Care During Chemotherapy and Beyond


(sil TUX I mab)

Trade name: Sylvant™ uses generic names in all descriptions of drugs. Siltuximab is the generic name for Sylvant™. In some cases, health care professionals may use the generic name siltuximab when referring to the trade drug name Sylvant™.

Drug type: Siltuximab is an interleukin-6 (IL-6) antagonist- (For more detail, see "How this drug works," below.)

What Siltuximab Is Used For:

Siltuximab is prescribed for the treatment of patients with multicentric Castleman’s disease (MCD) who are human immunodeficiency virus (HIV) negative and human herpesvirus-8 (HHV-8) negative.

Note: If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How Siltuximab Is Given:

  • Siltuximab is given intravenous (IV) every 3 weeks, infused over 1 hour.
  • The amount of siltuximab that you will receive depends on many factors, your general health or other health problems, and the type of cancer or condition being treated. Your doctor will determine your dose and schedule.

Side Effects:

Important things to remember about the side effects of siltuximab:

  • Most people do not experience all of the side effects listed.
  • Side effects are often predictable in terms of their onset and duration.
  • Side effects are almost always reversible and will go away after treatment is complete.
  • There are many options to help minimize or prevent side effects.
  • There is no relationship between the presence or severity of side effects and the effectiveness of the medication.

These side effects are less common side effects (occurring in about 10-29%) of patients receiving siltuximab:

Not all side effects are listed above. Some that are rare (occurring in less than 10% of patients) are not listed here. However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

  • Fever of 100.4° F (38° or higher, chills)
  • Sudden onset of shortness of breath, accompanied by cough and/or fever
  • Sudden stomach or bowel pain

The following symptoms require medical attention, but are not an emergency. Contact your health care provider within 24 hours of noticing any of the following:

  • Diarrhea (4-6 episodes in a 24-hour period).
  • Nausea (interferes with ability to eat and unrelieved with prescribed medication).
  • Vomiting (vomiting more than 4-5 times in a 24 hour period).
  • Unable to eat or drink for 24 hours or have signs of dehydration: tiredness, thirst, dry mouth, dark and decrease amount of urine, or dizziness.
  • Decreased appetite
  • Rash or itching
  • Sudden increase in swelling or weight gain
  • Cough with or without mucus
  • Other signs of infection, such as sore throat or pain with urination

Always inform your health care provider if you experience any unusual symptoms.


  • Before starting siltuximab treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.).
  • Vaccinations: Patients receiving siltuximab should not receive any live vaccines because siltuximab may alter the body’s normal immune response to these vaccinations. Do not receive any kind of immunization or vaccination without your doctor's approval while taking siltuximab. Your provider may discuss recommended vaccinations PRIOR to starting siltuximab.
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Pregnancy category C (siltuximab may be hazardous to the fetus. Women who are pregnant or become pregnant must be advised of the potential hazard to the fetus.)
  • For both men and women: Do not conceive a child (get pregnant) while taking siltuximab. Barrier methods of contraception, such as condoms, are recommended during treatment and for 3 months after stopping the treatment. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
  • Do not breast feed while taking this medication.
  • Any signs of an infection should be reported to your health care provider. You should not receive siltuximab if you have a severe infection.
  • Before starting siltuximab, you should tell your health care provider if you have or have had any stomach or bowel problems, such as ulcers or diverticulitis. Also, tell your provider if you develop any stomach pain while receiving siltuximab.

Self-Care Tips:

  • Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.
  • If you should experience nausea, take anti-nausea medications as prescribed by your doctor, and eat small frequent meals. Sucking on lozenges and chewing gum may also help.
  • Avoid sun exposure. Wear SPF 15 (or higher) sun block and protective clothing.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely. You should discuss this with your doctor.
  • Get plenty of rest.
  • Maintain good nutrition.
  • If you experience symptoms or side effects, be sure to discuss them with your health care team. They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing:

You will be checked regularly by your health care professional while you are taking siltuximab, to monitor side effects and check your response to therapy.

How Siltuximab Works:

Targeted therapy is the result of about 100 years of research dedicated to understanding the differences between cancer cells and normal cells. Standard cancer treatment historically have focused primarily on killing rapidly dividing cells because one feature of cancer cells is that they divide rapidly. Unfortunately, some of our normal cells divide rapidly too, causing multiple side effects.

Targeted therapy is about identifying other features of cancer cells. Scientists look for specific differences in the cancer cells and the normal cells. This information is used to create a targeted therapy to attack the cancer cells without damaging the normal cells, thus leading to fewer side effects. Each type of targeted therapy works a little bit differently but all interfere with the ability of the cancer cell to grow, divide, repair and/or communicate with other cells.

There are different types of targeted therapies, defined in three broad categories. Some targeted therapies focus on the internal components and function of the cancer cell. The targeted therapies use small molecules that can get into the cell and disrupt the function of the cells, causing them to die. There are several types of targeted therapy that focus on the inner parts of the cells. Other targeted therapies target receptors that are on the outside of the cell. Therapies that target receptors are also known as monoclonal antibodies. Antiangiogenesis inhibitors target the blood vessels that supply oxygen to the cells, ultimately causing the cells to starve.

While the cause of MCD currently is unknown, overproduction of IL-6 is considered a key mechanism in MCD. Siltuximab works as a monoclonal antibody by binding to human IL-6, a substance produced by various cells such as T cells, B cells, monocytes, fibroblasts and endothelial cells. An overproduction of IL-6 from activated B cells in affected lymph nodes has been implicated in the pathogenesis of, or mechanism causing, MCD. This IL-6 binds to cell surface receptors to cause cell growth. By binding to IL-6, siltuximab prevents the IL-6 from binding to IL-6 receptors blocking an important cell growth and survival pathway.

Research continues to identify which cancers may be best treated with targeted therapies and to identify additional targets for more types of cancer.

Note: We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit