October 2014 Myeloproliferative Neoplasms Angela Fleischman Division of hematology/Oncology

MPN are clonal disorders of the hematopoietic stem cell Essential Thrombocythemia (ET) Polycythemia Vera (PV) Myelofibrosis (MF) Platelets Marrow Fibrosis Red Cells Hematopoietic stem cell (HSC) JAK2V617F mutation CALR mutation

MPN are clonal disorders of the hematopoietic stem cell Polycythemia Vera (PV) Red Cells Hematopoietic stem cell (HSC) JAK2V617F mutation

MPN are clonal disorders of the hematopoietic stem cell Essential Thrombocythemia (ET) Platelets Hematopoietic stem cell (HSC) JAK2V617F mutation

MPN are clonal disorders of the hematopoietic stem cell Myelofibrosis (MF) Marrow Fibrosis Hematopoietic stem cell (HSC) JAK2V617F mutation

Molecular Defects in Classical MPNs JAK2 mutations (PV 96%, ET 30-50%, PMF 50%, Blast phase MPN 50% CALR (calreticulin) (25%-35% of patients with ET and PMF, 67-88% among JAK2 negative patients) BCR-ABL (CML 100%) Others: MPL mutations TET2 mutations ASXL1 mutations CBL mutations IDH1/2 mutations IKZF1 mutations LNK mutations

Activation of EPO-Receptor (Normal) JAK2 P JAK2 P Stat5 P Stat5 P Gene Transcription X

Activation of EPO-Receptor (JAK2V617F) Stat5 P Stat5 P Gene Transcription CHANGE JAK2 SHAPE AND COLOR X

Patient R.M. 59 yo man with 6 month history of itchy skin, headache CBC reveals WBC 15.0 Hct 60% Plt 600K Exam: obese, reddish skin, spleen tip felt, otherwise normal PMH: none SH: smokes FH: father died of leukemia

Patient R.M. 59 yo man with 6 month history of itchy skin, headache CBC reveals WBC 15.0 Hct 60% Plt 600K Exam: obese, reddish skin, spleen tip felt, otherwise normal PMH: none SH: smokes FH: father died of leukemia REFERRED TO HEMATOLOGY WHAT DO YOU DO NEXT?

Patient R.M. Serum Epo is low JAK2V617F mutation is present (allele burden 45%) Bone marrow biopsy shows hypercellular marrow, trilineage myeloproliferation, no increased fibrosis

Patient R.M. Serum Epo is low JAK2V617F mutation is present (allele burden 45%) Bone marrow biopsy shows hypercellular marrow, trilineage myeloproliferation, no increased fibrosis DIAGNOSIS?

Patient R.M. Serum Epo is low JAK2V617F mutation is present (allele burden 45%) Bone marrow biopsy shows hypercellular marrow, trilineage myeloproliferation, no increased fibrosis DIAGNOSIS? Polycythemia Vera

Patient R.M. Serum Epo is low JAK2V617F mutation is present (allele burden 45%) Bone marrow biopsy shows hypercellular marrow, trilineage myeloproliferation, no increased fibrosis DIAGNOSIS? Polycythemia Vera TREATMENT?

Patient R.M. Serum Epo is low JAK2V617F mutation is present (allele burden 45%) Bone marrow biopsy shows hypercellular marrow, trilineage myeloproliferation, no increased fibrosis DIAGNOSIS? Polycythemia Vera TREATMENT? ASA (81mg/day) and phlebotomize to Hct <45% Encourage weight loss and smoking cessation

Polycythemia vera Diagnosis Standard Therapies

Who CRITERIA FOR Polycythemia vera REQUIRES MEETING EITHER BOTH MAJOR CRITERIA AND ONE MINOR CRITERIA OR THE FIRST MAJOR CRITERIUM AND 2 MINOR CRITERIA MAJOR CRITERIA: HEMOGLOBIN > 18.5G/DL IN MEN, >16.5 G/DL IN WOMEN, OR EVIDENCE OF INCREASED RED CELL VOLUME PRESENCE OF JAK2V617F MUTATION OR OTHER FUNCTIONALLY SIMILAR MUTATION (EG., EXON 12 MUTATION) MINOR CRITERIA: BM BIOPSY SHOWING HYPERCELLULARITY FOR AGE WITH TRILINEAGE MYELOPROLIFERATION SERUM EPO BELOW REFERENCE RANGE ENDOGENOUS ERYTHROID COLONY FORMATION IN VITRO

Therapeutic goals in pv PREVENT THROMBOSIS CONTROL DISEASE-RELATED SYMPTOMS

TREATMENT STRATEGIES Reduction of CV risk factors Antiplatelet therapy (aspirin) ALL PATIENTS Phlebotomy (goal hct <45%) Cytoreduction (hydrea) HIGH RISK PATIENTS (age >60 or prior thrombosis)

Patient S.S. 65 yo woman found to have a plt count of 700K on 2 consecutive yearly exams Reactive? Primary (ET)?

