NCCN Guidelines for Patients® | Chronic Myeloid Leukemia

20 NCCN Guidelines for Patients ® : Chronic Myeloid Leukemia, 2018 Part 3 describes the main types of treatment for CML. Knowing what a treatment is will help you understand your treatment options listed in Part 4 or Part 5. There is more than one treatment for CML. Not every person will receive every treatment described in this chapter. Tyrosine kinase inhibitors Guide 2 lists the TKIs ( t yrosine k inase i nhibitors) used to treat CML. They are a standard treatment. TKIs belong to a class of drugs called targeted therapy. These drugs affect molecules that help cancer cells grow. Many targeted therapies stop the signals that tell a cell to grow. How TKIs work The protein made by the BCR-ABL1 gene is a tyrosine kinase. It moves chemicals, called phosphates, from one molecule to another. The phosphate “turns on” the next molecule in the signal pathway. TKIs block the transfer of phosphase and in turn stop growth signals. See Figure 7 . Each TKI works in a slightly different way. You may start with one drug that may not work or stop working over time. The latter often occurs when there’s a new mutation in CML cells. Switching to a different TKI that works against the mutation may help. Imatinib Imatinib was the first TKI approved by the U.S. FDA ( F ood and D rug A dministration) to treat CML. Thus, it is called a “first-generation” TKI. It attaches to the inactive site on the BCR-ABL1 protein to stop growth signals. Dasatinib Dasatinib is a second-generation TKI. Dasatinib is more potent than imatinib. It attaches to active and inactive sites on the BCR-ABL1 protein to block growth signals. It works against most BCL-ABL1 mutations. It also blocks SCR, PDGFR, and KIT kinases. Nilotinib Nilotinib is a second-generation TKI. It works in almost the same way as imatinib. However, nilotinib is more potent. It works against most BCL-ABL1 mutations. It also blocks PDGFR and KIT kinases. 3 Overview of cancer treatments Tyrosine kinase inhibitors Guide 2. TKIs for CML Generic (chemical) name Brand name (sold as) Generation Imatinib Gleevec ® First Dasatinib Sprycel ® Second Nilotinib Tasigna ® Second Bosutinib Bosulif ® Second Ponatinib Iclusig ® Third