Saphnelo (Anifrolumab)
Monoclonal antibody for moderate to severe systemic lupus erythematosus (SLE)
Quick facts about Saphnelo
Key takeaways about Saphnelo
- First-in-class type I interferon blocker: Saphnelo targets the root cause of inflammation in many SLE patients by blocking the type I interferon receptor
- Add-on therapy only: Saphnelo is given alongside existing SLE treatments such as corticosteroids, immunosuppressants, and antimalarials — it does not replace them
- Self-injectable option: The 120 mg pre-filled pen allows weekly self-injection at home after training by a healthcare professional
- Infection risk increased: Treatment may increase susceptibility to infections, including upper respiratory infections and herpes zoster (shingles)
- No live vaccines during treatment: Live or attenuated live vaccines must not be administered while on Saphnelo
What Is Saphnelo and What Is It Used For?
Saphnelo (anifrolumab) is a monoclonal antibody used to treat moderate to severe systemic lupus erythematosus (SLE) in adults whose disease is not adequately controlled with standard therapies. It works by blocking the type I interferon receptor, reducing the immune overactivity that drives lupus inflammation.
Saphnelo contains the active substance anifrolumab, a fully human monoclonal antibody that was developed specifically to target a key pathway involved in the pathophysiology of systemic lupus erythematosus. It was approved by the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) for the treatment of moderate to severe SLE in adult patients who are already receiving standard-of-care therapy but whose disease remains inadequately controlled.
Systemic lupus erythematosus is a chronic autoimmune disease in which the immune system mistakenly attacks the body's own cells and tissues. This causes widespread inflammation that can affect virtually any organ, including the skin, joints, kidneys, brain, heart, and lungs. SLE is characterised by periods of increased disease activity (flares) alternating with periods of relative remission. Symptoms commonly include joint pain and swelling, skin rashes (particularly the characteristic butterfly-shaped facial rash), profound fatigue, fever, and organ damage over time.
Saphnelo is always prescribed as an add-on to existing SLE treatment. It does not replace other medications you may be taking, such as oral corticosteroids (e.g. prednisolone), immunosuppressants (e.g. mycophenolate, azathioprine), or antimalarial drugs (e.g. hydroxychloroquine). Rather, it is added when these standard therapies alone are insufficient to control the disease.
How Does Saphnelo Work?
Research has shown that the majority of patients with SLE have elevated levels of proteins called type I interferons. These interferons are part of the innate immune system and normally help fight viral infections, but in SLE they become chronically overproduced. This overproduction drives excessive immune activation, triggering and sustaining the inflammation that damages tissues and organs.
Anifrolumab works by binding specifically to the type I interferon receptor subunit 1 (IFNAR1) on the surface of cells. By blocking this receptor, anifrolumab prevents all type I interferons (including interferon-alpha and interferon-beta) from delivering their pro-inflammatory signals. This effectively dials down the overactive immune response that characterises SLE, reducing inflammation and disease activity throughout the body.
In clinical trials (TULIP-1 and TULIP-2), patients treated with Saphnelo showed significantly greater reductions in disease activity compared to placebo when added to standard therapy. Importantly, Saphnelo also allowed many patients to reduce their daily corticosteroid dose to 7.5 mg or less of prednisolone equivalent, which is a clinically meaningful benefit given the serious long-term side effects of chronic corticosteroid use.
Clinical data demonstrate that Saphnelo can help reduce overall SLE disease activity, decrease the frequency and severity of lupus flares, lower skin disease burden, and enable corticosteroid dose reduction. These benefits were sustained over 52 weeks of treatment in pivotal clinical trials.
What Should You Know Before Taking Saphnelo?
Before starting Saphnelo, your doctor needs to know about any infections, history of cancer, planned vaccinations, or use of other biologic medicines. Saphnelo is not recommended during pregnancy or breastfeeding unless clearly necessary. Live vaccines must not be given during treatment.
Contraindications
You must not use Saphnelo if you are allergic to anifrolumab or any of the other ingredients in the medicine (histidine, histidine hydrochloride monohydrate, lysine hydrochloride, trehalose dihydrate, polysorbat 80, and water for injections). If you are unsure whether you may be allergic to any of these components, speak with your doctor or pharmacist before starting treatment.
Warnings and Precautions
Before starting treatment with Saphnelo, it is essential to inform your doctor about any current or recent health conditions. Several situations require particular caution and may influence whether Saphnelo is appropriate for you:
- Active infections: If you currently have an infection or have symptoms suggesting an infection (such as fever, cough, painful urination, or skin rashes), tell your doctor. Saphnelo should generally not be started during an active infection.
- Chronic or recurring infections: If you have a history of long-lasting infections or infections that keep coming back, your doctor will carefully assess whether the benefits of Saphnelo outweigh the risks in your case.
- Lupus nephritis or neuropsychiatric lupus: Saphnelo has not been extensively studied in patients with active, severe lupus affecting the kidneys or nervous system. Your doctor will consider this when deciding on treatment.
- History of cancer: If you have or have previously had cancer, discuss this with your doctor before starting Saphnelo, as the effect of reduced interferon signalling on cancer surveillance is not fully understood.
- Vaccinations: If you have recently received a vaccination or plan to get vaccinated, inform your doctor. Live or live-attenuated vaccines must not be given during Saphnelo treatment. Inactivated vaccines can generally be administered, but their effectiveness may be reduced.
- Other biologic therapies: The combination of Saphnelo with other biologic medicines (such as belimumab or rituximab) has not been studied and is not recommended.
Saphnelo can cause serious allergic reactions (anaphylaxis), though this is uncommon. Seek immediate medical attention if you experience swelling of the face, tongue, or mouth, difficulty breathing, or feeling faint or dizzy (due to a drop in blood pressure).
Contact your doctor as soon as possible if you notice signs of infection such as fever, flu-like symptoms, muscle aches, persistent cough, painful or frequent urination, diarrhoea, or a painful red skin rash (which may indicate shingles).
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor before using Saphnelo. It is not known whether Saphnelo can harm an unborn baby. Your doctor will weigh the potential benefits against the potential risks before deciding whether to continue or start treatment during pregnancy.
It is also not known whether anifrolumab passes into breast milk. If you are breastfeeding, your doctor will discuss with you whether to discontinue treatment or to stop breastfeeding, taking into account the benefit of breastfeeding for the child and the benefit of therapy for you.
Women of childbearing potential should discuss contraception with their doctor before starting Saphnelo. As a monoclonal antibody, anifrolumab may cross the placenta, particularly during the third trimester, potentially affecting the immune system of the developing foetus.
Children and Adolescents
Saphnelo is not approved for use in children and adolescents under 18 years of age. The safety and efficacy of anifrolumab have not been established in this age group, and therefore it should not be used in paediatric patients.
Driving and Using Machines
Saphnelo is not expected to affect your ability to drive or operate machinery. No studies on the effects on driving and machine operation have been performed, but the mechanism of action and the known side effect profile make such effects unlikely.
How Does Saphnelo Interact with Other Drugs?
Saphnelo's most important interactions are with live vaccines (contraindicated) and other biologic immunosuppressants (not recommended in combination). As a monoclonal antibody, it is not metabolised through the cytochrome P450 system and has limited pharmacokinetic drug interactions.
Anifrolumab is a monoclonal antibody that is cleared from the body through proteolytic degradation, not through hepatic cytochrome P450 (CYP) enzyme metabolism. This means it has a lower potential for traditional pharmacokinetic drug-drug interactions compared to small-molecule drugs. However, several clinically important interactions must still be considered:
| Interacting Drug/Class | Interaction Type | Clinical Significance | Recommendation |
|---|---|---|---|
| Live/attenuated vaccines | Immunosuppressive effect | Major | Contraindicated during treatment |
| Other biologics (e.g. belimumab, rituximab) | Additive immunosuppression | Major | Not recommended in combination |
| Inactivated vaccines | Reduced immune response | Moderate | Can be given; efficacy may be reduced |
| Corticosteroids (oral) | Additive immunosuppression | Moderate | Used together; monitor for infections |
| Immunosuppressants (e.g. azathioprine, mycophenolate) | Additive immunosuppression | Moderate | Used together as standard care; monitor |
| Antimalarials (hydroxychloroquine) | No significant interaction | Low | Safe to use together |
Always tell your doctor about all medicines you are taking, have recently taken, or plan to take. This includes prescription medicines, over-the-counter drugs, vitamins, and herbal supplements. While anifrolumab has limited pharmacokinetic interactions, the immunosuppressive effect of Saphnelo combined with other immunomodulating therapies may increase the overall risk of infection.
If you are due for any vaccinations, discuss your vaccination schedule with your doctor before starting Saphnelo. Ideally, all necessary live vaccines should be administered at least 4 weeks before beginning treatment. Inactivated vaccines (such as annual influenza shots) can be given during treatment but may produce a weaker immune response.
