Targeted therapy for acute lymphocytic leukemia

In recent years, new drugs that target specific parts of cancer cells have been developed. These drugs work differently than standard chemotherapy drugs. They often have different (and less severe) side effects. These drugs are often referred to as targeted therapy. Some of these drugs can be useful in certain cases of acute lymphocytic leukemia (ALL).

About 1 out of 4 adult patients with ALL have leukemia cells with the Philadelphia chromosome. This is an abnormal chromosome formed by the swapping of material between chromosomes 9 and 22. The Philadelphia chromosome is also found in the cells of a different leukemia – chronic myeloid leukemia (CML). Cells with this chromosome make an abnormal protein that helps the cells grow. Drugs have been developed that attack this protein. These include imatinib (Gleevec^®), dasatinib (Sprycel^®), nilotinib (Tasigna^®), bosutinib (Bosulif^®), and ponatinib (Iclusig^™). Although these drugs were mainly aimed at treating CML, some of them have been found to be helpful in treating patients with ALL that has the Philadelphia chromosome.

Early studies have found that adding one of these drugs to chemotherapy may help more patients go into remission after treatment and may help keep the leukemia from coming back. Larger studies are in progress to try to confirm this.

These drugs are taken daily as pills. Common side effects include diarrhea, nausea, muscle pain, fatigue, and skin rashes. These are generally mild. A common side effect is swelling around the eyes or in the hands or feet. Other possible side effects include lower red blood cell and platelet counts at the start of treatment. All of these side effects get worse at higher than usual doses of the drug. Other more serious side effects can occur, as well, which differ depending on which drug is used.