Stelara Biosimilars Are Here: What Lower-Cost Alternatives Mean for Your Psoriasis Treatment

The first swappable biosimilars for Stelara (ustekinumab) hit the market in 2025. Major insurers have already changed their drug lists. WEZLANA (Amgen) was the first FDA-approved biosimilar that pharmacists can swap in. In many states, they can do this without your doctor’s approval. For patients, this could mean thousands of dollars saved each year on one of the most common psoriasis biologics.

If you take Stelara for your psoriasis, you may have gotten a letter from your insurer about drug list changes. Or your pharmacist may have mentioned a switch at your last refill.

These changes are happening across the country. While they’re driven by cost savings, they raise practical questions: Will the biosimilar work as well? Is it safe to switch? And what should you do if your insurer is making the decision for you?

Here’s what you need to know.

What Is a Biosimilar?

A biosimilar is a drug that’s very close to an existing biologic (called the reference product). It has no meaningful differences in how it works, its safety, or its results. Biosimilars go through strict FDA review. This includes clinical trials that compare them directly to the original drug. They’re not generic drugs in the traditional sense but serve a similar purpose: providing the same treatment at a lower cost.

Regular generic drugs are exact copies of brand-name drugs. A generic ibuprofen pill is the same as a brand-name one.

Biologics are different because they’re made from living cells, which makes them too complex to copy exactly. A biosimilar is as close to the original as possible. It has the same amino acid sequence but may have tiny differences in the sugar molecules on the protein.

Those tiny differences don’t affect how the drug works in your body. The FDA requires lab, animal, and human testing to confirm a biosimilar works the same as the original before approval.

The term “interchangeable” goes a step further. An interchangeable biosimilar has met extra FDA tests. These show that switching between it and the original drug doesn’t reduce how well it works or increase side effects. WEZLANA has this designation for Stelara.

What Biosimilars Are Available for Stelara?

WEZLANA (by Amgen) was the first swappable biosimilar for Stelara. The FDA approved it in October 2023, and it launched in early 2025. Several more Stelara biosimilars are at different stages of approval and market launch. All treat the same conditions as Stelara: plaque psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis.

WEZLANA is the furthest along in terms of market availability. Its “interchangeable” status means that in many states, your pharmacist can swap it for Stelara at the counter. They don’t need to call your doctor for a separate approval. The rules vary by state, so check with your pharmacist about local requirements.

Additional biosimilars from other manufacturers are following. The biosimilar market for Stelara should grow through 2025 and 2026. This follows the same pattern seen with Humira biosimilars starting in 2023.

How Much Could You Save?

Stelara’s wholesale acquisition cost is approximately $30,000 per 90 mg dose. With maintenance dosing every 12 weeks, that’s roughly $130,000 per year. Biosimilar pricing varies. Based on the Humira biosimilar example, discounts of 50% to 85% off wholesale price are possible. That could mean annual savings of $65,000 to $110,000, depending on your insurance plan.

The actual amount you save depends on several factors:

• Your insurance plan’s formulary: If your plan removes Stelara and adds the biosimilar as preferred, your copay may drop significantly
• Copay structure: Some biosimilars offer manufacturer copay cards that reduce out-of-pocket costs further
• Dosing: Stelara dosing for psoriasis is typically every 12 weeks after loading doses, so total annual costs depend on your specific dose and schedule

The broader savings are significant for the health system. One pharmacy benefit manager, Navitus, estimated $120 million in savings by replacing Stelara with biosimilars. Those large-scale savings can lead to lower premiums and out-of-pocket costs over time.

Will the Biosimilar Work as Well as Stelara?

Yes. Studies required for FDA approval of these biosimilars show no loss in how well they work. They also show no increase in side effects when patients switch from Stelara. The FDA’s interchangeable label requires data showing that switching does not hurt treatment results.

This is the question most patients ask first, and the evidence is clear. The FDA’s approval process for these biosimilars includes “switching studies.” In these studies, patients alternate between the biosimilar and original drug several times.

These studies must demonstrate that the switching itself doesn’t cause problems like increased immune reactions or reduced drug levels in the blood.

For WEZLANA specifically, the switching data showed no meaningful differences in:

• Skin clearance rates
• Drug levels in the blood
• Side effect rates
• Development of anti-drug antibodies

If you’ve been stable on Stelara, switching to its interchangeable biosimilar should not change your treatment outcomes. Your dermatologist can monitor your response as they normally would.

What If Your Insurer Is Switching Your Formulary?

You’ll typically get a letter 30-60 days before a formulary switch. Your pharmacist may handle the substitution automatically for interchangeable biosimilars, or your doctor may need to write a new prescription. Your copay could go down. If you have a medical reason to stay on brand Stelara, your doctor can file an exception request.

