ALBERT

Description: BACKGROUND: Symptom burden in essential thrombocythemia (ET) and polycythemia vera (PV) is severe even among individuals with low risk disease (Blood 2012. 12;123(24):3803-10). New therapies exist which alleviate the severe symptom burden and reduce splenomegaly in ET and PV patients (N Engl J Med 2015; 372:426-435). This analysis is the first to date to evaluate thresholds at which symptom-based treatment can be considered for ET and PV patients who are intolerant or resistant to hydroxyurea (HU). METHODS: Patient demographics, symptom burden, and disease traits were collected from ET and PV patients at a single time point during therapy. The MPN-10 total symptom score (TSS, JCO 2012;30(33)4098-103) was utilized to assess symptom burden. Symptom criteria models were determined as previously described among a population of MF patients (Scherber et. al. EHA 2016: a2250). Cutoffs were then evaluated in a cohort of ET and PV patients to assess for utility as a symptom model among this population. RESULTS: Demographics and symptom burden: 838 PV and 867 ET patients with previous hydroxyurea therapy were included in this analysis. Patients were of mean age (54.9 years ET, 64.0 years PV) and gender (69.2% female ET, 55.7% female). Mean disease duration was 6.0 years for ET and 7.3 years for PV.Among ET and PV patients, 15.0% and 24.2% had prior thrombosis respectively. In evaluating prognostic risk, ET patients tended to be low (45.5%) or intermediate risk (42.9%) with only a minority of patient meeting criteria forhigh risk disease (11.6%). Laboratory findings: ET patients had a mean platelet value of 598.7x 109/L(SD=283.4). Among PV patients, mean hematocrit was 45.8% (SD=8.1) and 42.6% of patients had a hematocrit of greater than 45%. White blood cell count was normal between the two groups (ET mean 8.3 x 109/L, PV mean 9.0 x 109/L). Symptoms: Mean worst symptom severity was 6.4 out of 10 (SD=2.7). Among ET patients, worst symptom was most frequently fatigue (32.7%, mean 5.0/10, SD=3.1, overall prevalence 88%) followed by night sweats (13.6%, mean 2.0/10, SD=3.0, overall prevalence 53%) and concentration difficulties (8.6%, mean 3.1/10, SD=3.0, overall prevalence 68%). For PV, worst individual symptom items were most frequently fatigue (29.2%, mean 5.2/10, SD=3.0, overall prevalence 91%), pruritus (14.1%, mean 3.2/10, SD=3.2, overall prevalence 69%), and night sweats (12.8%, mean 2.5/10, SD=3.0, overall prevalence 57%). Cutoff Scoring: 47.0% of ET patients fit criteria for TSSgreater than to equal to 20; 59.0%% had a single itemgreater than 5; and 45.7% had both a TSS greater than or equal to 20 and a single item greater than 5. Among PV participants, 54.5% had aTSS greater than to equal to 20; 66.1% had a single itemgreater than 5; and 51.5% had both a TSS greater than or equal to 20 and a single item greater than 5. Each scoring method was significantly associated with individual item scores (Table 1). Prognostic scoring was not significantly associated with any of the symptom cutoffs evaluated. Correlations: Among ET patients, a prior history of thrombosis was significantly associated with having a worst symptom item greater than 5 (p=0.043). ET patients with lower hemoglobin were significantly more likely to meet criteria for a MPN-10 score greater than or equal to 20 or to meet combined criteria for a MPN-10 greater than or equal to 20 and single worst item greater than 5 (for both p=0.01 or less). For PV, lower hematocrit levels were significantly associated with having an individual worst symptom score of greater than 5 (44.9% versus 46.7%, p=0.0376). CONCLUSION: Assessment of ET and PV symptoms, now measurable through standardized and practical instruments such as the MPN-10, is an integral part of determining therapeutic impact of newer therapies in both clinical practice and trial settings. In our modeling, patients with severe symptom burden profiles are well represented by utilizing cutoff criteria including aworst individual symptom item of greater than 5 out of 10, an MPN-10 score of greater than or equal to 20, or combined criteria of both cutoffs. These cutoffs can be considered when determiningwhich HU intolerant or resistant patients would most benefit fromsymptom orientedtreatment. Disclosures Kiladjian: AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding. Schouten:Novartis: Consultancy; Sanofi: Consultancy. Etienne:BMS: Speakers Bureau; ARIAD: Speakers Bureau; Pfizer: Speakers Bureau; novartis: Consultancy, Speakers Bureau. Harrison:Incyte Corporation: Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Radia:Pfizer: Honoraria; Novartis: Honoraria. Cervantes:AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mesa:Promedior: Research Funding; Celgene: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy.

