CML Glossary

Reading medical texts are often a challenge for patients. The CML Advocates Network's CML glossary provides a list of terms commonly used in the area of CML. If you come across a term which is not listed here, please provide us with your suggestion here.

The glossary is released under the Creative Commons license (Attribution-NonCommercial 2.5) which means the glossary can be shared, adapted, translated, copied and redistributed for non-commercial purposes as long as the original source is being mentioned and a link to the license is being provided.





Chromosome anomaly, abnormality or mutation


Uptake of a drug into the bloodstream

Accelerated Phase

A phase of development of Chronic Myeloid Leukemia between chronic and blast phase. Untreated, the accelerated phase progresses to blast phase within a few months.


Of sudden onset, severe; of short duration.

Adenosine triphosphate

Adenosine triphosphate (ATP) is a molecule that provides energy for most of the energy-consuming processes of the cell.

Adjuvant therapy

Concomitant therapy is treatment that is given in addition to the main therapy. The aim of adjuvant therapy is to enhance the main therapy or to support the healing process.

Adverse event

An undesired or unintended occurrence or side effect that has a temporal relationship with the use of a medical treatment or procedure in a clinical study. An adverse event does not necessarily have a causal relationship with the study treatment.

Also called: AE


Being genetically different although belonging to or obtained from the same species, e.g. allogeneic stem cell transplantation.


Hair loss. May occur as a side effect of chemotherapy.


Generation of multiple DNA copies of an orginal DNA or RNA target sequence


Lack of red blood cells or decrease in red blood pigment (haemoglobin)


Creation or growth of new blood vessels. Tumor angiogenesis is an abnormal type of new blood vessel growth stimulated by cancer cells, which need extra supplies of oxygen and nutrients in order to keep growing.  Angiogenesis inhibitor drugs are a new class of drugs targeted against this abnormal process, which may block or slow tumor growth.


Inhibition of the formation of new blood vessels (angiogenesis) to cut off blood supply to cancer cells. Without a blood supply, cancer cells “starve". This is a potential new approach to tumour therapy.


Proteins are produced by immune cells (B lymphocytes) to recognize and bind foreign structures (antigenes) on the surface of pathogens, cells or molecules. Antibodies help the immune system to identify and destroy pathogens or abnormal cells.


Any substance that is foreign to the body and that prompts the immune system to generate antibodies.


Antihistaminics, also called histamine receptor blockers or histamine antagonists, weaken the effects of the body’s own messenger histamine. They are used mainly to treat allergies or inflammation of the mucous membranes of the stomach (gastritis).


Cytostatic substances that have similar chemical structures as naturally occurring molecules but differ enough to compete with or inhibit specific metabolites and interfere with the nucleic acid or protein metabolism (of cancer cells).



Antisense molecule

An antisense molecule is a DNA-molecule which is a complementary mirror image of a functional DNA-strand. It is assumed that the antisense molecule attaches to its mirror image which can be both DNA and mRNA. Thereby, the DNA or RNA strand is inactivated and the corresponding protein can no longer be made.


Apheresis or automated blood collection (ABC) is a procedure to remove and separate individual components of the blood such as stem cells, but also platelets. The remaining blood is then returned into the bloodstream of the patient. Apheresis may be performed via the veins of the arm. In general, however, a so called Shaldon or dialysis catheter is used. This catheter contains two lumens (channels) and is placed in a jugular or subclavian vein. The procedure does not cause pain or stress to the patient. A session takes about four hours and is repeated every day until an adequate quantity of cells has been collected, however not more than four times.


Acute promyelocytic leukemia; a subtype of acute myelogenous leukemia (AML)


Condition where the bone marrow is defective and cannot form any blood cells


Programmed cell death, triggered actively by the cell.

Arterial hypertension

Arterial hypertension or high blood pressure is a chronic medical condition in which the blood pressure in the arteries is higher than normal


American Society of Hematology


See adenosine triphosphate


Derived or transferred from the same individual (e.g. autologous bone marrow transplant), where donor and recipient are the same person.




