Kevzara: Uses, Dosage & Side Effects
An IL-6 receptor-blocking monoclonal antibody for the treatment of polyarticular juvenile idiopathic arthritis (pJIA) in children aged 2 years and older
Kevzara (sarilumab) is a prescription biologic medication belonging to the class of interleukin-6 (IL-6) receptor inhibitors. It is a fully human monoclonal antibody that specifically blocks the IL-6 receptor, thereby suppressing the inflammatory cascade responsible for joint damage, pain, swelling, and systemic symptoms in autoimmune arthritis. Kevzara is approved for the treatment of active polyarticular juvenile idiopathic arthritis (pJIA) in children aged 2 years and older who have had an inadequate response to prior therapy, and can be used alone or in combination with methotrexate. It is administered as a subcutaneous injection by a healthcare professional, with weight-based dosing calculated at each visit. Regular blood monitoring for neutrophil counts, liver enzymes, and lipid levels is required throughout treatment.
Quick Facts: Kevzara
Key Takeaways
- Kevzara (sarilumab) is a fully human monoclonal antibody that blocks the interleukin-6 (IL-6) receptor, a critical mediator of inflammation in autoimmune arthritis conditions including polyarticular juvenile idiopathic arthritis (pJIA) and rheumatoid arthritis.
- It is approved for children aged 2 years and older (weighing at least 10 kg) with active pJIA who have not responded adequately to previous treatment, and can be used as monotherapy or in combination with methotrexate.
- Dosing is weight-based and administered as a subcutaneous injection by a healthcare professional: 4 mg/kg for children weighing 10 to less than 30 kg, and 3 mg/kg for those weighing 30 kg or more, recalculated at each visit.
- Regular blood monitoring is essential during treatment to check for low neutrophil counts (neutropenia), elevated liver enzymes, and changes in cholesterol levels, as these are known effects of IL-6 receptor blockade.
- Kevzara must not be used in patients with active serious infections, and vaccination with live vaccines should be avoided during treatment due to the immunosuppressive effects of the medication.
What Is Kevzara and What Is It Used For?
Kevzara contains the active substance sarilumab, a fully human monoclonal antibody of the immunoglobulin G1 (IgG1) subclass. Monoclonal antibodies are highly specialized proteins that are engineered to recognize and bind to a single molecular target in the body with extraordinary precision. In the case of sarilumab, the target is the interleukin-6 receptor (IL-6R), both in its soluble form (sIL-6R) circulating in the blood and its membrane-bound form (mIL-6R) expressed on the surface of various cell types including immune cells, hepatocytes, and synovial fibroblasts.
Interleukin-6 (IL-6) is a pleiotropic pro-inflammatory cytokine that plays a central and multifaceted role in the immune system. Under normal physiological conditions, IL-6 contributes to host defense against infection, acute-phase protein synthesis in the liver, hematopoiesis (blood cell production), and bone metabolism. However, in autoimmune conditions such as juvenile idiopathic arthritis (JIA) and rheumatoid arthritis (RA), IL-6 is produced in excessive quantities within the inflamed synovial tissue (the lining of the joints). This persistent overproduction of IL-6 drives a self-perpetuating cycle of inflammation that manifests as joint pain, swelling, stiffness (particularly morning stiffness), warmth, and progressive damage to cartilage and bone. Beyond the joints, elevated IL-6 also contributes to systemic manifestations including fatigue, anemia of chronic disease, fever, elevated acute-phase reactants (C-reactive protein and erythrocyte sedimentation rate), and growth retardation in children.
By binding to both soluble and membrane-bound IL-6 receptors, sarilumab comprehensively blocks IL-6-mediated signaling through both the classical and trans-signaling pathways. This dual mechanism of action effectively interrupts the inflammatory cascade at a critical upstream point, leading to rapid and sustained reduction in joint inflammation, pain, and structural damage. Clinical studies have demonstrated that sarilumab treatment results in significant improvements in joint tenderness and swelling, reduced levels of inflammatory markers (CRP, ESR), and meaningful improvements in physical function and quality of life.
