Navigating chronic myeloid leukaemia

Where do blood cancers originate?

Blood cancer is a type of cancer that affects the blood cells and arises in the bone marrow, lymphatic system, or blood.¹

Leukaemia, lymphoma, and myeloma are some of the most common types of blood cancers.¹

What is chronic myeloid leukaemia (CML)?

Chronic myeloid leukaemia

Chronic – CML is a chronic, slow-growing type of leukaemia that develops and progresses over a long period of time.^3,4

Myeloid – In CML, the myeloid cell line in the bone marrow grows and divides abnormally.⁴

Leukaemia – Leukaemia is a type of blood cancer that affects the blood and bone marrow, characterised by the uncontrolled production of abnormal white blood cells called granulocytes.^3,4

There are three phases of CML³

• Chronic phase (by far the most common)
• Accelerated phase
• Blast phase (also called blast crisis)

What is Ph+ CML?

Ninety-five percent of CML cases are classified as Ph+ CML.^5,6

CML is caused by a genetic mutation called the Philadelphia (Ph) chromosome – a rearrangement in the genetic material between chromosomes 9 and 22.^2,3

The region where chromosome 9 joins chromosome 22 creates a new gene, called BCR-ABL.³

How is CML diagnosed?

Blood tests, molecular testing, and chromosome analysis are used for diagnosis.¹⁰

• In the early stage of CML, most people feel fine, and the condition is usually picked up by a routine full blood count showing too many white blood cells.⁶
• The diagnostic marker is the presence of the Philadelphia chromosome (Ph+).⁷
• A polymerase chain reaction (PCR) test will confirm the level of CML that is detectable in the body.⁸ It is used as a disease monitoring tool which is usually performed every three months to begin with.^6,8,9

Imaging studies, such as an ultrasound of the abdomen, may confirm the presence of liver and spleen enlargement, especially at diagnosis.^2,3,8

• Complete blood count (CBC)¹⁰
• Bone marrow aspiration and biopsy⁸
• Cytogenetic analysis⁸
• Fluorescent in situ hybridization (FISH)⁸
• Polymerase chain reaction (PCR)⁸

What are the symptoms of CML?

Symptoms can be similar to those caused by other illnesses and tend to be mild at first and get worse slowly.¹¹

They can include: ¹¹

• Feeling weak or tired
• Swelling of lymph nodes
• High temperature (fever)
• Picking up infections more often than usual
• Feeling full or pain in tummy (abdomen)
• Bruising and bleeding easily
• Loss of appetite
• Heavy sweating at night
• Pain in bones or joints
• Weight loss

What is the treatment for CML?

Every CML patient requires a multi-disciplinary individualised treatment approach comprising both psychosocial support and medical treatment. ^6,12

Treatment aims to control CML long-term, achieve remission, and prevent progression to advanced phases.² There are several kinds of treatment for CML:³

• Targeted therapy medicines, the most common treatment for CML, block the abnormal tyrosine kinase protein from the Philadelphia chromosome and have transformed its treatment and prognosis.^3,10
• Chemotherapy, which uses cytotoxic agents to kill or slow leukaemia cells, is rarely used in CML and mainly given in advanced phases.^2,3
• Supportive care controls symptoms of CML, like blood transfusion for anaemia (only if needed).³
• Stem cell transplantation, rarely used in CML, may be offered in advanced phases when targeted therapy or chemotherapy no longer work.^2,3

The treatment team will explain the treatments, their benefits, and possible side effects.³ 

What are the treatment milestones in CML?

There are three types of treatment responses when judging the effectiveness of CML treatment.¹³

Molecular response: A molecular response is a measurement of how much of the gene BCR-ABL is detected in the blood or bone marrow.

Cytogenetic response: A cytogenetic response is a measurement of the number of cells in bone marrow that have the Philadelphia chromosome.

Haematologic response: A haematologic response is a measurement of abnormal cells the blood that have returned to normal.

AT DIAGNOSIS¹³

The level of BCR-ABL gene in the body is different for every patient at diagnosis, as measured on the International Scale (IS).

EARLY MOLECULAR RESPONSE (EMR)¹³

An early molecular means that the level of BCR-ABL gene in the blood is ≤10% when measured on the IS.

COMPLETE CYTOGENETIC RESPONSE (CCyR)¹³

A complete cytogenetic response means that the level of BCR-ABL gene in the blood is equivalent to ≤1% when measured on the IS.

MAJOR MOLECULAR RESPONSE (MMR)¹³

An MMR (or molecular response of 3.0) means that the level of BCR-ABL gene in the blood is ≤0.1% when measured on the IS.

What factors may affect disease response to CML treatment?

Compliance

Poor adherence is a significant contributor to treatment failure and loss of response to therapy.⁶ 

Drug-drug interactions

Drug interactions between targeted therapies and other medicines can make treatment less effective and increase side effects in CML patients.¹⁴

Dietary interactions

Effective CML management requires dietary considerations to maximise treatment outcomes.¹⁶ Certain foods, like grapefruit and high-fat meals, potentially altering drug absorption and levels, increasing side effects or reducing efficacy.^15,16

Drug resistance

The development of resistance to the treatments can occur, which may require a change in therapy.^4,10,17