What Is the Correct Dosage of Saphnelo?
Saphnelo is given as a subcutaneous injection of 120 mg once weekly using a pre-filled autoinjector pen. For the intravenous formulation, the dose is 300 mg every 4 weeks by infusion. Always follow your doctor's instructions regarding dosing.
Saphnelo is available in two formulations with different dosing schedules. Your doctor will determine which formulation and route of administration is most appropriate for you based on your clinical situation and preference.
Adults
Subcutaneous injection (pre-filled pen)
Dose: 120 mg once weekly
Route: Subcutaneous injection in the front of the thigh, lower abdomen (at least 5 cm from the navel), or upper arm (caregiver only)
Administration: After appropriate training, patients or their caregivers can self-administer using the pre-filled autoinjector pen at home
Intravenous infusion
Dose: 300 mg every 4 weeks
Route: Intravenous infusion over at least 30 minutes
Administration: Must be administered by a healthcare professional in a clinical setting
Children and Adolescents
Saphnelo is not approved for use in patients under 18 years of age. The safety and efficacy of anifrolumab have not been established in this population, and no dosing recommendations can be made for paediatric patients.
Elderly Patients
No dose adjustment is required for elderly patients. However, clinical trial experience in patients aged 65 years and older is limited, so treatment should be initiated with caution and with appropriate monitoring for infections and other adverse effects.
How to Use the Pre-filled Pen
Before your first self-injection, a healthcare professional will show you or your caregiver how to correctly use the Saphnelo pre-filled autoinjector pen. Read the instructions for use carefully each time you receive a new pack. The key steps are:
- Remove the pen from the refrigerator and allow it to reach room temperature (20–25°C) for 60 minutes. Do not heat it in any other way (microwave, hot water, direct sunlight, or other heat sources).
- Inspect the pen: Check the expiry date, ensure the pen is not damaged, and look through the inspection window to verify the liquid is clear to opalescent and colourless to slightly yellow. Do not use if it is cloudy, discoloured, or contains visible particles. Small air bubbles are normal.
- Choose and clean the injection site: Select a site on the front of your thigh or lower abdomen (at least 5 cm from the navel). A caregiver may also inject in the upper arm. Do not inject into skin that is red, tender, hard, bruised, scarred, or tattooed. Clean with an alcohol swab and let air dry.
- Remove the cap only when ready to inject. Place the green needle guard flat against the skin at a 90-degree angle and press down firmly. Hold for approximately 15 seconds until the green plunger fills the inspection window. You may hear a first click when the injection starts and a second click when it is complete.
- Lift the pen straight up. The needle guard will automatically lock in place. Check the inspection window to confirm the green plunger has filled it completely. If it has not, contact your healthcare professional.
- Dispose of the used pen in a sharps disposal container immediately. Do not reuse or recap the pen.
Missed Dose
If you miss a dose of Saphnelo, inject the missed dose as soon as you remember. Then continue with your regular weekly dosing schedule from the new injection day, or return to your usual schedule provided there are at least 3 days between doses. Do not inject a double dose to make up for one you have missed. If you are unsure about when to inject, contact your doctor, pharmacist, or nurse.
Overdose
If you have used more Saphnelo than prescribed, contact your doctor immediately. In clinical studies, doses up to 900 mg intravenously have been administered. No dose-limiting toxicities were identified, but higher doses may increase the risk of infections and other adverse effects. There is no specific antidote for anifrolumab overdose; treatment would be supportive and symptom-directed.
Do not stop using Saphnelo without first discussing it with your doctor. Discontinuing treatment abruptly may lead to a return or worsening of your SLE symptoms. Your doctor will determine whether and when it is appropriate to stop treatment.
What Are the Side Effects of Saphnelo?
The most common side effects of Saphnelo are upper respiratory tract infections and bronchitis (very common, affecting more than 1 in 10 patients). Common side effects include sinusitis, pneumonia, herpes zoster (shingles), and hypersensitivity reactions. Serious allergic reactions (anaphylaxis) are uncommon but require immediate medical attention.
Like all medicines, Saphnelo can cause side effects, although not everybody gets them. Most side effects are mild to moderate in severity and are related to the medicine's immunosuppressive mechanism of action. The frequency categories below are based on data from clinical trials and post-marketing surveillance.