Description: Introduction: Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) characterized by expansion of the granulocytic, erythrocytic, and megakaryocytic lineages in the bone marrow and peripheral blood, and in most cases, by the presence of a JAK2 mutation. Survival of patients with PV is decreased compared with age-matched controls, and this is mainly due to thromboembolic complications followed by progression to post-PV myelofibrosis and acute leukemia. While no curative treatment exists, cytoreductive treatment with hydroxyurea (HU) or ropeginterferon is approved in EU for first-line therapy, and ruxolitinib (RUX) is approved in EU and US for second-line therapy in patients with HU intolerance or resistance. The current futility analysis assesses the efficacy of ruxolitinib in newly-diagnosed PV treated within the Ruxo-BEAT trial. Methods: This clinical trial entitled "Ruxolitinib versus Best Available Therapy in patients with high-risk Polycythemia Vera or high-risk Essential Thrombocythemia" (Ruxo-BEAT; NCT02577926) is a multicenter, open-label, two-arm phase-IIb trial with a target population of 380 pts with PV and ET. Patients in first-line PV and in first and later lines ET are randomized in a 1:1 manner to receive either RUX or best available therapy (BAT). Crossover from BAT to RUX is possible in eligible patients after 6 months. Patients with PV in the RUX arm receive a starting dose of 10 mg bid and may increase their dose up to 20 mg bid. Primary endpoint is the rate of complete clinicohematologic response rate (CHR) at month 6 as defined by Barosi et al Blood 2009. Secondary endpoints include differences in the absence of phlebotomies, spleen size, patient-reported outcomes, and survival. This is a pre-specified futility analysis of RUX in the PV arm, after 50 PV patients had been enrolled. Of the 50 patients, 28 patients with newly-diagnosed PV were randomized into the RUX arm and were analyzed (a maximum of 6 weeks of HU, anagrelide, or interferon therapy was allowed). The PV arm would have to be closed if no favorable trend were observed for RUX for any of the following variables: (1) improvement (decrease) in the hematocrit level during 6 months of treatment, (2) improvement (decrease) of the JAK2V617F allele burden during 6 months of treatment, or (3) improvement of one of the following three symptom variables assessed by physician´s judgement or via MPN Symptom Assessment Form (MPN-SAF) during 6 months of treatment: pruritus, night sweats, or bone pain. Differences between screening (Hct) or baseline (all other variables) and end of month 6 (all variables) were calculated using Fisher´s exact test (for physician-assessed pruritus and night sweats) or the Wilcoxon matched-pairs signed rank test (all other variables). Results: 28 patients received RUX for at least 6 months. After 6 months, the mean hematocrit level decreased from 45.9+/-5.6% to 41.0+/-5.0% (mean+/-SD) (p=0.0003). The number of phlebotomies calculated per year decreased from 4.2+/-3.9% to 0.96+/-2.1 (p=0.0009). Mean JAK2V617F allele burden decreased from 50.2+/28.4% to 44.0+/-28.5% (p=0.0039). The percentage of patients, as assessed by the physician, with pruritus or night sweats decreased from 41% to 26% (trending with p=0.13), and from 30% to 11% (p=0.02), respectively. The points reported by patients themselves on the MPN-SAF survey for pruritus decreased from 2.7+/-3.0 to 1.3+/-1.5 (p=0.0095) and there was a strong trend for reduction of night sweat points (from 3.1+/-3.6 to 1.6+/-2.4; p=0.0579), while the points for bone pain remained unaltered (2.0+/-2.8 to 1.4+/-2.2; p=0.215). Conclusion: Treatment with ruxolitinib in first line PV is efficient regarding the above-mentioned endpoints. Recruitment of our trial will be ongoing. In order not to weaken the study´s statistical power, comparison of both arms was not performed. Disclosures