CML Learning Programme for Nurses & Other Allied Health Care Professionals EBMT Nurses Group

1. CML Learning Programme for Nurses & Other Allied Health Care Professionals EBMT Nurses Group The European Group for Blood and Marrow Transplantation

2. Module 1 Understanding Chronic Myeloid Leukaemia (CML)

3. Aims of Module 1 This module explains the background to CML, it aims to: • Understand the definition of Chronic Myeloid Leukaemia (CML) and its pathophysiology • Understand CML’s etiology, increasing prevalence and symptoms

4. Aims of module 1 • Understand the different stages of CML, the way CML is diagnosed and different prognostic scoring systems • Understand historical developments in CML treatment

5. Definition of CML The World Health Organization (WHO) classifies chronic myeloid leukaemia (CML) as a myelo-proliferative disease characterised by the presence of the Philadelphia chromosome or BCR-ABL fusion oncogene Vardiman J.W. et al. Blood 2002,100:2292-302

6. Epidemiology of CML • CML is a complex disease that occurs in about 1 case per 100’000 of the population Black R.J. et al. Eur J Cancer 1997, 33: 1075-1107) • CML is estimated to account for approximately one of every five cases of adult leukaemia Sawyers C.L. et al. NEJM 1999, 340: 1330-1340) • CML affects men slightly more than women Ratio 1.7:1 Henderson, E.S., Lister, T.A., & Greaves, M.F. (2002.) Leukemia 7th ed.) New York: Saunders

7. Epidemiology of CML • The median age at diagnosis is 60 to 65 years ESMO Guidelines Working Group. Ann Oncol (2010) 21 (suppl 5): v165-v16 • There is no significant ethnic or geographical predisposition

8. Epidemiology of CML • Around 10 % of cases of CML occur in children aged 5 to 20 years Beutler E., Lichtman M.A., Coller B.S., Kipps T.J., & Seligsohn, U. (2001.) William’s hematology (6th ed.). New York: McGraw-Hill. • CML represents around 3% of all cases of childhood leukaemia Beutler E., Lichtman M.A., Coller B.S., Kipps T.J., & Seligsohn U. (2001) William’s hematology (6th ed.) New York: McGraw-Hill • The number of people living with CML has doubled since 2001 due to the development of new treatments (such as imatinib)

10. CML Prevalence Estimates • CML is one of the big success stories in cancer • With imatinib (and other TKI treatments) the survival in CML has improved from a median of 3 to 6 years with hydroxyurea and interferon alpha to an estimated 8 year survival rate of 80 to 90% with imatinib (Prevalence = incidence x duration of disease)

11. CML Prevalence Estimates • Prior to imatinib the annual mortality rate for CML was 15 to 20% of patients • Thus it is estimated that the prevalence of CML in the US in the next three decades may exceed 200’000 cases

12. CML Prevalence Estimates • Because the highly effective drugs are still fairly new, the average survival of people now being diagnosed with CML is not known • CML is currently undergoing transition from being a rare cancer to a chronic one

13. Epidemiology of CML • The risk of getting CML increases with age, with half of all CML patients older than 60 • CML is slightly more common among males than females. Ratio 1.3:1

14. Historical Milestones in CML 1845 John Hughes Bennett and Rudolph Virchow describe the first case of CML 1960 Peter C. Nowell and David Hungerford identify an abnormal chromosome called the Philadelphia chromosome in the blood cells and bone marrow of patients with CML Nowell & Hungerford. J Natl Cancer Inst 1960, 25: 85-109

15. Historical Milestones in CML 1973 Janet Rowley determines that the abnormal chromosome identified by Nowell and Hungerford results from the exchange of genetic material between two chromosomes Rowley J.D. et al. N Engl J Med 1973, 289:220-221)

16. Historical Milestones in CML 1982-1985 John Groffen, Nora Heisterkamp, Gerald Grosveld, E. Cannani, David Baltimore and Owen Witte show that an abnormal gene and protein called BCR-ABLis produced as a consequence of the chromosome rearrangement that characterizes CML

17. Historical Milestones in CML 1987 Nicholas Lydon and Alex Matter commence a drug discovery program to target proteins such as BCR-ABL, in collaboration with Brian Druker, Thomas Roberts and Charles Stiles Using a new technique called high throughput screening, in which thousands of molecules can be tested for their Biological activity, Lydon identified a compound called CGP57148B,later renamed STI-571

18. Historical Milestones in CML 1993 Brain Druker’s laboratory shows that STI57I (imatinib) is the best of the compounds developed by Lyndon’s group at specifically targeting and killing CML cells Druker B. et al. Nat Med 1996, 2: 561-566 1998 Brian Druker, Charles Sawyers, and Moshe Talpaz begin clinical trials of imatinib