Polyarticular Juvenile Idiopathic Arthritis (pJIA)
Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease of childhood, affecting approximately 1 in 1,000 children worldwide. The polyarticular subtype (pJIA) is characterized by arthritis affecting five or more joints during the first six months of disease and represents approximately 20-30% of all JIA cases. pJIA can be subdivided into rheumatoid factor (RF)-positive and RF-negative forms, with RF-positive pJIA closely resembling adult rheumatoid arthritis. Children with pJIA often experience significant functional limitations, school absenteeism, and reduced quality of life. Without adequate treatment, pJIA can lead to permanent joint damage, growth disturbances, and long-term disability.
Kevzara is specifically approved for the treatment of active pJIA in children aged 2 years and older who have had an inadequate response to, or are intolerant of, prior disease-modifying antirheumatic drug (DMARD) therapy. It can be used as monotherapy (alone) or in combination with methotrexate, which is the conventional first-line DMARD for pJIA. The approval was based on clinical trial data demonstrating significant improvements in the American College of Rheumatology (ACR) Pediatric response criteria, with a substantial proportion of treated children achieving ACR Pediatric 30, 50, 70, and 90 responses, indicating progressive levels of disease improvement.
Rheumatoid Arthritis in Adults
Kevzara is also widely approved for the treatment of moderate-to-severe active rheumatoid arthritis (RA) in adult patients who have had an inadequate response to, or are intolerant of, one or more conventional synthetic or biologic DMARDs. In adults, Kevzara is available in pre-filled syringes and pre-filled pens for self-injection at home, in addition to the vial formulation used in pediatric settings. The pivotal clinical trials in adult RA (MOBILITY, TARGET, MONARCH) demonstrated that sarilumab, both in combination with methotrexate and as monotherapy, significantly reduced signs and symptoms of RA, inhibited radiographic progression of joint damage, and improved physical function. Notably, the MONARCH trial demonstrated that sarilumab monotherapy was superior to adalimumab (a TNF inhibitor) monotherapy in reducing disease activity.
While TNF inhibitors (such as adalimumab, etanercept, and infliximab) have been the mainstay of biologic therapy for inflammatory arthritis, IL-6 receptor inhibitors like Kevzara offer a distinct mechanism of action that targets a different node of the inflammatory network. This is particularly important for patients who have not responded adequately to TNF inhibitors or who cannot tolerate them. IL-6 receptor blockade has unique effects on acute-phase reactants, hematopoiesis, and lipid metabolism that distinguish it from other biologic classes. Tocilizumab is another IL-6 receptor inhibitor; sarilumab differs in being a fully human (rather than humanized) antibody with a different binding affinity profile.
What Should You Know Before Taking Kevzara?
Contraindications
Kevzara must not be used if you (or your child) are allergic to sarilumab or to any of the other ingredients in the formulation, which include arginine, histidine, polysorbate 20, sucrose, and water for injections. Additionally, Kevzara must not be initiated in patients who have an active serious infection, including localized infections. This is because sarilumab suppresses the immune system's inflammatory response, which could impair the body's ability to fight existing infections and potentially allow them to become more severe or disseminated.
If you develop a serious infection during Kevzara treatment, the medication should be temporarily discontinued until the infection is fully resolved. Your healthcare provider will assess whether it is safe to restart treatment after the infection has been adequately treated.
Warnings and Precautions
Kevzara may increase the risk of serious infections including bacterial, viral, and opportunistic infections. Patients have developed serious infections leading to hospitalization, including tuberculosis, bacterial pneumonia, invasive fungal infections, and other opportunistic infections. If you develop signs of infection (fever, persistent cough, weight loss, fatigue, shortness of breath), contact your healthcare provider immediately. Treatment should be interrupted until the infection is controlled.
Before starting Kevzara, discuss the following important points with your healthcare provider:
- Infections: If you or your child frequently get infections, or have a history of recurring infections, tell your doctor. Kevzara can reduce the body's ability to fight infections, meaning you may be more susceptible to infections or existing infections may worsen. Common infections during treatment include upper respiratory tract infections and urinary tract infections.
