Sylvant
Sylvant (siltuximab) is a preferred infusion treatment for idiopathic multicentric Castleman disease (iMCD). This medication is given once every 3 weeks by a healthcare provider. It's brand only and might be expensive.
What is Sylvant (siltuximab)?
What is Sylvant (siltuximab) used for?
- Multicentric Castleman disease (MCD) in people who don't have human immunodeficiency virus (HIV) and human herpesvirus‑8 (HHV‑8), or idiopathic MCD (iMCD)
How Sylvant (siltuximab) works
Sylvant (siltuximab) is an interleukin-6 (IL-6) antagonist. In multicentric Castleman disease (MCD), the body makes too much of a chemical called IL-6. This causes abnormal signaling and inflammation, leading to organ damage and other harmful conditions. Sylvant (siltuximab) binds directly to IL-6 and stops it from interacting with its target receptor on immune cells. It's thought that this helps relieve common symptoms of MCD.
Drug facts
| Common Brands | Sylvant |
|---|---|
| Drug Class | Interleukin-6 (IL-6) antagonist |
| Controlled Substance Classification | Not a controlled medication |
| Generic Status | No lower-cost generic available |
| Availability | Prescription only |
Side effects of Sylvant (siltuximab)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Skin rash (28%)
- Itchy skin (28%)
- Upper respiratory tract infection (e.g., common cold, 26%)
- Swelling (26%)
- Weight gain (19%)
- High uric acid level in the blood (11%)
Less Common Side Effects
- Headache
- Lower respiratory tract infection (e.g., bronchitis, pneumonia)
- Mouth and throat pain
- Constipation
- Kidney damage
- Low platelet count
- High triglycerides (fat in the blood)
Sylvant (siltuximab) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Severe allergic reaction: trouble breathing, swelling of the lips, tongue, or face, chest tightness, rash
- Stomach or intestinal damage: sudden, severe pain or tenderness in your stomach
Pros and cons of Sylvant (siltuximab)
Pros
- First-choice treatment for idiopathic multicentric Castleman disease (iMCD)
- Only have to get it once every 3 weeks
- Might be able to receive the infusion in your home
- Dose can be adjusted based on your weight
Cons
- Must be given by a healthcare provider as an infusion into the veins
- Must get regular bloodwork done before and during treatment to make sure Sylvant (siltuximab) is safe for you to receive
- Not well studied in people over the age of 65, so it's unknown how well it works for them
- Only available as a brand medication, so it can be expensive
Pharmacist tips for Sylvant (siltuximab)
- Try not to make any other plans for the rest of the day after your first infusion, because you won’t know how your body will react to Sylvant (siltuximab). Your provider will be available to monitor you for any serious reactions.
- Make sure to tell your provider all of the medications you're taking before starting treatment. Sylvant (siltuximab) can interact with several medications, and your provider might need to adjust your dose accordingly.
- Mark your next Sylvant (siltuximab) infusion appointment on your calendar so you don't miss it. Even if you start to feel better, treatment typically continues every 3 weeks until your symptoms return. If your symptoms come back, it means the medication might not work as well anymore and your provider will discuss alternative treatment options with you.
- Remember to get your bloodwork done on time during treatment with Sylvant (siltuximab). For the first year, you'll need to get these blood tests done before each infusion. After this time, you'll need to get these tests done every 3 dosing cycles. Your provider must check your blood counts to make sure Sylvant (siltuximab) is safe for you to receive.
- Sylvant (siltuximab) can make it harder for you to fight off infections. Tell your healthcare provider right away if you feel sick during treatment so that you can be checked and treated for any infections.
- Since there's a potential risk of harm to your unborn baby if you receive Sylvant (siltuximab) while pregnant, use birth control during treatment and for 3 months after your last dose. Some forms of birth control might not work as well while you're receiving Sylvant (siltuximab), so ask your provider about birth control that's right for you. If you do become pregnant while receiving this medication, tell your provider.
- It's not recommended to breastfeed while receiving Sylvant (siltuximab) and for 3 months after your last dose. If you have questions or concerns, speak with your provider.
Risks and warnings for Sylvant (siltuximab)
Sylvant (siltuximab) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Infection risk
You shouldn't receive Sylvant (siltuximab) if you have a severe infection. This medication can hide signs of an infection (e.g., fever), which can prevent you from getting the proper treatment you might need to get healthy again. Additionally, Sylvant (siltuximab) can make it harder for you to fight off infections. Your provider might have you wait until your infection gets better before giving you Sylvant (siltuximab). Tell your healthcare provider right away if you feel sick anytime during treatment.
Avoid live vaccines
During Sylvant (siltuximab) treatment, you can receive most vaccines, but be sure to avoid any live vaccines. This is because Sylvant (siltuximab) can interfere with your immune system's normal response, so your body might respond to vaccines differently compared to healthy people. Make sure your vaccinations are up to date before starting Sylvant (siltuximab). Tell your provider that you're receiving Sylvant (siltuximab) before you get any vaccines so they can make sure which vaccines are appropriate for you.
Infusion-related reactions
Let your provider know if you start to feel unwell during your Sylvant (siltuximab) infusion. These infusion-related symptoms can include back pain, chest pain or discomfort, nausea and vomiting, flushing, skin redness, and feeling like your heart is racing.
If any of these reactions occur, your provider might need to adjust how fast you get Sylvant (siltuximab) through your vein (the infusion rate), temporarily stop the infusion, or give you medications (like acetaminophen (Tylenol), antihistamines, or steroids) to manage your symptoms. This might also mean you need to have these medications before your next infusion to prevent or lessen the severity of these symptoms. If you've previously had an infusion-related reaction, your provider may want to observe you for a little while to see how you respond to the infusion in case they need to give you appropriate treatment.
Rarely, Sylvant (siltuximab) can cause anaphylaxis (closing of the throat). If you experience trouble breathing, swelling of your lips, tongue, or face, chest tightness, or rash after receiving this medication, get medical help right away. If this happens during your infusion, your provider will stop the infusion and you won't receive Sylvant (siltuximab) anymore.
Risk of damage in stomach and intestines
- Risk factors: High risk for a stomach bleed
Although rare, Sylvant (siltuximab) can damage your stomach or intestines, which can result in serious bleeds. Let your provider know if you had any recent stomach surgery or have any problems with your gut. You should only use this medication if the benefit is greater than the risk for stomach damage. Call 911 if you get sudden, severe pain or tenderness in your stomach while taking Sylvant (siltuximab), because this could be a sign of stomach or intestinal damage.
Sylvant (siltuximab) dosage
Typical dosage for Sylvant (siltuximab)
Sylvant (siltuximab) is only available as an intravenous (IV) infusion that's administered by a healthcare provider. The dose depends on your body weight. In general, the typical dose is 11 mg/kg of body weight given over 1 hour through an infusion into your veins every three weeks.
