Key takeaways

Stelara is a biologic medication used to treat autoimmune conditions like plaque psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn’s disease. It is administered either by injection under the skin or by infusion into a vein.
Biosimilars are medications that are highly similar to an existing FDA-approved biologic product (the reference product) with no clinically meaningful differences in terms of safety, efficacy, and potency. Interchangeable biosimilars can be substituted for the reference product under state pharmacy laws, while non-interchangeable biosimilars require a specific prescription for substitution.
Biosimilars to Stelara, including Wezlana, Selarsdi, and Pyzchiva, are expected to be available in early 2025. Wezlana and Pyzchiva are interchangeable biosimilars, while Selarsdi is not.
Stelara costs about $37,052 per syringe without insurance or discounts. A SingleCare coupon can lower the cost by about $15,000.

In this article:

What is a biosimilar?
Stelara biosimilar availability
Stelara vs. Wezlana: Is there a difference?
Stelara vs. Wezlana
How to switch from Stelara to Wezlana

In this article

What is a biosimilar?
Stelara biosimilar availability
Stelara vs. Wezlana: Is there a difference?
Stelara vs. Wezlana
How to switch from Stelara to Wezlana

Stelara (ustekinumab) is a prescription monoclonal antibody used for various autoimmune inflammatory conditions. It is approved by the Food and Drug Administration (FDA) to treat plaque psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis. It is administered by subcutaneous injection under the skin, or by intravenous infusion (infusion into a vein). Because Stelara is expensive without insurance, averaging $37,052 per syringe, you may want to know if there is a generic available that can help save money. But Stelara is a biologic product, meaning it will have what’s called a biosimilar instead of a generic version. There have been several biosimilars approved, including Wezlana, Selarsdi, and Pyzchiva, but they are not expected to be available until early 2025. Continue reading to learn more about Stelara and its biosimilars.

What is a biosimilar?

When talking about most prescription drugs or over-the-counter (OTC) drugs, we often talk in terms of brand and generic. For example, Lipitor is a brand-name drug used for cholesterol, and its active ingredient and generic is called atorvastatin.

Certain medicines, like Stelara, are known as biologics, or biological products. According to the FDA, biological products are complex medicines made from living cells, like those from plants or animals. As such, biologics are harder to describe and analyze compared to simpler drugs.

We don’t refer to Stelara as a brand-name drug; instead, we call it a reference product. Some reference products have biosimilars—similar to how some brand-name drugs have generics. A biosimilar is considered “highly similar to and has no clinically meaningful differences from an existing FDA-approved reference product.”

One difference between biosimilars and generics is that biosimilars cannot be substituted for reference products unless they’re classified as an interchangeable biosimilar. So, if a healthcare provider prescribes Stelara, the pharmacy cannot automatically substitute a biosimilar. However, a healthcare provider can specifically prescribe a biosimilar by name, if desired.

Interchangeable biosimilars meet additional requirements and can be substituted for the reference product. Therefore, if a drug is an interchangeable biosimilar, and a healthcare provider prescribes Stelara, for example, the pharmacy may automatically substitute an interchangeable biosimilar, subject to state pharmacy laws.

Stelara biosimilar availability

As of July 2024, several biosimilars have been approved by the FDA but are not expected to be available until late February 2025, due to settlements and licensing agreements with Janssen Biotech, the manufacturer of Stelara.

Wezlana (ustekinumab-auub) was FDA approved on Oct. 31, 2023, as an interchangeable biosimilar to Stelara. It is made by the pharmaceutical company Amgen, Inc.
In April of 2024, the FDA approved Selarsdi (ustekinumab-aekn), a Stelara biosimilar made by the pharmaceutical companies Alvotech and Teva Pharmaceuticals. It is not an interchangeable biosimilar.
In July of 2024, the FDA approved Pyzchiva (ustekinumab-ttwe) as an interchangeable biosimilar to Stelara. Pyzchiva is made by Samsung Bioepis.

Stelara vs. Wezlana: Is there a difference?

