026.
• PSG. 2026 Formulary Changes: CVS Caremark.
• Oliver Wyman. Part D Formularies Enter a New Era in 2026. February 2026.
• Gabionline. Biosimilars approved in the US. Updated January 27, 2026.
• Cencora. STELARA Biosimilar Landscape Overview. Accessed May 2026.
• Managed Healthcare Executive. Stelara Biosimilar Yesintek Gains Coverage on Leading Formularies. May 6, 2025.
• CarelonRx. Medical Drug Clinical Criteria: Ustekinumab Agents. CC-0063. Revised June 2025.
• Gabionline. Stelara biosimilars enter US market with 85% discount in 2025. March 2025.