- Tuberculosis (TB): Before starting Kevzara, your doctor will test for tuberculosis. If you have symptoms of TB (persistent cough, weight loss, lethargy, low-grade fever) or have been in close contact with someone who has TB, inform your doctor. Patients with latent TB should receive standard antimycobacterial therapy before initiating Kevzara. During treatment, patients should be monitored for signs and symptoms of active TB.
- Viral hepatitis and liver disease: If you have had viral hepatitis or other liver disease, tell your doctor. Before starting Kevzara, your doctor will perform blood tests to check liver function (transaminases). Liver enzymes should be monitored regularly during treatment, as elevations in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are commonly observed with IL-6 receptor inhibitors.
- Diverticulitis: If you have had diverticulitis (inflammation of pouches in the intestinal wall), stomach ulcers, or intestinal sores, or if you develop symptoms such as fever and abdominal pain that do not resolve, contact your doctor. Gastrointestinal perforations have been reported in patients treated with IL-6 receptor inhibitors, primarily in those with a history of diverticulitis.
- Cancer: If you have had any type of cancer, inform your doctor. The role of IL-6 inhibition in the development or progression of malignancy is not fully understood. As with all immunosuppressive therapies, there is a theoretical risk of malignancy, and patients should be monitored accordingly.
- Vaccinations: If you have recently been vaccinated or plan to be vaccinated, tell your doctor. Live and live-attenuated vaccines should not be given during Kevzara treatment because the immune response may be insufficient. Inactivated vaccines may be given, but the immune response may be diminished. Ideally, all vaccinations should be brought up to date before starting treatment.
Blood Monitoring Requirements
Regular blood tests are an essential part of Kevzara treatment. Before starting therapy and at regular intervals during treatment, your doctor will monitor:
- Neutrophil counts: Sarilumab commonly causes a reduction in neutrophils (a type of white blood cell important for fighting infections). Treatment should not be initiated if the absolute neutrophil count (ANC) is below 2,000 cells/mm³. Dose modifications or interruption may be necessary if neutrophils drop below certain thresholds during treatment.
- Platelet counts: Reductions in platelet counts have been observed. Treatment should not be initiated if the platelet count is below 150,000 cells/mm³.
- Liver enzymes: ALT and AST levels should be monitored, as elevations commonly occur. Dose adjustment or interruption may be required for significant elevations.
- Lipid levels: IL-6 receptor blockade commonly leads to increases in total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Lipid parameters should be assessed approximately 4 to 8 weeks after starting treatment, and hyperlipidemia should be managed according to standard clinical guidelines.
Each time you receive a new pack of Kevzara, it is important to note the medicine name, date of use, and batch number (found on the packaging after "Lot") and keep this information in a safe place. This facilitates traceability in case of any safety-related recall or adverse event reporting.
Children and Adolescents
Kevzara is not recommended for children under 2 years of age. Additionally, Kevzara must not be given to children with pJIA who weigh less than 10 kg, as the safety and efficacy have not been established in this population. The pharmacokinetic profile and dosing recommendations for Kevzara in children are based on body weight, and the available clinical data support its use only in children aged 2 years and older who weigh at least 10 kg.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor before using Kevzara. The effects of sarilumab on human pregnancy have not been adequately studied, and it is not known whether sarilumab can cause harm to an unborn baby. As a monoclonal antibody of the IgG1 subclass, sarilumab is expected to cross the placenta, particularly during the second and third trimesters. Kevzara should not be used during pregnancy unless your doctor determines that the potential benefit clearly outweighs the potential risk to the fetus. Women of childbearing potential should use effective contraception during treatment and for at least 3 months after the last dose.
It is not known whether sarilumab passes into human breast milk. Human IgG antibodies are known to be present in breast milk, so a risk to the breastfed infant cannot be excluded. The decision whether to discontinue breastfeeding or to discontinue Kevzara treatment should be made in consultation with your doctor, considering the benefit of breastfeeding for the child and the benefit of therapy for the mother.
