Vaidya, Rakhee

Introduction: Diffuse Large B-cell Lymphoma (DLBCL) are aggressive B-cell non-Hodgkin lymphomas (NHL). One particular subtype, Primary Mediastinal B-cell Lymphoma (PMBCL), is often grouped with DLBCL, but it possesses distinct biological and clinical characteristics. While initial therapy successfully cures approximately two-thirds of patients (pts), those who do not respond or experience progression within the first two years have a poor prognosis despite novel cellular therapies and bispecifics and ultimately succumb to their disease. There is a pressing need for more effective therapeutic approaches in this patient population. Recent advances in the understanding of DLBCL pathogenesis have led to the targeting of various signaling pathways, including the PI3K-AKT-mTOR pathway. One such drug, copanlisib (C), a pan-PI3K inhibitor with potent PI3K-α/PI3K-δ inhibition, exhibited activity in both indolent and aggressive NHL. In preclinical studies using a DLBCL mouse model, treatment with C effectively reduced the immunosuppressive tumor-infiltrating T-regulatory cells (Tregs). Moreover, when combined with a surrogate anti-mouse programmed death -1 (PD-1) blocker, C demonstrated significant in vivo responses (75%) compared to the monotherapy groups (0%). These findings support the rationale for exploring the combination of nivolumab, a PD-1 blocker, and copanlisib (C-N) in DLBCL. Thus, a phase 2 prospective study has been developed, focusing on two relapsed/refractory (RR) cohorts (DLBCL and PMBCL), treated with the combination of C-N. A prespecified interim analysis was planned upon enrollment of 14 pts. Herein, we report outcomes of the 12 enrolled pts, as the study was halted prematurely due to a safety signal deemed possibly related to the combination. Study design: C 60 mg was given intravenously on days 1, 8, and 15 during cycles 1-8, and on days 1 and 15 in subsequent cycles. N 240 mg IV was given on days 1 and 15 during cycles 1-8, and 480 mg on day 1 on subsequent cycles. Each treatment cycle is 28 days. Therapy was given for up to 2 years, as long as there is no disease progression or unacceptable side effects. The primary objective of the study is to determine the ORR, which includes complete and partial responses (CR+PR). Secondary objectives include evaluating the safety of the combination, as well as assessing progression-free survival (PFS), duration of response (DOR), CR, and overall survival (OS). The study plan was to enroll a maximum of 106 pts, including a safety cohort of 6 pts. The study received funding from Bayer and conducted through NCI-CTEP (NCI Protocol #10193; NCT03484819). Results: Twelve pts who received at least one cycle of C-N were included in this analysis. Pt characteristics are illustrated in table 1. All enrolled pts had DLBCL histology. Only one patient received a prior autologous stem cell transplant. Interestingly 4/12 received prior chimeric antigen receptor T-cell therapy (CART). Of the 12 enrolled pts, seven were evaluated for response. The ORR was 25% (3/12) (95% CI: 5 - 57%), all CR. The median number of cycles received was 2.5 (range 1-24) with two pts receiving 23 and 24 cycles. Observed grade 3 and higher adverse events (AEs) were as follows: non-hematologic AEs in 10/12 (83.3%), while hematologic AEs were seen in 5/12 (41.7%) pts. A relatively higher incidence of cardiac events (4/12) were noted including one cardiac arrest after one cycle of therapy, and four atrial fibrillation events, all grade 3, but only two were deemed possibly attributed to therapy. The cardiac arrest was deemed unrelated to therapy. Conclusions: C-N combination had modest clinical activity in pts with R/R DLBCL with some prolonged responses. However, due to the relatively high number of cardiac events and the changing therapeutic landscape with recent approvals, a decision was made to halt the study. These findings likely reflect possibly older and sicker patient population. Biomarker studies for predictors of response are under consideration.