Koschmieder: Ariad: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers-Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis Foundation: Research Funding; CTI: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AOP Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Isfort:Mundipharma: Other: Travel reimbursement; Amgen: Other: Travel reimbursement; Hexal: Other: Travel reimbursement; BMS: Honoraria; Ariad: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Other: Travel reimbursement; Novartis: Consultancy, Honoraria, Other: Travel reimbursement; Roche: Other: Travel reimbursement; Alexion: Other: Travel reimbursement. Schafhausen:Novartis: Consultancy, Honoraria; Incyte: Consultancy, Equity Ownership, Honoraria. Griesshammer:Novartis: Consultancy, Honoraria, Speakers Bureau. Platzbecker:Abbvie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Döhner:CTI Biopharma: Consultancy, Honoraria; Daiichi: Honoraria; Jazz: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Janssen: Honoraria. Jost:Abbvie: Consultancy, Patents & Royalties: Royalty payments for the drug compound ABT-199, Research Funding; Bohringer: Consultancy, Research Funding; BMS: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Celgene: Other: Travel Support; Novartis: Research Funding. von Bubnoff:Novartis: Research Funding. Stegelmann:Novartis: Consultancy, Honoraria; Incyte: Consultancy, Honoraria. Crysandt:Amgem: Other: travel grant; celgene: Other: travel grant; Pfizer: Other: travel grant; Gilead: Other: travel grant; Incyte: Membership on an entity's Board of Directors or advisory committees. Gezer:AMGEM: Membership on an entity's Board of Directors or advisory committees. Brümmendorf:Merck: Consultancy; Pfizer: Consultancy, Research Funding; University Hospital of the RWTH Aachen: Employment; Janssen: Consultancy; Ariad: Consultancy; Novartis: Consultancy, Research Funding. OffLabel Disclosure: Ruxolitinib as first-line treatment in newly-diagnosed PV

Description: Abstract 3287 Poster Board III-1 Blast crisis (BC) in CML in the imatinib era is a rare event with 1–3% of newly diagnosed BC patients per year in the IRIS study, but prognosis, once BC has occurred, remains poor. Historical and recent studies with imatinib and second generation tyrosine kinase inhibitors (TKI) reported a median survival time of 7–10 months and two year survival probabilities of

Description: Abstract 783FN2 Introduction: The advent of second generation tyrosine kinase inhibitors (TKI) in the front line treatment setting of chronic myeloid leukemia (CML) has tightened the evaluation of imatinib response. Early assessment of response markers might identify slow responders harboring a BCR-ABL positive clone with an inferior susceptibility to tyrosine kinase inhibition. This group of patients could benefit from an early dose escalation or a change of treatment to a second generation TKI thus avoiding the risk of disease progression. Therefore we sought to evaluate the impact of molecular and cytogenetic response levels after 3 months of imatinib treatment on the further course of disease. Patients and methods: A total of 1,340 patients (median age 52 years, range 16–88, 40% female) were included into the randomized German CML study IV and treated with an imatinib based therapy consisting of imatinib 400 mg/d (n=381), imatinib 800 mg/d (n=399) and combinations of standard dose imatinib with interferon alpha (n=402) and low-dose cytarabine (n=158). Median follow-up was 4.7 years (range 0–9). Molecular response after 3 months was assessed in 743 patients, cytogenetic response in 498 patients. The BCR-ABL expression was determined by quantitative RT-PCR and standardized according to the international scale (BCR-ABL IS). Only patients expressing typical BCR-ABL transcripts (b2a2, b3a2, b2a2 and b3a2) were considered. Cytogenetic response was determined by conventional