Boccia, Ralph V.

Abstract Introduction: Renal impairment (RI) is a classic clinicopathological feature of MM, is associated with poor prognosis and shorter survival (Eleutherakis-Papaiakovou Leuk Lymphoma 2007), and can complicate drug dosing and limit treatment options. In clinical trials, the proteasome inhibitors K and V have demonstrated efficacy in RRMM pts with RI, with superior efficacy observed in K-treated pts (Dimopoulos Blood 2017). K and V have also been observed to improve renal function in RRMM pts (Dimopoulos Clin Lymphoma Myeloma 2009; Dimopoulos Blood Advances 2017). However, few studies have investigated the real-world effectiveness of K- and V-based regimens in renal rescue. This study aimed to describe and compare renal response rates in RRMM pts treated with K + dexamethasone (Kd) and V + dexamethasone (Vd) in oncology clinics. Methods: The Oncology Services Comprehensive Electronic Records (OSCER) database (Lau Clin Epidemiol 2011) contains electronic medical records (EMR) from community- and hospital-affiliated oncology clinics in the United States. MM pts aged ≥18 who entered an OSCER clinic Jan 2012‒Feb 2018; initiated Kd or Vd treatment as line 2 (2L), 3L, or 4L; and had baseline renal impairment (Modification of Diet in Renal Disease Study estimated glomerular filtration rate [eGFR] <50 mL/min from the most recent baseline serum creatinine measurement) were included. Index date was the date of Kd or Vd initiation. The baseline period was 60 d prior to index to 30 d post-index. Follow-up was 30 d after index date to 60 d after completion of the same line. Primary outcome was renal response during follow-up. Renal response was defined according to the International Myeloma Working Group criteria (Dimopoulos J Clin Oncol 2016): complete response (RCR; baseline eGFR <50 mL/min and best post-treatment eGFR ≥60 mL/min), partial response (baseline eGFR <15 mL/min and best post-treatment eGFR 30‒59 mL/min), minor response (baseline eGFR <15 mL/min and best post-treatment eGFR 15‒29 mL/min, or baseline eGFR 15‒29 mL/min and best post-treatment eGFR 30‒59 mL/min). Renal response rates in Kd- and Vd-treated pts were evaluated using the Kaplan-Meier method and log-rank test. Incidence rate ratios (IRR) and 95% confidence intervals (CIs) were calculated for renal overall response (ROR) and RCR using multivariate Cox proportional hazard models adjusted for baseline covariates (demographics, Eastern Cooperative Oncology Group Performance Status, International Staging System stage, baseline renal function, V use in 1L, time from MM diagnosis to line initiation, use of intravenous bisphosphonates, and baseline serum calcium, serum free light chain ratio, lactate dehydrogenase, and whole blood hemoglobin measurements). Missing baseline values were estimated by multiple imputations. Results: 543 Kd-treated and 1005 Vd-treated pts were included. Baseline characteristics were similar between cohorts, with no difference in baseline eGFR stages. More Kd pts were <65 yrs of age at MM diagnosis. Median time from diagnosis to line initiation was longer in Kd pts (Kd: 17.1 mos; Vd 16.1 mos). V-based regimens were the most common therapies in 1L. Median (interquartile range) treatment duration was 4.4 (2.3-8.3) mos for Kd and 4.3 (2.1-8.3) mos for Vd. Pts treated with Kd at 2L were more likely than those treated with Vd to achieve both ROR (51.4% [178/346] vs 39.6% [327/825]; log-rank test p<0.0001) and RCR (26.6% [92/346] vs 22.2% [183/825]; log-rank test p=0.0229). This pattern persisted when 3L and 4L pts were included, (ROR: 48.4% [263/543] vs 39.8% [400/1005]; log-rank p<0.0001; RCR: 26% [141/543] vs 22.1% [222/1005]; log-rank p=0.0084) (Figures 1A and 1B). Following adjustment for potential baseline confounders, 2L Kd pts were 45% more likely to achieve ROR (IRR, 95% CI: 1.45, 1.18‒1.78) and 68% more likely to achieve RCR (1.68, 1.24‒2.28) vs 2L Vd pts (Figure 2). Kd pts in 2‒4L were 36% more likely to achieve ROR (1.36, 1.15‒1.62) and 52% more likely to achieve RCR (1.52, 1.19‒1.94). Conclusions: Using one of the most complete oncology EMR databases available, we found that RRMM pts with baseline RI treated with Kd had higher rates of overall and complete renal response, and were more likely to have a renal response, compared with pts treated with Vd. A limitation of the study is that we could not account for all concomitant medications or comorbidities that affect renal function, as some may not be captured in OSCER. Disclosures