What is Kevzara (Sarilumab)?
Kevzara, the brand name for sarilumab, is a fully human monoclonal antibody. As a biologic drug, it's created using living cells and specifically targets the immune system to interrupt inflammation. Kevzara is an interleukin-6 (IL-6) receptor antagonist, administered via subcutaneous injection which patients can often self-administer at home.
The Mechanism of Action: How Kevzara Works
Cytokines like IL-6 are naturally produced by the immune system to regulate inflammation. However, in some autoimmune diseases, excessive IL-6 leads to chronic inflammation and tissue damage. Kevzara works by binding to the IL-6 receptor, preventing IL-6 from activating it and reducing inflammation. This action helps to:
- Decrease pain, swelling, and stiffness.
- Slow joint damage progression in conditions like rheumatoid arthritis.
- Lower levels of the inflammatory marker C-reactive protein (CRP).
What Conditions Does Kevzara Treat?
Kevzara is approved for treating several inflammatory conditions in adults and certain pediatric patients, often after other medications have been insufficient. These include:
- Moderately to severely active rheumatoid arthritis (RA): For adults who haven't responded well to or tolerated other DMARDs.
- Polymyalgia rheumatica (PMR): For adults with an inadequate response to corticosteroids or difficulty tapering their dose.
- Active polyarticular juvenile idiopathic arthritis (pJIA): For patients weighing 63 kg or more.
Kevzara vs. Other Treatments for RA
Kevzara is a biologic DMARD. Here's how it compares to some other RA treatments:
| Feature | Kevzara (Sarilumab) | Anti-TNF Biologics (e.g., Adalimumab/Humira) | JAK Inhibitors (e.g., Upadacitinib/Rinvoq) |
|---|---|---|---|
| Drug Class | IL-6 Receptor Antagonist (Biologic) | Tumor Necrosis Factor (TNF) Inhibitor (Biologic) | Janus Kinase (JAK) Inhibitor (Targeted Synthetic DMARD) |
| Mechanism | Blocks IL-6 cytokine signaling by binding to its receptor. | Blocks TNF-alpha cytokine signaling. | Blocks Janus kinase enzymes involved in inflammation signaling pathways. |
| Administration | Subcutaneous injection, typically every two weeks. | Subcutaneous injection, various frequencies depending on the drug. | Oral tablet, once daily. |
| Usage | Approved for RA, PMR, and pJIA. | Approved for RA, Crohn's, psoriasis, and more. | Approved for RA, psoriatic arthritis, ulcerative colitis, and more. |
| Efficacy | Can be effective as a monotherapy for RA, potentially superior to some TNF-inhibitors. | Established efficacy for RA and other inflammatory diseases. | Offers an alternative mechanism of action to biologics. |
| Considerations | Requires caution with other immunosuppressants due to infection risk. | Established safety and efficacy profile over many years. | Can have different side effects than biologics, including increased cardiovascular risk. |
Important Safety Information and Side Effects
Kevzara can cause side effects and requires careful monitoring. Key risks include:
- Serious Infections: Kevzara suppresses the immune system, increasing the risk of serious, potentially fatal infections like tuberculosis (TB). Patients need to be tested for latent TB before starting treatment.
- Gastrointestinal Perforation: Rare cases of tears in the stomach or intestines have occurred, particularly in patients with a history of diverticulitis or those taking certain other medications.
- Lab Abnormalities: Kevzara can affect blood test results, potentially causing low neutrophil and platelet counts, increased liver enzymes, and increased cholesterol levels.
- Cancer: An increased risk of certain cancers has been noted with immunosuppressive drugs.
- Allergic Reactions: Serious allergic reactions, such as facial swelling, have been reported.
- Live Vaccines: Live vaccines should not be given during Kevzara treatment.
Conclusion
Kevzara (sarilumab) is an effective treatment option for adults with moderate to severe rheumatoid arthritis and polymyalgia rheumatica, as well as certain pediatric pJIA patients, especially when other DMARDs haven't worked. It reduces inflammation by blocking the IL-6 receptor, helping to relieve symptoms and protect joints. However, its use requires close medical supervision and regular lab tests due to potential serious side effects, including increased infection risk and gastrointestinal issues. Discuss the benefits and risks with your healthcare provider to determine if Kevzara is right for you. You can find more information from resources like the American College of Rheumatology.
