Medication for Hairy Cell Leukemia

People with symptoms of hairy cell leukemia can often be treated successfully with medications. Clinical trials of BRAF inhibitors may also be an option.


Cladribine is a chemotherapy drug, meaning it helps destroy cancer cells throughout the body. It is given through a vein as an intravenous (IV) infusion every day for about a week, depending on the diagnosis.

Hairy cell leukemia often responds to cladribine and goes into remission. Remission is when the number of abnormal B lymphocytes is partly or completely reduced in the blood and bone marrow. Many people remain in remission for a decade or longer. If hairy cell leukemia comes back, doctors may treat it with cladribine again.

Pentostatin is another chemotherapy drug used to manage hairy cell leukemia. It may be given to people with cancer that does not respond to cladribine. Pentostatin is usually given through a vein as an IV infusion once every other week for three to six months. As with cladribine, pentostatin often results in long-lasting remission and can be given again if the cancer returns.

Monoclonal Antibodies

Hairy cells are B lymphocytes that have a protein called CD20 on their surface. A medication called rituximab, an anti-CD20 antibody, can be given to cause a remission.


Interferon is an immunomodulator, a medication composed of naturally occurring proteins that help the body mount an immune attack against the cancer, making it less likely that abnormal B lymphocytes survive and reproduce. Doctors may give interferon to people who do not respond to cladribine or pentostatin. Itā€™s given by injection under the skin.

Our doctors can decide on the right treatment schedule for you.

Managing Side Effects

Common side effects of the medications used to treat hairy cell leukemia include nausea, fatigue, fever, and infection. Our doctors can adjust the dosage, prescribe other medications, or refer you to NYU Langoneā€™s support services to help manage these side effects.

Clinical Trials

People with hairy cell leukemia that does not respond to traditional medications may be candidates for a clinical trialā€”a study that tests the effectiveness of new therapiesā€”involving a BRAF inhibitor.

Most people with hairy cell leukemia have a mutation in a gene called BRAF. Healthy versions of this gene help cells grow, divide, and eventually self-destruct. When the BRAF gene mutates, cells grow uncontrollably. BRAF inhibitors help to block the kinases, or proteins, that tell the abnormal cells to grow.

You and your NYU Langone doctor can discuss whether a clinical trial is right for you.

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