Kumar: AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding. Fu:Amgen: Employment, Equity Ownership. Mezzi:Amgen: Employment, Equity Ownership. Braunlin:Amgen: Employment. Kim:Amgen: Employment, Equity Ownership. Iskander:Amgen: Employment, Equity Ownership. Niesvizky:Amgen Inc.: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding. Jagannath:Celgene: Consultancy; Novartis: Consultancy; Merck: Consultancy; Medicom: Speakers Bureau; Multiple Myeloma Research Foundation: Speakers Bureau; Bristol-Myers Squibb: Consultancy. Boccia:Sandoz: Consultancy; Celgene: Speakers Bureau; Abbvie: Speakers Bureau; Genentech: Research Funding, Speakers Bureau; Amgen: Research Funding, Speakers Bureau; BMS: Research Funding; Pfizer: Consultancy; AstraZeneca: Research Funding, Speakers Bureau. Raje:Celgene: Consultancy; Janssen: Consultancy; Merck: Consultancy; Takeda: Consultancy; AstraZeneca: Research Funding; Research to Practice: Honoraria; Medscape: Honoraria; BMS: Consultancy; Amgen Inc.: Consultancy.

Abstract Abstract 2778 Introduction: Lenalidomide is approved for the treatment of del(5q) MDS in US and Japan. In Low to Intermediate-1 (Int-1) risk non-del(5q) MDS, lenalidomide treatment is less effective with a lower response rate (25%) and shorter response duration [Raza A. et al, Blood, 2008.111,1]. Ezatiostat, a glutathione S-transferase P1-1 (GST P1-1) inhibitor, activates Jun kinase, promoting the growth and maturation of hematopoietic progenitors while inducing apoptosis in malignant cells. Based on the novel mechanism of action, response rates, non-overlapping toxicities, and tolerability observed in a single agent ezatiostat Phase 2 study in MDS, a study of the combination of ezatiostat and lenalidomide was conducted to determine the safety and efficacy of ezatiostat with lenalidomide in non-del(5q) Low to Int-1 risk MDS. Methods: In this multicenter Phase 1 dose-ranging study, ezatiostat was given at a starting dose of 2000 mg in combination with lenalidomide at 10 mg, days 1–21 of a 28-day cycle. In stage 1, 3–6 patients in a standard 3+3 design were treated before escalation to the ezatiostat/lenalidomide 2500/10 mg dose level. Treatment was given until lack of MDS response or unacceptable toxicity. Hematologic improvement-erythroid (HI-E) rates were determined by the MDS International Working Group (IWG; 2006) criteria. Results: Eighteen pts (median age 73 yrs; range 57–82; 72% male), with World Health Organization classifications: 4 refractory anemia (RA), 2 RA with excess blasts-1, 4 refractory cytopenia with multilineage dysplasia (RCMD), 5 RCMD with ring sideroblasts, 2 MDS-unclassified, 1 MDS/myeloproliferative disorder-U were enrolled. Thirteen pts (72%) were Int-1 risk, 5 (28%) Low risk; 4 pts (22%) had abnormal cytogenetics. Twelve RBC transfusion-dependent pts (67%) required a median of 6 units (range 4–10)/8-weeks. Two pts (11%) were platelet transfusion dependent. A total of 67 treatment cycles were given (median 3.5 cycles/pt [range 1–11]) and only 6 cycles (9%) required dose reductions and 8 (12%) dose delays. Two of 6 pts reported DLTs (Grade 3 diarrhea and Grade 3 rash) at 2500/10 mg, with 9 additional pts receiving the recommended combination dose of 2000/10 mg. Eleven of 18 pts were evaluable (4 at 2500/10 mg and 7 at 2000/10 mg), and 3 pts are still on therapy with insufficient treatment duration to be evaluable. The HI-E rate was 43% (3/7; 95% CI, 10%–82%) for pts at the recommended 2000/10 mg dose and 6 pts are continuing therapy at the time of analysis. Three of 8 (38%; 95% CI, 9%–76%) RBC transfusion-dependent evaluable pts achieved transfusion independence including 1 responder who did not respond to prior lenalidomide. In responders, the median increase in hemoglobin level was 3.4 g/dL (from 7.9 g/dL). In 2 of 4 thrombocytopenic pts, a HI-platelet (HI-P) response was observed. A bilineage (HI-E and HI-P) response in 2 of 4 pts with anemia and thrombocytopenia was reported. One RBC and platelet transfusion-dependent pt who had a poor response to prior anti-thymocyte globulin treatment achieved complete RBC and platelet transfusion independence. The combination was generally well tolerated with no unexpected toxicities. Most common treatment-related non-hematologic adverse events (AEs) were Grades 1 and 2 including: fatigue (6%, 28%), swelling (0%, 11%), anorexia (11%, 6%), rash (0%, 6%), skin odor (11%, 6%), nausea (39%, 11%), diarrhea (22%,17%), vomiting (28%,17%), upper abdominal pain (5.6%, 5.6%), and constipation (11%, 0%). Grade 3 events were rash (11%), nausea (6%), diarrhea (17%), and vomiting (6%). Most common hematologic-related AEs were Grades 1 and 2 thrombocytopenia (11%, 6%) and neutropenia (0%, 11%). Grade 3–4 AEs were thrombocytopenia (11%, 17%), neutropenia (17%, 11%), anemia (6%, 6%), and febrile neutropenia (11%, 0%). Conclusions: Ezatiostat is the first GST P1-1 inhibitor to cause clinically significant reductions in RBC and platelet transfusions, including RBC and platelet transfusion independence. Since ezatiostat is non-myelosuppressive, it is a good candidate for combination with lenalidomide and in this study, the combination was well tolerated. Interestingly, ezatiostat may also have the potential to enhance lenalidomide's efficacy. The recommended doses of this combination regimen for future studies is the ezatiostat/lenalidomide 2000/10 mg. Disclosures: Off Label Use: Lenalidomide was used off-label in patients with non-del5q MDS. Mulford:Celgene: Speakers Bureau. Brown:Telik, Inc.: Employment, Equity Ownership. Meng:Telik, Inc.: Employment, Equity Ownership. Lyons:Incyte: Research Funding; Telik: Research Funding; Alexion: Consultancy, Honoraria; Novartis: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Sekeres:Celgene: Consultancy, Honoraria, Speakers Bureau. Mesa:NS Pharma: Research Funding; Astra Zeneca: Research Funding; SBio: Research Funding; Lilly: Research Funding; Incyte: Research Funding; Celgene: Research Funding.

Abstract Background: Patients with polycythemia vera (PV) can have a pronounced symptom burden that negatively impacts their quality of life (QoL). Traditional treatment options such as phlebotomy, hydroxyurea, and interferon provide clinical benefit but frequently do not alleviate symptoms. The ongoing REVEAL study is being conducted to describe contemporary demographics, burden of disease, clinical management, patient-reported outcomes, and healthcare resource utilization among patients with PV in the US. This preliminary analysis describes the burden of PV based on patient-reported outcomes (PROs), including health-related QoL and work productivity. Methods: REVEAL is a multicenter, noninterventional, nonrandomized, prospective, observational study. Eligible patients are ≥18 years of age with a PV diagnosis and currently under active management by a physician in the US. PROs are being collected at study enrollment and every 3 months thereafter. Each of the 10 items on the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) are graded from 0 (absent) to 10 (worst imaginable), with individual symptom scores ≥7 considered severe; total symptom score (TSS) ranges from 0-100. Raw scores for items on the 30-item European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire-Core 30 (EORTC QLQ-C30) are standardized by linear transformation to 0-100. Higher scores on the EORTC QLQ-C30 indicate better functioning for global health status/QoL and functional subscales and worse severity for symptom subscales. Outcomes with the 6-item Work Productivity and Activity Impairment Specific Health Problem questionnaire (WPAI-SHP) are presented as a proportion from 0% (minimal/no impairment) to 100% (maximal impairment/productivity loss). Analyses of these preliminary data were descriptive. Results: At the time of data cutoff (June 9, 2015), REVEAL had enrolled 865 patients (total planned enrollment, n=2000), the majority were male (55.5%) and white (89.5%), with a median age of 67 (range, 22-95) years. 782 patients had completed the PRO questionnaires at the enrollment visit. A majority of patients reported ≥1 PV-related symptom. Mean (SD) MPN-SAF symptom scores were highest for fatigue (3.5 [2.7]), early satiety (2.7 [2.8]), inactivity (2.7 [2.9]), itching (2.6 [3.1]), and concentration problems (2.1 [2.6]). The mean (SD) MPN-SAF TSS (sum of 10 symptom scores) was 19.6 (16.1). The most frequently reported severe symptoms were fatigue, itching, inactivity, early satiety, night sweats, concentration problems, and bone pain (Table 1). Mean (SD) global health status/QoL reported on the EORTC QLQ-C30 was 72.8 (23.4); functional subscales were as follows: cognitive functioning, 80.3 (24.5); emotional functioning, 80.7 (24.0); physical functioning, 83.1 (20.6); role functioning, 84.3 (26.1); and social functioning, 85.0 (25.0). The most severe mean (SD) symptom subscale scores were fatigue (30.7 [28.5]), insomnia (29.5 [34.5]), pain (20.9 [29.3]), and dyspnea (17.3 [28.6]). Among