Myeloproliferative Neoplasms Myeloproliferative Neoplasms The Path to Targeted Agents Disclosures • Member, Advisory Committee, 2011 – Incyte Corporation • I will discuss the off‐label use of medications and medications used in the context of clinical trials only. l l Outline of Topics Outline of Topics • • • • • • Case based Review Case‐based Review Historical Context Therapeutic Context h i C 2005 and the discovery of JAK2 Effects on Therapy? Where to now? Where to now? Case #1: JG Case #1: JG • 43 43 yo woman yo woman • In Aug of 2006  Abdominal Pain Abdominal Pain. • Idiopathic portal vein thrombosis Thought to thrombosis. Thought to be due to OCPs. • Anticoagulated. Anticoagulated • Mid 2010 – Abdominal pain and fatigue pain and fatigue Case #1: JG Case #1: JG Case #1: JG Case #1: JG • Labs demonstrated: Labs demonstrated: – WBC: 5.6 k/uL – Hgn: 13.6 gm/dL g g / – Platelet Count of 610 k/uL • Smear Smear shows polychromasia and burr cells, shows polychromasia and burr cells, occasional dacrocyte (or tear drop cell) • Liver Function Panel Normal Liver Function Panel Normal • Congenital Clotting Disorders – Negative • JAK2 gene mutation positive JAK2 gene mutation positive Case #2: EW Case #2: EW • 36 yo woman 36 yo woman • First Pregnancy Interuterine fetal demise Interuterine fetal demise at 22 wks gestation • Platelet count of 680 k/uL. • Jak 2 Positive • Consistent with a diagnosis of Essential Thrombocythemia Case #2: EW Case #2: EW • Pregnancy #2 Pregnancy #2 – Prophylactic level anticoagulation – Complicated by placental abruption, rapid Complicated by placental abruption rapid maternal hemorrhage, pre‐eclampsia and late fetal demise fetal demise Case #2: EW Case #2: EW • Pregnancy #3 Pregnancy #3 – Anticoagulation with therapeutic level low‐ molecular weight heparin and aspirin molecular weight heparin and aspirin – Anti‐XA levels measured (peak and trough), Q2 weeks. – Successful delivery of healthy infant • Same with Pregnancy #4 Same with Pregnancy #4 • Currently: 4.9>‐13.9<320 Myeloproliferative Disorders Myeloproliferative Disorders MPN (WHO 2008) MPN (WHO 2008) BCR/ABL Positive BCR/ABL Negative g PV ET PMF Others CML Epidemiology Polycythemia Vera Essential Thrombocytosis Primary Myelofibrosis Annual Incidence Annual Incidence Median Survival Median Survival 1.9‐2.3/100,000 12.6 years in PVSG studies 2.5/100,000 individuals. 10‐year survival roughly 64%‐80% May equal age‐matched controls t l 0.4‐1.3/100,000 Median survival ranges from less than 2 years to greater than 15 years to greater than 15 years on the basis of currently identified prognostic factors Polycythemia Vera Polycythemia Vera • Cardinal Features of PV Cardinal Features of PV – Increased red cell mass – Hypercellular BM with increased numbers of Hypercellular BM with increased numbers of erythroid, megakaryocytic, granulocytic precursor cells – Variable increase in reticulin fibers – Thrombotic Risk>Bleeding; Vasomotor SX Thrombotic Risk>Bleeding; Vasomotor SX – Arterial and Venous clotting – Risk of leukemic transformation Risk of leukemic transformation Essential Thrombocythemia Essential Thrombocythemia • Cardinal Features of ET Cardinal Features of ET – Increased Megakaryocytes and Platelets and Platelets – Median age 60; F>M – Propensity for hemorrhage Propensity for hemorrhage – Thrombosis includes stroke, TIA CVST abdominal veins TIA, CVST, abdominal veins – Pregnancy complications – Rare transformations to AML Rare transformations to AML – Progression to MF Primary Myelofibrosis Primary Myelofibrosis • Cardinal Cardinal Features of PMF Features of PMF • Previously called chronic idiopathic myelofibrosis (CIMF) and agnogenic myeloid myelofibrosis (CIMF) and agnogenic myeloid metaplasia • Often an older patient, with sx related to Of ld i ih l d splenomegaly – including fatigue, NS, weight loss. • Shorter OS, secondary to cytopenias, transformation to