19. Historical Milestones in CML 2001, May 10 Imatinib is FDA approved for use as a first-line treatment for people with accelerated phase or blast crisis CML or chronic phase CML patients who had not responded to interferon-alpha

20. Historical Milestones in CML 2003 The IRIS trial showed that imatinib was superior to the standard combination of interferon-alpha/cytarabine O’Brien S.G. et al . N Engl J Med 2003, 348: 994-1004 Charles Sawyers, Brian Druker, Andreas Hochhaus, and Francois-Xavier Mahon report that mutations of BCR-ABL are The major mechanism of imatinib resistance, leading to the development of second generation tyrosine kinase inhibitors such as dasatinib and nilotinib

21. Historical Milestones in CML 2006-2007 Dasatinib and nilotinib are FDA approved for Patients with imatinib resistance June 2010 FDA approval granted to nilotinib as first-line treatment in Ph+ CML October 2010 FDA approval granted to dasatinib as first-line treatment in Ph+ CML

22. Historical Milestones in CML December 2010 EMA and Swiss Medic approve nilotinib as first line treatment in Ph+ CML EMA approved dasatinib as first-line treatment in Ph+ CML (Taken, in part, from “50 Years in Hematology: Research that revolutionized patient care”. Published by the American Society of Hematology. Chapter 2. Targeted Therapy for Chronic Myeloid Leukemia. P 13.)

23. What is Philadelphia chromosome positive CML? • Chronic myeloid leukaemia (CML) is a haemato-poietic stem cell disease of the bone marrow and blood • CML is characterised by a massive overproduction of white blood cells

24. What is Philadelphia chromosome positive CML? • The uncontrolled growth of white blood cells in CML results from an acquired injury to the DNA of a stem cell in the bone marrow • The disease is called Philadelphia chromosome-positive CML because it results from the formation of the Philadelphia chromosome from the translocation of elements of chromosome 9 and 22

25. What is Philadelphia chromosome positive CML? The gene that breaks off from chromosome 9 is called ABL (after Abelson the scientist who first identified the gene), while the gene that splits from chromosome 22 is called BCR, short for breakpoint cluster region

26. What is Philadelphia chromosome positive CML? • The combination of BCR and ABL leads to the formation of an abnormal fusion gene responsible for the pathogenesis of CML • In the words of Brian Druker the BCR-ABL gene in CML acts “like the gas pedal in a car stuck in the ‘on’ position fuelling the excess growth of white blood cells”

27. What is Philadelphia chromosome positive CML? The presence of BCR/ABL rearrangement is the hallmark of CML, and responsible for accelerated cell growth and decelerated cell death (ASH, 50 Years in Hematology: Research that revolutionized patient care, 2008)

28. Biology of CML Chromosome 22 Chromosome 9 Philadelphia (Ph) chromosome Cytogenetics 9 BCR t (9;22) BCR ABL ABL 22 Ph+ + • Signaling pathways • Ras • AKT • PI3K • Other pathways • Deregulation • Cell proliferation • Cell survival • DNA repair • CML • WBC (myeloid)  • RBC  • Platelets  BCR-ABL (Tyrosine kinase) > > - Tyrosine kinase inhibitors (TKIs)

29. 20%-25% increase per year in projected prevalence Projection of CML Prevalence up to 2050 Assumptions: Population: 500 Mill., mortality: 2% per year, Incidence increasing by about 0.01/100.000 per year Modified from R. Hehlmann

30. Survival 1983-2008 Primary imatinib, 2002-2008 (CML IV)5-year survival 93% n = 2830 IFN or SCT, 1997-2008 (CML IIIA) 5-year survival 71% Survival probability IFN or SCT, 1995-2008 (CML III)5-year survival 63% (CML I, II) IFN, 1986-20035-year survival 53% Hydroxyurea, 1983-1994 Busulfan, 1983-1994 5-year survival 38% Courtesy of the German CML Study Group Year after diagnosis

31. Etiology of CML • The initiating factor of CML is still unknown, although exposure to radiation has been implicated • If people have had radiotherapy for another cancer this can increase risk of CML • Agents such as benzene are thought to be a possible cause Moloney W.C. et al. Blood 1987, 70 : 905-908

32. Etiology of CML • The risk of getting CML does not seem to be affected by smoking, diet, or infections • CML does not run in families since inherited mutations do not cause CML • Instead, DNA changes related to CML occur during the patient’s life time

33. Etiology of CML • People with low immunity after an organ transplant or due to HIV or AIDS are at increased risk • Ulcerative colitis can increase the risk • Being overweight can slightly increase risk

