Frequently asked questions

Castleman disease (CD) is a rare condition in which cells of the lymph nodes and related tissues grow rapidly but are not cancerous. If left undiagnosed and untreated, CD can lead to organ failure or other harmful conditions—even if it isn’t cancerous.

Unicentric Castleman disease (UCD): Affects only a single lymph node
Multicentric Castleman disease (MCD): Affects multiple lymph nodes

Idiopathic multicentric Castleman disease (iMCD), a subtype of Castleman disease, is a rare disorder in which multiple groups of lymph nodes are swollen and are accompanied by other symptoms like fluid accumulation, enlarged organs, and flu-like symptoms such as night sweats, fever, and fatigue.

Common symptoms of iMCD include swollen lymph nodes, fatigue, anemia, night sweats, fever, unintended weight change, flu-like symptoms, rash, fluid accumulation, and abnormal enlargement of organs, such as the liver and spleen.

It is believed that interleukin-6 (IL-6) is a common disease driver in iMCD and may be associated with the intensity of symptoms.

Typically, the production of IL-6, a type of cytokine, is an immune response of the body to an infection or tissue damage. In some patients with iMCD, IL-6 is found to be elevated during flare-ups, but the exact cause of this elevation remains unknown.

iMCD is not cancer; however, it can mimic the symptoms of many other diseases, including some cancers, and can be challenging to diagnose.

SYLVANT® (siltuximab) is the only therapy approved by the US Food and Drug Administration (FDA) for the treatment of people with multicentric Castleman disease (MCD) who have tested negative for human immunodeficiency virus (HIV) and human herpesvirus-8 (HHV-8).

Siltuximab (SYLVANT®) is recommended by the National Comprehensive Cancer Network® (NCCN®) as a preferred treatment option for iMCD.

SYLVANT is the preferred treatment for people with iMCD. It is administered via 1-hour intravenous (IV) infusions under the supervision of a healthcare professional at an infusion center.

SYLVANT works by targeting interleukin-6 (IL-6), a molecule found in overabundance in some people with iMCD. Over time, SYLVANT has been shown to resolve common symptoms of iMCD and to reduce lymph node size.

Any medication can be associated with side effects, and it can vary from person to person. Here are some of the most common side effects observed in people taking SYLVANT:
  • Rash
  • Itching
  • Upper respiratory tract infections
  • Swelling or fluid accumulation
  • Elevated uric acid in the blood, which is excreted through urine
  • Weight gain
The efficacy of SYLVANT was tested in a randomized clinical trial—the gold standard of clinical studies.

To see if you qualify for help with co-payments or other financial assistance, contact the R.A.R.E.® Patient Support Program, Monday-Friday, 9 AM to 5 PM ET: Phone: 1-855-299-8844, Fax: 1-888-223-1746.
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SYLVANT® (siltuximab) for injection

APPROVED USE

SYLVANT® (siltuximab) is a prescription medicine used to treat people with multicentric Castleman’s disease (MCD) who do not have human immunodeficiency virus (HIV) and human herpesvirus-8 (HHV-8) infection.

It is not known if SYLVANT is safe and effective in children.

IMPORTANT SAFETY INFORMATION

Do not take SYLVANT if you have had a severe allergic reaction to siltuximab or any of the ingredients in SYLVANT. See the Patient Information for SYLVANT for a complete list of ingredients.

SYLVANT® (siltuximab) for injection

APPROVED USE

SYLVANT® (siltuximab) is a prescription medicine used to treat people with multicentric Castleman’s disease (MCD) who do not have human immunodeficiency virus (HIV) and human herpesvirus-8 (HHV-8) infection.

It is not known if SYLVANT is safe and effective in children.

IMPORTANT SAFETY INFORMATION

Do not take SYLVANT if you have had a severe allergic reaction to siltuximab or any of the ingredients in SYLVANT. See the Patient Information for SYLVANT for a complete list of ingredients.

Tell your healthcare provider if you have an infection. You should not receive SYLVANT if you have a severe infection.

Tell your healthcare provider if you have had a recent vaccination or are scheduled to receive any vaccinations. You should not receive a live vaccine during your treatment with SYLVANT.

Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known if SYLVANT will harm your unborn baby. You should not become pregnant while receiving treatment with SYLVANT. Females who are able to become pregnant should use effective birth control during treatment with SYLVANT and for 3 months after stopping treatment.

Tell your healthcare provider if you are breastfeeding or plan to breastfeed. It is not known if SYLVANT passes into your breast milk. You and your healthcare provider should decide if you will take SYLVANT or breastfeed. You should not do both.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

The most common side effects of SYLVANT include rash, itching, upper respiratory tract infection, swelling, weight gain, and increased blood level of uric acid.

These are not all the possible side effects of SYLVANT. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

For more information, please see the full Prescribing Information.

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