4071 Background: Selection of patients for HER2-targeted therapy is based on HER2 analysis in primary EACs. Since EACs metastasize via regional lymph nodes, concordance of HER2 gene amplification results between primary tumors and their metastatic lymph nodes (MLN) is a clinically important issue. Methods: Resected EACs (N = 103) having at least three distinct regional MLNs (total 508 MLNs; median 4 [range 3-11]) were sectioned using routine procedures and tested for HER2 amplification by fluorescence in situ hybridization (FISH). Primary tumors were also evaluated for HER2 protein expression by immunohistochemistry (IHC) and by FISH. Amplification was defined as HER2/CEP17 ≥ 2. IHC was scored as 0, 1+, 2+, or 3+. Primaries whose HER2 status was positive by both FISH and IHC (ie, amplified and IHC3+), or negative by both (ie, nonamplified and IHC0-1+), were selected. HER2 status was compared between primaries and their MLNs (kappa). Results: Concordant HER2 results between primaries and their MLNs were found in 92% (95/103) of EACs (Table; κ = .76 [95% CI .60 - .92]). However, among patients with HER2-positive primaries, 19% (4/21) had HER2-nonamplified MLNs; among these cases, either all MLNs were HER2-nonamplified (n = 2), or both HER2-nonamplified and –amplified MLNs were present (n = 2). Among HER2-negative primary EACs, 5% (4/82) of cases had MLNs that were all HER2-amplified (n = 3) or both HER2-nonamplified and -amplified (n = 1). Conclusions: A patient subset whose primary EACs were HER2-positive (by both FISH and IHC) were unexpectedly found to lack HER2 amplification in corresponding MLNs. Conversely, a subgroup with HER2-negative primaries had HER2-amplified MLNs, and would have been deemed ineligible for HER2-targeted therapy. These preliminary data suggest that evaluating MLNs in resected EACs has the potential to better identify patients who benefit from HER2-targeted therapy. [Table: see text]

Abstract Abstract 277 Background: Current information on the natural history of polycythemia vera (PV) is mostly derived from early studies based on the PV Study Group diagnostic criteria. The World Health Organization (WHO) diagnostic approach to PV is currently the gold standard. The main objective of the current study was to describe survival, disease complication rates and risk factors in WHO-defined PV. Methods: Under the auspices of an International Working Group, seven international centers of excellence for myeloproliferative neoplasms submitted a total of 1,430 patients, locally diagnosed with “WHO-defined PV”. The two principle investigators (AT and TB) reviewed all the cases and selected 1,263 patients who were age 18 years or older, diagnosed after 1970, and whose submitted data included diagnostically essential information. Results I: Presenting Features: Median age was 60 years (range, 18–95; 51% females). The number of patients diagnosed between 1970–1990, 1991–2000, and 2001–2011 were 136 (11%), 337 (27%) and 790 (62%), respectively. Arterial/venous thrombosis history before or at diagnosis was documented in 142/73 and 80/42 patients, respectively. Other features at diagnosis included pruritus (37%), microvascular disturbances (29%), palpable splenomegaly (37%), abnormal karyotype (13%), and leukoerythroblastosis (6%). History of hypertension (45%), hyperlipidemia (17%), diabetes (9%), and tobacco use (15%) was also obtained. Results II: Clinical Course: To date, 228 (18%) deaths, 42 (3%) leukemic progressions, and 101 (8%) fibrotic transformations have been recorded. Post-diagnosis arterial or venous thrombosis occurred in 139 (11%) and 85 (7%) patients, respectively. Cytoreductive therapy had not been used in 342 (27%) patients whereas 154 (12%) patients were exposed to two or more cytoreductive drugs. Results III: Risk Factors: Multivariable analysis identified advanced age, leukocytosis, venous thrombosis history and abnormal karyotype as significant (p<0.01) risk factors for overall survival (OS). Receiver operating characteristic (ROC) plots delineated ages 69 (AUC 0.83) and 59 (AUC 0.61) years and leukocyte count 13 × 109/L (AUC=0.61) as the best discriminant levels in this regard; HR (95% CI) were 11.4 (7.7–16.9) for age ≥70 years, 3.8 (2.6–5.7) for age 60–69 years, and 2.0 (1.5–2.6) for leukocyte count ≥15 × 109/L. Results IV: Risk Stratification: HR-based risk scores were assigned to age ≥70 years (3 points), age 60–69 years (2 points) and leukocyte count ≥15 × 109/L (one point), in order to create four risk groups: low (zero points; n=492; median survival 322 months), intermediate-1 (one or 2 points; n=353; median survival 208 months; HR 3.8, 95% CI 2.5–5.8), intermediate-2 (3 points; n=286; median survival 132 months; HR 10.7, 95% CI 6.9–16.5), and high (4 points; n=56; median survival 90 months; HR 22.7, 95% CI 13.9–37.1) (Figure 1). Similar results were obtained when analysis was restricted to the 1,011 JAK2 mutation-positive patients (Figure 2). The particular risk model was equally robust in predicting leukemia-free survival (p=0.001). Conclusions: Age and leukocyte count matter the most in predicting survival in PV. The current study suggests additional prognostic value from karyotype and venous thrombosis history. Disclosures: Vannucchi: Novartis: Honoraria. Gisslinger:Novartis: Speakers Bureau; Celgene Austria: Speakers Bureau; AOP-Orphan: Speakers Bureau.

Abstract Abstract 2806 Background: A high degree of prognostic certainty is required to recommend or discourage high risk treatment procedures in primary myelofibrosis (PMF). The Dynamic International Prognostic Scoring System (DIPSS-plus) uses eight risk factors to predict overall survival (OS) in PMF: unfavorable karyotype, peripheral blood (PB) blast count ≥1%, platelet count <100 × 109/L, white blood cell count (WBC) >25 × 109/L, hemoglobin level <10 g/dL, red blood cell transfusion need, constitutional symptoms, and age >65 years (Gangat et al. JCO 2011;29 :392). The presence of four or more of these risk factors defines high-risk disease. purpose: The purpose of the current study was to enhance the prognostic weight of some of the DIPSS-plus risk factors with the intent to identify one or two parameters that can reliably predict death in the first two years of disease. Methods: An updated Mayo Clinic database of 884 karyotypically-annotated patients with PMF was used. Calculations of 2-year mortality rates and variables considered for prognostic value were from time of referral to the Mayo Clinic. Cytogenetic risk categorization per DIPSS-plus was further refined to capture additional prognostic information from monosomal karyotype (MK) (Vaidya et al. Blood 2011;117 :5612) and inv(3)/i(17q) abnormalities (Caramazza et al. Leukemia 2011;25 :82). Receiver operating characteristic (ROC) analysis was employed to define best discriminant levels. Results: To date, 564 (64%) deaths have been documented. Each one of the aforementioned DIPSS-plus risk factors was associated with a 2-year mortality rate that ranged from 42% (PB blast count ≥1%) to 60% (unfavorable karyotype). High-risk disease per DIPSS-plus was associated with 57% two-year mortality. The only risk factors that were associated with >80% two-year mortality were MK (n =19) and inv(3)/i(17q) abnormalities (n =8) and both were associated with significantly worse survival, compared to other unfavorable karyotype (n =102): HR (95% CI) of 5.1 (3.1−8.4) and 3.9 (1.7−8.8), respectively. ROC analysis identified PB blast counts of 2% and 9% (AUC 0.62) and WBC of 43 × 109/L (AUC 0.66) as best discriminant levels for predicting 2-year mortality; OS was significantly worse in the presence of PB blast >9% (HR 4.1, 95% CI 2.8–6.1) vs. 2% to 9% (HR 1.8, 95% CI 1.5–2.2) vs. <2%; the corresponding 2-year mortality rates were 73%, 46% and 25%. OS was also significantly worse in the presence of WBC ≥40 × 109/L (HR 2.8, 95% CI 2.2–3.6) vs. 26–39 × 109/L (HR 1.6, 95% CI, 1.2–2.1) vs. <26 × 109/L; the corresponding 2-year mortality rates were 63%, 42% and 28%. Two-year mortality rates exceeded 80% in the presence of any two of the following: PB blast count >9%, WBC ≥40 × 109/L or unfavorable karyotype other than MK or inv(3)/i(17q). Conclusions: A greater than 80% 2-year mortality in PMF is predicted by the presence of MK, inv(3)/i(17q) abnormalities, or any two of the following: PB blast >9%, WBC ≥40 × 109/L, other unfavorable karyotype. Such patients and those with high DIPSS-plus risk should be referred to allogenic stem cell transplantation earlier than later. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 4971 Background Marked splenomegaly severely compromises quality of life in primary myelofibrosis (PMF). Preliminary results from the use of small molecule JAK2 inhibitors suggest prominent activity in reducing spleen size. In order to put such salutary effect of investigational drug therapy in context, it is important to determine the value of conventional therapy in this regard. Methods Study population was selected from the Mayo Clinic PMF database and consisted of patients treated with hydroxyurea (HU) as first-line therapy for symptomatic, marked splenomegaly (palpable at >10 cm below the left costal margin) and in whom follow-up information was available to assess response. Palpable spleen size measurements were recorded before and after 3, 6 and 12 months of HU therapy. Spleen response was defined as minimal (< 25% reduction), minor (25-50%), or major (>50%). Standard statistical procedures were used to correlate spleen response with other clinical and laboratory parameters, including cytogenetic and JAK2V617F mutational status. Results 46 consecutive patients (median age, 62 years; range 38-75; 30 