Major pharmacy benefit managers began dropping Stelara from preferred drug lists in mid-2025. They replaced it with biosimilars. If you’re affected, here’s what to expect:

1. You’ll get a letter. Your insurer or pharmacy benefit manager will notify you before making the switch, typically 30-60 days in advance.
2. Your doctor may need to write a new prescription. Depending on your state and insurance plan, your pharmacist may handle the switch automatically, or your doctor may need to update your prescription.
3. Your copay may change. It could go down (biosimilars are often on lower copay tiers) or stay the same. Ask your pharmacist or insurer for specifics.
4. You can request an exception. If you have a medical reason to stay on brand Stelara (such as a documented adverse reaction to a biosimilar), your doctor can file an exception request with your insurer.

The switch can feel unsettling, especially when it’s not your choice. But the clinical data supports that biosimilar switches are safe, and the potential cost savings are real.

What About Patient Assistance Programs?

Both Stelara and its biosimilars offer financial support. Janssen CarePath provides copay assistance for Stelara, and Amgen Assist covers WEZLANA. Other biosimilar makers also offer their own copay cards. Ask your skin doctor’s office to link you with a specialty pharmacy that has financial counselors.

Both Stelara and its biosimilars offer financial support programs:

• Stelara (Janssen CarePath): Copay assistance for eligible patients with commercial insurance
• WEZLANA (Amgen Assist): Patient assistance program for eligible patients
• Additional biosimilar manufacturers: Each typically offers their own copay cards and assistance programs

If cost is a barrier regardless of which version you’re taking, ask your dermatologist’s office to connect you with a specialty pharmacy that has financial counselors. Many biologic patients qualify for assistance they don’t know about.

Questions to Ask Your Doctor About the Switch

1. Do I need to do anything differently? For most patients, the answer is no. The dosing, injection technique, and monitoring schedule remain the same.
2. Should I expect any adjustment period? Switching studies haven’t shown a transition period where the drug works less well. You should maintain the same level of skin clearance.
3. What if my psoriasis flares after switching? Any flare after a switch should be evaluated the same way as a flare on the original medication. It may or may not be related to the switch.
4. Is the injection device the same? Biosimilars may come in slightly different prefilled syringes or self-injection devices. Ask your pharmacist to walk you through any differences.

The Bigger Picture: What Biosimilars Mean for Psoriasis Access

Stelara biosimilars are part of a larger trend that’s slowly making biologic psoriasis treatments easier to get. Humira biosimilars launched in 2023 with discounts up to 92% off wholesale price. Stelara biosimilars are following the same pattern.

For people with psoriasis who’ve been priced out of biologic therapy or faced repeated insurance denials, growing biosimilar competition may make it easier to get effective treatment. It won’t solve every access problem, but it shifts the economics in the right direction.

For people now on Stelara, the main point is simple: the same treatment you’ve been using is now sold at a lower cost under a different name. The science behind it is sound.

Frequently Asked Questions

Is a biosimilar the same drug as Stelara?

A biosimilar is highly similar to Stelara with no clinically meaningful differences in safety or effectiveness. It’s made from the same type of protein (ustekinumab) but by a different manufacturer.

Can my pharmacist switch me without my doctor’s approval?

If the biosimilar has an “interchangeable” designation (like WEZLANA), many states allow pharmacists to make the substitution without prescriber approval. Your pharmacist is typically required to notify your doctor about the switch.

Will I need new blood tests or monitoring after switching?

No additional testing is typically required beyond your standard monitoring schedule. Your dermatologist may want to check in after your first few doses on the biosimilar as a precaution.

Does the biosimilar treat the same conditions as Stelara?

Yes. Approved Stelara biosimilars carry the same FDA-approved indications: plaque psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis.

What if the biosimilar doesn’t work for me?

If you experience a change in your treatment response after switching, contact your dermatologist. You may be able to switch back to brand Stelara through a medical exception with your insurer, or your doctor may recommend a different treatment entirely.

Are biosimilars available for other psoriasis biologics?

Humira (adalimumab) biosimilars have been available since 2023. Biosimilars for other psoriasis biologics like Cosentyx and Skyrizi are further out in the pipeline. As biologic patents expire, more biosimilars will enter the market.

Sources

1. GoodRx. “Biosimilars for Humira, Stelara, and Remicade: Cost Savings.” GoodRx. 2025. https://www.goodrx.com/drugs/savings/biosimilars-humira-stelara-remicade-cost
2. Navitus Health Solutions. “Navitus to Remove Stelara from Formulary July 1, 2025.” Navitus. 2025. https://navitus.com/benefit-design-cost-management/formulary-benefit-design-cost-management/navitus-to-remove-stelara-from-formulary-july-1-2025/
3. Dermatology Advisor. “Biosimilars for Psoriasis.” Dermatology Advisor. 2025. https://www.dermatologyadvisor.com/features/biosimilars-for-psoriasis/
4. Navion RX. “The Biosimilar Shift: How New Options for Stelara and Humira Are Reshaping Specialty Care for Payers.” Navion RX. 2025. https://www.navionrx.com/the-biosimilar-shift-how-new-options-for-stelara-and-humira-are-reshaping-specialty-care-for-payers/