Driving and Operating Machinery
Kevzara is not expected to significantly affect the ability to drive or operate machinery. However, if you or your child experience tiredness or malaise after receiving Kevzara, you should refrain from driving, cycling, or using machines until you feel well enough to do so safely.
Important Information About Ingredients
Kevzara contains polysorbate 20, at a concentration of approximately 2 mg/mL (2.28 mg per 1.14 mL injection solution). Polysorbates may cause allergic reactions in susceptible individuals. If you or your child have any known allergies to polysorbates or other excipients, inform your healthcare provider before starting treatment.
How Does Kevzara Interact with Other Drugs?
Drug interactions with biologic therapies like Kevzara occur through different mechanisms than those seen with traditional small-molecule drugs. While sarilumab itself is not metabolized by cytochrome P450 (CYP450) enzymes, it can indirectly affect the metabolism of other drugs through its pharmacological action on IL-6 signaling. Under inflammatory conditions, elevated IL-6 levels suppress the expression of several CYP450 enzymes in the liver, including CYP1A2, CYP2C9, CYP2C19, and CYP3A4. When Kevzara blocks IL-6 signaling and reduces inflammation, the activity of these CYP450 enzymes returns toward normal levels. This normalization of enzyme activity can increase the metabolism of drugs that are substrates of these enzymes, potentially reducing their blood levels and therapeutic effectiveness.
Drugs That Must Not Be Combined with Kevzara
The following drug combinations are contraindicated or should be strictly avoided:
- Janus kinase (JAK) inhibitors (e.g., tofacitinib, baricitinib, upadacitinib): These drugs should not be used together with Kevzara due to the risk of additive immunosuppression without established benefit. The combination has not been studied in clinical trials and may significantly increase the risk of serious infections.
- Other biologic DMARDs used to treat arthritis or pJIA (e.g., TNF inhibitors such as adalimumab or etanercept, other IL-6 inhibitors such as tocilizumab, T-cell co-stimulation modulators such as abatacept): Combining two biologic therapies significantly increases the risk of serious infections and other immune-related adverse events without proven additional clinical benefit.
Drugs Requiring Dose Monitoring or Adjustment
The following medications may require dose adjustments when starting or stopping Kevzara, as their blood levels may be affected by the normalization of CYP450 enzyme activity:
| Drug / Drug Class | Interaction Mechanism | Clinical Significance | Action Required |
|---|---|---|---|
| Statins (atorvastatin, simvastatin) | Increased CYP3A4 metabolism | Reduced statin blood levels | Monitor cholesterol; dose adjustment may be needed |
| Oral contraceptives | Increased CYP3A4 metabolism | Potentially reduced contraceptive efficacy | Consider additional contraceptive measures; discuss with doctor |
| Theophylline | Increased CYP1A2 metabolism | Reduced theophylline levels | Monitor theophylline levels; dose increase may be needed |
| Warfarin | Increased CYP2C9 metabolism | Reduced anticoagulant effect (lower INR) | Monitor INR closely; warfarin dose adjustment may be necessary |
| Cyclosporine | Increased CYP3A4 metabolism | Potentially reduced cyclosporine levels | Monitor drug levels; dose adjustment as needed |
| Benzodiazepines (midazolam) | Increased CYP3A4 metabolism | Potentially reduced sedative effect | Inform doctor; clinical monitoring |
It is particularly important to inform your healthcare provider about all medications you or your child are taking, including prescription drugs, over-the-counter medications, herbal supplements, and vitamins. When starting Kevzara, your doctor may need to check the blood levels of drugs with a narrow therapeutic index (such as warfarin, theophylline, and cyclosporine) more frequently and adjust doses accordingly. The same monitoring should be performed when Kevzara is discontinued, as CYP450 enzyme activity may be suppressed again as IL-6 levels rise with the return of inflammation.
Kevzara can be used in combination with methotrexate for the treatment of pJIA. No formal pharmacokinetic interaction study has been conducted between sarilumab and methotrexate, but clinical trials have demonstrated that the combination is safe and effective. Population pharmacokinetic analyses have not identified a significant effect of methotrexate on sarilumab clearance.
