Immunotherapy is also called biologic therapy. It's a type of treatment that boosts your immune system to help it find and kill cancer cells. It does this using human-made versions of substances that are normally made in the body and boost the immune system.

This treatment isn't done commonly for Kaposi sarcoma (KS). But it might be used if other treatments aren't working or KS comes back after treatment.

The main immunotherapy medicine used to treat KS is a human-made version of interferon-alfa. This is a chemical in the body that normally helps boost the immune system. It's thought to help the immune system fight off viral infections.

Other medicines that can be used are:

• Thalidomide.
• Pomalidomide.
• Lenalidomide.

Many other kinds of immunotherapy medicines are also showing promise. These aren't widely used at this time but might be available in a clinical trial.

Interferon-alfa is given daily as a shot (injection). It's injected either into a muscle or under the skin. You or a caregiver can learn to give these shots at home.

The other medicines are pills you take at home.

Interferon-alfa often causes flu-like symptoms, such as fever, severe tiredness (fatigue), weakness, and muscle pain. People often feel sick while getting this treatment. That's one of the reasons it isn't used often. It can also cause liver problems, low blood cell counts, and confusion or mood changes.

Thalidomide and the medicines related to it can cause serious blood clots, including deep vein thrombosis (DVT) and pulmonary embolism (PE). They can also lower your blood cell counts. And they can cause constipation, nerve damage, nausea, and fatigue.

It's important to know which medicines you're taking. Write down the names of your medicines and how to take them. Ask your health care team how the medicines work and what side effects they might cause. Always takes medicines exactly as directed by your doctor.

Talk with your doctor about what symptoms to watch for and when to call them. Make sure you know what number to call with questions. Know how to reach them after office hours, on holidays, and on weekends.

It may help to keep a diary of your side effects. A written list will make it easier for you to remember your questions when you go to your appointments. It will also make it easier for you to work with your health care team to make a plan to manage your side effects.