Ruben A. Mesa, MD, FACP

1. Case Study: A Young Patient with PV has a Major Thrombotic Event and Worsening Leukocytosis - Is she Progressing to Post-PV MF? Ruben A. Mesa, MD, FACP Chair, Division of Hematology & Medical OncologyDeputy Director, Mayo Clinic Cancer CenterProfessor of Medicine

2. Co-Presenters Jeffrey C. Bryan, PharmD, RPh Clinical Pharmacy Specialist, Leukemia Division of Pharmacy, University of Texas MD Anderson Cancer Center Houston, TX Otitolola Arterbery, MSN, RN, OCN Clinical Nurse MD Anderson Cancer Center Houston, TX

3. Case Study: Trisha K. • Diagnosed with PV at the age of 32 years • Disease features at diagnosis • Hb: 17.4 g/dL • Hematocrit: 56% • Leukocyte count: 9.2 x 109/L • Platelet count: 520 x 109/L • Suboptimal serum EPO • 0% circulating blasts on smear • Spleen not palpable; asymptomatic • JAK2V617F mutation • No history of thrombosis or major bleeding events • Mild hypertension

4. Case Study (cont.): Trisha K. Conventional risk stratification in PV is based on: • Risk of progression to myelofibrosis • Risk of leukemic transformation • Risk of death • Risk of thrombosis • Risk of major hemorrhage

5. Case Study (cont.): Trisha K. Conventional risk stratification in PV is based on: • Risk of progression to myelofibrosis • Risk of leukemic transformation • Risk of death • Risk of thrombosis • Risk of major hemorrhage

6. Risk Stratification in PV Based on Thrombotic Risk • Novel biomarkers of increased thrombosis risk include leukocytosisand JAK2V617F allele burden. 1. Barbui T et al. J ClinOncol. 2011;29(6):761-770; 2. Vannucchi AM. Blood. 2014 Oct 2. [Epub ahead of print].

7. Rates of Thrombotic Events During The Clinical Course of PV • Rate estimates for thrombosis in patients with PV range from 2.7 to 3.8 per 100 patients/year1-3 1. Marchioli R, et al. J ClinOncol. 2005;23(10):2224-32; 2. Marchioli R, et al. N Engl J Med. 2013;368(1):22-33;3. Tefferi A et al. Leukemia 2013;27:1874-81.

8. Low-Dose Aspirin in Management of PV • Persistently enhanced platelet activation contributes to the higher risk of thrombosis in patients with PV1,2 • Placebo-controlled ECLAP trial (N= 518) demonstrated that low-dose aspirin can safely prevent thrombotic complications in patients with PV who have no contraindications to aspirin2 1. Patrono C, et al. Blood.2013;121(10):1701-11;2. Landolfi R, et al. N Engl J Med 2004;350: 114-24.

9. European Collaboration on Low-Dose Aspirin in Polycythemia Vera (ECLAP) Trial • Low-dose aspirin (100 mg) reduced the risk of nonfatal myocardial infarction, nonfatal stroke, pulmonary embolism, major venous thrombosis, or death from cardiovascular causes (relative risk, 0.40; 95% CI, 0.18 to 0.91; P = 0.03) • Incidence of major bleeding episodes was not significantly increased in the aspirin group (relative risk, 1.62; 95% CI, 0.27 to 9.71). Landolfi R, et al. N Engl J Med 2004;350: 114-24.

10. Estimated Rates of Upper GI Complications in Men Receiving Regular Treatment with Low-Dose Aspirin 1. Patrono C, et al. Blood.2013;121(10):1701-11.

11. Low-Dose Aspirin in Management of PV • Primary prevention with low-dose aspirin (81-100 mg) is currently recommended for almost all patients with PV1,2 • Risks may include increased risk of bleeding, especially GI bleeds • Benefit/risk balance depends on the level of thrombotic and hemorrhagic risks for the individual patient 1. Patrono C, et al. Blood.2013;121(10):1701-11; 2. BarbuiT et al. J Clin Oncol. 2011;29(6):761-770.

12. Hematocrit (Hct) Control is a Key Therapeutic Goal • Maintaining Hct<45% significantly decreases the risk of cardiovascular death and major thrombotic events Death from cardiovascular causes or thrombotic events Total cardiovascular events Low Hct – target <45% High Hct – target 45 – 50% Marchioli R, et al. N Engl J Med. 2013;368(1):22-33. .

