Rystiggo (Rozanolixizumab)
FcRn inhibitor for generalized myasthenia gravis (gMG)
Rystiggo (rozanolixizumab) is a prescription biologic medicine used to treat generalized myasthenia gravis (gMG) in adults. It belongs to a new class of therapies called FcRn inhibitors, which work by lowering levels of harmful IgG autoantibodies that cause muscle weakness. Given as a subcutaneous injection in treatment cycles, Rystiggo has been shown to significantly improve muscle strength and quality of life in clinical trials. This comprehensive guide covers uses, dosage, side effects, drug interactions, storage, and important safety information.
Quick Facts
Key Takeaways
- Rystiggo is approved for generalized myasthenia gravis (gMG) in adults with anti-AChR or anti-MuSK autoantibodies, used alongside standard therapy.
- It works by targeting FcRn to reduce harmful IgG autoantibody levels, improving muscle strength and reducing disease symptoms.
- Treatment is given in cycles of weekly subcutaneous injections for 6 weeks, with dosing based on body weight.
- The most common side effects are headache, diarrhea, and fever; serious but rare risks include aseptic meningitis and increased infection susceptibility.
- After training, patients can self-administer Rystiggo at home using either an infusion pump or manual push injection.
What Is Rystiggo and What Is It Used For?
Rystiggo contains the active substance rozanolixizumab, a humanized monoclonal antibody specifically designed to recognize and bind to the neonatal Fc receptor (FcRn). FcRn plays a critical role in immunology by recycling immunoglobulin G (IgG) antibodies, effectively extending their lifespan in the bloodstream. By blocking this receptor, Rystiggo accelerates the breakdown of IgG antibodies, including the pathogenic autoantibodies responsible for the symptoms of myasthenia gravis.
Generalized myasthenia gravis (gMG) is a chronic autoimmune neuromuscular disorder characterized by fluctuating weakness of skeletal muscles. In gMG, the immune system produces IgG autoantibodies that attack proteins at the neuromuscular junction — the point where nerve signals are transmitted to muscles. These autoantibodies most commonly target acetylcholine receptors (AChR) or, less frequently, muscle-specific kinase (MuSK). This immune-mediated attack disrupts the normal communication between nerves and muscles, leading to progressive muscle weakness that can affect the eyes, face, throat, limbs, and respiratory muscles.
Rystiggo is indicated for use in adults with gMG who are seropositive for anti-AChR or anti-MuSK antibodies. By reducing the overall IgG levels — including these disease-causing autoantibodies — Rystiggo helps restore more normal neuromuscular transmission. In clinical trials, patients treated with Rystiggo demonstrated statistically significant improvements in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score and the Quantitative Myasthenia Gravis (QMG) score compared to placebo, reflecting meaningful improvements in muscle strength and daily functioning.
Rystiggo was approved by the European Medicines Agency (EMA) and represents an important advancement in the treatment landscape for gMG. Unlike some older therapies that broadly suppress the immune system, Rystiggo offers a more targeted approach by specifically reducing IgG levels through FcRn inhibition, potentially offering a better safety profile for some patients while effectively managing their disease.
What Should You Know Before Taking Rystiggo?
Contraindications
Rystiggo is contraindicated in patients with a known hypersensitivity to rozanolixizumab or to any of the excipients in the formulation, which include histidine, histidine hydrochloride monohydrate, proline, polysorbat 80, and water for injections. If you have previously experienced an allergic reaction to any of these substances, inform your healthcare provider before starting therapy.
Warnings and Precautions
Before initiating or during treatment with Rystiggo, your healthcare provider will assess several important risk factors. It is essential to discuss any of the following situations with your doctor, pharmacist, or nurse:
Your doctor may not prescribe Rystiggo if you are being treated, or are likely to require treatment, with mechanical ventilation due to severe muscle weakness caused by a myasthenic crisis. Myasthenic crisis is a medical emergency requiring intensive care management, and the safety of initiating Rystiggo during such episodes has not been established.
Aseptic meningitis (inflammation of the protective membranes surrounding the brain and spinal cord without bacterial infection) has been observed in patients receiving Rystiggo. Seek immediate medical attention if you develop symptoms including severe headache, fever, neck stiffness, nausea, vomiting, and/or sensitivity to bright light. This condition is typically reversible but requires prompt medical evaluation.
Rystiggo reduces IgG antibody levels, which may decrease your natural resistance to infections. Before starting and during treatment, inform your doctor if you experience any signs of infection such as feeling warm, fever, chills, shaking, cough, sore throat, or mouth sores. Your doctor may need to delay treatment or monitor you more closely during active infections.
