I’ve just been diagnosed with CML. Could you answer my questions? Sameer Tulpule Royal Hallamshire Hospital Sheffield

What now? Leukemia Can be cured

Fast Facts Rare disease 1 to 1.5 new cases per 100,000 population per year Rare in young adults under 19 years Not inherited – cannot pass down to kids

How did I get it? In almost all cases there are no identifiable predisposing causes Radiation is the only clearly established external factor predisposing to development of CML Benzene is implicated only on an anecdotal basis

What is CML Wang et al. Genes Chromosomes Cancer. 2001;32:97

Diagnostic Considerations in Chronic Myeloid Leukemia Demonstrating the presence of the t(9;22) or its gene product is absolutely essential in diagnosing a patient with CML Karyotyping in CML 1) Allows for the diagnosis of CML 2) Requires a bone marrow aspirate for optimal metaphases

Yellow → fusion of Bcr and Abl FISH in CML Bcr- Ch 22 Ch 9 Ch 22 Abl – Ch 9 Bcr-Abl Fusion Red → Bcr probe Green → Abl Probe Yellow → fusion of Bcr and Abl

Diagnostic Considerations in Chronic Myeloid Leukemia Bcr-Abl Bcr Abl cDNA Quantitative RT-PCR for Bcr-Abl in CML 1) Allows for the diagnosis of CML 2) Does not require a bone marrow aspirate for optimal results 3) Can quantify the amount of disease

Disease Diagnosis and Monitoring in CML Test Target Tissue Sensitivity (%)* Use Cytogenetics Ph chromosome BM 1-10 ▪ Confirm diagnosis of CML ▪ Evaluate karyotypic abnormalities other than Ph chromosome (ie, clonal evolution) FISH Juxtaposition of bcr and abl PB/BM 0.5-5 ▪ Routine monitoring of cytogenetic response in clinically stable patients ▪ Routine measurement of MRD RT-PCR bcr-abl mRNA 0.0001-0.001 ▪ Determine the breakpoints of the fusion genes *Number of leukemic cells detectable per 100 cells. BM = bone marrow; FISH = fluorescence in situ hybridization; PB = peripheral blood; MRD = minimal residual disease; RT-PCR = reverse transcriptase polymerase chain reaction. Wang et al. Genes Chromosomes Cancer. 2001;32:97

Normal Bcr-Abl Signaling* The kinase domain activates a substrate protein, eg, PI3 kinase, by phosphorylation This activated substrate initiates a signaling cascade culminating in cell proliferation and survival Substrate Bcr-Abl Effector P P ADP Bcr-Abl is a disregulated tyrosine kinase protein capable of both auto- and substrate phosphorylation. Highly plastic structure with both open (active) and closed (autoinhibited) stages. State is regulated both intramolecularly and by other proteins. Bcr-Abl signaling begins when adenosine triphosphate (ATP) binds to the kinase domain. This allows the binding of the substrate to be phosphorylated. Following phosphate transfer, the phosphosubstrate is competent to bind to and activate downstream effector molecules. P ATP P P P SIGNALING ADP = adenosine diphosphate; ATP = adenosine triphosphate; P = phosphate. Savage and Antman. N Engl J Med. 2002;346:683 Scheijen and Griffin. Oncogene. 2002;21:3314. Hantschel O, Superti-Furga G. Regulation of the c-Abl and Bcr-Abl tyrosine kinases. Nat Rev Mol Cell Biol. 2004;5:33-44. Savage DG, Antman KH. Imatinib mesylate–a new oral targeted therapy. N Engl J Med. 2002;346:683-693. Scheijen B, Griffin JD. Tyrosine kinase oncogenes in normal hematopoiesis and hematological disease. Oncogene. 2002;21:3314-3333.

Imatinib Mesylate: Mechanism of Action* Imatinib mesylate occupies the ATP binding pocket of the Abl kinase domain This prevents substrate phosphorylation and signaling A lack of signaling inhibits proliferation and survival Bcr-Abl P ATP At the molecular level, imatinib mesylate targets a specific part of the tyrosine kinase region of Bcr-Abl. Imatinib mesylate is an ATP-mimetic agent that binds Bcr-Abl with greater affinity than ATP at its ATP-binding site. The tyrosine kinase activity of Bcr-Abl is dependent on its ATPase activity. Bcr-Abl–bound imatinib mesylate prevents ATP binding and hydrolysis and hence the tyrosine kinase action of Bcr-Abl. This blocks the downstream substrate of Bcr-Abl, which is dependent on phosphorylation for activation. This in turn blocks downstream signal transduction pathways activated by Bcr-Abl. Imatinib mesylate SIGNALING Savage and Antman. N Engl J Med. 2002;346:683. Savage DG, Antman KH. Imatinib mesylate–a new oral targeted therapy. N Engl J Med. 2002;346:683-693. Scheijen B, Griffin JD. Tyrosine kinase oncogenes in normal hematopoiesis and hematological disease. Oncogene. 2002;21:3314-3333.

IRIS 8-Year Update Overall Survival (Intent-to-Treat) – Imatinib Arm Estimated overall survival at 8 years was 85% (93%, considering only CML related deaths) 1 2 3 4 5 6 7 8 9 A l i v e , % M o n t h s S c R a d m z u r : w C L O % Alive 13

IRIS Study: Most Frequently Reported AEs Imatinib is a Safe Drug.... IRIS Study: Most Frequently Reported AEs Most Common Adverse Events (by 5 Years) All Grade AEs Patients, % Grade 3/4 AE’s Patients % Superficial Edema 60 2 Nausea 50 1 Muscle cramps 49 Musculoskeletal pain 47 5 Diarrhea 45 3 Rash/skin problems 40 Fatigue 39 Headache 37 <1 Abdominal pain 4 Joint pain 31 Only Serious Adverse Events (SAEs) were collected after 2005 Grade 3/4 adverse events decreased in incidence after years 1-2 IRIS 8 year update

How often do I need tests

Definitions of Treatment Response Level of Response Definition Complete hematological response Normal CBC and differential, no extramedullary disease Major cytogenetic response 0-35% Ph-positive metaphases* - Partial cytogenetic response 1%-35% Ph-positive metaphases* - Complete cytogenetic response 0% Ph-positive metaphases* Major molecular response ≥ 3-log reduction of BCR-ABL mRNA from baseline Complete molecular remission Negativity by RT-PCR * Cytogenetic response is based on analysis of at least 20 metaphases Deininger, 2005; National Comprehensive Cancer Network, 2007.

Do I need repeated Bone marrows? No Usually only at diagnosis Part of trial If there is loss of response

CML – Phases of Disease Phase Characteristics Chronic Indolent course, often asymptomatic and found incidentally on routine physical exam Predominance of mature white blood cells Approximately 90% of patients are diagnosed at this stage Median survival is 4–7 years (pre-tyrosine kinase inhibitor [TKI] therapy) Accelerated Transition generally occurs over a period of 1 year or more. Duration is 6 months to 1 year Associated with progressive leukocytosis, thrombocytosis or thrombocytopenia, basophilia, increased blasts, splenomegaly, fever, bone pain Clonal evolution may be present Blast Lasts only a few months – survival is poor if untreated Associated with increasing blasts (>20%), progressive splenomegaly despite treatment, and clonal evolution National Comprehensive Cancer Network, 2007; National Cancer Institute, 2007; Calabretta & Perrotti, 2004; Cortes et al., 2006.

Summary Rare disease Potentially curable disease Good long term survival Imatinib has a good safety profile