AML MF Transformation PV 20 yr: 30% ET 20yr: 20% AML Transformation PV 20 yr: 15% ET 20yr: 8% Thrombosis: PV 22-35% 22 35% ET: 23-29% MF 20yr: 25% Topics to Cover Topics to Cover • • • • • Overview of Diseases Overview of Diseases Historical context Therapy Up to Now h Therapy In the Future? Pitfalls and Open Questions ESSENTIAL THROMBOCYTHEMIA EMIL EPSTEIN & ALFRED EMIL EPSTEIN & ALFRED GOEDEL Hemorrhagic Thrombocythemia… a case of extreme thrombocytosis of extreme thrombocytosis, erythocytosis and mucocutaneous bleeding and no panmyelosis…. MYELOFIBROSIS GUSTAV HEUCK Falle von Leukamie mit Falle von Leukamie mit eigenthumlichem Blut‐resp. Knochenmarksbefund “Two cases of leukemia with peculiar blood and bone marrow findings” Arch Pathol Anat Physiol Virchows 1879 POLYCYTHEMIA VERA Louis Henri Vasquez 40 yr old man with chronic cyanosis*, vertigo, dyspnea, palpitations, hepato‐ splenomegaly and and erythrocytosis WILLIAM OSLER WILLIAM OSLER 4 cases of chronic cyanosis, with polycythemia and enlarged spleen *Cyanosis = ruddiness, congestion From Description to Hypothesis William Dameshek (1900 William Dameshek (1900‐1969) 1969) ….is it possible that these various conditions is it possible that these various conditions – “myeloproliferative myeloproliferative disorders”– are all somewhat variable manifestations of proliferative activity of the bone marrow cells, perhaps due to a hitherto undetected stimulus? … William Dameshek, 1951, Blood Essential Questions for Neoplasia Essential Questions for Neoplasia • Clonal? • What is the cell of origin? Answers to both of these questions addressed with • Answers to both of these questions addressed with studies of women who were heterozygotes for G6PD A Stem Cell Disorder? A Stem Cell Disorder? • Early Early studies used Females who were G6PD studies used Females who were G6PD heterozygotes Fialkow ‐‐ MPN generally were clonal in generally were clonal in origin  Adamson ‐‐ Adamson clonality was present in WBCs, platelets and RBCs p  Confirmed in recent studies (T‐cell, B‐cells, NK cells, also)  Xa Xb Xb Xa Xb Xa Xa Xb Xb Xb Xb Xb Xb Xb Xb b Xb Xb Xa Xa Xb Xb Xa Xa Xb Xb Xa Xa Xb Xb Xa Xa Xb Xb Xb Xb Xa Xa Xb Xa Xa So… by the mid‐1970s So… by the mid 1970s • Myeloproliferative Myeloproliferative Disorders are considered Disorders are considered variations of the same disease. • They are proven to be clonal ‐‐ They are proven to be clonal and • In 1974, studying individuals with PV, researchers found that h f d h – Blood cells could grow in the absence of erythropoeitin h ii – Demonstrated constitutative proliferative capacity Then… in 1973 Then… in 1973 Implications • First First off off – separated out CML as a unique separated out CML as a unique molecular entity • Within 20 years led to the development of Within 20 years led to the development of Imatinib – a targeted agent that blocks the kinase activity of the BCR ABL molecule kinase activity of the BCR‐ABL molecule • Spurred additional research on what could be the molecular pathogenesis of the BCR‐ h l l h i f h BCR negative MPDs Molecular Understanding of MPNs 1951 Essential Thrombocythemia y (ET), ( ) PV and Myelofibrosis y (MF) ( ) recognized as similar syndromes by Dameshek 1974 Discovered that the erythroid precursors in PV grow in the absence b off EPO stimulation ti l ti 1983--2003 1983 Mutations in tyrosine kinases described in other MPDs, including CML, Mastocytosis, Eosinophilia 2001--2004 2001 EPO-independent EPOp g growth shown to be dependent p on JAKJAKSTAT signaling pathway. 