The abnormal gene that characterizes Chronic Myeloid Leukemia, which is a fusion of the BCR gene of chromosome 9 and the ABL gene of chromosome 22

BCR-ABL ratio

The BCR-ABL ratio is a quantitative determination of the CML-typical BCR-ABL gen. The number of BCR-ABL “copies” in relation to a control gen which is present in all cells is a measure of disease activity or "tumour burden" of CML. In lab reports, this value is frequently stated in percent, but sometimes also as a "ratio" or "quotient". In general, the control gen "ABL" is used to calculate the quotient, but other genes may also be used (e.g. BCR, GUSB, G6PD).


Twice a day (Latin: bis in die)


A pharmacological parameter denoting the fraction of unchanged substance (as a drug) which is available in the circulation. It indicates the degree and rate at which a substance (as a drug) is absorbed into a living system or is made available at the site of physiological activity.


Collection of a tissue sample for microscopic examination. During bone marrow biopsy, e.g. from the pelvic bone, bone marrow is removed for cytogenetic testing.


Biosimilars also known as follow-on biologics are biologic medical products whose active drug substance is made by a living organism or derived from a living organism. Biosimilars or follow-on biologics are terms used to describe officially approved subsequent versions of biopharmaceutical products made by a different sponsor following patent and exclusivity expiry on the original product


An immature white blood cell that normally represents an early phase of the development process of a blood stem cell in the bone marrow

Blast crisis

The third phase of development of CML after chronic and accelerated phases. It is characterized by the presence of increasing numbers of immature blood cells ("blasts") in the blood and bone marrow.


Bone Marrow Transplant


Bosutinib (development name SKI-606, trade name Bosulif), a second generation tyrosine kinase inhibitor.

Also called Bosulif|SKI-606|SKI606

Brand name

Name under which a drug is marketed by a specific manufacturer, which is different to the compound name which describes the active ingredient contained in a pharmaceutical product


Complementary and Alternative Medicine


Cardiovascular disease (also called heart disease) is a class of diseases that involve the heart, the blood vessels (arteries, capillaries, and veins) or both


Abbreviation for Complete Cytogenetic Response, which is the absence of cells with the Philadelphia Chromosome in the bone marrow, usually detected by cytogenetics or FISH diagnostics

Cell cycle

Sequence of events that lead to division and replication of cells. The cell cycle consists of mitosis and interphase.


Proteins that regulate protein folding in the cell


Chemotherapy is the use of drugs to treat cancer by destroying or slowing the growth of fast-growing cancer cells. The term chemotherapy also includes treatment with antibiotics.


The presence of cells or tissues from two individuals (recipient and host), following stem cell or bone marrow transplantation




A chromatid is one copy of a duplicated chromosome, which generally is joined to the other copy by a centromere, for the process of nuclear division.


A chromosome is a structure of DNA that carries the genetic makeup in the nucleus of the cell. Chromosomes contain giant chain molecules of DNA, coiled and folded as aggregates with specific proteins. Chromosomes ensure that during cell division the hereditary information is evenly distributed to the daughter cells. Normal human body cells have 46 chromosomes. Cancer cells can have a different number and/or structure of chromosomes.

Chromosome aberration

A chromosome anomaly or mutation


Long-lasting, slowly developping

Chronic Myeloid Leukemia

also called: Chronic Myelogeneous Leukemia

Chronic phase

The earliest phase of CML development.


Chronic lymphocytic leukemia

Clonal evolution

The accumulation of DNA (chromosome) changes which leads to progression of the disease


Chronic Myeloid Leukemia, also called Chronic Myelogenous Leukemia

CML-CAB Objectives


  • Providing researchers, academics, government, policy makers, authorities and the pharmaceutical industry with advice and input on different issues that impact on patients’ lives 
  • Promoting best-in-class CML research as well as the harmonisation of good clinical practice, standard of care and access to best available CML therapies and diagnostic tools 
  • Ensuring patient needs are considered when setting research priorities
  • Developing patient-friendly clinical trials and helping interested patients access these
  • Addressing problems CML patients face in accessing optimal diagnosis, monitoring, treatment and care
  • Improving the outcomes of CML patients
  • Improving the quality of patient information and education
  • Building CML advocacy community capacity

Chronic Myelomonocytic Leukemia


Complete molecular response means undetectable residual disease on a certain molecular test. Given "completeness" of response depends also on the sensitivity of the CML diagnostics used, this term has been replaced my MR4, MR4.5, which states a molecular remission with a reduction of residual disease below a given level.