What Is the Correct Dosage of Kevzara?
Kevzara treatment should be initiated and supervised by a physician experienced in the diagnosis and treatment of juvenile idiopathic arthritis or rheumatoid arthritis. The dosing regimen depends on the patient population and body weight. Kevzara is administered as a subcutaneous injection (an injection under the skin), typically into the abdomen, thigh, or upper arm.
Children with pJIA (2 Years and Older)
The dosage of Kevzara for children with polyarticular juvenile idiopathic arthritis is determined by body weight and is recalculated at each administration to account for growth:
Children weighing 10 kg to less than 30 kg
Dose: 4 mg per kg body weight, administered subcutaneously every 2 weeks
Example: A child weighing 20 kg would receive 80 mg (20 kg × 4 mg/kg) per injection.
Children weighing 30 kg or more
Dose: 3 mg per kg body weight, administered subcutaneously every 2 weeks
Example: A child weighing 40 kg would receive 120 mg (40 kg × 3 mg/kg) per injection.
The injection is prepared and administered by a healthcare professional using the vial formulation. The required volume is withdrawn from the vial based on the calculated dose. Kevzara must not be given to children with pJIA who weigh less than 10 kg.
Adults with Rheumatoid Arthritis
For adult patients with moderate-to-severe rheumatoid arthritis, the recommended dose is 200 mg administered subcutaneously once every two weeks. In cases where laboratory abnormalities occur (such as neutropenia, thrombocytopenia, or elevated liver enzymes), the dose may be reduced to 150 mg every two weeks, or treatment may be temporarily interrupted. Adult patients may self-inject at home using a pre-filled syringe or pre-filled pen after receiving proper training from a healthcare professional.
Elderly Patients
No dose adjustment is required for elderly patients based on age alone. However, as elderly patients may be more susceptible to infections and may have reduced hepatic and renal function, careful clinical monitoring is recommended. The same dose modification guidelines based on laboratory parameters (neutrophil counts, liver enzymes, platelet counts) apply to elderly patients as to younger adults.
Dose Modifications for Laboratory Abnormalities
| Laboratory Parameter | Result | Recommended Action |
|---|---|---|
| ANC (Neutrophils) | 500–1,000 cells/mm³ | Withhold Kevzara until ANC > 1,000; then resume at reduced dose |
| ANC (Neutrophils) | < 500 cells/mm³ | Discontinue Kevzara |
| Platelet Count | 50,000–100,000 cells/mm³ | Withhold Kevzara until platelets > 100,000; then resume at reduced dose |
| ALT (Liver enzyme) | 1–3 × upper limit of normal (ULN) | Consider dose reduction of concomitant methotrexate; monitor closely |
| ALT (Liver enzyme) | 3–5 × ULN | Withhold Kevzara until ALT < 3 × ULN; then resume at reduced dose |
| ALT (Liver enzyme) | > 5 × ULN | Discontinue Kevzara |
Missed Dose
If a dose of Kevzara is missed, the action depends on how much time has passed:
- 3 days or fewer since the missed dose: Take the missed dose as soon as possible, then continue with the next dose at the usual scheduled time.
- 4 days or more since the missed dose: Skip the missed dose and take the next dose at the usual scheduled time. Do not take a double dose to make up for the one that was missed.
If you are unsure when to take your next dose, contact your healthcare provider, pharmacist, or nurse for advice.
Overdose
If you or your child have used more Kevzara than prescribed, contact your healthcare provider, pharmacist, or nurse immediately. There is limited experience with overdose of sarilumab in clinical trials. In the event of an overdose, the patient should be monitored for signs and symptoms of adverse reactions, and appropriate symptomatic treatment should be initiated as clinically indicated.
Do not stop using Kevzara without first consulting your doctor, even if you feel better. Stopping treatment may cause your arthritis symptoms to return and potentially worsen. Your doctor will discuss the best approach if treatment needs to be adjusted or discontinued.
What Are the Side Effects of Kevzara?