Causes of thrombocytosis Myeloid malignancy Essential thrombocythemia Polycythemia vera Primary myelofibrosis Chronic myeloid leukemia Refractory anemia with ringed sideroblasts and thrombocytosis Myelodysplatic syndrome assoicated with isolated del(5q) Reactive (secondary thrombocytosis Blood loss or iron deficiency Infection or inflammation Disseminated malignancy Drug effect (vincristine,epinephrine, ATRA) Hyposplenism or congenital absence of spleen Hemolytic anemia Familial thrombocytosis Mutations in TPO, MPL, JAK2V617I or unknown genes Spurious thrombocytosis Cryoglobulinemia Cytoplasmic fragmentation accompanying myeloid or lymphoid neoplasia Red cell fragmentation

Bone Marrow Biopsy JAK2V617F not present

Essential thrombocythemia Diagnosis Standard Therapies

WHO Diagnostic criteria for ET MUST MEET ALL 4 CRITERIA: Sustained platelet count ≥450 x 109/L Bone marrow biopsy specimen showing proliferation mainly of the megakaryocytic lineage with increased numbers of enlarged, mature megakaryocytes; no significant increase or left-shift of neutrophil granulopoiesis or erythropoiesis Not meeting WHO criteria for PV, PMF, CML, MDS or other myeloid neoplasm Demonstration of JAK2 V617F or other clonal marker, or in the absence of a clonal marker, no evidence for reactive thrombocytosis

CALRETICULIN MUTATIONS IN MPN In December 2013 2 groups identified calreticulin (protein designated CRT, gene designated CALR) in MPN Present in >65% of ET and MF patients without JAK2V617F mutation Does not occur in PV Patients either have JAK2V617F or CALR NOT both CRT is an ER chaperone protein and on the cell surface serves as an “eat me” signal for phagocytes

Treatment goals in ET REDUCE RISK OF BLOOD CLOTS RELIEVE SYMPTOMS

Blood clot Risk assessment in ET High risk No high-risk features Low risk Intermediate risk Age > 60 y Age < 40 y Age 40-60 y Prior thrombosis Platelets >1500 × 109/L Aspirin + cytoreductive agent Aspirin alone (and encourage to reduce cardiovascular risk factors as much as possible (smoking, weight, etc)

Choice of cytoreductive agent Age group First line Second line < 40 y Interferon Hydroxyurea Anagrelide 40-75 y > 75 y Pipobroman Busulphan Radioactive phosphorus

PATient j.l. 73 yo man with 2 years of slowly progressive anemia, fatigue Workup by PCP unrevealing, referred to hematology CBC – WBC 9.5 (1% blasts), Hct 28%, Plt 150 Splenomegaly on exam BM biopsy shows 4+ fibrosis, <5% blasts JAK2V617F not detected

myelofibrosis Diagnosis Standard Therapies

Diagnostic criteria for pmf MUST MEET ALL 3 MAJOR AND 2 MINOR CRITERIA Major criteria: Presence of megakaryocyte proliferation and atypia, usually accompanied by either reticulin or collagen fibrosis Not meeting WHO criteria for polycythemia vera, BCR-ABL1–positive chronic myelogenous leukemia, myelodysplastic syndrome, or other myeloid disorders Demonstration of JAK2 V617F or other clonal marker, or, in the absence of the above clonal markers, no evidence that bone marrow fibrosis is secondary to other causes Minor criteria: Leukoerythroblastosis (immature cells in blood) Increase in serum lactate dehydrogenase level Anemia Palpable splenomegaly (enlarged spleen)

Dynamic international prognostic scoring system for mf (DIPSS) Obtained at any time during follow-up 0 = Low 1-2 = Intermediate-1 3-4 = Intermediate-2 5-6 = High Passamonti et al, Blood 2010

Causes of Death in PMF Cervantes et al, Blood 2009.

Symptomatic Burden in MF Constitutional Symptoms Splenomegaly Myeloproliferation Functioning Percentage of patients reporting symptoms Scherber et al, Blood 2011

Consequences of Increased Inflammation HSC exhaustion Stress hematopoiesis Constitutional Symptoms -weight loss -fatigue -fever

Management of pmf Treatment for anemia Treatment for splenomegaly Erythropoietin (growth factor) Corticosteroids Androgens (danazol) +/- Prednisone Thalidomide /lenalidomide+ Prednisone Transfusions Treatment for splenomegaly Hydroxyurea Splenectomy Ruxolitinib

Ruxolitinib (JAKAFI) Dual JAK1/JAK2 inhibitor FDA approved in Nov 2011 for: Intermediate or high-risk Myelofibrosis (=80-90% of MF patients) JAK2V617F NOT required

ruxolitinib WHAT IT DOES: Reduces spleen size Relieves symptoms WHAT IT DOESN’T DO: Improve anemia Significantly reduce the JAK2V617F allele burden WHAT IT MAY DO: Retard progression of fibrosis Extend lifespan

Treatment goals for mpn Prevent thrombosis Prevent hemorrhage Alleviate constitutional symptoms Minimize primary and iatrogenic disease progression Improve QOL and survival

Questions?