metaphase analysis. Disease progression was defined by the incidence of accelerated phase, blastic phase or death from any reason. A landmark analysis was performed for progression free survival (PFS) and overall survival (OS). Results: Disease progression was observed in 149 patients (11.1%), 127 patients died (9.5%). After 3 months of treatment the median BCR-ABL IS was 2.6% (0-100), the median proportion of Philadelphia chromosome positive metaphases (Ph+) was 8% (0-100). The BCR-ABL landmarks of 1% and 10% after 3 months of imatinib both proved to discriminate significantly for PFS and OS: BCR-ABL IS 65% (n=84), p=0.004 for PFS and p=0.011 for OS. A 3 group stratification did not reach statistical significance. Conclusions: The achievement of molecular and cytogenetic response landmarks after 3 months of imatinib treatment is predictive for long term progression free and overall survival. At 3 months a BCR-ABL IS of 10% or more is associated with a 5-year overall survival of 87% suggesting an early change of treatment, whereas a BCR-ABL IS of 1% or less indicates a favorable 5-year overall survival of 97%. Disclosures: Schnittger: Münchner Leukämie Labor: Equity Ownership. Haferlach:Münchner Leukämie Labor: Equity Ownership. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.

Description: Abstract 862 Rapid relapse after discontinuation of imatinib, the need for indefinite therapy and residual disease in most patients are the major challenges in management of CML. Combinations of imatinib with IFN simultaneously, or consecutively preceding imatinib, or with araC may improve treatment outcome. The German CML Study Group therefore designed a randomized trial to compare standard imatinib vs. imatinib + interferon alpha (IFN) vs. imatinib + low dose araC vs. imatinib after IFN failure (for low- and intermediate-risk patients, high risk patients received imatinib 800 mg instead). The current evaluation represents the prefinal results of the pilot phase of the trial. Inclusion criteria were newly diagnosed BCR/ABL positive CML in chronic phase (CP). Primary aims are: prolongation of survival (overall, OS, and progression free, PFS), determination of rates of hematologic, cytogenetic and molecular remissions, adverse events (AE) and role of allografting. By the end of 2005, 670 patients were randomized, 13 had to be excluded (no CML (n=3), pregnancy, no CP (n=1 each), imatinib 800 mg (n=8)). Analysis was according to intention to treat. 657 patients were evaluable (174 with imatinib 400 mg, 196 with imatinib+IFN, 158 with imatinib+araC and 129 with imatinib after IFN-failure). 656 patients were evaluable for hematologic, 611 for cytogenetic, and 618 for molecular responses. Patient characteristics of treatment arms were similar for age (median 53 years), sex (40% female), median values for Hb (12.6 g/dl), WBC (66.2/μl), platelets (383/μl) and for Euro risk score (low 35%, intermediate 54%, high 10%). The median dose of imatinib was 400mg/die in all arms, of araC 10 mg per treatment day and of IFN 4.2 Mio I.U./die in the imatinib after IFN arm and 1.8 Mio I.U./die in the imatinib+IFN arm. Median observation time was 57.3 months. 55 patients died, 73 patients were transplanted in 1st CP, 81 patients progressed, 59 patients were switched to second generation TKIs. After 3 years 126 patients (72%) of the imatinib 400mg arm still received the initial therapy as well as 60 patients (30%) of the imatinib+IFN arm and 53 patients (34%) of the imatinib+araC arm. 9 patients (7%) of the imatinib after IFN arm are still on IFN. 5-year OS of all patients is 91%. 5-year PFS of all patients (no death, patient still in first chronic phase) is 87%. 