Presence of one or more additional disorders or diseases occuring at the same time with a primary disease; or the effect of such additional disorders or diseases.


Presence of an additional disorder or disease occuring at the same time with a primary disease

Complete blood count

A complete blood count (CBC) measures several components in the blood, including red blood cells (RBC), white blood cells (WBC), platelets, haematocrit and haemoglobin. Abnormally high or low blood counts may indicate the presence of a disease.

Also called full blood count (FBC)

Complete Cytogenetic Response


Complete Hematologic Response



Willingness of a patient to reliably adhere to treatment measures and follow medical instructions.

Compound name

Name of the active ingredient contained in a pharmaceutical product, e.g. Imatinib, Dasatinib, Nilotinib, Bosutinib, Ponatinib, etc.

Concomitant medications

Two or more drugs used or given at or almost at the same time (one after the other, on the same day, etc.)


A condition or specific situation in which a particular treatment or diagnostic or therapeutic procedure should not be used because it may be harmful to the patient.

Control group

In a clinical trial, this group tof patients either receives the standard treatment being compared to the new treatment, or receives a placebo (a pill that contains no active ingredients)

Copy drug

A medicine provided by third party manufacturers despite the medicine is still patented


Medicine that is deliberately and fraudulently mislabeled with respect to identity and/or source. Counterfeiting can apply to both branded and generic products. Counterfeit products may include products with the correct ingredients or the wrong ingredients, lacking active ingredients, with incorrect quantities of active ingredients, or fake packaging.


(Also called Coronavirus or SARS-Cov 2) An infectious disease caused by a newly discovered coronavirus in 2019. Most people infected with the COVID-19 virus experience mild to moderate respiratory illness and recover without requiring special treatment. Older people and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer, are more likely to develop serious illness.


Occurrence of the same severe side effect(s) during treatment with two different drugs


Disappearance of the disease and return to a “normal” healthy state.


Microscopic examination of the number and structure of chromosomes in cells obtained from swabs, blood or tissues (biopsies).


The study of cells. A branch of biology dealing with the structure and function of cells.


The condition of having a deficient number of one or more elements in the blood. Depending on which types of blood cells are decreased, the condition is also called leuko(cyto)penia, granulopenia, lympho(cyto)penia, mono(cyto)penia, erythro(cyto)penia or thrombo(cyto)penia.


Trade name: Sprycel, development name: BMS-354825, inhibits BCR-ABL and SRC tyrosine kinases. Authorized for marketing in the EU since 2006 for the treatment of CML and Ph+ALL.
Other names: BMS-354825|BMS354825|Sprycel

Dentritic cells

Specialized form of white blood cells presenting antigens in such a way that the immune system can respond by forming antibodies


Drugs that aid the passing of urine (diuresis) and thereby help the body eliminate extracellular fluid, for instance, when there is an abnormal accumulation of fluid (oedema).


In a clinical trial, this is a method used to prevent bias in a clinical trial. Neither the patients nor the investigators know which participants are taking the study drug and which are not.


Abnormal amount of lipids (e.g. cholesterol and/or fat) in the blood. Most dyslipidemias are hyperlipidemias; that is, an elevation of cholesterol or fat in the blood.


Eastern Cooperative Oncology Group Index to classify the quality of life of cancer patients on a scale ranging from 0 (fully active, able to carry on all predisease activities without restriction) to 5 (death).

Also often referred to as ECOG performance status.


Abnormal accumulation of fluid in body tissues.

Also called oedema

ELN treatment recommendations

Treatment recommendations of the European LeukemiaNet, the pan-European network of physicians, scientists and patients with an interest in in leukemia

Also called: ELN recommendations, ELN guidelines


A condition in which there is a lower than normal number of eosinophil granulocytes in peripheral blood.


The formation and accumulation of an abnormally large number of eosinophils in the blood. A special type of leukocytosis (an abnormal increase in leukocytes).