34. Symptoms of CML The clinical manifestations of CML are insidious and often discovered incidentally when an elevated white blood cell count is revealed by a routine blood count or when an enlarged spleen is revealed during a general physical examination

35. Common CML symptoms include • Feelings of satiety and decreased food intakes due to the enlarged spleen encroaching on the stomach • Nonspecific tiredness resulting from anaemia • Low-grade fever and excessive sweating related to hyper metabolism

36. Symptoms of CML • Bone pain or joint pain caused by leukaemia cells spreading from the marrow cavity to the surface of the bone or into the joint • In very rare cases, patients with very high white blood count may present with Hyperviscosity syndrome, including priapism, cerebrovascular accidents, tinnitus, confusion and stupor

37. Phases of CML The progression of Ph+ CML that occurs when the condition is left untreated is described in three phases: • Chronic Phase CML • Accelerated CML • Blast Crisis CML Chronic Accelerated Blast

38. Phases of CML The phases of CML depend on a number of different factors, mainly the number of leukaemic blast cells (blasts) that are found in the blood and bone marrow and the severity of symptoms that the patient is experiencing

39. Chronic Phase CML • In the chronic phase of Ph+ CML there are few blasts • Approximately 90 % of patients with Ph+ CML are diagnosed in this phase • Newer forms of therapy aim to delay progression of the disease from chronic phase to accelerated or blast phase • Patients usually respond to standard treatments

40. Accelerated Phase CML • Blasts 10 to 19% of WBCs in peripheral and/or nucleated bone marrow cells • Peripheral blood basophils (> 20%) • Persistent thrombocytopenia (<100 x 10 ⁹/L) unrelated to therapy, or persistent thrombocytosis (>1000 x 10 ⁹/ L) unresponsive to therapy

41. Accelerated Phase CML • Increasing spleen size and increasing WBC count unresponsive to therapy • Cytogenetic evidence of clonal evolution WHO Criteria. IARC Press: Lyon 2008 • The accelerated phase can last 6 to 18 months, where it either responds to treatment or progresses to the next phase • CML in the accelerated phase does not respond as well to treatment as CML in the chronic phase

42. Blast Crisis WHO Criteria • Blasts >20% of peripheral blood white cells or of nucleated bone marrow cells • Extra medullary blast proliferation • Large foci or clusters of blasts in the bone marrow biopsy (WHO. IARC Press: Lyon 2008) International Bone Marrow Transplant Registry • >30% blasts in the blood, marrow or both • Extra medullary infiltrates of leukemic cells (DeVita VT, Hellman S et al. Cancer: Principles and Practice of Oncology, 6th Edition. Vol 2. pgs 2433-2447. 2001 Lippincott, Williams & Wilkins.)

43. Disease Progression The exact molecular mechanism by which CML transforms to more advanced stages of the disease is unknown

44. Disease Progression However, it is thought likely that one of the drivers of the progression from chronic phase through acceleration and blast crisis is the acquisition of new chromosomal abnormalities in addition to the Philadelphia chromosome With modern treatment only about 10% of patients show progression every year

45. Techniques used to diagnose/monitor CML • Complete Blood Counts • Cytogenetic analysis • More sensitive testing

46. Complete Blood Counts • Most patients with CML show an increase in the number of leukocytes in the blood with many immature cells • Sometimes CML patients also have anaemia and thrombocytopenia • Even though such findings suggest leukaemia • further tests will be needed to confirm the diagnosis

47. Cytogenetic analysis • Involves looking at DNA from bone marrow under the microscope to determine how many cells contain the Philadelphia chromosome • A complete cytogenetic response occurs when no cells are found to have the Philadelphia chromosome

48. More sensitive testing For CML patients who are cytogenetically Ph-chromosome–negative (Ph-) the following special techniques can be used to detect BCR-ABL : • Fluorescence in situ hybridization (FISH) • Reverse transcriptase polymerase chain reaction (RT-PCR)

49. Fluorescence insitu hybridization (FISH) • Uses fluorescent dye probes to bind to specific pieces of DNA • For CML 2 probes may be used, 1 to bind to the BCR gene, and 1 to bind to the ABL gene • When the probes bind to their target genes each dye emits a fluorescent glow • Reveals whether BCR and ABL genes are next to each other (as in the Philadelphia chromosome), or on separate chromosomes (as in normal cells)

50. Fluorescence insitu hybridization (FISH) • If copies of the gene are found it means that the leukaemia is still present even when cells aren’t visible under the microscope • Can be used on used on regular blood or bone marrow samples without culturing the cells first