Ilumetri (Tildrakizumab)

What Is Ilumetri and What Is It Used For?

Ilumetri (tildrakizumab) is a biologic medicine belonging to the interleukin inhibitor class. It is used to treat moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. It works by selectively blocking interleukin-23 (IL-23), a cytokine central to the inflammatory process driving psoriasis.

Tildrakizumab is a humanized IgG1/kappa monoclonal antibody that targets the p19 subunit of interleukin-23 (IL-23). IL-23 is a naturally occurring cytokine that plays a critical role in regulating inflammatory and immune responses. In plaque psoriasis, IL-23 is produced in excess, driving the activation and proliferation of T-helper 17 (Th17) cells, which release pro-inflammatory cytokines such as IL-17 and IL-22. These cytokines promote the rapid turnover of skin cells characteristic of psoriatic plaques.

By selectively binding to the p19 subunit of IL-23, tildrakizumab prevents IL-23 from interacting with its receptor on the surface of immune cells. This interrupts the downstream inflammatory signalling cascade without broadly suppressing the entire immune system. This targeted approach distinguishes IL-23 inhibitors like tildrakizumab from older biologics that block broader cytokine pathways, potentially offering a more favourable balance between efficacy and safety.

Ilumetri was first authorised in the European Union in September 2018 based on two pivotal phase III clinical trials — reSURFACE 1 and reSURFACE 2 — that demonstrated significant improvements in psoriasis severity scores compared to placebo and the active comparator etanercept. In the United States, tildrakizumab is marketed under the brand name Ilumya. Both formulations contain the same active substance and have comparable clinical evidence supporting their use.

The use of Ilumetri leads to improvement of skin healing and reduction of symptoms such as scaling, redness, thickness, itching, and pain associated with psoriatic plaques. Clinical data indicate that the majority of patients achieve significant skin clearance within the first 12 to 28 weeks of treatment, with sustained response during long-term maintenance therapy.

What Should You Know Before Taking Ilumetri?

Before starting Ilumetri, your doctor will screen you for active infections including tuberculosis. You must not use Ilumetri if you are allergic to tildrakizumab or have a clinically significant active infection. Discuss all current medications, vaccination plans, and pregnancy considerations with your healthcare provider.

Contraindications

You must not use Ilumetri in the following circumstances:

• Hypersensitivity: If you are allergic to tildrakizumab or any of the other ingredients in this medicine, including L-histidine, L-histidine hydrochloride monohydrate, polysorbate 80 (E 433), sucrose, and water for injections
• Active infections: If you have a clinically significant active infection that your doctor considers important, such as active tuberculosis (TB), which is an infectious disease primarily affecting the lungs

Before initiating treatment, your doctor will evaluate you for tuberculosis. Screening typically involves a tuberculin skin test or interferon-gamma release assay (IGRA) blood test. If latent TB is identified, treatment for TB should be started before commencing Ilumetri. This precaution is necessary because biologic therapies that modulate immune function can potentially reactivate latent infections.

Warnings and Precautions

Talk to your doctor, pharmacist, or nurse before using Ilumetri if any of the following apply to you:

• You experience allergic reactions with symptoms such as chest tightness, wheezing, or swelling of the face, lips, or throat — do not inject more Ilumetri and contact your doctor immediately
• You currently have an infection or have long-term or recurrent infections
• You have recently received or plan to receive a vaccination

It is important that each time you receive a new pack of Ilumetri, you record the date and the batch number (found on the packaging after “Lot”) and store this information in a safe place. This helps with traceability and reporting of any adverse events.

Use in Children and Adolescents

Ilumetri is not recommended for use in children and adolescents under 18 years of age. This is because the medicine has not yet been studied in this age group. Clinical trials to date have enrolled only adult patients, and the safety and efficacy profile in paediatric populations has not been established. If psoriasis treatment is needed for a child or teenager, other therapeutic options should be discussed with a paediatric dermatologist.

Drug Interactions

Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines. This is particularly important for:

• Live vaccines: You should not receive live vaccines while using Ilumetri. There is no clinical experience with the concurrent use of Ilumetri and live vaccines. Live vaccines include measles-mumps-rubella (MMR), varicella (chickenpox), oral polio, yellow fever, and BCG vaccines
• Immunosuppressive medicines: Medicines that affect the immune system (such as ciclosporin, methotrexate, or other biologics) have not been formally studied in combination with Ilumetri. Use caution and discuss the risks and benefits with your doctor
• Inactivated vaccines: Inactivated vaccines (such as influenza, COVID-19 mRNA vaccines, and pneumococcal vaccines) can generally be given during Ilumetri treatment, although immune response may be somewhat reduced

No formal drug-drug interaction studies have been conducted with tildrakizumab. Based on its mechanism of action (a monoclonal antibody cleared by intracellular catabolism), tildrakizumab is not expected to be metabolised by hepatic cytochrome P450 enzymes and is therefore unlikely to interact with medicines metabolised through these pathways.

