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Imuldosa
Generic name: ustekinumab-srlf
What is Imuldosa?
Imuldosa (ustekinumab-srlf) is an injectable prescription medicine that is a biosimilar to Stelara, 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 in October 2024 as a biosimilar to Stelara. 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.
Imuldosa is a biosimilar but is not interchangeable with Stelara.
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.
Note that Imuldosa is not approved for some indications that Stelara is approved for (such as children with Crohn's disease), because of marketing exclusivity for Stelara.
It is not known if Imuldosa is safe and effective in children less than 18 years of age with ulcerative colitis or in children less than 6 years of age with plaque psoriasis or psoriatic arthritis.
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. Imuldosa should look clear to slightly opalescent and colorless to slightly yellow. Do not use it if it is discolored or cloudy, or if it 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 dose is given as an injection under the skin (subcutaneous injection) 8 weeks after the infusion, then every 8 weeks after that.
- 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, it is recommended that Imuldosa is 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, because the dose is based on your weight at the time of dosing.
- 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.
- If you receive two 45 mg prefilled syringes for a 90 mg dose, you will need to give two injections, one right after the other, using a different site for the second injection.
- Do not shake the syringe.
- Use a needle and syringe only once and then place them in an FDA-cleared sharps disposal 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.
Before taking this medicine
You should not use Imuldosa if you are allergic to ustekinumab products, or to any of the inactive ingredients in Imuldosa. Ask your doctor if you are not sure.
Before you start treatment with this injection, your doctor should evaluate you for tuberculosis. Imuldosa should not be given to people with active tuberculosis, and treatment for latent tuberculosis should be started before Imuldosa is given.
- Tell your doctor if you have ever had tuberculosis, or if you have been in close contact with someone with tuberculosis.
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, sweats or chills, muscle aches, cough, shortness of breath, blood in phlegm, weight loss, warm, red or painful skin or sores, diarrhea or stomach pain, burning 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 ever had an allergic reaction to an ustekinumab product
- have new or changing skin lesions within psoriasis areas or on normal skin
- have ever had any type of cancer
- 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. You should avoid receiving the BCG vaccine during the one year before receiving Imuldosa or one year after you stop receiving Imuldosa
- are pregnant or plan to become pregnant
- are breastfeeding or plan to breastfeed.
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, and you and your doctor should decide together whether you will receive Imuldosa.
Data from a pregnancy registry, published studies, and safety reporting have not identified a link between ustekinumab and major birth defects, miscarriage, or other harmful effects on the mother or baby. Inflammatory bowel disease itself carries risks in pregnancy, and more active disease has been linked with preterm delivery, low birth weight, and babies that are small for their gestational age.
Antibodies like ustekinumab cross the placenta, particularly in the third trimester, so a baby may be exposed to the medicine before birth. Talk to your doctor and your baby's healthcare provider about what this may mean for your baby.
Breastfeeding
Limited data suggest that ustekinumab is present in human breast milk. There are no data on the effects on milk production, and the effects on a breastfed infant are unknown. Talk to your doctor about the benefits of breastfeeding alongside your need for Imuldosa and any possible effects on your baby.
Imuldosa side effects
The most common Imuldosa side effects are:
- nasal congestion, sore throat, and runny nose
- upper respiratory tract infections
- fever
- headache
- tiredness
- itching
- nausea and vomiting
- influenza
- redness at the injection site
- vaginal yeast infections
- urinary tract infections
- sinus infection
- bronchitis
- diarrhea
- stomach pain
- joint pain.
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 with Imuldosa.
- 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, sweats or chills, muscle aches, cough, shortness of breath, blood in phlegm, weight loss, warm, red or painful skin or sores on your body, diarrhea or stomach pain, burning when you urinate or urinating more often than normal, or feeling very tired. These may be signs of infections such as chest infections, or skin infections or shingles, that could have serious complications.
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. People who take Imuldosa may also be more likely to get these infections.
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. Your doctor may monitor you more closely if you are over 60 years of age, have taken medicines that suppress the immune system for a long time, or have had PUVA treatment.