Like all medicines, Kevzara can cause side effects, although not everyone will experience them. The side effects observed in children with pJIA are generally consistent with those known from the adult rheumatoid arthritis population, with the safety profile reflecting the immunomodulatory mechanism of IL-6 receptor blockade. Most side effects are manageable with appropriate monitoring and dose modifications.
Serious Side Effects
Tell your doctor immediately if you think you or your child may have an infection. Signs and symptoms include fever, sweating, chills, muscle aches, persistent cough, weight loss, or burning sensation during urination. Infections may occur in up to 1 in 10 patients treated with Kevzara and can become serious if not promptly recognized and treated.
Serious infections that have been reported with Kevzara include pneumonia, cellulitis (skin infection), herpes zoster (shingles), urinary tract infections, diverticulitis, and appendicitis. In rare cases, opportunistic infections (infections caused by organisms that usually do not cause disease in people with healthy immune systems) have been reported, including tuberculosis. Gastrointestinal perforations have also been reported, primarily in patients with a history of diverticular disease.
Side Effects in Children with pJIA
The following side effects have been observed in clinical trials of Kevzara in children with polyarticular juvenile idiopathic arthritis:
Very Common
May affect more than 1 in 10 patients
- Upper respiratory tract infections (sinus infections, sore throat, runny or stuffy nose, nasopharyngitis)
- Low white blood cell counts (neutropenia), shown in blood test results
- Injection site reactions (redness, itching, pain at the injection site)
Common
May affect up to 1 in 10 patients
- Abnormal liver function tests (elevated alanine aminotransferase / ALT)
- Elevated cholesterol and triglyceride levels
- Low platelet counts (thrombocytopenia)
Uncommon
May affect up to 1 in 100 patients
- Serious infections (pneumonia, cellulitis, herpes zoster)
- Oral herpes (cold sores)
- Elevated creatine phosphokinase (CPK)
Rare
May affect up to 1 in 1,000 patients
- Gastrointestinal perforation
- Severe hypersensitivity reactions (anaphylaxis)
- Opportunistic infections (including tuberculosis)
Additional Side Effects Known from Adult Studies
The following additional side effects have been reported in clinical trials and post-marketing surveillance in adult patients with rheumatoid arthritis. While these have not all been specifically reported in the pediatric population, they are considered class effects of IL-6 receptor inhibitors and should be monitored for in all patients:
- Infections: Upper respiratory tract infections (very common); urinary tract infections, nasopharyngitis, oral herpes (common)
- Blood disorders: Neutropenia (very common); thrombocytopenia (common); leukopenia (common)
- Metabolic effects: Hypercholesterolemia, hypertriglyceridemia (common)
- Liver effects: Elevated transaminases (common)
- Skin reactions: Injection site erythema, injection site pruritus (common)
Reporting Side Effects
If you or your child experience any side effects, including those not listed above, tell your healthcare provider, pharmacist, or nurse. You can also report suspected side effects directly to your national pharmacovigilance authority. In the United States, report to the FDA MedWatch program. In the European Union, report to your national competent authority. In the United Kingdom, report via the Yellow Card scheme. Reporting side effects helps to continuously monitor the benefit-risk balance of medicines and ensures patient safety.
How Should You Store Kevzara?
Proper storage of Kevzara is essential to maintain the stability, potency, and safety of the medication. As a biologic product containing a monoclonal antibody protein, sarilumab is sensitive to temperature extremes, freezing, and light exposure. Improper storage can lead to protein degradation, aggregation, or loss of efficacy.
- Refrigerated storage: Store in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze the medication. If the solution has been frozen, do not use it, even if it has been thawed.
- Room temperature storage: Once removed from the refrigerator, Kevzara vials may be stored at room temperature up to 25°C (77°F) for a maximum of 14 days. Write down the date when the vial was removed from the refrigerator on the designated space on the outer carton. Once removed from the refrigerator, do not return the vial to the refrigerator.
- Light protection: Keep the vial in the original carton to protect from light. Do not store the vial outside its carton.
- Expiry date: Do not use after the expiry date printed on the label and carton after "EXP." The expiry date refers to the last day of that month.