males) met the above stipulated eligibility criteria for study inclusion. Pre-treatment IPSS risk categories were low, intermediate-1 (int-1), int-2 and high in 4, 13, 10 and 19 patients, respectively; 7 patients were transfusion-dependent. Quantitative JAK2V617F and pre-treatment cytogenetic information were available in 25 and 36 patients, respectively; 15 (60%) patients were positive for JAK2V617F and mutant allele burden was > 50% in 6 patients; 17 (47%) patients carried either favorable (n=5) or unfavorable (n=12) cytogenetic abnormalities. Overall response rate (major and minor) was 35% (16 of 46 patients) and major response rate 17%. Overall response rates were 10%, 67% and 33% in patients with undetectable JAK2V617F or mutant allele burden of < or ≥ 50%, respectively (p=0.04). Overall response rates in patients with normal, favorable and unfavorable karyotype were 32%, 40% and 33%, respectively (p=0.9). Response was not affected by age, sex, HU dose or pretreatment status regarding spleen size, IPSS score or transfusion need. Conclusions The current study provides background information on the value of conventional chemotherapy for controlling PMF-associated marked splenomegaly. The study also suggests a positive effect of JAK2V617F on treatment response to HU, a detail that needs to be considered when assessing the corresponding effect from a JAK2 inhibitor therapy. Disclosures Off Label Use: Hydroxyurea use in myelofibrosis.

Abstract Abstract 3850 Background: We have recently shown that primary myelofibrosis (PMF) was associated with increased plasma levels of IL-1b/IL-1RA/IL-2R/IL-6/IL-8/IL-10/IL-12/IL-13/IL-15/TNF-α/G-CSF/INF-α/MIP-1α/MIP-1b/HGF/IP-10/MIG/MCP-1/VEGF in PMF (J Clin Oncol 2011; 29: 1356). In addition, increased levels of IL-8, IL-2R, IL-12, IL-15 and IP-10 were independently associated with inferior survival. In the current study, we focused on the plasma cytokine profile in polycythemia vera (PV) and examined how it compares with PMF or in a cohort of PV patients whose samples were collected during follow-up. We also looked for phenotypic and prognostic correlates. Methods: Study inclusion for patients with PV required availability of archived plasma within one year of diagnosis. Samples from PV patients seen at different points post-diagnosis were also collected, in order to compare their cytokine profile with that of patients whose samples were collected within one year of diagnosis. Standard procedures were followed to centrifuge peripheral blood samples at 4°C and store aliquots at −80°C. Concentrations of 30 plasma cytokines/chemokines were analyzed in duplicates using Multiplex Bead-based Luminex Technology (Invitrogen, Carlsbad, CA, USA): IL-1β, IL-1RA, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, EGF, eotaxin, FGF-b, GM-CSF, G-CSF, HGF, IFN-α, IFN-γ, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF. Measurements were performed on a Luminex 200 analyzer (Luminex Corporation, Austin, TX, USA) and resulting data were evaluated using STarStation Software Version 2.3 (Luminex Corporation, Austin, TX, USA). Results I: Plasma cytokines in PV (n=36 for samples collected within one year of diagnosis and n=40 for samples collected beyond that time point) vs. PMF (n=92) vs. normal controls (n=35) There was no significant difference between the three groups in the plasma levels of the following cytokines: IL-1β, IL-2, IL-4, EGF, and IL-17. PV and normal controls had similar levels of IL-2R, IL-5, FGF-b, and TNF-α; all four cytokines were elevated in PMF. The levels of the following cytokines were equally increased in PV and PMF: IL-1RA, IL-7, HGF, MIG, and VEGF. The following cytokines were also elevated in both PMF and PV but predominantly so in PV (MIP-1α) or PMF (IL-6, IL-8, IL-12, IL-13, IL-15, MIP-1β, IP-10, and MCP-1). Eotaxin and GM-CSF were elevated in PV but not PMF. Compared to normal controls, significantly lower levels were noted for IL-10 in PV and IFN-α and IFN-γ for PMF. IFN-α and IFN-γ levels were both elevated in PV. Comparison of PV samples collected within one year of diagnosis (n =36) vs. those collected beyond that time point (n =40) showed significantly increased levels of IL-8 (p=0.0005) and borderline significant increases in IP-10 (p=0.09) and IL-2R (p=0.09). Results II: Clinical correlates of plasma