Pronunciation: im-ull-doze-a
Generic name: ustekinumab
Dosage form: subcutaneous injection single-dose prefilled syringe (45 mg/0.5 mL or 90 mg/mL), injection for intravenous infusion single-dose vial 130 mg/26 mL (5 mg/mL)
Drug class: Interleukin inhibitors

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 30, 2024.

What is Imuldosa?

Imuldosa (ustekinumab-srlf) is an injectable prescription medicine which is a biosimilar to Stelara that may be used to treat certain types of plaque psoriasis, active psoriatic arthritis, Crohn’s disease, and ulcerative colitis, which are all autoimmune conditions.

Imuldosa's mechanism of action involves blocking certain inflammatory proteins in your body, called IL-12 (interleukin-12) and IL-23 (interleukin-23). These proteins are known as cytokines and they are responsible for the inflammation associated with certain autoimmune conditions. By blocking their activity, Imuldosa reduces inflammation, pain, swelling, and skin symptoms.

Imuldosa gained FDA approval on June 28, 2024, as the fifth biosimilar to Stelara to be approved. A biosimilar is a biological product that is like the reference biologic (in this case Stelara) and for which there are no clinically meaningful differences in terms of safety, purity, and potency. Other biosimilars to Stelara include Wezlana (November, 2023), Selarsdi (April, 2024), Pyzchiva (July, 2024), and Otulfi (September, 2024). Imuldosa is expected to be available in early 2025.

Imuldosa uses

Imuldosa may be used to treat:

• Plaque psoriasis (moderate to severe) in adults and children aged 6 years and older who are candidates for phototherapy or systemic therapy
• Psoriatic arthritis (active) in adults and children aged 6 years and older
• Crohn’s disease (moderately to severely active) in adults 18 years and older
• Ulcerative colitis (moderately to severely active ) in adults 18 years and older.

Imuldosa side effects

The most common Imuldosa side effects are:

• fever, flu-like symptoms
• infections, such as those affecting the vagina, urinary tract, or lungs
• headache
• tiredness
• itching
• stomach pain, nausea, vomiting, diarrhea
• cough with mucus, shortness of breath, chest discomfort
• headache, tiredness
• redness at the injection site
• nasal congestion, sore throat, and runny nose.

Serious Imuldosa side effects and warnings

Imuldosa can cause the following serious side effects.

Serious infections. Imuldosa may lower the ability of your immune system to fight infections and may increase your risk of infections. Some people have serious infections while taking ustekinumab products, including tuberculosis (TB), and infections caused by bacteria, fungi, or viruses. Some people have to be hospitalized for treatment of their infection.

• Your doctor should check you for TB before starting Imuldosa.
• If your doctor feels that you are at risk for TB, you may be treated with medicine for TB before you begin treatment with Imuldosa and during treatment.
• Your doctor should watch you closely for signs and symptoms of TB while you are being treated with Imuldosa.

You should not start taking Imuldosa if you have any kind of infection unless your doctor says it is okay.

After starting Imuldosa, call your doctor right away if you have any symptoms of an infection such as fever, chills, muscle pain, shortness of breath, weight loss, diarrhea or stomach pain, burning when you urinate, feeling very tired, skin warmth or redness, painful skin sores, or coughing up blood. People who have a genetic problem where the body does not make any of the proteins interleukin 12 (IL-12) and interleukin 23 (IL-23) are at a higher risk for certain serious infections. These infections can spread throughout the body and cause death. 

Cancers. Imuldosa may decrease the activity of your immune system and increase your risk for certain types of
cancers. Tell your doctor if you have ever had any type of cancer. Some people who are receiving ustekinumab
products and have risk factors for skin cancer have developed certain types of skin cancers. During your treatment with Imuldosa, tell your doctor if you develop any new skin growths. 

Imuldosa may cause a rare but serious condition affecting the brain called Posterior Reversible Encephalopathy Syndrome (PRES). Tell your doctor right away if you have a headache, confusion, vision problems, or a seizure.

Imuldosa may decrease the activity of your immune system, and there may be an increase in your risk for certain types of cancers. Tell your doctor if you have ever had any type of cancer. Some people who are receiving this medicine and have risk factors for skin cancer have developed certain types of skin cancers. During your treatment with this medicine, tell your doctor if you develop any new skin growths.

Lung inflammation. Cases of lung inflammation have happened in some people who receive ustekinumab
products, such as Imuldosa, and may be serious. These lung problems may need to be treated in a hospital. Tell your doctor right away if you develop shortness of breath or a cough that doesn't go away during treatment with Imuldosa.