Very Common
- Upper respiratory tract infections (nasopharyngitis, common cold)
- Bronchitis (chest cold, airway infection)
Common
- Sinusitis or pneumonia (sinus or lung infection)
- Herpes zoster (shingles) — a painful red skin rash with a burning sensation
- Hypersensitivity reactions (allergic reactions)
Uncommon
- Anaphylaxis (serious allergic reaction with swelling, breathing difficulty, drop in blood pressure)
Not Known
- Arthralgia (joint pain)
Understanding the Infection Risk
Because Saphnelo reduces the activity of type I interferons, which play a role in the body's defence against infections, patients treated with Saphnelo may have a higher risk of developing infections. The most frequently reported infections in clinical trials were respiratory tract infections (nasopharyngitis and bronchitis), which are generally mild and self-limiting.
Herpes zoster (shingles) deserves special attention. The risk of shingles is increased with Saphnelo treatment because type I interferons are important in controlling latent herpes virus reactivation. Most cases in clinical trials were non-serious and did not require treatment discontinuation, but you should contact your doctor if you develop a painful skin rash, particularly one that follows a band-like pattern on one side of the body.
In rare cases, more serious infections such as pneumonia can occur. If you develop fever, persistent cough, difficulty breathing, or any other signs of infection during treatment, contact your healthcare provider promptly. Early treatment of infections is important to prevent complications.
Allergic Reactions
Allergic reactions to Saphnelo range from mild hypersensitivity (skin rash, itching) to rare but serious anaphylaxis. If you experience any of the following symptoms after an injection, seek immediate medical attention:
- Swelling of the face, tongue, or mouth
- Difficulty breathing or wheezing
- Feeling faint, dizzy, or light-headed (due to blood pressure drop)
- Severe skin rash or hives spreading across the body
Seek immediate medical attention if you experience signs of a serious allergic reaction (anaphylaxis) such as difficulty breathing, facial swelling, or feeling faint after your Saphnelo injection. Although anaphylaxis is uncommon, it can be life-threatening and requires immediate treatment with epinephrine.
Reporting Side Effects
Reporting suspected side effects after a medicine has been approved is important for ongoing safety monitoring. Healthcare professionals and patients are encouraged to report side effects to their national pharmacovigilance authority (such as the MHRA in the UK, the FDA MedWatch programme in the US, or the EMA EudraVigilance system in the EU).
How Should You Store Saphnelo?
Store Saphnelo in a refrigerator at 2°C to 8°C in the original packaging to protect from light. Do not freeze, shake, or expose to heat. If needed, the pre-filled pen may be kept at room temperature (20–25°C) for up to 7 days.
Proper storage of Saphnelo is essential to ensure the medicine remains effective and safe to use. Follow these storage guidelines carefully:
- Refrigerate: Store the pre-filled pen in a refrigerator at 2°C to 8°C (36°F to 46°F).
- Protect from light: Keep the pen in its original outer carton to protect it from light.
- Do not freeze: Never freeze Saphnelo. If the pen has been frozen, do not use it.
- Do not shake: Shaking may damage the protein structure of the medicine.
- Do not expose to heat: Keep away from direct sunlight and other heat sources.
- Room temperature option: If needed, you may store the pre-filled pen at room temperature (20–25°C / 68–77°F) for up to 7 days, protected from light. Once a pen has reached room temperature, do not return it to the refrigerator. If not used within 7 days of removal from the refrigerator, discard it.
- Check expiry date: Do not use after the expiry date (EXP) printed on the label and carton. The expiry date refers to the last day of that month.
- Keep out of reach of children.
Do not dispose of medicines via the drain or in household waste. Ask your pharmacist how to properly dispose of medicines you no longer use. These measures help protect the environment.
What Does Saphnelo Contain?
Each Saphnelo pre-filled pen contains 120 mg of anifrolumab as the active substance, along with excipients including histidine, lysine hydrochloride, trehalose dihydrate, polysorbat 80, and water for injections.
Active Ingredient
The active substance is anifrolumab, a fully human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody produced in Chinese hamster ovary (CHO) cells by recombinant DNA technology. Each pre-filled autoinjector pen contains 120 mg of anifrolumab in 0.8 mL solution.
Inactive Ingredients (Excipients)
The other ingredients are:
- Histidine
- Histidine hydrochloride monohydrate
- Lysine hydrochloride
- Trehalose dihydrate
- Polysorbat 80 (E 433)
- Water for injections
This medicine contains 0.4 mg of polysorbat 80 (E 433) per pre-filled pen, equivalent to 0.5 mg/mL. Polysorbates may cause allergic reactions. Inform your doctor if you have any known allergies to polysorbates.
