Northwestern University Feinberg School of Medicine Blood Clotting Complications in the Myeloproliferative Neoplasms Tampa MPN Patient Symposium Brady L. Stein, MD MHS April 3, 2014

A case from the hematology clinic 27 year-old, recently pregnant woman with pain under her R rib cage Removal of her gallbladder 3 weeks prior Enlarged liver and spleen noted during her surgery Review of her records: – Intermittently high white blood cell and platelet counts for ~5 years

A Case from the clinic Medical testing revealed extensive blood clots occluding the large vein that drains the liver Complete Blood Count – White blood cell and platelet number normal Diagnosed with the “Budd Chiari Syndrome” and found to have increased blood pressure in the abdominal system along with an enlarged spleen

Additional evaluation No evidence of an inherited blood clotting tendency Bone marrow biopsy – No specific abnormalities-not diagnostic of a specific entity JAK2 V617F Mutation: – Positive, confirming that she has an MPN

Classical Myeloproliferative Neoplasms: Shared Clinical Features ET PV MF Blood clotting complications -Epidemiology -Signs and symptoms -Risk factors -Treatment strategies -Chicago Roundtable Research Splenomegaly Marrow fibrosis Disease acceleration/ transformation

Epidemiology—How common are arterial or venous blood clotting complications in MPN? Elliot, MA Seminars in Thrombosis and Hemostasis 2007; Barbui, T Blood 2010; Elliot Haematologica 2010

Clotting Manifestations: “Small Vessel” Disturbances Disrupt Quality but not Quantity of Life Headache, Dizziness, Transient Visual Disturbances, Numbness/Tingling, Color changes or Pain in the digits Often responsive to aspirin Picture from the Erythromelalgia Association Website Erythromelalgia: Redness, swelling, and pain of the extremities

Clotting Manifestations: “Large Vessel” Disturbances Stroke – Transient or prolonged weakness, numbness, difficulty with speech, vision, drooping of the face Heart Attack – Chest pain, neck/jaw, or arm pain, sweating, nausea, shortness of breath Deep vein thrombosis or Pulmonary Embolism – Swelling, tightness/discomfort, redness of the limb, typically the leg – Chest pain, difficulty breathing, irregular heart beats

Clotting Manifestations: Unusual Locations and “Occult MPN” ®Stephan Moll, MD Portal Vein Thrombosis Mesenteric Vein Thrombosis Hepatic Vein Thrombosis: Budd-Chiari Splenic Vein Thrombosis 32% will have MPN 41% will have MPN As reviewed in Barbui et al, Blood 2013

Thrombosis Risk Factors: Generic, but accepted and consistent: Age less than 60 No clotting history High blood pressure Diabetes ↑Cholesterol Smoking Age over 60 Prior blood clot Lower RiskIntermediate RiskHigh Risk

MPN-specific risk factors JAK2 mutation linked to blood clotting Stem Cells Progenitors Increased Red blood cell count linked to blood clotting Increased white blood cell count likely linked to blood clotting Increased Platelet count itself NOT linked to blood clotting

A New Player: CALR mutations in ET and MF Klampfl et al, Late Breaking Abstracts and Klampfl, T et al. NEJM P. Vera ET: 67% with CALRMF: 88% with CALR CALR mutated patients appeared to have a lower Hgb and leukocyte count, higher platelet count, and lower rate of thrombosis

Revised Classification for ET: IPSET Age > 60: 1 point History of blood clot: 2 points Cardiovascular Risk factors: 1 point JAK2 V617F: 2 points Low Risk: < 2 points Intermediate Risk: 2 points High Risk: > 2 points Barbui et al Blood 2012

Managing Thrombosis Risk Age less than 60 No clotting history High blood pressure Diabetes ↑Cholesterol Smoking Age over 60 Prior blood clot Lower RiskIntermediate RiskHigh Risk Aspirin in PV, JAK2+ ET, or small vessel disturbance Lifestyle Modification “Cytoreduction” This is a generic approach rather than personalized!