Serious allergic reactions. Serious allergic reactions can occur with Imuldosa. Stop using Imuldosa and get
medical help right away if you have any of the following symptoms of a serious allergic reaction such as hives; chest pain, difficulty breathing; feeling light-headed; or swelling of your face, lips, tongue, or throat.

Also, call your doctor at once if you have:

• a mole that has changed in size or color
• swelling, pain, warmth, or redness anywhere on your body
• stomach pain that is sudden and severe or comes on slowly, changes in bowel habits (diarrhea or constipation)
• new or worsening cough, sudden chest pain, feeling short of breath
• pain or burning when you urinate or
• severe headache, confusion, change in mental status, vision problems, and/or seizure (convulsions).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088 or to Sandoz Inc. at 1-800-525-8747. 

Related/similar drugs

Before taking this medicine

You should not use Imuldosa if you:

• are allergic to the active ingredient ustekinumab, Imuldosa, Stelara, or any of the inactive ingredients contained in Imuldosa.
• have received a BCG (Bacillus Calmette and Guérin) vaccine within 1 year before, during, or 1 year following treatment
• have active tuberculosis.

Before you start treatment with this injection, your doctor may perform tests to make sure you do not have tuberculosis.

• Tell your doctor if you have ever had tuberculosis, if anyone in your household has tuberculosis, or if you have recently traveled to an area where tuberculosis is common.

To make sure Imuldosa is safe for you, tell your healthcare provider about all your medical conditions, including if you:

• have signs of infection (fever, chills, cough, muscle aches, painful skin sores, diarrhea, pain when you urinate, feeling very tired)
• are being treated for an infection or have any open cuts
• get a lot of infections or have infections that keep coming back
• have new or changing skin lesions within psoriasis areas or on normal skin
• have a latex allergy as the needle cover on the prefilled syringe contains latex
• receive or have received phototherapy (light therapy) for psoriasis
• are receiving or have received allergy shots, especially for serious allergic reactions. Allergy shots may not work as well for you during treatment with Imuldosa. Imuldosa may also increase your risk of having an allergic reaction to an allergy shot
• recently received or are scheduled to receive any vaccine. People who take this medicine should not receive live vaccines. Tell your doctor if anyone in your house needs a live vaccine. The viruses used in some types of live vaccines can spread to people with a weakened immune system and can cause serious problems
• are pregnant or plan to become pregnant
• are breastfeeding.

Some people using this medicine have developed skin cancer (non-melanoma). However, these people may have had a higher risk of skin cancer. Talk to your doctor about this risk and what skin symptoms to watch for. You may need to have regular skin exams.

Pregnancy

It is not known whether Imuldosa will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. If you are pregnant, your name may be listed on a pregnancy registry to track the effects of ustekinumab on the baby.

If you did receive Imuldosa while you were pregnant you must tell your baby’s healthcare provider before any vaccinations are given to your baby.

Breastfeeding

It may not be safe to breastfeed while using this medicine. Imuldosa can pass into your breast milk in small amounts. Talk to your doctor about the best way to feed your baby if you receive this medicine.

How is Imuldosa administered?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.  Imuldosa is intended for use under the guidance and supervision of your doctor. Prepare your injection only when you are ready to give it. Do not use it if the medicine looks cloudy, has changed colors, or has particles in it. Call your pharmacist for new medicine.

• Crohn’s disease and ulcerative colitis: The first dose of Imuldosa is given through a vein in the arm (intravenous infusion) by your healthcare provider. It takes at least 1 hour to receive the infusion. Your next doses will be given as an injection under the skin (subcutaneous injection) every 8 weeks.
• Psoriasis or psoriatic arthritis: Imuldosa is given as an injection under the skin (subcutaneous injection) as described below.

How to administer subcutaneous Imuldosa

In children 6 years and older, Imuldosa should be administered by a healthcare provider.

If your doctor decides that you or a caregiver may give your injections at home, you should receive training on the right way to prepare and inject Imuldosa. 

• Your doctor will determine the right dose for you, the amount for each injection, and how often you should receive it. Your dose needs may change if you gain or lose weight.
• Do not try to inject yourself unless you or your caregiver have been shown how to use it by your doctor or nurse.
• Inject Imuldosa under the skin in your upper arms, buttocks, upper legs (thighs), or stomach area (abdomen). 
• Do not give an injection in an area of the skin that is tender, bruised, red, or hard. 
• Use a different injection site each time you use this medicine. 
• Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets. Throw away any unused portion of Imuldosa.
• Be sure to keep all of your scheduled follow-up appointments.