- Visual inspection: Before use, inspect the solution in the vial. Do not use if the solution is cloudy, discolored, or contains visible particles, or if any part of the vial appears damaged.
- Keep out of reach of children: Store this medicine out of the sight and reach of children.
Unused or expired medication should not be disposed of via household waste or wastewater. Healthcare professionals are responsible for the proper disposal of unused medication. These measures help to protect the environment. In many countries, unused medicines can be returned to pharmacies for safe disposal.
What Does Kevzara Contain?
Each vial of Kevzara contains 270 mg of sarilumab in 1.54 mL of solution, yielding a concentration of approximately 175 mg/mL. Sarilumab is a fully human monoclonal antibody of the IgG1 subclass, produced by recombinant DNA technology in Chinese hamster ovary (CHO) cells.
Active Ingredient
| Component | Amount per Vial | Concentration |
|---|---|---|
| Sarilumab | 270 mg in 1.54 mL | 175 mg/mL |
Inactive Ingredients (Excipients)
The following inactive ingredients are included in the formulation to ensure stability, maintain the correct pH, and preserve the protein structure of the monoclonal antibody:
- Arginine: An amino acid used as a stabilizer to prevent protein aggregation
- Histidine: An amino acid used as a buffer to maintain optimal pH
- Polysorbate 20 (E 432): A surfactant that prevents protein adsorption and aggregation (2 mg/mL)
- Sucrose: A sugar used as a stabilizer and tonicity agent
- Water for injections: The solvent for the injectable solution
Appearance and Packaging
Kevzara solution for injection is a clear, colorless to pale yellow liquid supplied in single-use glass vials. Each vial contains 1.54 mL of solution. Kevzara is available in packs containing 2 vials. Not all pack sizes may be marketed in every country.
The marketing authorization holder is Sanofi Winthrop Industrie, Gentilly, France. The product is manufactured at multiple sites including Sanofi Aventis Deutschland GmbH (Frankfurt am Main, Germany) and Genzyme Ireland Ltd. (Waterford, Ireland).
Frequently Asked Questions About Kevzara
Both Kevzara (sarilumab) and tocilizumab are IL-6 receptor inhibitors, but they differ in several important ways. Sarilumab is a fully human monoclonal antibody, whereas tocilizumab is a humanized monoclonal antibody. This means that sarilumab's protein sequence is entirely human in origin, which may reduce the risk of anti-drug antibody formation. Additionally, sarilumab has a higher binding affinity for the IL-6 receptor compared to tocilizumab. In clinical practice, both medications are effective for treating inflammatory arthritis, but individual patients may respond differently to each drug. Your doctor will recommend the most appropriate treatment based on your specific clinical situation, previous treatment history, and individual risk factors.
Kevzara does not cure juvenile idiopathic arthritis (JIA). It is a disease-modifying therapy that effectively controls the symptoms and underlying inflammatory process of the disease. By blocking the IL-6 receptor, Kevzara reduces joint inflammation, pain, swelling, and stiffness, and helps prevent progressive joint damage. Many patients experience significant improvement in their symptoms and quality of life while on treatment. However, if Kevzara is discontinued, the symptoms of JIA may return. Long-term treatment is typically necessary to maintain disease control, and your doctor will regularly assess whether continued treatment is appropriate.
Many patients begin to notice improvement in their symptoms within the first 2 to 4 weeks of starting Kevzara. Reductions in joint pain, swelling, and morning stiffness are typically among the earliest benefits. Laboratory markers of inflammation (such as C-reactive protein and erythrocyte sedimentation rate) often decrease rapidly, sometimes within days of the first injection. However, the full therapeutic benefit may continue to develop over 12 to 24 weeks of treatment. Your doctor will typically evaluate the effectiveness of Kevzara after approximately 12 weeks. If there is insufficient response by that time, the treatment plan may be reassessed.