2005 Inhibitors of JAK2  hampered erythroid production in PV cell lines Adapted from Campbell NEJM 2006 Janus Kinase 2 (JAK2) Janus Kinase 2 (JAK2) • JAK2 is a cytoplasmic tyrosine kinase which instigates intracellular signaling when instigates intracellular signaling when triggered by the receptors – Erythropoeitin y p – Thrombopoetin – IL3 – GCSF – GMCSF 2005 Discoveries 2005 Discoveries • Four major studies – all published within 3 weeks of one another • All generally confirmatory of one another, but also each one with slightly different methods and aims with slightly different methods and aims • All four groups identified a single recurrent mutation Baxter EJ et al Lancet March 19, 2005 Kralovics R et al NEJM April 28, 2005 James et al Nature April 28, 2005 Levine RL et al Cancer Cell April 2005 2005 Discoveries 2005 Discoveries • A A single point mutation identified single point mutation identified in the JAK2 kinase which changed a G T in exon 14 This exon is a a G T in exon 14. This exon is a crucial brake on kinase activity • The mutation results in the substitution of a The mutation results in the substitution of a valine at position 617 to a phenylalanine. • Analysis demonstrates this is a highly conserved Analysis demonstrates this is a highly conserved residue • This mutation ubiquitous in PV, less often found hi i bi i i Vl f f d in ET and MF. FERM SH2 Pseudokinase JH2 Pseudokinase Domain V617F KINASE Campbell NEJM 2006 2005 Discoveries 2005 Discoveries • DNA samples from patients with PV, ET or MF DNA samples from patients with PV, ET or MF • Sequencing performed in – Granulocyte subsets Granulocyte subsets – T‐Cell subsets – DNA obtained from buccal swabs • Mutation in JAK2 exon 14 discovered • In vitro and in vivo confirmatory experiments to prove gain of function and genotype‐phenotype relationship In Vitro Data In Vitro Data • Grew Grew cell lines that express the EPO Receptor and cell lines that express the EPO Receptor and either JAK2 WT or JAK2 V617F Data from Levine, Cancer CELL 2005 In vivo data In vivo • Mutant Mutant JAK2 transfected into mouse bone JAK2 transfected into mouse bone marrow cells • Polycythemia and splenomegaly 28 days after Polycythemia and splenomegaly 28 days after transplantation • In different genetic backgrounds (murine), I diff i b k d ( i ) there were subtle differences in the phenotypes – h i i.e. marked leukocytosis and k dl k i d fibrosis in BALb/c mice JAK2 mutational presence JAK2 mutational presence JAK2 Mutation Present JAK Mutation Present 95% 50% 50% 50% 20% 3% PV ET PMF RARS Non‐classic de novo MPD AML Since then…. Since then…. • The The same labs that began that investigation same labs that began that investigation have discovered numerous other, less ubiquitous mutations ubiquitous mutations • Some are complementary to the JAK2 • Some are already in clinical practice S l d i li i l i Mutation Mechanism? Jak2V617F Derails kinase regulatory activity; mutant allele burden appears to coincide with disease activity; not-necessarily initiating event Jak2, exon 12 Multiple mutations described. Induces erythrocytosis in mice if a certain conserved region is disrupted MPL Encodes the thrombopoeitin receptor. Mutations seems to disrupt negative regulatory elements in the cytosol of the thrombopoeitin receptor – for a gain of function  JAK-STAT JAK STAT activation TET2 With or without JAK2; biclonal disease described; ? Pathologic impact ASXL1 Aberrant RAR signaling CBL Wt CBL responsible for ubiquitination of kinases, kinases including FLT3, FLT3 mouse models implicate role in mast-cell disease IDH1/IDH2 exon 4 Isocitrate dehydrogenase mutations. Role in decreased NADPH production ?early events or develop during transformation production. IKZF1 19% of blast phase MPN JAK-STAT activation Adapted from Tefferi, Leukemia, 2010 Novel Mutations Novel Mutations Mutation Chromosome Frequency Jak2* 9p24 PV=96%;ET=55%;PMF=65%; blast phase MPN=50% Jak2, exon 12* 9p24 PV=3% MPL* 1p34 PV=rare;ET=3%;PMF=10% TET2 4q24 PV=16%;ET=5%;PMF=17%; blast phase MPN=17% PV=16%;ET=5%;PMF=17%; blast phase MPN=17% ASXL1 20q11.1 Blast phase MPN=19% CBL 11q23.3 PMF=6% PMF 6% IDH1/IDH2 exon 4 2q33.3/15q26 PMF=4% .1 IKZF1 7p12 Blast phase MPN=19% *affect lymphoid and myeloid cells Adapted from Tefferi, Leukemia, 2010 Clonal or Oligoclonal? Tefferi, Leukemia, 2010 So What? So What?  