13. Reducing the Risk of Vascular Complications: Lifestyle Interventions • Weight control • Physical exercise • Adherence to antihypertension, antidiabetes, and/or antihypercholestrolemia/hyperlipidemia medications • Avoidance of oral contraceptives • Smoking cessation • Avoidance of situations that carry a risk of bleeding VannucchiAM. Blood. 2014 Oct 2. [Epub ahead of print]. .

14. Risk-Adapted Management of Patients with PV1,2 1. Barbui T et al. J Clin Oncol. 2011;29(6):761-770; 2. Vannucchi AM. Blood. 2014 Oct 2. [Epub ahead of print]; 3. Marchioli R, et al. N Engl J Med. 2013;368(1):22-33; 4. Stein BL, et al. Ann Hematol. 2014; Oct 2 [Epub ahead of print].

15. Case Study (cont.): Trisha K. • Classified as ‘Low-Risk’ at diagnosis (age <65 years; no history of thrombosis) • Control of hypertension, reduction of CV risk factors • Phlebotomies to maintain Hct < 45% plus low-dose aspirin • 9 phlebotomies over the first 3 months, every 1.5 -2 months thereafter • Fatigue related to iron deficiency (repeated phlebotomies) • 6 years later, she experienced venous thromboembolism (DVT) in her right leg • Anticoagulation with low-molecular weight heparin (LMWH) was instituted at time of thrombosis followed by vitamin K antagonists • She had a good outcome

16. Case Study (cont.): Trisha K. • Due to her DVT event and underlying PV, she is at high-risk for re-thrombosis. Q: Despite her younger age (38 years), Trisha is now at high risk for thrombosis (high-risk PV). What would you suggest for management? • Continue with phlebotomy plus low-dose aspirin • Maintain on oral anticoagulation instead of aspirin • Combine oral anticoagulation and aspirin • Institute oral anticoagulation plus cytotreductive therapy (hydroxyurea or interferon) • Other strategy

17. Case Study (cont.): Trisha K. • Due to her DVT event and underlying PV, she is at high-risk for re-thrombosis. Q: Despite her younger age (38 years), Trisha is now at high risk for thrombosis (high-risk PV). What would you suggest for management? • Continue with phlebotomy plus low-dose aspirin • Maintain on oral anticoagulation instead of aspirin • Combine oral anticoagulation and aspirin • Institute oral anticoagulation plus cytotreductive therapy (hydroxyurea or interferon) • Other strategy

18. Risk-Adapted Treatment for Patients with High-Risk PV • If prior thrombosis or age >60 years or poor compliance to phlebotomy • Or progressive myeloproliferation (splenomegaly, leukocytosis, thrombocytosis) • First-line cytoreductive therapy is hydroxyurea or interferon alfa. Busulfan in age >75 years High risk • Trisha K. managed with oral anticoagulation plus interferon alfa therapy BarbuiT et al. J Clin Oncol. 2011;29(6):761-70;

19. PV is a Progressive Disease • Estimated probability of evolution to post-PV MF (N=116): 16% at 10 years and 34% at 15 years1 • Events During the Clinical Course (N=1543)2 • Most common causes of death (>10 pts)2 • Acute leukemia - 36 • Second malignancy - 36 • Thrombotic complications – 32 • Heart failure – 13 • Non-leukemic progressive disease – 12 1. Alvarez-Larran A, et al. Br J Haematol. 2009;146(5):504-509; 2. TefferiA et al. Leukemia2013;27:1874-81.

20. Adverse Prognostic Factors in Patients with PV • Adverse Prognostic Factors • Age > 67 yrs (5 points) • Age 57-66 yrs (2 points) • Leukocyte count >15 x 109/L (1 point) • Venous thrombosis (1 point) • Low risk – 0 points • Intermediate risk - 1 or 2 points • High risk - >3 points • Based on this prognostic model, Trisha K is ‘Intermediate Risk’ • Leukocyte count >15 x 109/L (1 point) • Venous thrombosis (1 point) Tefferi A et al. Leukemia2013;27:1874-81.