Pregnancy and Breastfeeding

Ilumetri should preferably be avoided during pregnancy. The effects of this medicine on pregnant women are not known. Animal reproductive toxicity studies with tildrakizumab have not revealed any direct or indirect harmful effects with respect to pregnancy, embryonic/foetal development, parturition, or postnatal development; however, animal studies are not always predictive of human response.

Women of childbearing potential should use effective contraception during treatment and for at least 17 weeks after the last dose of Ilumetri. This 17-week period is based on the estimated elimination half-life of tildrakizumab (approximately 23 days) multiplied by five half-lives, ensuring the medicine has been substantially cleared from the body.

It is not known whether tildrakizumab is excreted in human breast milk. As immunoglobulins can pass into breast milk, a risk to the breastfed infant cannot be excluded. A decision must be made whether to discontinue breastfeeding or to discontinue Ilumetri therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman. Discuss this with your doctor before starting treatment.

Driving and Using Machines

Ilumetri has no or negligible influence on the ability to drive and use machines. You can continue to drive and operate machinery while on treatment with Ilumetri.

How Does Ilumetri Interact with Other Drugs?

Ilumetri has a relatively low potential for drug-drug interactions because it is a monoclonal antibody cleared by intracellular catabolism rather than hepatic metabolism. The most important interaction is with live vaccines, which must be avoided during treatment. Caution is advised when combining with other immunosuppressants.

Since tildrakizumab is a humanized monoclonal antibody, it is degraded by proteolytic enzymes distributed throughout the body rather than being metabolised by liver enzymes. This significantly reduces the potential for pharmacokinetic interactions with small-molecule drugs. However, pharmacodynamic interactions — where two medicines affect the same biological pathway — remain a consideration when combining Ilumetri with other immunomodulatory therapies.

If you are planning surgery, including dental surgery, inform your surgical team that you are receiving Ilumetri. While there is no formal guidance requiring treatment interruption before surgery, your doctors may consider the potential for altered immune function when planning the procedure and post-operative care.

What Is the Correct Dosage of Ilumetri?

The recommended dose of Ilumetri is 100 mg by subcutaneous injection at week 0, week 4, and then every 12 weeks. Patients with severe disease or body weight over 90 kg may benefit from a 200 mg dose. Ilumetri is intended for use under the guidance of a physician experienced in diagnosing and treating psoriasis.

Always use this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure. This medicine is for single use only and should be discarded after use.

Adult Dosage

Your doctor will decide how long you need to use Ilumetri. After proper training in subcutaneous injection technique, you may inject Ilumetri yourself if your doctor decides it is appropriate. Talk to your doctor about when you should receive your injections and when to schedule follow-up appointments. Response to treatment is typically assessed at week 28, and your doctor will review whether to continue therapy based on your clinical response.

Children and Adolescents

The safety and efficacy of Ilumetri in children and adolescents under 18 years of age have not been established. Therefore, Ilumetri is not recommended for use in this age group. Paediatric-specific dosing guidelines are not available, and off-label use in children should only be considered by specialist dermatologists in exceptional circumstances.

Missed Dose

If you have forgotten or missed an injection of Ilumetri, take the dose as soon as possible. Then continue taking your doses at the regularly scheduled intervals from the date of the missed dose. Do not inject a double dose to make up for a forgotten dose. If you are uncertain about when to take your next dose, contact your doctor, pharmacist, or nurse for guidance.

Overdose

If you have injected more Ilumetri than prescribed, or if you have taken the dose earlier than your doctor instructed, tell your doctor immediately. In clinical trials, single doses up to 10 mg/kg intravenously have been administered without dose-limiting toxicity. In the event of overdose, the patient should be monitored for signs or symptoms of adverse reactions and appropriate symptomatic treatment should be initiated immediately.

Stopping Treatment

The decision to stop using Ilumetri should be discussed with your doctor. Do not stop treatment without medical advice. Your psoriasis symptoms may return if you stop using the medicine. Psoriasis is a chronic condition, and long-term treatment is often necessary to maintain skin clearance. Some patients may experience a disease flare after discontinuation that can be more severe than their pre-treatment baseline, although rebound is considered uncommon with IL-23 inhibitors compared to some other biologic classes.

How Do You Self-Inject Ilumetri?

Ilumetri is supplied in a pre-filled pen designed for subcutaneous self-injection. After proper training from a healthcare professional, you can inject the medicine at home. Always allow the pen to reach room temperature for 30 minutes before injection and follow the step-by-step instructions carefully.