Academically Interesting??  Prognostic – Marker of Outcome in the absence of treatment??  Predictive – Marker of Outcome in the presence of treatment??  Therapeutic Target? Topics to Cover Topics to Cover • • • • • Overview of Diseases Overview of Diseases Historical context Therapy Up to Now h Therapy In the Future? Pitfalls and Open Questions Therapy: MPDs Therapy: MPDs • Polycythemia Vera Polycythemia Vera – Untreated patients‐ Median OS of 6‐18mo – Treated patients – Treated patients 10+ years 10+ years – Goal: Prevent clotting – Symptom Management: headache, weakness, S t M t h d h k dizziness, epigastric distress, and pruritus. Therapeutic Context Therapeutic Context Early part of the century Early part of the century Skeletal radiation, potassium arsenite, nitrogen mustard, busulfan, 6‐MP, etc. Most common: P‐32 and Phlebotomy Early retrospective studies showed benefit to P‐32 Polycythemia Study Group – founded 1967 Concern re toxicity of P‐32 therapy Dissolved in 1987 after 14 studies. Last official publication in 1997 PVSG and others PVSG and others Study Question PVSG 01 PVSG‐01 Phlebotomy vs Phl b t Phlebotomy + P‐32 or Chlorambucil Results P OS 12 6 OS=12.6yrs P+C 9.1‐10.9 yrs Conclusion: Increased AML in intervention arm – Reversal of conclusions from retrospective data PVSG‐08 Hydrea vs Hydrea vs phlebotomy (NR) Hydrea =less Hydrea less early thromboses early thromboses 6.6 vs 14% at 2 years 5.9% risk of AML w/ hydrea Conclusion: Hydroxyurea likely helpful to prevent clots in PV Conclusion: Hydroxyurea likely helpful to prevent clots in PV Possible risk of AML – but this is retrospective, no randomized data Therapy: Polycythemia Vera Therapy: Polycythemia Vera Phlebotomy: Safe and efficacious Phlebotomy: Safe and efficacious Hydroxyurea In high In high‐risk risk patients better in preventing thrombosis patients better in preventing thrombosis Prospective studies show no single agent g y leukemogenicity Low‐dose Aspirin No excess bleeding risk g Positive antithrombotic properties Therapy: ET Therapy: ET • Essential Thrombocythemia Essential Thrombocythemia – Most patients with ET enjoy a normal life expectancy without associated disease‐related complications – Goal: Prevent clotting and bleeding – Symptom Management: vasomotor symptoms • Aspirin • For High‐risk patient (over 60, history of clot, Platelets>million)  Hydroxyurea Therapy: ET Therapy: ET • Most Most important randomized study important randomized study • UK study . Outcome: composite end point of stroke bleeding MI embolic event or death stroke, bleeding, MI, embolic event or death • Published in NEJM, 2005 • N=809, High‐Risk ET patients • Randomized to Low‐Dose Aspirin p – + Hydrea – +Anagrilide Anagrilide Therapy: PMF Therapy: PMF Differences – Less about preventing clot or bleeding. L b t ti l t bl di – Much more symptomatic – Much shorter life expectancy M h h lif • Current drug therapy in PMF is neither curative nor essential for survival. • Risk stratification has been attempted – DIPSS PLUS DIPSS‐PLUS Low ‐ 0 risk factors – Med OS: 15.4 yrs Intermediate 1 ‐ 1 risk factor – Med OS: 6.5 yrs y Intermediate 2 – 2‐3 risk factors – Med OS: 2.9 yrs High – 4+ risk factors – Med OS: 1.3 yrs 1. 2 2. 3. 4. 5. 6. 7. 