The science of the distribution and incidence of a disease in defined populations


The first development stage of a unipotent stem cell in the development of the red blood cell (erythrocyte). Erythroblasts develop into normoblasts, then reticulocytes and eventually into erythrocytes (normocytes).


Red blood cells (RBCs); erythrocytes deliver oxygen to the body tissues via the blood flow through the circulatory system.


Formation and development of erythrocytes (red blood cells)

Exclusion criteria

Exclusion criteria define which subjects may not participate in a clinical study (e.g. smokers, pregnant women, patient with heart diseases, patients who are too young or too old). Exclusion criteria help minimize the risk of influences that distort the study results. They also protect study subjects. Patients with a heart disease, for instance, must not be included in a study testing drugs which impose a burden on the circulation.


An agency of the United States Department of Health and Human services. The FDA is responsible for protecting and promoting public health through the regulation and supervision of food and drugs.


Capacity to produce offspring (to conceive or induce conception)


Material resembling fibrin. Fibrinoid tissue changes show a staining pattern like that of fibrin. Such changes are typical of immune responses and are usually degenerative (fibrinoid degeneration, fibrinoid necrosis).

First-line therapy

The first treatment given after a disease has been diagnosed. Patients who do not respond to or do not tolerate this treatment, will receive second-line therapy.

Also called induction therapy or primary treatment.


Abbreviated "Fluorescence In Situ Hybridization", a specific diagnostic test to detect genetic changes in chromosomes, like the BCR-ABL gene

Gastrointestinal tumours

Tumours of the gastrointestinal tract which is commonly defined as the stomach and the intestine.


A unit of information present as DNA; a gene usually contains the blueprint for a protein.

Generic drug

A medical product that is comparable to a brand/reference listed medical product in dosage form, strength, route of administration, quality and efficacy, and intended use. A generic drug can only be marketed after patent protection and market exclusivity ends


A class of medicinal products where the drug is comparable to a branded product in dosage form, strength, route of administration, quality and efficacy, and intended use. A generic drug can only be marketed after patent exclusivity protection ends.

Growth factors

Growth factors are produced by cells and promote the transition of cells from the G0 phase (a resting phase where the cell has left the cycle and stopped dividing) or G1 phase (a preparation phase) into the cell cycle. Growth hormones stimulate the proliferation of precursors of blood cells and thereby promote the formation of blood (hematopoiesis).


ß-glucuronidase; an enzyme


Graft versus Host Disease, the immune reaction of the donor cells against the body of the patient


Relating to blood or the formation of blood

Also called: hematological

Haematoma or hematoma

A collection of blood outside of a blood vessel, e.g. in soft tissue.


The formation of blood.

Also called: hematopoiesis


The formation of blood or blood cells

Also called: hematopoietic


A physician who has specialized in blood diseases, including leukemia ("heme" means "blood" in Greek language)


The study of the structure, composition and function of the body tissues


Human Leukocyte Antigen - the proteins on the surface of all cells that must be matched for bone/stem cell transplants to avoid immune reactions of the donor's immune system against the body of the recipient


Corresponding, for example, in structure, position and origin


Human Papilloma Virus


Increased blood sugar levels


Abnormal, too high amount of lipids (e.g. cholesterol and/or fat) in the blood


Absence of normal skin pigmentation




Imatinib, trade name Glivec/Gleevec, development name STI-571, a first-generation BCR-ABL tyrosine kinase inhibition. Authorized for marketing since 2002 for the treatment of CML and Ph-positive ALL.
Other names: Gleevec|Glivec


Suppressing a response by the body’s immune system, e.g. after transplantation


The number of new cases of a specific disease occurring during a certain period, e.g. one year

Inclusion criteria

Inlusion criteria define which subjects may participate in a clinical study. Study subjects must fulfill all inclusion criteria (e.g. with regard to sex, age, previous diseases). This ensures a uniform composition of the study population and minimizes the risk of influences that distort the study results.


In medicine, a reason to use a certain diagnostic test, therapeutic procedure or medication. The opposite of indication is contraindication.

Informed Consent

A document that provides key facts about a clinical trial study (study medication or procedure, any diagnostic tests patients may have to take, and possible risks and benefits.) All participants in the studies must sign this to be allowed to participate.