Serious allergic reactions
Serious allergic reactions, including anaphylaxis and angioedema (swelling under the skin), have been reported with ustekinumab products both in clinical trials and after these medicines were approved. Serious allergic reactions can cause death. One death has been reported in a person who developed chest tightness and shortness of breath during their first infusion.
Some serious allergic reactions have happened during the first intravenous dose, which is given in a healthcare setting where staff can treat a reaction straight away. In the Crohn's disease trials two people had reactions, one after a subcutaneous injection and one after the first intravenous dose. Both were treated with antihistamines or corticosteroids, and their symptoms settled within an hour.
Stop using Imuldosa and get medical help right away if you have any symptoms of a serious allergic reaction, such as:
- feeling faint or light-headed
- swelling of your face, eyelids, lips, tongue, or throat
- chest discomfort or tightness
- trouble breathing or shortness of breath
- hives, a skin rash, or flushing.
Do not take another dose of Imuldosa unless your doctor tells you it is safe to do so.
Posterior Reversible Encephalopathy Syndrome (PRES)
Imuldosa may cause a rare but serious condition affecting the brain called PRES, which can cause death. PRES has been reported a few days to several months after starting an ustekinumab product, and in a few cases a year or longer afterwards. People recovered with supportive care once the medicine was stopped. Tell your doctor right away if you have a headache, confusion, vision problems, or a seizure.
Lung inflammation
Cases of lung inflammation, including interstitial pneumonia, eosinophilic pneumonia, and cryptogenic organizing pneumonia, have happened in some people who receive ustekinumab products such as Imuldosa, and may be serious. These have been reported after one to three doses and have sometimes led to respiratory failure and prolonged hospitalization. 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.
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 Accord BioPharma Inc. at 1-866-941-7875.
Imuldosa dosing information
Your healthcare provider will work out the right dose for you based on your condition and, where relevant, your weight at the time of dosing.
Imuldosa dosage for plaque psoriasis
Adults:
- 100 kg or less: 45 mg
- More than 100 kg: 90 mg.
Children 6 years and older:
- 60 kg to 100 kg: 45 mg
- More than 100 kg: 90 mg.
For both adults and children, Imuldosa is given as a subcutaneous injection initially and 4 weeks later, then every 12 weeks.
Imuldosa dosage for psoriatic arthritis
Adults:
- 45 mg, regardless of weight
- 90 mg for people who also have moderate to severe plaque psoriasis and weigh more than 100 kg.
Children 6 years and older:
- 60 kg or more: 45 mg
- More than 100 kg with co-existing moderate to severe plaque psoriasis: 90 mg.
For both adults and children, Imuldosa is given as a subcutaneous injection initially and 4 weeks later, then every 12 weeks.
Imuldosa is not available in a form that allows weight-based dosing for children who weigh less than 60 kg.
Imuldosa dosage for Crohn's disease and ulcerative colitis
Adults receive a single intravenous infusion first, based on weight:
- 55 kg or less: 260 mg
- More than 55 kg to 85 kg: 390 mg
- More than 85 kg: 520 mg.
A 90 mg subcutaneous injection is then given 8 weeks after the initial intravenous dose, and every 8 weeks after that.
Imuldosa is available as
Subcutaneous injection:
- Imuldosa 45 mg/0.5 mL single-dose prefilled syringe
- Imuldosa 90 mg/mL single-dose prefilled syringe.
Intravenous infusion:
- Imuldosa 130 mg/26 mL (5 mg/mL) solution in a single-dose vial.
Unlike some other ustekinumab biosimilars, Imuldosa is not available as a subcutaneous vial or as an autoinjector.
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.
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:
- medicines with a narrow safety margin that are broken down by CYP450 liver enzymes, such as warfarin (Coumadin, Jantoven) and cyclosporine (Gengraf, Neoral, Sandimmune). Blocking IL-12 and IL-23 can change how quickly the liver clears these medicines, so your doctor may check your levels or response and adjust your dose when Imuldosa is started or stopped
- allergen immunotherapy (allergy shots). Imuldosa may reduce how well allergy shots work and may increase the risk of an allergic reaction to them, so caution is advised, particularly where there is a risk of anaphylaxis.