5-year-OS and PFS according to treatment arm are shown in the Table. At 5 years, the cumulative incidences of achieving complete cytogenetic remission or major molecular remission (MMR) as determined by competing risks (death, progression) are not different (Table). Type and severity of adverse events (AE) over a 5-years period did not differ from those reported previously (Table). Hematologic AEs grade III/IV were similar in all therapy arms except leukopenia grade III/IV, which was more frequently observed in the imatinib after IFN arm (14%). Non hematologic AEs were mainly fluid retention, neurological and gastrointestinal symptoms and fatigue. Neurologic symptoms and fatigue were more often reported for the therapy arms with IFN. Imatinib 400mgImatinib+IFNImatinib+AraCImatinib after IFN5-Year Survival and Response RatesOS87%93%92%92% PFS84%91%88%84% CCR92%92 %89%83% MMR83%78%80%70% Adverse Events, WHO Grade III/IVAnemia7%1%3%3% Leukopenia4%5%2%14% Thrombocytopenia5%6%6%6% WHO Grade I-IVEdema15%13%5%0% Neurological5%15%5%22% Gastrointestinal17%27%21%15% Fatigue8%13%9%23% This analysis shows excellent survival and durable response rates in all arms. Currently, survival in all treatment arms is equal to, or better than in IRIS. To verify possible differences in survival, e.g. imatinib 400 mg vs. imatinib + IFN, longer observation is planned. Although cytogenetic and molecular responses in the imatinib after IFN failure arm at 5 years are inferior to that in the other treatment arms, the question of whether the consecutive therapy with IFN first and imatinib after IFN-failure provides a survival advantage requires long term follow-up. Imatinib in combination with, or after IFN, or with low dose araC are feasible and safe treatment modalities. We expect that the study will optimize and improve therapy outcome in CML. Disclosures: German CML Study Group: Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; German Competence Net : Research Funding; European LeukemiaNet: Research Funding; Roche: Research Funding; Essex: Research Funding.

Description: Abstract 357 Treatment of CML with imatinib of 400 mg can be unsatisfactory. Treatment optimization is warranted. The German CML-Study group has therefore conducted a randomized study comparing imatinib 800 mg vs 400 mg vs 400 mg + IFN. A significantly faster achievement of MMR at 12 months has been observed with imatinib 800 mg in a tolerability adapted manner and MMR by 12 months has been found to translate into better overall survival. Since stable CMR has been associated with durable off-treatment remissions we sought to analyse the impact of tolerability-adapted imatinib 800 mg on CMR and survival. Standardized determinations of molecular response and evaluation of its impact on outcome are goals of CML-Study IV. CMR4 is defined as a BCR-ABL/ABL ratio of

Description: Recently, the identification of the gain of function mutation JAK2V617F delivered important insights into the pathogenesis of BCR/ABL negative myeloproliferative disorders (MPD). JAK2V617F is detectable in more than 90% of polycythemia vera (PV) patients (pts) and in approximately 50% of pts with essential thrombocythemia (ET) or primary myelofibrosis (PMF), representing the genetic hallmark of BCR/ABL negative disease. However, about 30% of MPD pts lack the JAK2V617F mutation and previous studies on ET and PV demonstrated that clonality exceeds the percentage of V617F mutated cells. These findings suggest that additional genetic alterations are involved in the pathogenesis of MPD, in both JAK2 mutated and unmutated pts. To identify novel genetic aberrations and to determine whether specific lesions are associated with disease phenotype, genomic DNA from granulocytes of 72 MPD pts classified according to the WHO criteria was analyzed using high-resolution, genome-wide microarray techniques [disease, number analyzed, JAK2 mutation status: PMF, n=14, 9/14; post-ET MF, n=5, 3/5; post-PV MF, n=5, 5/5; PV, n=37, 37/37; ET, n=11, 11/11]. In a first approach, all cases were investigated by comparative genomic hybridization to 8k arrays (array CGH) with an average probe spacing of less than 1 Mb. While no genomic imbalances were found in ET, 11% of PV pts (n=4) exhibited large (〉10 Mb) deletions on 20q (n=2) or gains on 9p and 1q (n=1, each). In addition, small (