Appearance and Pack Sizes
Saphnelo is a clear to opalescent, colourless to slightly yellow solution for injection. It is available as:
- Pack of 1 pre-filled autoinjector pen
- Pack of 4 pre-filled autoinjector pens
- Multipack of 12 (3 packs of 4) pre-filled autoinjector pens
Not all pack sizes may be marketed in all countries. The marketing authorisation holder is AstraZeneca AB, and the medicine is manufactured by AstraZeneca AB in Sodertalje, Sweden.
Frequently Asked Questions About Saphnelo
Saphnelo (anifrolumab) is used to treat moderate to severe systemic lupus erythematosus (SLE) in adults whose disease is not adequately controlled with standard therapies such as oral corticosteroids, immunosuppressants, and/or antimalarials. It is given as an add-on to existing SLE treatment, not as a standalone therapy. Saphnelo helps reduce disease activity, decrease the frequency of lupus flares, and may allow your doctor to reduce your corticosteroid dose.
Saphnelo is a monoclonal antibody that blocks the type I interferon receptor (IFNAR1). People with SLE often have elevated levels of type I interferons, which overstimulate the immune system and drive the inflammation that damages tissues and organs. By blocking the receptor through which these interferons signal, Saphnelo effectively reduces the overactive immune response that characterises lupus, leading to decreased inflammation and disease activity.
The most common side effects are upper respiratory tract infections (nasopharyngitis, common cold) and bronchitis, which affect more than 1 in 10 patients. Common side effects (up to 1 in 10) include sinusitis, pneumonia, herpes zoster (shingles), and allergic reactions. Serious allergic reactions (anaphylaxis) are uncommon but can occur. Most side effects are related to the medicine's effect on the immune system and are generally manageable.
You must not receive live or live-attenuated vaccines during Saphnelo treatment, as the medicine suppresses certain immune pathways that could allow a live vaccine virus to cause infection. Inactivated vaccines (such as the standard flu shot or COVID-19 mRNA vaccines) can generally be given during treatment, but their effectiveness may be reduced. Discuss your vaccination schedule with your doctor before starting Saphnelo — ideally, complete any needed live vaccinations at least 4 weeks before beginning treatment.
Saphnelo comes in a pre-filled autoinjector pen for weekly subcutaneous self-injection. Before your first injection, your healthcare provider will train you on proper technique. Key steps include: let the pen reach room temperature for 60 minutes, choose and clean an injection site (front of thigh or lower abdomen), remove the cap, press the pen flat against the skin at 90 degrees, and hold for about 15 seconds until the green plunger fills the inspection window. Dispose of the used pen in a sharps container. Rotate injection sites to avoid irritation.
If you miss a dose, inject it as soon as you remember. Then continue your weekly schedule from the new injection day, or return to your usual schedule as long as there are at least 3 days between doses. Never inject a double dose. If you are unsure about when to take your next dose, contact your doctor, pharmacist, or nurse for guidance.
References
This article is based on the following peer-reviewed sources and regulatory documents:
- European Medicines Agency (EMA). Saphnelo (anifrolumab) — Summary of Product Characteristics. Last updated 2025. Available at: EMA EPAR: Saphnelo.
- Morand EF, Furie R, Tanaka Y, et al. Trial of Anifrolumab in Active Systemic Lupus Erythematosus (TULIP-2). N Engl J Med. 2020;382(3):211-221. doi:10.1056/NEJMoa1912196.
- Furie RA, Morand EF, Bruce IN, et al. Type I interferon inhibitor anifrolumab in active systemic lupus erythematosus (TULIP-1): a randomised, controlled, phase 3 trial. Lancet Rheumatol. 2019;1(4):e208-e219.
- U.S. Food and Drug Administration (FDA). Saphnelo (anifrolumab-fnia) Prescribing Information. Revised 2024.
- Fanouriakis A, Kostopoulou M, Andersen J, et al. EULAR recommendations for the management of systemic lupus erythematosus: 2023 update. Ann Rheum Dis. 2024;83(1):15-29.
- Jayne D, Rovin B, Genovese MC. The type I interferon pathway as a therapeutic target in SLE. Nat Rev Rheumatol. 2022;18(4):228-241.
- World Health Organization (WHO). Model List of Essential Medicines — 23rd edition. Geneva: WHO; 2023.
- British National Formulary (BNF). Anifrolumab. National Institute for Health and Care Excellence (NICE). Accessed December 2025.
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