Hypersensitivity (allergic reactions): As a protein-based medicine, Rystiggo has the potential to cause allergic reactions in some individuals. These may manifest as skin rash, swelling, or itching. During each infusion, you will be monitored for signs of infusion-related reactions both during and for at least 15 minutes after the administration. If a severe allergic reaction occurs, the infusion will be stopped and appropriate medical treatment will be initiated immediately.
Vaccinations: Inform your doctor if you have received any vaccination within the past 4 weeks or if you plan to be vaccinated in the near future. Because Rystiggo lowers IgG levels, it may reduce the effectiveness of certain vaccines. Vaccination with live attenuated or live vaccines is not recommended during treatment with Rystiggo. If vaccination is necessary, your healthcare provider will work with you to determine optimal timing relative to your treatment cycles.
Hyperprolinemia: Rystiggo contains proline (29 mg per ml). Proline can be harmful for patients with hyperprolinemia, a rare genetic disorder in which excess proline accumulates in the body. If you have been diagnosed with hyperprolinemia, do not use Rystiggo unless specifically directed by your physician. The formulation also contains polysorbat 80 (0.3 mg per ml), which may cause allergic reactions in susceptible individuals.
Children and Adolescents
Rystiggo has not been studied in patients under 18 years of age. The safety and efficacy in the pediatric population have not been established, and this medicine should not be administered to children or adolescents. If myasthenia gravis affects a child or teenager, other treatment options should be discussed with a specialist neurologist experienced in managing neuromuscular disorders in younger patients.
Pregnancy and Breastfeeding
The effects of Rystiggo during pregnancy have not been adequately studied in humans. As rozanolixizumab is an IgG-based monoclonal antibody, it has the potential to cross the placental barrier, particularly during the second and third trimesters. Because Rystiggo reduces IgG levels, there is a theoretical risk that it could lower protective antibody levels in the developing fetus. For these reasons, Rystiggo should not be used during pregnancy unless the potential benefit clearly outweighs the potential risk, as determined by your physician.
It is currently unknown whether rozanolixizumab is excreted in human breast milk. Many IgG antibodies are present in breast milk, and the potential effects on a breastfed infant have not been studied. Women who are breastfeeding or planning to breastfeed should discuss the benefits and risks with their healthcare provider to make an informed decision about whether to continue breastfeeding during Rystiggo treatment.
If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor or pharmacist before using Rystiggo. Effective contraception should be considered for women of childbearing potential during treatment.
Driving and Using Machines
Rystiggo is not expected to affect your ability to drive vehicles or operate machinery. However, as with any treatment for myasthenia gravis, your overall disease status and muscle strength should be taken into consideration when assessing your fitness to drive or perform activities requiring full physical coordination.
How Does Rystiggo Interact with Other Drugs?
Because Rystiggo works by reducing overall IgG levels in the bloodstream, it can affect the efficacy of other IgG-based therapeutic agents. Similarly, certain treatments that alter IgG levels or remove proteins from the blood may interfere with the effectiveness of Rystiggo. It is therefore critical to inform your healthcare provider about all medications you are currently taking, have recently taken, or may plan to take, including over-the-counter medicines, supplements, and herbal products.
Major Interactions
| Interacting Drug/Therapy | Effect | Clinical Recommendation |
|---|---|---|
| Rituximab | Rystiggo may reduce the effectiveness of rituximab by lowering its IgG levels in the blood | Coordinate timing with your physician; avoid concurrent administration if possible |
| Intravenous Immunoglobulin (IVIg) | Bidirectional interaction: IVIg may reduce Rystiggo efficacy; Rystiggo may reduce IVIg efficacy | Discuss optimal timing and sequencing with your specialist |
| Subcutaneous Immunoglobulin (SCIg) | Bidirectional interaction similar to IVIg | Coordinate administration schedule with your physician |
| Plasmapheresis (plasma exchange) | Plasmapheresis removes proteins from the blood, potentially reducing Rystiggo efficacy | Inform your doctor if plasmapheresis is planned during a treatment cycle |
| Live attenuated vaccines | Rystiggo may reduce vaccine immunogenicity; risk of vaccine-associated infection with live vaccines | Live vaccines are not recommended during treatment; discuss timing with your doctor |
Other Considerations
Rystiggo may also reduce the effectiveness of other therapeutic monoclonal antibodies that rely on IgG-mediated mechanisms. If you are receiving or planning to receive any biologic therapy, your specialist will need to consider the potential interaction with Rystiggo and may adjust the timing or dosing of either treatment accordingly.