cytokines in PV Among the above-listed cytokines that were abnormally increased or decreased in PV, significant correlations were seen with sex (IP-10 and GM-CSF), age (IP-10, eotaxin), platelet count (MIG), hemoglobin level (IL-6), arterial thrombosis (IFN-γ, IL-1RA, VEGF, MIP-1α), and abnormal karyotype (IL-13, MIP-1α). None of the cytokines correlated with leukocyte count, venous thrombosis, pruritus or microvascular symptoms. The following, treated as continuous variables, were associated with inferior survival: IL-7, HGF, IFN-α, MCP-1, GM-CSF and IL-10 (p<0.05 for all). The number of events and sample size were too small to perform multivariable analysis. Conclusions: Plasma cytokine levels in PV are markedly abnormal and show both similarities and differences with PMF; the similarities became more pronounced in patients whose samples were examined at later stages of their disease. The current study suggests prognostic implications that warrant validation in a larger number of patients. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction: "High grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements" (HG DH/THL) is a new diagnosis per the revised 2016 WHO classification. It has been colloquially called "double hit/triple hit lymphoma" and is significant for its aggressive clinical course. However, under this umbrella diagnosis there are several morphologic and cytogenetic variants with either controversial or unknown clinical significance. Herein, we investigate the prognostic significance of several of these parameters, including morphology, immunoglobulin gene (IG) vs non-IG MYC translocation partners, and BCL2/BCL6 translocation status in HG DH/THL in the Mayo Clinic Rochester practice. Materials and methods: All cases, which were identified through the Mayo Clinic Lymphoma Database, University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), and the Mayo Clinic Cytogenetics Laboratory, had diffuse large B-cell lymphoma (DLBCL) or high grade B-cell lymphoma (HGBCL) morphology, were CD20-positive, and had a MYC translocation with concurrent BCL2 and/or BCL6 translocations. Morphology was re-reviewed by four hematopathologists when possible. Cell of origin (germinal center B-cell (GCB) vs non-GCB phenotype) was determined by paraffin section immunohistochemistry using the Hans classifier. Interphase FISH was performed on either tissue paraffin sections or bone marrow aspirate smears using a breakapart probe for MYC, followed by dual fusion probes for IGH/MYC, IGL/ MYC and IGK/MYC, a BCL6 breakapart probe, and either a BCL2 breakapart probe or an IGH/BCL2 dual fusion probe. Outcome analysis was restricted to patients with de-novo HG DH/THL or HG DH/THL at transformation of a previously diagnosed low-grade lymphoma and who were treated with anthracycline-based chemotherapy. Overall survival (OS) was defined as time from DH/THL diagnosis to death from any cause. Results: There were 100 patients with a median age of 61 years (range 29-87). The consensus re-review morphologic diagnosis (n=65) was HGBCL in 39 (60%) and DLBCL in 26 (40%). The HGBCL group had inferior survival (2-year OS = 35%) compared to DLBCL (2-year OS=62%, p= 0.058). By interphase FISH, the MYC translocation partner was an IG gene (IG/MYC) in 52 cases (60%; 39 IGH, 6 IGK and 7 IGL) and a non-IG gene (non-IG/MYC) in 35 cases (40%). No difference in OS was identified between IG/MYC and non-IG/MYC cases (p=0.85, Figure 1). By FISH, 87 cases (87%) had a BCL2 translocation (59 MYC/BCL2, 20 MYC/BCL2/BCL6, and 8 MYC/BCL2/[BCL6 unknown]) and 13 (13%) lacked a BCL2 translocation (MYC/BCL6). Those with a BCL2 translocation were all of GCB phenotype (N=85), while 6 of 12 of the MYC/BCL6 cases (50%) were of non-GCB phenotype (p <0.0001). All 13 MYC/BCL6 cases were de novo diagnoses, while 38% of cases with a BCL2 translocation represented either transformation (n=22) or recurrence (n=11) events (p=0.025). The MYC/BCL6 group had better survival (2-year OS=73%) than those with BCL2 translocation (2-year OS=43%, p= 0.13). Conclusion: As HG DH/THL's frequently have morphologic characteristics of DLBCL (40% in this series), it is important to perform complete interphase FISH analysis on all cases with DLBCL or HGBCL morphology to exclude the possibility of HG DH/THL. Furthermore, within the diagnosis of HG DH/THL, there are several morphologic and cytogenetic subtypes that are biologically and clinically significant. High grade morphology (HGBCL) tends to predict for a more aggressive clinical course independent of all other parameters (p= 0.058). Unlike a recent report (Blood 2015;126:2466), our data suggest MYC translocation partner (IG versus non-IG) may have no impact on overall survival (Figure 1). HG DH/THL's with a BCL2 translocation appear restricted to GCB phenotype, frequently represent either transformation or recurrence events, and tend to have inferior OS. In contrast, those without BCL2 translocations may be of either GCB or non-GCB phenotype, typically arise de novo, and tend to have a superior OS. Careful morphologic review and complete interphase FISH studies are essential in all HG DH/THL for prognostic and potential therapeutic purposes. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract Background: B-cell lymphomas with a MYC/8q24 rearrangement coupled with translocations involving BCL2 and/or BCL6, often referred to as double hit or triple hit (DH/TH) lymphomas, typically have an aggressive clinical course. A new WHO subtype, "high grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements", has been established for this entity (Swerdlow et al. Blood; 127: 2375-2390, 2016). Herein we report the treatment and outcomes of DH/TH patients at our institution. Materials and Methods: Cases were identified through the Mayo Clinic Lymphoma Database, University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), and the Mayo Clinic Cytogenetics Laboratory. Interphase FISH was performed clinically on either paraffin sections of the tissue specimens or on smears of the bone marrow aspirate specimens using break-apart probes for MYC and BCL6, dual fusion probes for IGH/MYC, IGL/MYC, and IGK/MYC, and either a BCL2 break-apart probe or an IGH/BCL2 dual fusion probe. Consensus pathology re-review was performed to define morphology as diffuse large B-cell lymphoma (DLBCL) vs. high-grade B-cell lymphoma (HGBCL). Patients with de-novo DH/TH or diagnosis of DH/TH at the time of transformation of a previously diagnosed low-grade lymphoma and who were treated with anthracycline-based chemotherapy were included in this analysis. Patients with DH/TH first identified at the time of recurrent aggressive B-cell lymphoma were excluded. Overall survival (OS) was defined as time from DH/TH diagnosis to death from any cause. EFS12 was defined as event-free status 12 months from diagnosis of DH/TH. Results: Clinical outcome analysis was performed on 71 patients (Table 1). The median age was 61 years (range 29-82). 60 patients had de-novo DH/TH and 11 patients had transformation of a previously diagnosed low-grade lymphoma. In 65 cases in which there was consensus morphology on pathology re-review, there were 39 (60%) with HGBCL morphology and 26 (40%) with DLBCL morphology. At a median follow-up of 21 months (range 1-87), the event free survival at 12 months was 43%, and the median overall survival (OS) was 22 months (95% CI: 13-NA). The OS at 5 years was 48% (95% CI: 36%-63%). Patients with DH/TH at transformation of previously diagnosed low-grade lymphoma had a very poor outcome (median OS=10.8 months, EFS12 = 10%), which was inferior to patients with de-novo DH/TH (P=0.0069). When compared to all other therapies, patients treated with R-CODOX-M/IVAC had better EFS12 (p=0.03) with a trend in improved OS (p=0.08) though this may be confounded by patient selection bias as these patients were significantly younger (p=0.0001) than patients treated with other anthracycline based regimens (table 1). Conclusion: In "high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements", induction failure occurs early. Although transformation to DH/TH from previously diagnosed low-grade lymphoma is associated with a particularly poor outcome, the overall survival for the entire cohort at 5 years was 48%, suggesting long-term cures in a subset of patients. Treatment with R-CODOX-M/IVAC may result in superior outcomes in patients less than 60 years of age. Table 1 Table 1. Figure Figure. Disclosures Ansell: BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Nowakowski:Celgene: Research Funding; Morphosys: Research Funding; Bayer: Consultancy, Research Funding.