patients who were employed at baseline (n=273), mean (SD) PV-related WPAI-SHP scores were as follows: absenteeism (ie, work time missed), 2.9% (10.6%); presenteeism (ie, impairment at work/reduced on-the-job effectiveness), 10.7% (20.4%); work productivity loss (ie, absenteeism plus presenteeism), 12.0% (22.2%); and activity impairment, 21.0% (28.0%). Conclusion: Preliminary descriptive data from patients currently enrolled in REVEAL suggest that patients with PV have notable impairment in QoL because of their disease; patient-reported scores on the MPN-SAF and EORTC QLQ-C30 were similar to those reported previously for patient populations with MPNs. Similarly, PV is associated with marked work productivity loss among patients who are currently employed. Subsequent analyses from REVEAL will evaluate changes over time in PROs and investigate correlations with disease progression and treatment. REVEAL can provide novel insights into questions related to the contemporary real-world QoL burden and its impact on PV-related symptoms and work productivity. Disclosures Mesa: Pfizer: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Promedior: Research Funding. Boccia:Incyte Corporation: Honoraria. Moliterno:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Naim:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Stein:Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Abstract Background: Patients with polycythemia vera (PV) have an increased symptom burden (eg, fatigue, pruritus, and splenomegaly-related symptoms) and an increased risk of mortality compared with the general population, often resulting from thrombotic events, disease transformation to myelofibrosis, or secondary malignancies. There are limited data regarding PV burden and treatment patterns in a contemporary, real-world US setting. REVEAL is an ongoing observational study being conducted to describe contemporary demographics, burden of disease, clinical management, patient-reported outcomes, and healthcare resource utilization among patients with PV in the US. The objective of this assessment is to describe the clinical characteristics at enrollment among patients currently enrolled in REVEAL (enrollment from July 22, 2014 to June 9, 2015). Methods: REVEAL is a multicenter, noninterventional, nonrandomized, prospective, observational study. Eligible patients are ≥18 years of age with a PV diagnosis and currently under active management by a physician in the US. Data regarding disease and clinical characteristics, patient-reported outcomes, and health resource utilization are being collected at usual-care visits over a planned 36-month observation period. Analyses of these preliminary data were descriptive. Results: At data cutoff, 865 patients were enrolled (total planned enrollment, n=2000) from 174 sites (academic, n=27; community, n=147). Median (range) age at enrollment was 67 (22-95) years, 55.5% were male, 89.5% were white, and 45.4% had a history of smoking. Most patients (99.4%) had health insurance, including Medicare (56.0%), PPO (24.3%), or HMO (11.6%). Fifty-two percent were retired, 29.6% were employed, and 4.5% were unable to work or disabled. A total of 40.2% of patients completed a college/graduate degree, 19.9% had some college, and 32.5% completed high school or the equivalent. Documented major World Health Organization diagnostic criteria included JAK2V617F mutation in 50.9% of patients, elevated hemoglobin in 52.3%, and red cell mass in 5.5%. A bone marrow biopsy was conducted in 24.0% of patients, approximately half of whom (52.4% of the 24.0%) had trilineage myeloproliferation. Erythropoietin levels were abnormal in 19.7% of patients. Approximately half (46.6%) of patients had physician-reported PV-related symptoms at diagnosis, most frequently fatigue (25.2%) and pruritus (14.0%). At enrollment, median disease duration was 52.6 months; 42.3% of patients were diagnosed ≥5 years before enrollment. The most common comorbidities were hypertension (51.3%), obesity (14.2%), dyspnea (13.4%), myalgia (11.2%), and diabetes mellitus (11.1%). Mean hematocrit was 44.9%, hemoglobin was 14.5 g/dL, white blood cell count was 11.4×109/L, platelet count was 363.7×109/L, and absolute neutrophil count was 363.7×109/L. Twenty-one percent of patients had a history of thrombotic events, with 13.1% and 8.6% of patients experiencing ≥1 venous or arterial thromboembolic event, respectively. Of the 261 reported thrombotic events, 43.7% occurred after diagnosis