Standard myasthenia gravis treatments such as pyridostigmine (cholinesterase inhibitors), corticosteroids, and conventional immunosuppressants (e.g., azathioprine, mycophenolate mofetil) do not have the same type of interaction with Rystiggo and are commonly used alongside it. Rystiggo is specifically indicated for use in combination with such standard therapies.
Regarding inactivated (non-live) vaccines, while Rystiggo may reduce their effectiveness by lowering IgG levels, they are generally considered safe to administer. Your healthcare provider may recommend checking antibody titers after vaccination to confirm adequate immune response, or may suggest optimal timing of vaccination relative to your Rystiggo treatment cycle.
What Is the Correct Dosage of Rystiggo?
Treatment with Rystiggo should be initiated and supervised by a specialist physician experienced in the management of neuromuscular or neuroinflammatory disorders. The dosing regimen is based on the patient's body weight and is administered in defined treatment cycles. Each cycle consists of one subcutaneous infusion per week for 6 consecutive weeks.
Adults — Weight-Based Dosing
| Body Weight | Dose per Infusion | Volume Required |
|---|---|---|
| 35 kg to <50 kg | 280 mg | 2 ml |
| 50 kg to <70 kg | 420 mg | 3 ml |
| 70 kg to <100 kg | 560 mg | 4 ml |
| ≥100 kg | 840 mg | 6 ml |
The frequency of treatment cycles varies between patients. Your physician will evaluate your clinical response and determine whether and when a subsequent treatment cycle is appropriate. The decision to start a new cycle is based on the return of symptoms and the clinical assessment of your disease activity.
How Rystiggo Is Given
Rystiggo is administered as a subcutaneous (under the skin) infusion, typically into the lower abdomen below the navel. The injection should not be given into areas where the skin is tender, bruised, red, or hard, or into areas with scars or stretch marks. Administration can be performed in two ways:
- Infusion pump (syringe pump): The medication is delivered at a controlled flow rate of up to 20 ml per hour using a programmable infusion pump.
- Manual push injection: The medication is administered manually without a pump at a flow rate comfortable for the patient.
Initially, Rystiggo will be administered by a healthcare professional in a clinical setting. After receiving proper training from a qualified healthcare provider, patients may self-administer the medication at home, or a trained caregiver may give the injections. Self-administration should only be attempted after thorough instruction and demonstrated competence in proper technique, including aseptic preparation, injection site selection, pump operation (if applicable), and recognition of potential reactions.
Missed Dose
If you miss a scheduled dose of Rystiggo, contact your doctor immediately to arrange a replacement appointment. The missed dose should be administered within the next 4 days if possible. After receiving the missed dose, subsequent infusions should continue according to the original dosing schedule until the treatment cycle is complete. Do not attempt to make up for a missed dose by administering a double dose.
Overdose
If you suspect that you have inadvertently received a higher dose of Rystiggo than prescribed, contact your physician promptly for advice. There is limited clinical experience with overdose of rozanolixizumab. In the event of an overdose, the patient should be monitored for any signs or symptoms of adverse reactions, and appropriate supportive treatment should be initiated as needed.
Stopping Treatment
Do not discontinue Rystiggo without first consulting your physician. Abrupt cessation of treatment may result in a return or worsening of myasthenia gravis symptoms, including muscle weakness, difficulty swallowing, and breathing difficulties. If you and your doctor decide to stop treatment, a gradual transition plan with appropriate monitoring should be put in place to manage any potential disease flare-ups.
What Are the Side Effects of Rystiggo?
Like all medicines, Rystiggo can cause side effects, although not everyone will experience them. The side effects observed in clinical trials are categorized below by their frequency of occurrence. Most side effects are mild to moderate and tend to resolve on their own. However, some side effects may be serious and require prompt medical attention.
Very Common
May affect more than 1 in 10 people
- Headache (including migraine)
- Diarrhea
- Fever (pyrexia)
Common
May affect up to 1 in 10 people
- Angioedema (rapid swelling under the skin, particularly of the face, throat, arms, and legs)
- Joint pain (arthralgia)
- Skin rash, sometimes with red bumps (papular rash)
- Injection site reactions, including rash, redness (erythema), inflammation, discomfort, and pain
- Nasopharyngeal infections (nose and throat infections)
- Nausea
- Vomiting
Not Known
Frequency cannot be estimated from available data
- Aseptic meningitis (reversible, non-infectious inflammation of the brain and spinal cord membranes), presenting with severe headache, fever, neck stiffness, nausea, vomiting, and/or light sensitivity
- Viral infections, including herpes zoster (shingles) and herpes simplex (cold sores)
Contact your doctor or seek emergency medical care immediately if you experience: severe headache combined with fever and neck stiffness (signs of aseptic meningitis), difficulty breathing, significant swelling of the face, lips, tongue, or throat (signs of severe allergic reaction), or signs of a serious infection such as high fever with chills, persistent cough, or painful skin lesions.
