Chronic myeloid leukemia (CML), also called chronic myelogenous leukemia, has several treatment options. Two CML treatments are tyrosine kinase inhibitors (TKIs) and chemotherapy. While both target leukemia cells, they work in different ways and have different effects on the body.

Your doctor should discuss with you which CML treatment option is better suited to your specific case of CML. Factors that play into this decision include:

• Your age
• Your overall health
• Your CML phase
• Any mutations (changes) in your cancer cells

TKI Therapy for CML

TKIs take advantage of the genetic mutations in CML cells to control the cancer.

CML cells contain an abnormal gene, BCR-ABL1, also known as the Philadelphia (Ph) chromosome. The gene forms when two different chromosomes break off and swap pieces. The BCR-ABL1 gene isn’t a normal gene, and it isn’t found in healthy cells.

The BCR-ABL1 gene in CML cells makes an abnormal tyrosine kinase protein. Tyrosine kinase proteins tell cells to grow and divide, which is important for creating new cells and repairing damage. However, cells with a mutated BCR-ABL1 gene grow and divide on their own, which can lead to cancer.

TKIs target proteins in leukemia cells and have been used successfully to treat CML for many years.

TKIs are drugs that inhibit the protein made by these genes, stopping the cells from dividing uncontrollably. There are first-, second-, and third-generation TKIs that have been developed to treat CML.

TKI treatments work best in people with chronic-phase CML and most people with accelerated-phase CML, although they may also be used in blast phase. While some of them require you to fast (stop eating) before taking them, others can be taken with food.

When cancer drugs target specific mutations and proteins, they’re known as targeted therapies. One benefit of targeted therapies is that they target the CML cells that contain the abnormal gene. Healthy cells are generally spared, meaning there are typically fewer serious side effects compared to chemotherapy.

In studies that followed people with CML for up to 14 years, TKIs were found to be effective in treating the condition.

Imatinib

Imatinib (Gleevec) was approved by the U.S. Food and Drug Administration (FDA) in 2001 as a first-generation TKI used to treat Philadelphia chromosome-positive (Ph-positive) CML. Almost all people with CML who take imatinib respond well, and for many years. This drug is typically taken once daily with food.

In some cases, imatinib may stop working over time because the CML cells become resistant to the drug (known as imatinib resistance). In cases of resistance, higher doses of imatinib can be given or another TKI can be used.

Nilotinib

Nilotinib is sold under the brand names Tasigna and Danziten.

Tasigna was approved by the FDA in 2007 as a second-generation TKI for treating CML. It can be used to treat people with newly diagnosed Ph-positive CML in the chronic phase or in cases where Ph-positive CML is resistant to imatinib. This drug is taken twice daily and can’t be taken with food.

Danziten was FDA-approved in 2024. It can be used as a CML treatment for newly diagnosed Ph-positive chronic-phase CML, or in those whose accelerated- or chronic-phase Ph-positive CML is resistant to other treatments, including imatinib. Unlike Tasigna, Danziten can be taken with food.

Dasatinib

Dasatinib (Sprycel) was approved by the FDA in 2006 as a second-generation TKI for treating Ph-positive CML. It can be used as a first treatment. Dasatinib may also help people who can’t take imatinib because of side effects or because it doesn’t work well enough. It’s typically taken once daily, and it may be taken with food or without it.

Bosutinib

Bosutinib (Bosulif) was approved by the FDA in 2012 as a second-generation TKI for treating Ph-positive CML. It can be used to treat newly diagnosed cases of CML as a front-line treatment, but it can also be used as a second-line therapy. It’s taken with food once daily.

Ponatinib

Ponatinib (Iclusig) was approved by the FDA in 2012 as a third-generation TKI to treat Ph-positive CML that’s resistant to at least two other TKIs. It can also be used in those with a T315I mutation. It’s not recommended for people with newly diagnosed CML. Ponatinib is typically taken once daily, with or without food.

Asciminib

Asciminib (Scemblix) was FDA-approved in 2024 to treat people with Ph-positive CML. It may be used as a first-line treatment, in those with or without the T315I mutation, and in people who have already tried other TKIs. It’s typically taken one or two times daily and shouldn’t be taken with food.

Chemotherapy for CML

Unlike targeted therapies (such as TKIs), chemotherapy uses cell-killing drugs that work to destroy cells that grow and divide quickly. CML cells are killed by chemotherapy. However, hair follicles, healthy blood cells, and cells that line the stomach and intestines, which also divide quickly, can also be killed.

Before TKIs became available, chemotherapy was the most common treatment for CML. Chemo is still used when TKIs no longer work.

Before the invention of TKIs, chemotherapy was the main treatment for CML. Now, targeted therapies are used as front-line treatments because they work much better and with milder side effects.

Chemotherapy is still used to treat some cases of CML, especially in people whose cancer becomes resistant to TKI therapy and those who have blast-phase CML. Chemotherapy can also be used to prepare the bone marrow for a transplant.

Examples of chemotherapy drugs used to treat CML include:

• Cyclophosphamide
• Cytarabine (Ara-C)
• Hydroxyurea
• Omacetaxine, used to treat chronic-phase and accelerated-phase CML
• Vincristine

Combination Therapy Using TKIs and Chemotherapy

Numerous research studies have been published looking at treatment with both imatinib and chemotherapy. Studies using hydroxyurea or cytarabine with imatinib investigated whether the combination improved remission rates. Unfortunately, these therapies did not seem to help. In some cases, they made imatinib less effective.

CML research keeps making advances, and more treatment options have become available in recent years.

CML research continues to make advances and improve the outlook for this chronic form of blood cancer. Talk to your oncology team about which CML treatments may be right for you.

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