of PV. The most common PV symptoms recorded at enrollment (using the Myeloproliferative Neoplasm Symptom Assessment Form) were fatigue (37.1%), pruritus (24.0%), headache (18.6%), insomnia (17.0%), dizziness (13.2%), bone pain (10.5%), and blurred vision (7.9%); 19.7% of 518 evaluable patients had palpable splenomegaly. Fewer than half of patients were receiving aspirin at enrollment (47.7%). The most common PV treatments ± aspirin were phlebotomy (PBT; 63.5%), hydroxyurea (HU; 42.2%), watchful waiting (5.3%), and ruxolitinib (3.1%); 23.0% of patients received PBT + HU. Conclusion: The REVEAL study is unique in that it captures data from both academic and community centers, and therefore includes a broader segment of the PV population typically not described in the literature. REVEAL can provide novel insights into questions related to the contemporary demographics of PV, practice patterns regarding diagnosis and therapy, and the real-world burden of PV and its impact on patients' quality of life and work productivity. Preliminary descriptive data from this early subset of patients suggest that a high proportion of patients report having PV-related symptoms at diagnosis, fewer patients are treated with aspirin than expected, and that thromboembolic event rates remain high after diagnosis. Disclosures Stein: Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Moliterno:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Boccia:Incyte Corporation: Honoraria. Naim:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Mesa:Promedior: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; NS Pharma: Research Funding; CTI Biopharma: Research Funding; Gilead: Research Funding; Pfizer: Research Funding; Incyte Corporation: Research Funding; Genentech: Research Funding.

Abstract Background: Lenalidomide (Revlimid®) in combination with dexamethasone was approved in the US on June 29, 2006 for the treatment of subjects with multiple myeloma who had received at least one prior therapy. On February 28, 2005 based upon a positive interim analysis of two pivotal placebo-controlled Phase III studies, an independent Data Safety Monitoring Board recommended the studies be unblinded and all subjects in both studies be given access to lenalidomide. In April 2005, the FDA in association with myeloma patient advocacy groups requested Celgene establish an expanded access program to make lenalidomide plus dexamethasone available to subjects with relapsed or refractory multiple myeloma while the treatment was awaiting approval. Aim: To provide lenalidomide to multiple myeloma subjects with a high likelihood of benefit and to obtain additional safety data. Methods: Subjects with relapsed or refractory multiple myeloma that received at least 1 prior therapy were eligible. Subjects received 25 mg lenalidomide plus high-dose dexamethasone in 4-week cycles until disease progression was documented, study drug was discontinued, or lenalidomide became commercially available for this indication. Results: Between September 8, 2005 and July 25, 2006, approximately 1400 subjects in the US and Canada were enrolled into the study. A data snapshot taken March 17, 2006 demonstrated that 746 subjects had been enrolled, median age was 63 years, 60% were male, and 66.5% had Stage III disease. Median time on study was 7.1 weeks (0.1–24.4) and median daily dose was 20.5 mg. At least one Grade 3 or 4 adverse event was reported in 261 (35%) of the 746 subjects. Most commonly reported Grade 3–4 events were neutropenia (7.9% of subjects), thrombocytopenia (6.0%), fatigue (3.6%), anemia (3.5%), pneumonia (3.1%) and hyperglycemia (2.0%). These most commonly reported Grade 3–4 adverse events were the same as those found in the previous pivotal studies, however, their frequencies of occurrence were lower in the current study probably due to ongoing data collection and differences in study maturity. Likewise, the most commonly reported adverse events (all grades) were the same as those reported in the two previous pivotal studies. Conclusion: Preliminary data from this expanded access program in over 1400 subjects with multiple myeloma are consistent with results from two earlier Phase III pivotal studies. The EAP of lenalidomide plus dexamethasone in multiple myeloma represents a model of how government, advocacy groups, healthcare providers and industry can work together to quickly provide treatment to subjects in need while a clearly active treatment regimen is awaiting approval.