Preparation

Before each injection, take the following steps:

1. Remove one pre-filled pen from the refrigerator and allow it to reach room temperature for at least 30 minutes. Do not shake the pen or warm it by any other means (microwave, hot water, or direct sunlight)
2. Gather your supplies: alcohol swab, cotton ball or gauze pad, adhesive bandage, and a sharps disposal container
3. Check the pen: ensure the expiry date has not passed and inspect the solution through the dose window — the liquid should be clear to slightly opalescent and colourless to slightly yellow. It is normal to see one or more air bubbles
4. Wash your hands thoroughly with soap and water

Choosing an Injection Site

Recommended injection sites include:

• Front of the thighs
• Abdomen (excluding the area within 5 cm of the navel)
• Back of the upper arms (if someone else is administering the injection)

Rotate injection sites between each administration. Do not inject into skin that is tender, abnormally red, bruised, hardened, or affected by psoriasis. Clean the chosen site with an alcohol swab and allow it to air-dry before injecting.

Performing the Injection

1. Remove the grey needle shield by pulling it straight off. You may need to pull firmly. Do not touch the yellow safety guard
2. Pinch the skin at the injection site. Hold the pen with the dose window facing you and place it at a 90-degree angle to the skin with the yellow safety guard flat against the surface
3. Press the pen firmly against the skin. A first click sound indicates the injection has started
4. Continue holding the pen against the skin. A second click sound indicates the injection is nearly complete. Hold the pen in place for a total of 15 seconds after the first click to ensure the full dose is delivered
5. Check the dose window — it should be completely yellow, confirming the full dose has been injected
6. Lift the pen straight up from the skin. The safety guard will automatically cover the needle

What Are the Side Effects of Ilumetri?

Like all medicines, Ilumetri can cause side effects, although not everybody gets them. The most common side effect is upper respiratory tract infections. Serious allergic reactions are possible but rare. Most side effects reported in clinical trials were mild to moderate in severity.

The safety of tildrakizumab has been evaluated in multiple clinical trials involving over 1,800 patients with moderate-to-severe plaque psoriasis. The overall safety profile of Ilumetri is considered favourable, with most adverse events being mild to moderate in intensity. Below is a summary of reported side effects organised by frequency.

Long-term extension studies with tildrakizumab, following patients for up to five years, have not identified new safety signals. The incidence of serious infections, malignancies, and major adverse cardiovascular events (MACE) has remained low and comparable to rates observed in the general psoriasis population. This supports the long-term safety profile of tildrakizumab for chronic use.

If you experience any side effects, including any not listed above, talk to your doctor or pharmacist. You can also report side effects directly to your national medicines regulatory authority. By reporting side effects, you can help provide more information on the safety of this medicine.

How Should You Store Ilumetri?

Ilumetri must be stored in the refrigerator at 2–8°C in its original packaging to protect from light. It must not be frozen or shaken. Once removed from the refrigerator, it can be used within 30 days if kept at room temperature (up to 25°C), but it must not be returned to the fridge.

Proper storage of biologic medicines is essential to maintain their efficacy and safety. Tildrakizumab is a protein-based medicine that can be damaged by temperature extremes, light exposure, or physical agitation. Follow these storage instructions carefully:

• Keep the medicine out of the sight and reach of children
• Do not use after the expiry date printed on the carton and pen label after “EXP”. The expiry date refers to the last day of that month
• Store in the original packaging to protect from light
• Store in a refrigerator at 2°C to 8°C. Do not freeze
• Do not shake the pen

Room Temperature Storage

When you take a pre-filled pen out of the refrigerator for use, allow approximately 30 minutes for the solution to reach room temperature (up to 25°C) before injecting. Do not warm the pen by any other method. Once removed from the refrigerator:

• The pen must not be stored above 25°C
• The pen must not be placed back in the refrigerator
• Record the date the pen was removed from the fridge in the space provided on the outer carton
• Use the pen within 30 days of removing it from the refrigerator, or by the expiry date, whichever comes first

When Not to Use

Do not use the medicine if:

• The liquid contains visible particles
• The solution is cloudy
• The solution is clearly brown in colour
• The grey needle shield has been removed or is damaged
• The yellow plunger is visible in the dose window before use

Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.

What Does Ilumetri Contain?

Each pre-filled pen of Ilumetri contains 100 mg of tildrakizumab as the active substance. The other ingredients include L-histidine, L-histidine hydrochloride monohydrate, polysorbate 80 (E 433), sucrose, and water for injections.

Ilumetri 100 mg solution for injection in a pre-filled pen is a clear to slightly opalescent and colourless to slightly yellow solution. It is supplied in packs containing one pre-filled pen.

The marketing authorisation holder is Almirall, S.A., based in Barcelona, Spain. The medicine is manufactured by SUN Pharmaceuticals Industries (Europe) B.V. in Hoofddorp, Netherlands, and Industrias Farmaceuticas Almirall, S.A. in Sant Andreu de la Barca, Barcelona, Spain.

For additional information about Ilumetri, including the full Summary of Product Characteristics (SmPC) and European Public Assessment Report (EPAR), visit the European Medicines Agency website.