Managing MPN-specific Risk Factors JAK2: JAK inhibitors Interferon Investigational agents Stem Cells Progenitors Phlebotomy for PV: Hematocrit lowering <45% Hydroxyurea JAK2 inhibitors Interferons RBCWBC Platelet count alone should not dictate therapy unless > 1.5 million Plts

The “lowly hematocrit” Target hematocrit (Hct) for patients with PV debated for decades 365 patients with PV, randomized to low Hct (< 45%) vs. high Hct (45-50%) Four-fold lower rate of serious cardiovascular complications in low Hct (4.4%) vs. high Hct (10.9%) group But…white cell count remained higher in the high Hct group Going forward, phlebotomy target to goal Hct < 45% Marchioli et al NEJM 2013 Spivak NEJM 2013

Is Anagrelide Coming back? ANAHYDRET PT-1 study suggested hydroxyurea/aspirin was superior to anagrelide/aspirin in ET patients in the prevention of arterial blood clots 259 ET patients, randomized to hydroxyurea or anagrelide No difference between the 2 drugs in the following: – Major or minor arterial or venous blood clots – Severe bleeding – Discontinuation rates – Myelofibrosis or leukemia not seen Conclusion: Anagrelide does not appear to be inferior to Hydroxyurea in the prevention of blood clotting Gissingler et al Blood 2013

Chicago Roundtable Laura Michaelis Olatoyosi Odenike Damiano Rondelli Jamile Shammo Brady Stein Are younger MPN patients at low risk for blood clotting complications? Informal Case Discussion Research Question Draft proposal, submit to each institution’s review board Medical Chart Review 6 monthly “dinner rounds to attract community providers

Our Results CharacteristicYounger PV Patients (≤ 45 yrs) N=120 Older PV Patients N=84 (≥ 65 yrs) % Women7655 % MPN Family History1011 Avg Disease Duration8 years4.5 years Avg white blood cell count (x 10 9 /L) JAK2 mutation, %9895 JAK2 Burden, %5166 No real differences in Aspirin, Phlebotomy, or Hydroxyurea Use Stein et al Leuk Lymphoma 2013

Our Results Overall rate of blood clotting: 27% vs. 31% (Younger vs. Older) Stein et al Leuk Lymphoma 2013

How do our results compare to other studies? Portal Vein Thrombosis Mesenteric Vein Thrombosis Hepatic Vein Thrombosis: Budd-Chiari Splenic Vein Thrombosis Pieri et al, ASH Abstract cases reviewed of abd vein clotting Majority (88-93%) JAK2 V617F positive Typically younger (44 yrs) women (61%) 22% presented ~40 mos before an official MPN diagnosis! Clinical trials evaluating Ruxolitinib and Peg-interferon in this patient population

Our study: conclusions Overall clotting complications similar by age group, but the locations differ – Younger women particularly at risk for clotting of the abdominal veins These clotting complications can be quite serious – Our patient required a procedure to lower the pressure in the abdominal blood pressure system – Likely to require blood thinners indefinitely Our understanding of the mechanisms of blood clotting in the MPN is incomplete

Many factors can influence MPN-thrombosis MPN-associated thrombosis Advanced Age Prior history of blood clotting Type of mutation, burden JAK2 > CALR JAK2 allele burden Inflammation Gender Blood cell membrane fragments (Microparticles) Activated Platelets Increased white cell count and activated WBC’s Activation of the blood vessel lining Increased Hematocrit/Blood viscosity Adapted from McMahon and Stein, Seminars in Thrombosis and Hemostasis 2012 “Masked PV:” ASH abstract 1581 (Barbui et al) Type of MPN PV, “masked PV” Prefibrotic MF, ET MF

Questions and Goals for the Future…. How do we personalize the risk classification to avoid over or under-treatment? – Develop reproducible assays to measure JAK2 burden, markers of blood cell/vessel activation, microparticles What is the ideal blood thinning agent? – Warfarin for those with venous clotting, but for how long (limited or indefinite (abdominal veins)) – Injected blood thinners? “Target Specific” blood thinners? Is there a role for twice daily Aspirin or Aspirin/Clopidogrel? Will JAK inhibitors impact clotting rates?

Thank you for your attention