Chemotherapy for Chronic Myelomonocytic Leukemia (CMML)

Chemotherapy (chemo) is the use of certain types of drugs to treat cancer. The drugs can be swallowed as pills or injected into a vein or muscle. Chemo is considered systemic treatment because these drugs enter the bloodstream and reach most areas of the body.

This type of treatment is useful for chronic myelomonocytic leukemia (CMML) because the leukemia cells are not just in one part of the body. Chemo can help kill the leukemia cells in the bone marrow and allow normal ones to grow back.

Chemo for CMML is typically done using either hydroxyurea or a hypomethylating agent.

Hydroxyurea

Hydroxyurea is a chemo drug that can help some people with CMML. This drug comes as a capsule that's taken by mouth, typically once or twice a day. It can bring the numbers of white blood cells, including monocytes, down to normal. It may also help shrink an enlarged spleen.

Possible side effects of hydroxyurea

Because the main effect of hydroxyurea is to lower blood cell counts, anyone taking this drug will need to have their blood counts checked regularly.

Other side effects are usually mild and can include mouth sores, skin rash or changes in skin color, and nail changes.

Hypomethylating agents

These drugs affect the way some genes inside cells are controlled. They activate some genes that help cells mature. They also kill cells that are dividing rapidly. This helps the normal bone marrow cells grow again, often leading to improved blood cell counts and the need for fewer transfusions.

Examples of this type of drug include:

• Azacitidine (Vidaza)
• Decitabine (Dacogen)

These drugs are given as a shot under the skin or as an infusion into your blood (IV), often for several days in a row, followed by several weeks off.

• Inqovi is a newer drug that combines decitabine with cedazuridine, which helps stop the decitabine from being broken down in the digestive system. This allows the drug to be taken by mouth as a tablet, typically once a day for 5 days in a row. This is repeated every 4 weeks.

Possible side effects of hypomethylating agents

Side effects of hypomethylating agents are usually mild and rarely lead to stopping treatment. Still, these drugs can have some of the same side effects as standard chemo drugs, including:

• Low blood cell counts (most often white blood cells or platelets)
• Fever
• Nausea/vomiting
• Diarrhea or constipation
• Fatigue and weakness

Other chemotherapy drugs

Other chemo drugs have sometimes been used to treat CMML, especially if the drugs above are no longer working. This type of chemo might help a small number of people, but it can also have more serious side effects, which limits how useful it is, especially in people who are in poorer health.

For people with CMML who are healthy enough, the goal is usually to have a stem cell transplant if it can be done, because this offers the best chance to cure CMML.