Stelara works by blocking certain proteins called cytokines that trigger inflammation, specifically interleukin-12 and interleukin-23, helping to calm an overactive immune system and reduce symptoms of autoimmune conditions. As an interchangeable biosimilar, Wezlana has the same therapeutic effect as Stelara, but may be more affordable. As biosimilars are defined, Wezlana is expected to be highly similar to Stelara. The table below compares Stelara vs. Wezlana. As you can see, Wezlana is highly similar to Stelara.

Stelara vs. Wezlana
	Stelara	Wezlana
Uses	Adults and pediatric patients 6 years and older with moderately to severely active psoriatic arthritis (alone or with methotrexate) Adults and pediatric patients 6 years and older with moderate to severe plaque psoriasis who are candidates for phototherapy or systemic therapy Adults with moderate to severe active Crohn’s disease Adults with moderate to severe active ulcerative colitis	Adults and pediatric patients 6 years and older with moderately to severely active psoriatic arthritis (alone or with methotrexate) Adults and pediatric patients 6 years and older with moderate to severe plaque psoriasis who are candidates for phototherapy or systemic therapy Adults with moderate to severe active Crohn’s disease Adults with moderate to severe active ulcerative colitis
Standard dosage	Varies by patient age, weight, and conditions	Varies by patient age, weight, and conditions
Common side effects	Common cold symptoms Sinus infection Bronchitis Headache Fever Tiredness Itching Nausea, vomiting, diarrhea, stomach pain Injection site redness Vaginal yeast infection Urinary tract infection	Common cold symptoms Sinus infection Bronchitis Headache Fever Tiredness Itching Nausea, vomiting, diarrhea, stomach pain Injection site redness Vaginal yeast infection Urinary tract infection
Contraindications	Allergies to ingredients Active infection	Allergies to ingredients Active infection
Other considerations	Read the medication guide that comes with your prescription and ask your healthcare provider if you have any questions Avoid live vaccines while using this medicine, including BCG vaccine Tell your healthcare provider about all medical conditions, including pregnancy or breastfeeding Also tell your healthcare provider about all the medicines you take, so they can screen for drug interactions May cause serious side effects including serious infections (some of which may require hospitalization), cancers (including certain types of skin cancer), and other serious conditions including posterior reversible encephalopathy syndrome If you have symptoms of a serious allergic reaction, such as hives, shortness of breath, or swelling, get emergency medical help You can report adverse effects to the FDA at 800-FDA-1088	Read the medication guide that comes with your prescription and ask your healthcare provider if you have any questions Avoid live vaccines while using this medicine, including BCG vaccine Tell your healthcare provider about all medical conditions, including pregnancy or breastfeeding Also tell your healthcare provider about all the medicines you take, so they can screen for drug interactions May cause serious side effects including serious infections (some of which may require hospitalization), cancers (including certain types of skin cancer), and other serious conditions including posterior reversible encephalopathy syndrome If you have symptoms of a serious allergic reaction, such as hives, shortness of breath, or swelling, get emergency medical help You can report adverse effects to the FDA at 800-FDA-1088
Cost	$37,052 for 1, 1mL syringe*	N/A

*Average price at the time of publication without insurance or discounts

How to switch from Stelara to Wezlana

If you’re considering switching from Stelara to a biosimilar such as Wezlana once available, talk to your healthcare provider about your options. If you obtain your prescription through a specialty pharmacy, you can reach out to the pharmacy in February 2025 for details on the availability of Stelara biosimilars and which specific biosimilars they will stock. Wezlana is anticipated to have the same therapeutic effects as Stelara, so switching to a biosimilar should be straightforward if your healthcare provider permits it.

If your prescription specifies that a substitution is allowed, the pharmacy can dispense an interchangeable biosimilar like Wezlana or Pyzchiva, in accordance with state laws. However, if you are considering a biosimilar that is not interchangeable, such as Selarsdi, your healthcare provider must specifically indicate this biosimilar on your prescription for it to be dispensed.

Stelara generic availability, cost, and more