Abstract Abstract 4104 Background: The International Prognostic Scoring System (IPSS) for primary myelofibrosis (PMF) uses five predictors of inferior survival: age > 65 years, hemoglobin < 10 g/dL, leukocytes > 25 × 109/L, circulating blasts ≥ 1% and constitutional symptoms (Cervantes F et al. Blood 2009; 113: 2895). The dynamic IPSS (DIPSS) utilizes the same prognostic variables but can be applied at any time during the disease course (Passamonti F et al. Blood 2010; 115: 1703). IPSS-independent risk factors for survival have since been described and include unfavorable karyotype, red cell transfusion need and platelets < 100 × 109/L. Objectives: i) To determine if the aforementioned IPSS-independent risk factors for survival in PMF (i.e. unfavorable karyotype, red cell transfusion need and platelets < 100 × 109/L) are also DIPSS-independent. ii) To develop and validate a refined DIPSS model that incorporates DIPSS-independent prognostic factors for survival. iii) To establish a prognostic model for leukemia-free survival in PMF. Methods: The Mayo Clinic database for PMF was used to identify patients in whom bone marrow histologic and cytogenetic information was obtained at the time of their referral. WHO criteria were used for PMF diagnosis and leukemic transformation (Vardiman JW et al. Blood 2009; 114: 937). None of the patients in the current study were included in the original group of patients used to describe DIPSS (Passamonti F et al. Blood 2010; 115: 1703). Results: A total of 793 patients met the above-stipulated criteria. The study population was divided into two groups based on whether or not patients were seen at the Mayo Clinic within (n=428; training set) or beyond (n=365; test set) their first year of diagnosis. i) Objective 1: Multivariable analysis that included DIPSS risk category (low, intermediate-1, intermediate-2 and high risk), karyotype (favorable or unfavorable), platelet count (≥ or <100 × 109/L) and transfusion status (independent or dependent) was performed using the training set and all four variables were found to be significant as independent predictors of survival (p<0.0001, <0.0001, 0.0008 and 0.01, respectively). ii) Objective 2: Using the respective hazard ratios (HR) obtained during the multivariable prognostic analysis in the training set, HR-weighted adverse points were assigned: 3 points for high-risk DIPSS, 2 points for intermediate-2 risk DIPSS, and 1 point each for intermediate-1 risk DIPSS, unfavorable karyotype, platelets < 100 × 109/L or transfusion need. Accordingly, a refined DIPSS model (i.e. DIPSS-plus) was devised using the training set (Figure 1) and subsequently validated in the test set (Figure 2): low-risk (0 adverse points), intermediate-1 risk (1 adverse point), intermediate-2 risk (2-3 adverse points) and high-risk (4-6 adverse points). Considering the entire group of 793 study patients, the respective median survivals were 185, 78, 35 and 16 months (p<0.0001). ii) Objective 3: Multivariable analysis identified platelet count (p=0.0007) and karyotype (p=0.04) but not DIPSS or transfusion status as independent predictors of leukemia-free survival. We used these two variables to classify patients into a low (favorable karyotype and platelets ≥ 100 × 109/L) or high (unfavorable karyotype or platelets < 100 × 109/L) risk category for leukemic transformation; the respective 5- and 10-year risk of leukemic transformation were 6% and 12% vs. 18% and 31%, respectively (p<0.0001; HR 3.3, 95% CI 1.9–5.6). Conclusions: DIPSS-plus effectively incorporates prognostic information from karyotype, platelet count and transfusion status into the DIPSS prognostic model for PMF. Unfavorable karyotype or platelets <100 × 109/L is associated with a significantly higher risk of leukemic transformation in PMF. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 4122 Background: We have previously identified sole +9, 13q- or 20q- as “favorable” and sole +8 or complex karyotype as “unfavorable” cytogenetic abnormalities in primary myelofibrosis (PMF) (Blood 2010; 115: 496). The purpose of the current study, which includes more than twice the number of patients included in previous studies, was to identify additional prognostically-relevant cytogenetic abnormalities in PMF and refine cytogenetic risk categorization for overall and leukemia-free survival. Methods: Clinical and laboratory data were collected from consecutive patients with PMF seen at our institution and in whom cytogenetic information at or within 1 year of diagnosis was available. Diagnosis of PMF and acute myeloid leukemia were according to the World Health organization (WHO) criteria. Results: A total of 433 patients with PMF were included in the current study. Median age at diagnosis was 65 years. IPSS risk distributions were low in 12% of patients, intermediate-1 in 25%, intermediate-2 in 24% and high in 39%. JAK2V617F mutational frequency was 60%. Cytogenetic findings were normal in 275 (64%) patients. Among the 158 (36%) patients with abnormal karyotype, 109 (69% of abnormal cases) represented sole abnormalities, 23 (15%) two abnormalities and 26 (17%) three or more (i.e. complex) abnormalities. In an effort to identify cytogenetic categories of similar prognosis, each one of 12 operational cytogenetic categories was separately compared with both normal and complex karyotype. Accordingly, we were able to devise a two-tired cytogenetic risk stratification with highly significant differences in overall and leukemia-free survival (Figures 1 and 2): unfavorable (complex karyotype or sole or two abnormalities that include +8, -7/7q-, i(17q), inv(3), -5/5q-, 12p- or 11q23 rearrangement) and favorable (all other cytogenetic findings including normal karyotype). Median survivals of patients with favorable and unfavorable karyotype were 5.2 and 2.0 years, respectively (p<0.0001). The corresponding 5-year survival rates were 51% and 8% (HR 3.1, 95% CI 2.2–4.3; p<0.0001). Multivariable analysis confirmed the IPSS-independent prognostic value of cytogenetic risk categorization (p<0.0001; HR 2.1, 95% CI 1.5–3.1) and also identified thrombocytopenia (platelet count < 100 × 109/L) as another independent predictor of inferior survival (p<0.0001; HR 1.9; 95% CI 1.4–2.6). A similar multivariable analysis showed that cytogenetic risk profile (p=0.001; HR 4.1, 95% CI 1.7–9.6) and platelet count (p=0.04; HR 2.3, 95% CI 1.0–5.0), but not IPSS (p=0.27), predicted leukemia-free survival; the 5-year leukemic transformation rates for unfavorable and favorable karyotype were 46% and 7%, respectively (HR 5.5, 95% CI 2.5–12.0; p<0.0001). These results, in terms of both overall and leukemia-free survival analysis, did not change when patients receiving allo-SCT were censored at the time of their transplant. Among patients with favorable karyotype; the incidences of leukopenia and thrombocytopenia were highest in patients with sole 20q- (41% and 38%, respectively) and lowest in those with sole 13q- (0% and 0%, respectively). Conclusions: The current study provides the rationale and necessary details for incorporating cytogenetic findings and platelet count in future prognostic models for PMF. The study also revealed a highly significant association between sole 20q- and both leukopenia and thrombocytopenia, which suggests a 20q- haploinsufficient gene effect. Disclosures: No relevant conflicts of interest to declare.