Drug interactions (also called interactions) can occur when two or more drugs are used at the same time. The desired action of the drugs can be increased, decreased or eliminated altogether, and additional side effects can also occur.

Also called drug interaction


With interruptions, at intervals

Intervention Group

In a clinical trial, this group of patients is receiving the new treatment that's being tested in a clinical trial.


White blood cells. Leukocytes are an important component of the body's defence system. There are different types of leukocytes: granulocytes, lymphocytes and monocytes.


Condition with an elevated number of circulating white blood cells (leukocytes)


Condition with a decreased number of circulating white blood cells (leukocytes)


A subgroup of white blood cells which carry immunological function. They are essential for the body's immune defence. The precursor cells originate in the bone marrow whereas further stages of development take place in the lymphatic organs. Lymphocytes are divided on the basis of their function into B and T lymphocytes.

Lymphoma, malignant

A cancer originating in the lymphatic system

Maintenance therapy

Treatment (e.g. chemotherapy) that is usually given for a long time to stabilize the success of induction or consolidation therapy.


Tendency of a medical condition, especially tumors, to grow out of control and spread to other parts of the body. This can eventually lead to death.


The process of becoming mature. Cells undergo different stages of maturation.


Transformation of adult tissue into another tissue.


Loss of a part of a gene

Minimal residual disease

A type of deep remission in CML where BCR-ABL is however still detectable by PCR


Major Molecular Response (MMR), a level of response to CML therapy where the BCR-ABL ratio is equal or below 0,1%


Treatment with only one drug


The incidence of a disease in a population.

Mortality rate

The proportion of deaths to population at risk.


Molecular response, or molecular remission, with a reduction of 4 log (BCR-ABL <0,01%)


Molecular response, or molecular remission, with a reduction of 4.5 log (BCR-ABL <0,0032%)


Molecular response, or molecular remission, with a reduction of 5 log (BCR-ABL <0,001%)

Natural killer cells

Natural killer cells (or NK cells) are a type of cytotoxic lymphocyte which is critical to the  immune system


Trade name: Tasigna, development name: AMN107, inhibits BCR-ABL tyrosine kinase. Authorized for marketing in the EU since 2007 for the treatment of CML and Ph+ALL.
Other names: |AMN107|Tasigna


Part of the term oncology (study and science dealing with cancer).


A clinical trial in which researchers and participants know which treatment is being provided to each patient (opposite to "blinded trials" or "double-blind studies")




Higher than age-specific reduction in bone density, leading to bone fractures.


Therapy aimed at alleviating symptoms or preventing complications in incurable cancers. The opposite is curative.

Partial Cytogenetic Response

Between 1-35% of all cells still have the Philadelphia chromosome


Something that causes disease or illness


Relating to or caused by disease


Polymerase Chain Reaction, a very sensitive diagnostic test that allows the detection of certain genes (DNA) on a very sensitive level. PCR can detect up to one single gene in about 1 million genes.


Abbreviation for Partial Cytogenetic Response, meaning in the CML context that in cytogenetic tests, between 1-35% of all cells had the Philadelphia Chromosome


Pegylated interferon: interferon (IFN) that has PolyEthylene Glycol (PEG) molecules attached to it, which causes the interferon to be released to the body slowly


Permanent or continued existence


Abbreviation for "Philadelphia-Chromosome-positive", meaning the presence of a certain change in chromosomes (on chromosome 22) found in 95% of patients who have CML. The Philadelphia chromosome results from a mutation that involves the fusion of parts of chromosome 9 and chromosome 22 (the bcr-abl fusion gene).


The science of the interactions between drugs and the body

Philadelphia chromosome



(1) A substance containing no medication and prescribed or given to reinforce a patient's expectation to get well.
(2) An inactive substance or preparation used as a control in an experiment or test to determine the effectiveness of a medicinal drug.


Platelets are small cell fragments that circulate in the blood and help the clotting process. Platelets prevent bleeding and are therefore indispensable.

Also called thrombocytes

Pleural effusion

The accumulation of fluid in the fluid-filled space that surrounds the lungs




Trade name: Iclusig, development name: AP24534; a third-generation tyrosine kinase inhibitor
Other names: AP24534|Iclusig.