Description: Abstract 4111 Background: Although an increasing number of gene mutations provide new insights into the pathogenesis of myeloproliferative neoplasms (MPN), the biological origins of myelofibrosis (MF) remain poorly understood. Most likely, to date unknown genetic lesions contribute to disease phenotype and influence clinical outcome. Recently, mutations of EZH2 (enhancer of zeste 2) in 7q36.1 encoding the catalytic subunit of the histone methyltransferase PRC2 (polycomb repressive complex 2) have been identified in myeloid malignancies including MF. Functional studies indicate that EZH2 plays an important role in stem cell renewal by epigenetic repression of target genes. Mutations of EZH2 are considered to result in loss of tumor suppressor activity. These data indicate that EZH2 mutations may be important in the pathogenesis of myeloid malignancies such as MF. Aim: To explore the frequency of EZH2 mutations in a cohort of genetically and clinically well-characterized MPN patients with MF and acute myeloid leukemia (AML) secondary to MPN with 7q alteration. Methods: All coding exons of EZH2 (2-20) were analyzed for mutations in 89 MPN patients using DNA sequencing: primary MF (PMF), n=62; secondary MF (SMF), n=21; AML secondary to MPN (sAML) with 7q alteration, n=6. Data on the mutation status of IDH1/IDH2 (Exon 4), JAK2 (V617F), and MPL (W515L) were available in all cases. In addition, all cases were analyzed on Affymetrix 250K (n=66) or 6.0 (n=23) SNP-arrays allowing for genome-wide screening of copy-number alterations (CNA) and uniparental disomies (UPD) at high resolution. Results: In total, 10 EZH2 mutations were identified in 8 patients (PMF, n=6; SMF, n=1; sAML, n=1) resulting in an overall mutation frequency of 9% (8/89); two PMF cases showed two EZH2 mutations each. The mutation frequency was not significantly different between PMF (6/62, 10%) and SMF (1/21, 5%) patients (p=0.67). EZH2 alterations identified in our study consisted of 8 missense mutations in exons 3, 9, 14–17, and 19, one insertion in exon 17 (c.1957_1958insT), and one deletion in exon 10 (c.1160_1161delAA). Eight of the 10 mutations were heterozygous; in one PMF and one post-PMF AML patient homozygous missense mutations were detected in exon 15 (c.G1720C) and 17 (c.A1947C), respectively; only the mutation in the latter patient was associated with UPD in 7q. None of the remaining 9 patients (PMF, n=4; sAML, n=5) with UPD (n=3) or deletion (n=6) in 7q had EZH2 mutations. EHZ2 mutations occurred in JAK2 mutated and unmutated patients (n=4, each) and none of the cases harbored additional mutations in IDH1/IDH2 or MPL. Furthermore, there was no correlation of the EZH2 mutation status with distinct CNA and/or UPD identified by SNP-arrays: in 5/8 patients, CNA such as trisomy 8, gains in 3q (29 Mb) and 6p (28 Mb), as well as loss in 13q (63 Mb), 18p (13.5 Mb), and 20q (22 Mb) were found. Four patients had large UPD (28-101 Mb) in 7q (n=1), 9p (n=2), or 11q (n=1). In total, only 2 of 8 cases lacked genomic aberrations; with regard to clinical characteristics, EZH2 mutations were associated with marked splenomegaly (20-28 cm) and leukocytosis (median white blood cell counts: 13.8 × 109/L vs. 7.3 × 109/L; p