21. Case Study (cont.): Trisha K. • Managed with oral anticoagulation plus interferon alfa therapy. Two years later: • Increasing constitutional symptoms (esp. pruritus) • Unintentional weight loss of 5% in past 4 months; full on smaller meals • Worsening leukocytosis (22 x 109/L) and thrombocytosis • Newly palpable spleen (3 cm)

22. Case Study (cont.): Trisha K. Q: How can we tell if the patient has progressed to post-PV MF? • Re-evaluate PV risk status • Assess JAK2 allele burden • Perform bone marrow biopsy • Obtain cytogenetic profile

23. Case Study (cont.): Trisha K. • Managed with oral anticoagulation plus interferon alfa therapy. Two years later: • Increasing constitutional symptoms (esp. pruritus) • Unintentional weight loss of 5% in past 4 months; full on smaller meals • Worsening leukocytosis (22 x 109/L) and thrombocytosis • Newly palpable spleen (3 cm) Q: How can we tell if the patient has progressed to post-PV MF? • Re-evaluate PV risk status • Assess JAK2 allele burden • Perform bone marrow biopsy • Obtain cytogenetic profile

24. IWG-MRT Criteria for the Diagnosis ofPost-PV-MF 1 of 2 required criteria 3 of 4 additional criteria • Diagnosis of PPV-MF requires at least two additional criteria beyond the two main criteria. • According to the European classification (scale 0-3) or standard classification (scale 0-4) • ** Below the reference range for appropriate age, sex, gender, and altitude considerations.

25. European Classification (scale 0-3) on Grading of Bone Marrow Fibrosis in MF* O 1 *Grade 2 or 3 required for post PV-MF criteria 2 3 Silver impregnation after Gomori ; x180 Thiele J et al. Haematologica2005; 90:1128-1132.

26. Standard Classification (scale 0-4) on Grading of Bone Marrow Fibrosis in MF* O 1 2 3 4 Collagen fibers (blue) – Mason’s trichrome stain *Grade 3 or 4 required for post PV-MF criteria 0-4: Reticulin silver stain; x200. Kuter DJ et al. Br J Haematol. 2007; 139: 351–362.

27. Case Study (cont.): Trisha K. • Clinical findings (review) • Increasing constitutional symptoms (esp. pruritus and night sweats) • Spleen is now palpable (3 cm) • Worsening leukocytosis (32 x 109/L); reduced need for phlebotomy • No peripheral blasts • Bone marrow biopsy findings: • Grade 1 fibrosis (0-3 scale) (ie, loose meshwork of thin reticulin fibers with many intersections) • Megakaryocyte proliferation, atypia • Increased JAK2 allele burden vs baseline assessment (at diagnosis)

28. Case Study (cont.): Trisha K. Q: Which of the below best describes this patient’s clinical picture? • Adequately controlled PV • Uncontrolled/advancing PV • Progression to post-PV myelofibrosis • Transformation to leukemia

29. Case Study (cont.): Trisha K. Q: Which of the below best describes this patient’s clinical picture? • Adequately controlled PV • Uncontrolled/advancing PV – Grade 1 BM fibrosis is not sufficient for post-PV MF diagnosis • Progression to post-PV myelofibrosis • Transformation to leukemia

30. Case Study (cont.): Trisha K. IWG-MRT Criteria for the diagnosis of Post-PV-MF 1 of 2 required criteria 3 of 4 additional criteria • Diagnosis of PPV-MF requires at least two additional criteria beyond the two main criteria. • According to the European classification (scale 0-3) or standard classification (scale 0-4) • ** Below the reference range for appropriate age, sex, gender, and altitude considerations.

31. Case Study (cont.): Trisha K. • Interferon therapy was stopped and she was started on hydroxyurea (HU) to manage cytopenias and splenomegaly (with continued oral anticoagulation) IFN-alfa + oral anticoagulation HU + oral anticoagulation Phlebotomy + low-dose aspirin 0 6 8 Years from PV diagnosis • To date, no therapeutic used to treat PV has been proven to prevent transformation to post-PV MF

32. HU Resistance and/or Intolerance in PV • 20-25% of patients will become resistant and/or intolerant to HU 1,2 • Increased complications and symptom burden • Worsening disease transformation • Reduced survival Criteria3 • HU Resistance - After 12 weeks of HU, at a total dose ≥2 g/day: • Need for phlebotomy to maintain Hct at <45% • Elevated platelet and WBC counts or • <50% reduction in splenomegaly or failure to completely relieve splenomegaly symptoms • HU Intolerance • Leg ulcers or other unacceptable HU-related toxicity • ANC <1 x 109/L or Hgb <10 g/dL 1. Sever M et al. Leuk Lymphoma. 2014; Early Online: 1-6; 2. Stein BL, et al. Ann Hematol. 2014; Oct 2 [Epub ahead of print]; 3. Barbui T et al, J Clin Oncol 2011;29(6):761–70.