In psoriasis studies, ustekinumab has not been evaluated in combination with medicines that suppress the immune system or with phototherapy. In studies in psoriatic arthritis, Crohn's disease, and ulcerative colitis, taking methotrexate, azathioprine, 6-mercaptopurine, or oral corticosteroids alongside ustekinumab did not appear to change how safe or effective it was.
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
Store Imuldosa vials and prefilled syringes in a refrigerator between 36°F to 46°F (2°C to 8°C). Store vials standing up straight. Keep the medicine in the original carton to protect it from light until time to use it. Do not freeze. Do not shake.
If needed, individual Imuldosa prefilled syringes may also be stored at room temperature up to 86°F (30°C) for a maximum single period of up to 30 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, do not return it to the refrigerator.
- Throw away the syringe if it is not used within 30 days at room temperature.
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 monohydrochloride monohydrate, polysorbate 80, and sucrose.
Single-dose vial for intravenous infusion: edetate disodium, histidine, histidine monohydrochloride monohydrate, methionine, polysorbate 80, and sucrose.
The needle cover on the prefilled syringe does not contain latex.
Imuldosa is manufactured by Accord BioPharma Inc., 8041 Arco Corporate Drive, Suite 200, Raleigh, North Carolina 27617. It was developed by Dong-A ST with Meiji Seika Pharma, and is commercialized in the US by Accord BioPharma.
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 (ustekinumab) - Janssen Biotech, Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
| Single-Dose Vial | 90 mg/mL Discontinued |
View Stelara information in detail.
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.
Imuldosa (ustekinumab-srlf) - Accord BioPharma Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
Otulfi (ustekinumab-aauz) - Fresenius Kabi USA, LLC
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Otulfi information in detail.
Pyzchiva (ustekinumab-ttwe) - Samsung Bioepis Co., Ltd.
| Formulation type | Strength |
|---|---|
| Autoinjector | 45 mg/0.5 mL |
| Autoinjector | 90 mg/mL |
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Pyzchiva information in detail.
Selarsdi (ustekinumab-aekn) - Alvotech USA Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Selarsdi information in detail.
Starjemza (ustekinumab-hmny) - Bio-Thera Solutions, Ltd.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Starjemza information in detail.
Steqeyma (ustekinumab-stba) - CELLTRION, Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Steqeyma information in detail.
Wezlana (ustekinumab-auub) - Amgen Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Wezlana information in detail.
Yesintek (ustekinumab-kfce) - Biocon Biologics Inc.
| Formulation type | Strength |
|---|---|
| Pre-Filled Syringe | 45 mg/0.5 mL |
| Pre-Filled Syringe | 90 mg/mL |
| Single-Dose Vial | 130 mg/26 mL (5 mg/mL) |
| Single-Dose Vial | 45 mg/0.5 mL |
View Yesintek information in detail.
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
Wezlana (ustekinumab-auub) - Amgen Inc.
| Formulation type | Strength |
|---|---|
| Autoinjector | 45 mg/0.5 mL |
| Autoinjector | 90 mg/mL |
View Wezlana information in detail.
Yesintek (ustekinumab-kfce) - Biocon Biologics Inc.
| Formulation type | Strength |
|---|---|
| Autoinjector | 45 mg/0.5 mL |
| Autoinjector | 90 mg/mL |
View Yesintek information in detail.
Common questions about Imuldosa
Biosimilars vs Biologics: What are they and how do they compare?
How long can you keep Stelara in or out of the fridge?
How quickly or how long before Stelara starts to work?
Can you get a flu shot or take antibiotics while on Stelara?
What blood tests are needed for Stelara?
How is Stelara injected or administered?
Do I qualify for the Stelara copay card & how can I save?
Related medicines
Content is provided for education and is not medical advice. See our medical disclaimer. Source page medically reviewed by Carmen Pope, Senior Medical Editor, B. Pharm on October 15, 2026.