Description: Abstract 3411 Background: Dose of therapy and time to response may be different in the elderly as compared to younger patients with CML. This has been reported previously for interferon α (Berger et al., Leukemia 2003). For imatinib, contradictory results have been presented (Rosti et al. Haematologica 2007, Guliotta et al. Blood 2009). Aims: An analysis comparing dose-response relationship in patients more or less than 65 years (y) of age is warranted. Methods: We analysed the German CML-Study IV, a randomized 5-arm trial to optimize imatinib therapy by combination, dose escalation and transplantation. Patients older and younger than 65y randomized to imatinib 400 mg (IM400) or 800 mg (IM800) were compared with regard to time to hematologic, cytogenetic and molecular remissions, imatinib dose, adverse events (AEs) and overall survival (OS). Results: From July 2002 to April 2009, 1311 patients with Ph+ CML in chronic phase were randomized, 623 patients were evaluable, 311 patients for treatment with IM400 and 312 for IM800. 84 (27%) and 66 (21%), respectively, were older than 65 years. All patients were evaluable for hematologic, 578 (140 〉65y and 438

Description: Abstract 4715 Non-Langerhans-cell-histiocytosis (Non-LCH) represents a rare disorder with a broad spectrum of clinical features and various outcome. We here report on a 61 years old man with Non-LCH with severe skin and bone marrow involvement. At the time of diagnosis in 2006, the patient presented with up to four centimeter large cutaneous papules involving face, stem, hands and feet. Since two years, the patient also developed an increasing tricytopenia due to an extensive bone marrow infiltration of histiocytes (80%). Since diagnosis, the patient received a large number of various therapies including daily glucocorticoids at different dosages (continuously since diagnosis), low-dose methotrexate (10-40mg s.c. per week; from may to september 2007), experimental treatment with lenalidomide (5-10mg per day; from february to june 2008), continous oral trofosfamide (100mg per day; from july to august 2008), cladribine monotherapy (2,1mg/m2 d1-5; 4 cycles; from December 2008 to march 2009) and the combination of cladribine (2.1mg/m2 d1-5) and cytarabine (40 mg s.c. d1-7; 3 cycles; from january to march 2010). The patient did not respond to any of these therapies. Due to the persistent distinctive clinical symptoms (massive skin involvement, tricytopenia), we started in July 2010 an experimental therapy with sorafenib at a dosage of 200mg per day for four days, followed by 400mg per day for another four days, and subsequently increased the dosage to 800mg daily. After four weeks, the marked skin papules flattened to skin level at all preferential sites. Small skin ulcers at the cheeks healed up. In parallel, there was a significant improvement of hematopoiesis since start of therapy with haemoglobin levels raising from 8,6g/dl to 12,2g/dl and normalization of leukocyte count (from 3.1/nl to 5.2/nl). Bone marrow rebiopsy is intended after three month of therapy, data on the actual grade of infiltration will be presented at the meeting. Based on the impressive clinical improvement under sorafenib, we analyzed selected target genes of the multityrosine kinase inhibitor: mutation screening was performed on the FLT3 (internal tandem duplication, point mutations of the tyrosine kinase domain) and KIT genes (exon 8 and exon 17) as well as for the recently described BRAF V600E mutation found in a significant number of patients with LCH (G. Badalian-Very et al., Blood prepublished online June 2, 2010; DOI 10.1182/blood-2010-04-279083). However, in none of these genes, mutations were found and further molecular analysis of the patient's bone marrow is currently under investigation. To our knowledge, this is the first report on the efficacy of sorafenib in a case of histiocytosis. However, the underlying genetic mechanisms of Non-LCH still have to be elucidated. Disclosures: Off Label Use: Sorafenib is approved for unresectable hepatocellular carcinoma and advanced renal cancer. We present an off-label use of sorafenib in a case of a severe orphan disease refractory to all standard therapies. Zenz:Roche: Honoraria; Boehringer: Honoraria; GSK: Honoraria; Celgene: Honoraria.