Primary therapy

Treatment given to a patient when a disease (cancer) first occurs.

Also called: primary treatment, first-line therapy or first-line treatment


Prediction of the probable course and outcome of a disease or condition based on existing findings.


Worsening of a cancer

Progressive disease

Disease with a worsening course


Multiplication of cells


Measures taken to prevent health problems


A large molecule composed of over 100 amino acids or peptides.


The action plan for the research work, which explains key objectives and procedures. In case of a clinical trial, the protocol defines e.g. the purpose of the study, how many people will participate, eligibility criteria, the medical intervention, etc.


Referring to the lungs (Latin: pulmo)


Once a day (Latin: quaque die)


In a clinical trial, patients are assigned by chance (often by a computer) to receive either one or the other treatment. This is to avoid bias in recruiting patients with specific characteristics into single arms of a trial.


Red blood cell count; number of red blood cells


Binding site for signaling substances; e.g. hormone receptor


The ability to withstand the effects of a drug, e.g. resistance of cancer cells to a specific therapy.

Response rate

Proportion of patients (in percent) in whom a specific therapy led to a decrease in or disappearance of signs and symptoms of a disease.


In the context of clinical studies: initial examination to find out whether a subject is eligible for inclusion in the study


Stem Cell Transplant

Second-line therapy

First-line therapy is the first treatment given to a newly diagnosed patient. Second-line therapy is given when first-line therapy doesn’t work or stops working.

Also called second-line treatment


Analytical level of detection of a test

Side effect

Adverse effects of a treatment:, side effects limit the maximum tolerable dose in particular during chemotherapy.

Southern blot

A method used in molecular biology to analyze DNA. During this procedure DNA is digested with restriction enzymes, and visualized using a radiolabeled DNA probe. Southern blot has been mostly replaced by PCR for the detection of point mutations, deletions and insertions. More formally called DNA blot.


The process of sperm cell development


Enlargement of the spleen. A number of diseases which are related to the immune system is associated with splenomegaly. This includes leukemias. A normal-sized spleen cannot be palpated (felt) during the physical examination of the abdomen, except in slender people. An enlarged spleen is usually palpable during careful physical examination.

Stem cells

Stem cells are cells that have the potential to develop into many different types of cell in the body including red blood cells (erythrocytes), white blood cells (leukocytes) as well as platelets (thrombocytes). Stem cells are formed in bone marrow and also in blood.
Stem cells usually come from two main sources: embryos and adult tissue. Embryonic stem cells can multiply and differentiate and ultimately form the entire organism whereas adult stem cells are generally thought to have limited ability to differentiate based on their tissue of origin. They are able to regenerate cells from their original organ.


Under the skin

Substandard drugs

Products whose composition and ingredients do not meet the correct scientific specifications and which are consequently ineffective and often dangerous to the patient. Substandard products may occur as a result of negligence, human error, insufficient human and financial resources or counterfeiting.


A sign of disease or disorder (Greek; accident, happening)


Abbreviation for Treatment-Free Remission. In CML is referred to having a stable deep molecular response without the need for ongoing Tyrosine Kinase Inhibitor (TKI) treatment after having been in deep molecular residual disease over a longer period of time.


Disorder in which there is a high number of thrombocytes (platelets) in the blood.

Thrombotic events

Blood clot occurring inside a blood vessel


A condition in which there is a lower than normal number of platelets (thrombocytes) in the blood; thrombocytopenia may cause bleeding in the skin and mucosa or in organs.

Also called: thrombocytopaenia, thrombopenia,thrombopaenia


Tyrosine Kinase Inhibitors, a class of drugs that block an enzyme involved in the mechanism of division of cells


The quality of being poisonous; harm resulting from drugs, e.g. side effects of chemotherapy.

Tumor marker

A substance that can be found in the blood, urine, or body tissue in some people with cancer. Tumor markers can help diagnose cancer.

Tumour board

Cross-functional group of experts from all medical disciplines, e.g. surgery, oncology and radiology, assessing choices of treatment.

Also called: tumor board

Tyrosin kinase

An enzyme that stimuates the growth of leukaemia cells


White blood cell count, number of white blood cells

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