Live and live-attenuated vaccines (such as MMR, varicella, rotavirus, and oral polio vaccine) should not be given while your child is receiving Kevzara, as the immunosuppressive effects of the medication may lead to an inadequate immune response or, in rare cases, the vaccine organism could cause infection. Inactivated vaccines (such as influenza, pneumococcal, and tetanus/diphtheria vaccines) can be given during treatment, although the immune response may be somewhat reduced. It is highly recommended that all vaccinations be brought up to date before starting Kevzara treatment. Discuss your child's vaccination schedule with their doctor to ensure appropriate timing and protection.
Regular blood tests are an essential part of Kevzara treatment because the medication affects several blood parameters. IL-6 receptor blockade commonly causes a decrease in neutrophil counts (a type of white blood cell that fights infections), which can increase susceptibility to infections. It can also affect platelet counts, liver enzyme levels (ALT, AST), and lipid levels (cholesterol and triglycerides). By monitoring these parameters regularly, your doctor can detect changes early and make appropriate dose adjustments or temporarily pause treatment if needed. Typically, blood tests are performed before starting treatment, after 4 to 8 weeks, and then periodically throughout the course of therapy. This proactive monitoring is key to ensuring the safety and effectiveness of treatment.
If your child develops signs of an infection while receiving Kevzara, such as fever, persistent cough, sore throat, burning during urination, unusual fatigue, or chills, contact your healthcare provider promptly. Mild infections (such as common colds) may be managed without interrupting treatment, but your doctor will assess the situation. For more serious infections, Kevzara treatment will typically be paused until the infection has been fully treated and resolved. Do not restart Kevzara without your doctor's approval. It is important to note that because Kevzara suppresses the IL-6-mediated inflammatory response, some of the usual signs of infection (such as fever and elevated CRP) may be blunted, so be vigilant for any symptoms that seem unusual.
References
- European Medicines Agency (EMA). Kevzara (sarilumab) – Summary of Product Characteristics. Last updated 2025. Available at: ema.europa.eu/kevzara
- U.S. Food and Drug Administration (FDA). Kevzara (sarilumab) – Prescribing Information. Revised 2024. Available at: accessdata.fda.gov
- Genovese MC, Fleischmann R, Kivitz AJ, et al. Sarilumab Plus Methotrexate in Patients With Active Rheumatoid Arthritis and Inadequate Response to Methotrexate: Results of a Phase III Study (MOBILITY). Arthritis Rheumatol. 2015;67(6):1424-1437. doi:10.1002/art.39093
- Fleischmann R, van Adelsberg J, Lin Y, et al. Sarilumab and Nonbiologic Disease-Modifying Antirheumatic Drugs in Patients With Active Rheumatoid Arthritis and Inadequate Response or Intolerance to Tumor Necrosis Factor Inhibitors. Arthritis Rheumatol. 2017;69(2):277-290. doi:10.1002/art.39944
- Burmester GR, Lin Y, Patel R, et al. Efficacy and safety of sarilumab monotherapy versus adalimumab monotherapy for the treatment of patients with active rheumatoid arthritis (MONARCH): a randomised, double-blind, parallel-group phase III trial. Ann Rheum Dis. 2017;76(5):840-847. doi:10.1136/annrheumdis-2016-210310
- Ringold S, Angeles-Han ST, Engel ME, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Treatment of Juvenile Idiopathic Arthritis. Arthritis Care Res. 2019;71(6):717-734. doi:10.1002/acr.23885
- Ravelli A, Consolaro A, Horneff G, et al. Treating Juvenile Idiopathic Arthritis to Target: recommendations of an international task force. Ann Rheum Dis. 2018;77(6):819-828. doi:10.1136/annrheumdis-2018-213030
- Petty RE, Southwood TR, Manners P, et al. International League of Associations for Rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001. J Rheumatol. 2004;31(2):390-392.
- World Health Organization (WHO). Model List of Essential Medicines for Children. 9th edition, 2023. Available at: who.int
- British National Formulary (BNF). Sarilumab. National Institute for Health and Care Excellence (NICE). Available at: bnf.nice.org.uk
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iMedic Medical Editorial Team – Specialists in Rheumatology, Immunology, and Clinical Pharmacology
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