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Treatment for hairy cell leukaemia that has come back

You usually have further treatment for hairy cell leukaemia if it comes back (a relapse). This is called second line treatment.


Most people have chemotherapy as a first treatment for hairy cell leukaemia, with either cladribine or pentostatin. The second line treatment depends on: 

  • the time since your last treatment
  • what treatment you have already had

If your last treatment was more than 2 years ago, you might have the same chemotherapy drug again. But if it was less than 2 years, you might have a different drug.

This means that if you had cladribine treatment the first time, you might have pentostatin the second time.

Targeted cancer drugs and immunotherapy


As well as chemotherapy, you might have rituximab. Rituximab is a type of targeted drug called a monoclonal antibody. It works by seeking out a protein that is found on some normal and leukaemic white blood cells. The protein is called CD20.

Once it has found the CD20 positive cells, rituximab sticks to them. This helps the immune system to find them and kill them.

You usually have rituximab as a drip (infusion) into your bloodstream.

You might have rituximab, or a biosimilar of rituximab, such as Truxima. A biosimilar is not exactly the same as the original drug. But it is very similar and has undergo strict testing to check they work just as well as the original drug. 


Your doctor might suggest that you have interferon if you're not well enough to have chemotherapy or rituximab.

Interferon is a natural substance that our bodies produce as part of our immune response. Interferon therapy works by helping to stop the leukaemia cells growing. It might also encourage the immune system to attack the cancer.

You have interferon as an injection just under the skin, usually 3 times a week for a year.

Clinical trials

Doctors and researchers do trials to make existing treatments better and develop new treatments. As HCL a is rare, there are fewer trials, compared to some types of cancer. There may not always be a trial available or suitable for your situation. But do discuss this with your specialist if you're interested in taking part in a trial.

Doctors often work together across different countries to run trials and share information.