Imuldosa dosing information

The dosage of Imuldosa is dependent on the patient's weight. Your healthcare provider will calculate this for you.

• Adults less than or equal to 100 kg: Imuldosa 45 mg
• Adults more than 100 kg: Imuldosa 90 mg.

Crohn’s disease and ulcerative colitis: Imuldosa is given as an infusion for the first dose then as a subcutaneous injection every 8 weeks thereafter. 

Psoriasis and Psoriatic Arthritis: Imuldosa is given as a subcutaneous injection initially and 4 weeks later, then a dose is given every 12 weeks.

Imuldosa is available as:

Subcutaneous Injection

• Imuldosa 90 mg/mL single-dose prefilled syringe
• Imuldosa 45 mg/0.5 mL single-dose prefilled syringe.

Intravenous Infusion

• Imuldosa single-dose vial 130 mg/26 mL (5 mg/mL).

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Imuldosa?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Do not receive a "live" vaccine while using this medicine, and avoid coming into contact with anyone who has recently received a live vaccine. There is a chance that the virus could be passed on to you. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

You should not receive the BCG vaccine during the one year before receiving Imuldosa or one year after
you stop receiving Imuldosa.

Non-live vaccines (including flu shots) may not work as well during your treatment, and may not fully protect you from disease. Make sure you are current on all vaccines before you begin treatment with this medicine.

What other drugs will affect Imuldosa?

Other drugs may interact with Imuldosa, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

It is important to tell your doctor if you are taking any of the following: 

• anticoagulants (blood thinners) such as warfarin (Coumadin, Jantoven)
• medications that suppress the immune system such as azathioprine (Azasan, Imuran), cyclosporine (Gengraf, Neoral, Sandimmune), methotrexate (Otrexup, Rasuvo, Trexall, Xatmep), sirolimus (Rapamune), and tacrolimus (Astagraf, Envarsus, Prograf)
• oral steroids such as dexamethasone (Hemady), methylprednisolone (Medrol), and prednisone (Rayos). 

Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Not all possible interactions are listed here.

Storage

Imuldosa vials and prefilled syringes

Store vials and prefilled syringes in a refrigerator between 36°F to 46°F (2°C to 8°C) standing up straight. Do not freeze.

This medicine should be stored in the original carton to protect it from light until time to use it. Do not shake.

If needed, individual Imuldosa prefilled syringes may also be stored at room temperature up to 30°C (86ºF) for a maximum single period of up to 60 days in the original carton to protect from light. Record the date when the prefilled syringe is first removed from the refrigerator on the carton in the space provided.

Once a syringe has been stored at room temperature, you may return the prefilled syringe to the refrigerator 1 time only for a maximum of 3 days, either during the 60 days or at the end of the 60 days.

• Discard the prefilled syringe if not used within 60 days of room temperature storage and you did not return it to the refrigerator, or if it has been returned to the refrigerator and is not used within 3 days.

Do not use Imuldosa after the expiration date on the carton or on the prefilled syringe.

Imuldosa Ingredients

Active ingredient: ustekinumab-srlf 

Inactive ingredients 

Single-dose prefilled syringe for subcutaneous use: histidine, histidine hydrochloride monohydrate, polysorbate 80, and sucrose.

Single-dose vial for intravenous infusion: edetate disodium, histidine, histidine hydrochloride monohydrate, methionine, polysorbate 80, and sucrose. 

Available as:

• Subcutaneous injection: Imuldosa 45 mg/0.5 mL or 90 mg/mL solution in a single-dose prefilled
  syringe
• Intravenous infusion: Imuldosa 130 mg/26 mL (5 mg/mL) solution in a single-dose vial.

Who makes Imuldosa?

Dong-A ST and Meiji Seika Pharma make Imuldosa.

Imuldosa Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There is 1 for Imuldosa.

Stelara interchangeable products

Interchangeable biosimilar products can be dispensed by a pharmacist without the intervention of the prescriber of the reference product.

Pharmacy laws for biosimilar prescribing may vary by state.

Stelara biosimilar products

Biosimilar products can only be dispensed in place of the reference product if the healthcare provider specifically prescribes the biosimilar product by name.

Pharmacy laws for biosimilar prescribing may vary by state

Popular FAQ

More FAQ

• What are the new drugs for plaque psoriasis?
• What biosimilars have been approved in the United States?
• How quickly or how long before Stelara starts to work?

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer