Chronic Myeloid Leukemia Treatment

Chronic myeloid leukemia (CML) is a blood cancer that begins in the bone marrow and leads to an overproduction of abnormal white blood cells. The main risk factor is a genetic mutation known as the Philadelphia chromosome, which occurs when parts of chromosomes 9 and 22 exchange segments. This translocation creates the BCR-ABL1 fusion gene, which produces an abnormal protein that fuels uncontrolled cell growth and drives the development of leukemia.

CML is relatively rare, accounting for approximately 15% of adult leukemias. The condition primarily affects adults aged 45 to 65 and is slightly more common in men. Symptoms may include fatigue, unintentional weight loss, night sweats and spleen enlargement. Typically, the diagnostic process involves blood work, bone marrow analysis and genetic testing to confirm the presence of the BCR-ABL1 mutation.

Treatment options for CML may include targeted therapy, chemotherapy or bone marrow transplantation.

Targeted therapy for chronic myeloid leukemia

The cornerstone of CML treatment is targeted therapy, which involves the use of tyrosine kinase inhibitors (TKIs). These specialized medications are designed to block the activity of the abnormal BCR-ABL1 protein, which promotes the growth of leukemic cells. Commonly prescribed TKIs include:

• Imatinib
• Dasatinib
• Nilotinib
• Bosutinib
• Ponatinib

The specific drug and dosage can vary based on the stage of the leukemia and the overall health of the patient. Targeted therapy is typically taken daily and often continued indefinitely to maintain cancer control.

What does targeted therapy for chronic myeloid leukemia involve?

After a diagnosis of CML is confirmed, treatment with targeted therapy typically begins immediately. Most patients are prescribed a tyrosine kinase inhibitor, which will be taken orally in pill form. Ongoing monitoring will be essential to evaluate the treatment response and guide any necessary adjustments. This may involve blood work, bone marrow biopsies, molecular analyses and polymerase chain reaction (PCR) tests to measure BCR-ABL1 transcript levels in the blood.

What are the potential benefits of targeted therapy for chronic myeloid leukemia?

Studies show that targeted therapy has greatly improved the long-term outlook for CML, enabling many patients to achieve deep molecular remission, where the cancer is undetectable by standard testing. For many, this treatment approach can transform chronic myeloid leukemia from a once life-threatening illness into a manageable chronic condition. While taking TKIs, many patients can maintain a full and active lifestyle, and some may even qualify for treatment-free remission if their molecular response remains stable over time.

What are the possible side effects of targeted therapy for chronic myeloid leukemia?

Although targeted therapy for CML is generally well tolerated, side effects can occur. Common issues include:

• Diarrhea
• Fatigue
• Fluid retention
• Joint and muscle pain
• Nausea
• Skin rash

Less common but more serious side effects may include liver toxicity, heart problems and low blood cell counts. Because some TKIs are associated with a risk of vascular complications, regular monitoring will be essential to detect and address any emerging concerns. Dosage adjustments or medication changes may be necessary if side effects interfere with the patient’s quality of life.

What is the recovery process like?

Most patients taking TKIs for CML can maintain their usual routine with minimal disruption. Instead of a short-term recovery period, treatment represents an ongoing process of disease management. Lifelong follow-up will be essential to ensure the leukemia remains under control, and for those who achieve deep remission, therapy may eventually be discontinued under careful medical supervision.

Chemotherapy for chronic myeloid leukemia

While targeted therapy is the standard treatment for CML, chemotherapy may be considered if TKIs are not well tolerated or lose effectiveness. It can also play a role in managing a blast crisis, an advanced phase of chronic myeloid leukemia marked by a rapid increase of cancerous blast cells in the blood and bone marrow.

Chemotherapy for CML works by targeting fast-dividing cells, including leukemic cells, to lower the number of abnormal white blood cells in the body. Depending on the stage of the leukemia and the overall health of the patient, chemo may be given alone or in combination with targeted therapy or a bone marrow transplant.

What does chemotherapy for chronic myeloid leukemia involve?

Chemotherapy for CML often involves cytotoxic drugs, such as cytarabine and hydroxyurea. Depending on the treatment plan, these medications may be given orally, intravenously or subcutaneously. Hydroxyurea is sometimes used to rapidly lower white blood cell counts before targeted therapy is initiated, while other chemotherapy agents are more commonly reserved for advanced stages of chronic myeloid leukemia. Treatment is usually delivered in cycles, with each period of active therapy followed by a period of rest to allow the body time to recover.

What are the potential benefits of chemotherapy for chronic myeloid leukemia?

Chemotherapy can help manage CML symptoms and reduce the disease burden, particularly during an accelerated phase or blast crisis, when the condition behaves more like acute leukemia. Chemo may also be used before a bone marrow transplant to help eliminate any remaining leukemic cells.

While chemotherapy is generally less effective than targeted therapy for chronic myeloid leukemia, it can still play a valuable role in managing cancer progression. It may also provide an additional treatment option for a patient who does not respond to other therapies.

What are the possible side effects of chemotherapy for chronic myeloid leukemia?

The side effects of chemotherapy for CML can vary based on the specific drug regimen. Common issues include:

• Fatigue
• Increased risk of infection
• Loss of appetite
• Nausea and vomiting

Chemotherapy may also cause anemia, bleeding, hair loss and mouth sores. Because it can suppress the immune system and affect organ function, the patient will be closely monitored throughout treatment. Supportive medications can help reduce any adverse effects and prevent complications.

What is the recovery process like?

Recovery from chemotherapy can vary depending on the intensity and duration of treatment and the patient’s overall health. Afterward, the patient will likely undergo periodic blood testing to monitor blood cell counts and evaluate the effectiveness of treatment. Fatigue and other side effects may linger for several weeks, and supportive care can aid healing. In some cases, chemotherapy serves as a bridge to a more definitive therapy, such as bone marrow transplantation, which will be followed by its own period of healing and adjustment.

Bone marrow transplantation for chronic myeloid leukemia

Bone marrow transplantation (BMT) may be considered for a patient whose CML progresses to an advanced stage or does not respond to targeted therapy. This intensive treatment involves replacing damaged bone marrow with healthy blood-forming cells that can restore normal blood cell production. While BMT is not typically used as a first-line therapy for chronic myeloid leukemia, it may offer the possibility of long-term remission or even cure in carefully selected cases.

What does bone marrow transplantation for chronic myeloid leukemia involve?

Often, BMT begins with high-dose chemotherapy, sometimes combined with total body irradiation, to destroy the abnormal bone marrow. Once this conditioning regimen is complete, healthy blood-forming cells will be infused into the patient’s bloodstream, where they will travel to the bone marrow and begin to generate healthy blood cells. The blood-forming cells may come from a matched donor (allogeneic transplant) or the patient (autologous transplant), although the latter option is rarely used in CML treatment. Finding a suitable donor is a critical step and may involve testing family members or searching a donor registry.

What are the potential benefits of bone marrow transplantation for chronic myeloid leukemia?

For certain patients with advanced or treatment-resistant CML, a bone marrow transplant may offer the best chance for a durable remission or possible cure. Significantly, BMT can eliminate residual leukemic cells that remain after other treatments. In a patient with accelerated-phase or blast-crisis chronic myeloid leukemia, this treatment may help restore normal blood cell production and prevent further cancer progression. However, due to the significant risks involved, it is generally considered only after all targeted therapy options have been exhausted or the cancer becomes highly aggressive.

What are the possible side effects of bone marrow transplantation for chronic myeloid leukemia?

BMT carries several serious risks, including:

• Excessing bleeding
• Infection
• Organ damage (due to the rigorous pretransplant conditioning regimen)

One of the most significant potential adverse effects of allogeneic transplantation is graft-versus-host disease (GVHD), which occurs when the donor’s immune cells attack the recipient’s tissues. Other possible complications include graft failure, anemia and long-term immune suppression. Close monitoring and supportive care will be essential to manage these risks and address any complications that arise.

What is the recovery process like?

Recovery after a bone marrow transplant can be intensive and may take up to a year or longer. Most patients remain hospitalized for several weeks before transitioning to outpatient care with regular monitoring. Because the procedure temporarily weakens the immune system, there is a heightened risk of infection and other complications, such as organ problems. Frequent follow-up visits, blood tests and imaging studies can help the physician assess the engraftment and detect any signs of graft-versus-host disease or relapse. Over time, many patients experience improved blood cell counts and gradually resume their daily activities, although long-term management of side effects may be necessary.

Benefit from world-class care at Moffitt Cancer Center

If you would like to learn more about chronic myeloid leukemia treatment, you can request an appointment with a specialist in the highly acclaimed Malignant Hematology Program at Moffitt by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.