The mechanism by which Rystiggo causes headache is thought to be related to its effect on FcRn and the subsequent reduction in IgG levels. Headache is the most frequently reported side effect and typically occurs during or shortly after the infusion. In most cases, headache is mild to moderate in severity and resolves with standard analgesic treatment such as paracetamol or ibuprofen.
Injection site reactions are localized and generally mild. Rotating the injection site between the left and right lower abdomen can help minimize local reactions. If you notice persistent redness, swelling, or hardening at the injection site, inform your healthcare provider.
Because Rystiggo lowers overall IgG levels, including protective antibodies, there is an inherent increased risk of infection during treatment. You should be vigilant for any signs of infection and report them to your healthcare provider promptly. Your doctor may check your immunoglobulin levels periodically during treatment and may delay or modify your treatment cycle if levels fall too low or if you develop an active infection.
How Should You Store Rystiggo?
Proper storage of Rystiggo is essential to maintain the medication's effectiveness and safety. The following guidelines should be followed carefully:
- Refrigeration: Store vials in a refrigerator at 2°C to 8°C (36°F to 46°F). Keep the vials in the original outer carton to protect from light.
- Do not freeze: Rystiggo must never be frozen. If the solution has been accidentally frozen, it must be discarded and not used.
- Room temperature storage: Rystiggo may be removed from the refrigerator and stored at room temperature (up to 25°C / 77°F) for a single continuous period of no more than 20 days. There is a space on the carton where you can write the date the medication was removed from the refrigerator. Do not return the vial to the refrigerator once it has been stored at room temperature.
- Before use: Allow the vial to reach room temperature before administration to increase comfort during injection. This process typically takes 30 to 120 minutes. Do not use any other method to warm the solution (e.g., microwave, hot water).
- Single-use vials: Each vial is for single use only. Any unused medicine remaining in the vial after injection must be discarded.
- Visual inspection: Before use, check that the solution is colorless to pale brownish-yellow and clear to slightly opalescent (pearly white). Do not use the medicine if the solution appears cloudy, contains visible particles, or has changed color.
- Expiry date: Do not use Rystiggo after the expiry date stated on the vial label and outer carton after “EXP.” The expiry date refers to the last day of the stated month.
Keep Rystiggo out of the sight and reach of children. Dispose of unused medicine and waste materials according to local regulations. Do not throw away medicines via household waste or wastewater. Ask your pharmacist for guidance on proper disposal to help protect the environment.
What Does Rystiggo Contain?
Rystiggo is a solution for subcutaneous injection supplied in single-use glass vials. The formulation is specifically designed to ensure stability and compatibility for subcutaneous delivery. The full composition is as follows:
Active Substance
| Vial Size | Rozanolixizumab Content | Concentration |
|---|---|---|
| 2 ml vial | 280 mg | 140 mg/ml |
| 3 ml vial | 420 mg | 140 mg/ml |
| 4 ml vial | 560 mg | 140 mg/ml |
| 6 ml vial | 840 mg | 140 mg/ml |
Inactive Ingredients (Excipients)
- Histidine — buffer to maintain pH stability
- Histidine hydrochloride monohydrate — buffer component
- Proline — stabilizer (29 mg per ml; note: patients with hyperprolinemia should consult their doctor)
- Polysorbat 80 — surfactant to prevent protein aggregation (0.3 mg per ml; may cause allergic reactions in some individuals)
- Water for injections — solvent
The solution is colorless to pale brownish-yellow and clear to slightly opalescent (pearly white) in appearance. Each carton contains 1 vial. Not all vial sizes may be marketed in every country. The administration supplies (syringe, transfer needle or vented vial adapter, infusion tubing with needle, alcohol swabs, tape, and a sharps disposal container) are not included in the Rystiggo package and must be obtained separately.
Rystiggo is manufactured by UCB Pharma S.A. at their facility in Braine-l'Alleud, Belgium. The marketing authorization holder is UCB Pharma S.A., Allee de la Recherche 60, B-1070 Brussels, Belgium.
