In a nutshell
This review summarized recent changes in treatments of patients with chronic myeloid leukemia (CML).
Some background
Patients with CML carry a cancerous tyrosine kinase (TK) enzyme called BCR-ABL1. Traditionally CML had been treated by non-specific drugs with side effects. Stem cell transplants are alternatives but not recommended for older patients. Lately, the use of specific TK inhibitors (TKIs) improved survival among patients. Many changes in CML management happened so far which need to be summarized in 2020.
Methods & findings
Four TKIs are currently given as initial treatment for newly diagnosed CML in chronic phase (CML-CP). These are imatinib (Gleevec), nilotinib (Tasigna), dasatinib (Sprycel), and bosutinib (Bosulif). In a 2016 trial, 74% of patients receiving imatinib and 9% of patients without imatinib had a complete cytogenetic response (CCyR). CCyR occurs when no cells with BCR-ABL1 are left in the bone marrow. 83.3% of patients receiving imatinib and 78.8% of patients without imatinib survived for 10 years.
In later trials, CCyR occurred in 77% of patients receiving dasatinib or bosutinib and 66% of patients receiving imatinib within 12 months. The estimated survival after 2 and 5 years of therapy was similar in all groups. Nilotinib also caused similar 10-year survival compared to imatinib. However, major molecular response (MMR) was achieved in 22% of patients in the imatinib group and 43-44% of patients in the nilotinib group. MMR means 1 in 1000 blood cells are left with BCR-ABL1.
Patients whose leukemia returns after initial therapy are treated with newly marketed TKIs. Their doses depend on additional medical conditions and the CML stage. Some patients are resistant to all old and new TKIs except ponatinib (Iclusig). They have a special genetic abnormality called T315I. Patients with CML-CP who failed to respond to at least 2 TKIs and all patients with advanced phase CML must undergo transplantations. Transplants are also given to older patients with higher BCR-ABL1 levels who are not responsive to TKIs. They can achieve long-term survival under continuous therapy with an effective and less toxic TKI.
The bottom line
This review summarized recent changes in treatments of patients with chronic myeloid leukemia (CML).
Published By :
American Journal of Hematology
Date :
Apr 02, 2020
