Tyrosine Kinase Inhibitors (TKIs)

Tyrosine kinase inhibitors (TKIs) are a type of targeted therapy that can be used to treat certain types of cancer. Tyrosine kinases are enzymes involved in many cellular functions such as cell signaling, growth, and division. These enzymes can be hyperactive in some types of cancer cells, and inhibiting the abnormally active tyrosine kinases can help slow or even stop cancer cell growth.

TKIs Used to Treat Chronic Myelogenous Leukemia (CML)

Several types of TKIs are used to treat chronic myeloid leukemia (CML). These drugs are thought to act by blocking the abnormal signals transmitted to the CML cells by the BCR-ABL mutation. Discuss with your physician to determine which treatment may be right for you. 

The TKIs used to treat CML include Imatinib (Gleevec®), Dasatinib (Sprycel®), Nilotinib (Tasigna®), Bosutinib (Bosulif®) and Ponatinib (Iclusig®). All of these TKIs inhibit the ABL tyrosine kinase that is part of the BCR-ABL mutation encoded by the Philadelphia Chromosome that is always found in CML cells. The ABL kinase can also have small mutations that alter its sensitivity to these TKIs and the choice of the most appropriate TKI depends upon your clinical condition and sometimes, the molecular details of your BCR-ABL mutation.

All of these medications are generally well tolerated but many patients experience some mild to moderate side effects when starting the medication (partially listed below). These side effects often improve and go away over time. Some uncommon side effects are severe. Some can be experienced by patients taking any of the TKIs used for CML but others are most common to specific drugs. You should always report any side effects you may be experiencing to your medical team.

  • Diarrhea
  • Muscle pain/aches
  • Edema (fluid buildup) around the eyes, feet, or abdomen
  • Pruritus (itchy skin) and skin rashes
  • Fatigue
  • Nausea
  • Decreased white blood cell and platelet counts

More information: https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0032716/

TKIs to treat Polycythemia Vera (PV) and Myelofibrosis (MF):

Ruxolitinib is a TKI that is used to treat polycythemia vera and myelofibrosis.

Richard T. Silver MD Myeloproliferative Neoplasms Center 525 East 70th St., Starr Pavillion, 3rd Floor New York, NY 10021 SilverMPNCenter@med.cornell.edu