Frequently Asked Questions About Rystiggo
Rystiggo (rozanolixizumab) is used to treat generalized myasthenia gravis (gMG) in adults who produce IgG autoantibodies against acetylcholine receptors (AChR) or muscle-specific kinase (MuSK). It is administered alongside standard therapy to help improve muscle strength and reduce symptoms such as muscle weakness, difficulty swallowing, and fatigue. Rystiggo is not indicated for ocular myasthenia gravis or for patients who are seronegative for these specific autoantibodies.
Rystiggo belongs to a new class of treatments called FcRn (neonatal Fc receptor) inhibitors. Unlike traditional immunosuppressants that broadly suppress the immune system, Rystiggo specifically targets the mechanism that maintains IgG antibodies in circulation. By blocking FcRn, it accelerates the clearance of all IgG, including the pathogenic autoantibodies causing myasthenia gravis. This targeted approach may offer advantages in terms of a more predictable effect on disease-causing antibodies while potentially preserving other aspects of immune function.
Yes, after receiving proper training from a healthcare professional, you or a trained caregiver may administer Rystiggo at home. Self-administration requires thorough training in proper injection technique, vial preparation, aseptic practices, injection site selection, recognition of adverse reactions, and proper disposal of sharps. Your doctor will determine when you are ready to self-administer. The first few infusions are typically given in a clinical setting under medical supervision before transitioning to home administration.
The duration of each Rystiggo infusion depends on the dose and the method of administration. When using an infusion pump set at the maximum flow rate of 20 ml per hour, a 6 ml dose (840 mg) would take approximately 18 minutes, while a 2 ml dose (280 mg) would take about 6 minutes. Manual push injection may be faster, as the flow rate is adjusted to the patient's comfort. Additionally, you should allow 30 to 120 minutes for the vial to reach room temperature before injection, and you will be monitored for at least 15 minutes after the infusion in clinical settings.
Headache is the most common side effect of Rystiggo and is usually mild to moderate, resolving with standard pain relief such as paracetamol or ibuprofen. However, if you experience a severe headache accompanied by fever, neck stiffness, nausea, vomiting, or sensitivity to light, seek immediate medical attention as these could be signs of aseptic meningitis. This is a rare but serious condition that requires prompt medical evaluation. In most cases, aseptic meningitis associated with Rystiggo is reversible with appropriate treatment.
Each treatment cycle of Rystiggo consists of 6 weekly infusions. The timing between treatment cycles varies from patient to patient and is determined by your physician based on your individual clinical response. Your doctor will assess your symptoms, disease activity, and IgG levels to decide when a new treatment cycle is appropriate. Some patients may need cycles more frequently, while others may have longer intervals between cycles. Regular follow-up appointments are important for optimal treatment planning.
References
This article is based on the following evidence-based sources and international medical guidelines:
- European Medicines Agency (EMA). Rystiggo (rozanolixizumab) — Summary of Product Characteristics. EMA/2023. Available at: www.ema.europa.eu
- Bril V, Drucke B, et al. Safety and efficacy of rozanolixizumab in generalized myasthenia gravis: a randomized, double-blind, placebo-controlled, adaptive phase 3 study (MycarinG). The Lancet Neurology. 2023;22(5):383-394.
- Nowak RJ, Coffey CS, et al. Phase 2 trial of rozanolixizumab in generalized myasthenia gravis. Neurology. 2022;98(24):e2448-e2459.
- Sanders DB, Wolfe GI, et al. International consensus guidance for management of myasthenia gravis: Executive summary. Neurology. 2016;87(4):419-425.
- Myasthenia Gravis Foundation of America (MGFA). Clinical Classification of Myasthenia Gravis. Available at: myasthenia.org
- Gilhus NE, Tzartos S, Evoli A, et al. Myasthenia gravis. Nature Reviews Disease Primers. 2019;5(1):30.
- World Health Organization (WHO). Model List of Essential Medicines. 23rd edition, 2023.
- Ulrichts P, Guglietta A, et al. Neonatal Fc receptor antagonist efgartigimod and rozanolixizumab in generalized myasthenia gravis: a review of current evidence. Therapeutic Advances in Neurological Disorders. 2023;16.
Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, composed of licensed specialist physicians with expertise in neurology, clinical pharmacology, and autoimmune disorders.
iMedic Medical Editorial Team — specialists in neurology and clinical pharmacology with documented clinical experience in neuromuscular disorders.
iMedic Medical Review Board — independent review according to EMA, FDA, and international treatment guidelines. All medical claims verified against peer-reviewed literature.
All information follows the GRADE evidence framework. Sources include EMA-approved product information, randomized controlled trials (Lancet Neurology, Neurology), international consensus guidelines, and WHO recommendations. No commercial funding or pharmaceutical industry influence.