33. Ruxolitinib (JAK1/JAK2 Inhibitor) in the Treatment of MPNs * For PV, the approved starting dose is 10 mg orally twice daily. Jakafi (ruxolitinib) prescribing information, 2014.

34. Phase III Study of Ruxolitinib vs BAT (RESPONSE) Extended treatment phase Ruxolitinib 10 mg BID • Primary endpoint (composite): % of patients who achieved both Hct control and spleen response at week 32 • Hctcontrol: No phlebotomy eligibility from week 8 to 32, with no more than 1 post-randomization phlebotomy eligibility up to week 8 • Phlebotomy eligibility was defined as Hct > 45% and ≥ 3% higher than baseline or > 48% • Spleen response : ≥ 35% reduction from baseline in spleen volume by MRI Week 208 • Resistance to or intolerance of HU (modified ELN criteria) • Phlebotomy requirement • Splenomegaly n = 110 Crossover to ruxolitinib Pre-randomization (day −28 to day −1) Hct 40%-45% Randomized (1:1) Week 208 BAT n = 112 Week 32 (primary endpoint) Week 48 Week 80 Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

35. RESPONSE (Primary Response at Week 32) • Phase 3 study of ruxolitinib in PV patients resistant to or intolerant of HU (N = 222) Primary Endpoint Individual Components of Primary Endpoint P < .0001 OR, 28.64(95% CI, 4.50-1206) • To achieve Hct control, patients could not be eligible for phlebotomy based on protocol-defined Hctvalues • Phlebotomy eligibility defined as Hct > 45% and ≥ 3% higher than baseline or a Hct > 48% • 91% of patients who achieved the primary endpoint had a confirmed response at week 48 SV, spleen volume. Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

36. RESPONSE: Improvement in Symptoms Percentage of Patients With a ≥ 50% Improvement in MPN-SAF Symptom Score at Week 32a 63 71 n = 71 80 74 80 74 81 MPN-SAF Total Symptom Score Cytokine Symptom Cluster Splenomegaly Symptom Cluster Hyperviscosity Symptom Cluster Tiredness Itching Muscle ache Night sweats Sweating while awake Fullness/early satiety Abdominal discomfort Headache Concentration problems Dizziness Skin redness Vision problems Ringing in ears Numbness/tingling in hands/feet a In patients with scores at both baseline and week 32. MPN-SAF, Myeloproliferative Neoplasm Symptom Assessment Form. Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

37. RESPONSE: Thromboembolic Events to Week 32 a 1 patient in the BAT group had both myocardial infarction and pulmonary embolism. • A higher proportion of patients in the ruxolitinib arm had a history of prior thromboembolic events at baseline than in the BAT arm (35.5% vs 29.5%) • There was 1 additional event in the ruxolitinib group over the course of randomized treatment (median exposure 81 weeks) Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

38. RESPONSE: Nonhematologic Adverse Eventsto Week 32 (Regardless of Causality) Events occurring in at least 10% of patients in either treatment group. • When adjusted for exposure (per 100 patient-years), the rates of adverse events and grade 3/4 adverse events over the entire course of treatment were lower in patients randomized to ruxolitinib compared with those randomized to BAT (64.7 vs 145.6 and 28.8 vs 44.0) • Rate of herpes zoster infection was higher in the ruxolitinib group (6.4% vs 0; all grade 1-2) Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

39. RESPONSE: New or Worsening Hematology Laboratory Values to Week 32 • No patients discontinued treatment because of anemia or thrombocytopenia Verstovsek S et al. J ClinOncol 2014;32 (5s): Abstract 7026.

40. Case Study (conclusion): Trisha K. • Trisha’s case illustrates a clinical course for a typical PV patient (i.e., high thrombotic risk as well as progressing underlying PV disease) • She has taken JAK inhibitor therapy (ruxolitinib) for 2 months • Good spleen response and symptom improvement • We monitor CBC every 2-4 weeks • Treatment-related cytopenias managed with dose modifications

41. Conclusions • Contemporary treatment for patients with PV combines: • Modification of CV risk factors • Antiplatelet therapy • Phlebotomy • Cytoreduction (HU, IFN-alfa, busulfan) • Recently, ruxolitinib demonstrated benefit in PV patients resistant or intolerant to HU (RESPONSE trial)