Abstract Background:Patients with polycythemia vera (PV) often present with a broad range of clinical characteristics that may contribute to increased risks of cardiovascular (CV) morbidity and mortality, including thrombotic events (TE). Limited contemporary real-world data have been reported about the clinical burden of PV and treatment patterns in the United States. The ongoing REVEAL study collects data on disease burden, clinical management, patient-reported outcomes, and healthcare resource utilization for patients with PV in the United States. This analysis reports clinical characteristics, including underlying CV risk factors, for patients enrolled in the REVEAL study as of April 28, 2016. Methods: REVEAL is a multicenter, nonrandomized, prospective, observational study enrolling patients ≥18 years of age with a PV diagnosis who are actively managed in an academic or community setting. For this analysis, data regarding PV disease and diagnosis, clinical characteristics, and treatment patterns were collected at enrollment during usual-care visits and were based on physician assessment, electronic medical records, and local laboratory values. Ten-year CV risk factors selected for this analysis were adapted from the Framingham Heart Study for CV diseases. Results: At data cutoff, 2307 patients were available for this analysis. Mean (SD) age was 66.3 (12.2) years, 54.4% were male, 89.9% were white, 62.7% had at least some college education, and 51.1% were retired. Approximately 6% of patients had a family history of PV, primarily in parents (35.1%) and siblings (33.8%). A history of second malignancies was reported for 344 patients (14.9%). The majority of patients (84.6%) were diagnosed with PV based on an abnormal blood test alone or in combination with a bone marrow test. Among patients who were diagnosed with a mutational test (n=1078), 95.2% were diagnosed via an abnormal JAK2V617F test result. Abnormal hemoglobin (57.3%), hematocrit (55.4%), or both (47.5%) were among the most common blood values assessed for PV diagnosis. At diagnosis, 58.5% of patients were classified with high-risk PV (age ≥60 years or history of a TE); this percentage increased to 77.3% at REVEAL enrollment. The average (SD) disease duration from diagnosis to enrollment was 5.8 (6.1) years. At enrollment, 91.5% of patients were under active management for PV (phlebotomy ± aspirin, 34.0%; hydroxyurea ± aspirin, 27.0%; and phlebotomy + hydroxyurea ± aspirin, 23.2%). Underlying CV risk factors that were either diagnosed or treated in 86.0% of enrolled patients included hypertension (66.5%), history of smoking (46.2%), current smoking at enrollment (10.9%), obesity (34.2%), hyperlipidemia (27.4%), and diabetes (14.8%). At enrollment, 431 (18.7%) patients reported having ≥1 TE, including 181 patients who had a TE between PV diagnosis and enrollment. Venous and arterial TEs were reported in 11.1% and 8.6% of patients, respectively. Most commonly reported venous TEs were deep vein thrombosis (5.9%) and pulmonary embolism (2.5%); most common arterial TEs were cerebrovascular arterial thrombosis including transient ischemic attack (5.1%) and acute myocardial infarction (1.7%). Increased rates of TEs were observed among patients with hyperlipidemia (23.6%) and hypertension (21.0%; Table 1), compared with patients who did not have any risk factors (10.5%). Conclusion: A large proportion of patients in the REVEAL study had 1 or more underlying CV risks, including age, hypertension, smoking, obesity, hyperlipidemia, and diabetes, which may contribute to the risk of thrombosis. Longitudinal data from REVEAL will provide a better understanding of how these factors affect CV outcomes over time. Disclosures Stein: Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Naim:Incyte Corporation: Employment, Equity Ownership. Grunwald:Janssen: Research Funding; Forma Therapeutics: Research Funding; Medtronic: Equity Ownership; Alexion: Membership on an entity's Board of Directors or advisory committees; Ariad: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Oh:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; CTI: Research Funding. Paranagama:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Boccia:Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen/Onyx: Consultancy, Honoraria, Speakers Bureau; Gilead: Speakers Bureau; Genentech: Consultancy, Honoraria, Speakers Bureau; Eisai: Consultancy, Honoraria, Speakers Bureau. Mesa:Ariad: Consultancy; CTI: Research Funding; Gilead: Research Funding; Galena: Consultancy; Novartis: Consultancy; Promedior: Research Funding; Celgene: Research Funding; Incyte Corporation: Research Funding.