8. Thrombocytopenia; Pls <100K Age>65 Hgn<10gm/dL RBC transfusion requirement Constitutional Symptoms *unfavorable karyotype includes complex Circulating blasts >1% karyotype or sole or two abnormalities that Unfavorable karyotype* Unfavorable karyotype include +8, ‐7/7q‐, i(17q), inv(3), ‐5/5q‐, l d / ( ) ( ) / Leukocytosis >25,000 12p‐ or 11q23 rearrangement “Conventional Conventional therapies therapies” ‐‐ PMF • Symptom management: Anemia Symptom management: Anemia – ESAs, danazol, thalidomide, corticosteroids, androgens lenalidomide+Prednisone androgens, lenalidomide+Prednisone • Splenomegaly – Hydrea, cladribine, thalidomide, lenalidomide Hydrea cladribine thalidomide lenalidomide – Splenectomy – Radiotherapy R di th • Allo‐SCT capable of inducing CR Allo‐SCT Allo SCT ‐‐ Myelofibrosis  British Society of BMT (Stewart et al 2010) et al 2010)  CIBMTR review (Ballen KK et al. 2010)  N=51 PMF  27=myeloablative (MA) (19 (MA) (19‐ 54yrs)  24= reduced‐intensity conditioning (RIC)(20‐64yrs)  3yr OS was 44% for MA and 31% f d for RIC transplant  Relapse rate = 15% (MA)46%, ((RIC))  Nonrelapse mortality rates = 41% (MA) and 32% (RIC)  Extensive chronic graft‐versus‐ host disease (GVHD) rates = 30% host disease (GVHD) rates = 30% and 35%  N=289 patients with PMF  Treatment Treatment‐related related mortality mortality (TRM) was 27% at 1 year and 35% at 5 years.  Five‐year OS were 37% and 30% in related and unrelated donor in related and unrelated donor settings, respectively.  Outcome did not appear to be favorably affected by RIC. But now we have a gene, right?? But now we have a gene, right?? JAK 2 Inhibitor JAK 2 Inhibitor • Multiple under investigation p g • Only one has been FDA approved: ruxolitinib g • Tested in MF – both JAK2 and JAK2 Negative Ruxolitinib Phase I/II : N Engl J Med 2010;363:1117‐27. / g ; N=153; MF – JAK2+ and JAK2‐ 15 mg twice daily; DLT ‐‐ reversible thrombocytopenia Outcomes: Symptom improvement, spleen size. S Secondary Outcomes: Survival, PFS d O t S i l PFS Confirmed in two Phase III studies  FDA approval Confirmed in two Phase III studies  FDA approval N Engl J Med 2010;363:1117‐27. JAK2 inhibitor Ruxolitinib JAK2 inhibitor Ruxolitinib Phase III study (COMFORT 1) N= 309 patients BID oral ruxolitinib (155 patients) vs placebo. After median FU of 32 weeks After median FU of 32 weeks Ruxolitinib >> Placebo for spleen reduction Ruxolitinib >> Placebo for symptom control Reduction in proinflammatory cytokines (e.g. IL‐1RA, IL‐6, d fl k ( TNF‐a, MIP‐1b) was documented and correlated with improvement in constitutional symptoms. No change to JAK2V617F allele burden No change to JAK2V617F allele burden Little change to bone marrow pathology Slight increase in Overall Survival reported at 2011 update ASH, 2011 N Engl J Med 2010;363:1117‐27. N Engl J Med 2010;363:1117‐27. Ruxolitinib • • • • • 12/2011 Survival Analysis: 12/2011 Survival Analysis: Median follow up 52 weeks 13 ruxolitinib died 3 li i ib di d 24 placebo pts died A hazard ratio of death (95% CI) of 0.499 ( (0.254, 0.98) (p=0.0395) for ruxolitinib‐treated , ) (p ) pts. Withdrawal Syndrome Withdrawal Syndrome • Clinical Clinical problems in MF are due to the problems in MF are due to the underlying abnormal myeloproliferation and a reactive cytokine‐driven reactive, cytokine driven inflammatory state. inflammatory state • There is an acute relapse of sx on drug discontinuation • In 5 patients requiring hospitalization and even ICU stays ICU JAK2 inhibitors in PV and ET? JAK2 inhibitors in PV and ET? Drug Disease Phase Results INCB018242 PV and ET – refractory to HU Phase II, US and Italy sites PV, n=34 97% with phlebotomy independence 59% with decrease in spleen size. ET n=39 ET, 49% with normal plt counts PV/ET Phase II ↓ Spleen size (83%) Improved pruritis (all) Improved pruritis (all) Reduction in phlebotomy (3/5) 5 thrombotic events GI disturbance 2010 ASH CEP701 Cephalon 2009 ASH Back to the Patient Back to the Patient • JG JG – Discussed JAK2 inhibitors with her. Discussed JAK2 inhibitors with her. Because of her clotting risk and elevated platelets, I started her on hydroxyurea • Have also discussed stem cell transplant with her, given her young age • Fatigue, not splenomegaly is her primary complaint • Real goal for her will be long‐term survival – not symptom relief Wrap Up Wrap Up • • • • • Overview of Diseases Overview of Diseases Historical context Therapy Now h Therapy Soon? Pitfalls and Open Questions