Abstract: Background: Standard therapy of acute promyelocytic leukemia has long relied on the combination of All-trans-retinoic acid (ATRA) and chemotherapy. The introduction of arsenic trioxide (ATO) in APL treatment has allowed achievement of similarly high remission and survival rates coupled with significantly reduced myelosuppression. Recent results of the APL0406 trial by the GIMEMA-AMLSG-SAL study groups showed that the combination of ATRA and arsenic trioxide (ATO) is superior to standard ATRA and chemotherapy (CHT) in front-line therapy of low/intermediate risk acute promyelocytic leukemia (APL). The implications of these results for the clinical practice of APL patients in Germany have been uncertain given the fact that ATO is not formally licensed for front-line therapy of APL. Aim:In order to provide evidence and a reflection of the clinical reality of APL patient care in Germany an intergroup APL registry (National acute promyelocytic leukemia (APL) observational study, NAPOLEON) was recently initiated by several AML study groups. Methods:Eligible patients are adults at least 18 years of age with newly diagnosed or relapsed APL not beyond the first year of diagnosis. Here we report the first analysis on the series of patients prospectively enrolled into this registry. The study was conducted in accordance with the Declaration of Helsinki, received IRB approval by all participating centers and was registered at ClinicalTrials.gov (NCT02192619). Results: As of August 1st 2016, 88 patients have been included into the study with a median age of 57 years (range 22-87). All had newly diagnosed APL (100%) with 66% (n=58) being of low/intermediate risk according to the Sanz score. Out of those patients 76% (n=44) received an ATO-ATRA based induction regimen followed by a median of 4 courses of consolidation (according to the APL 0406 study).Of 41 patients evaluable for response to induction, 40/41 (98%) patients achieved complete remission (CR) with the ATRA-ATO arms. Early death rate within 30 days of therapy was 2% (1/44). After a median follow-up of 12 months, the event-free survival, cumulative incidence of relapse and overall survival at 12 months for these patients were 97%, 0% and 97%, respectively. Therapy was well tolerated and no new safety signals have been obtained. Conclusion:These real life data from a prospective German registry provide further evidence for the safety and sustained anti-leukemic efficacy of ATRA-ATO in low/intermediate risk APL. These results further support ATRA-ATO as the new standard of care in this clinical setting. Table Demographic, clinical and laboratory characteristics of the eligible patients. Table. Demographic, clinical and laboratory characteristics of the eligible patients. Disclosures Platzbecker: TEVA: Honoraria, Research Funding. Greiner:BMS: Research Funding. Thiede:AgenDix: Employment, Other: Ownership. Hochhaus:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding.

Abstract: Background Chronic myeloid leukemia (CML)-study IV was designed to explore whether treatment with imatinib (IM) at 400mg/day (n=400) could be optimized by doubling the dose (n=420), adding IFN (n=430) or cytarabine (n=158) or using IM after IFN-failure (n=128). Methods From July 2002 to March 2012, 1551 newly diagnosed patients in chronic phase were randomized into a 5-arm study. The study was powered to detect a survival difference of 5% at 5 years. The impact of patients' and disease factors on survival was prospectively analyzed. At the time of evaluation, at least 62% of patients still received imatinib, 26.2% were switched to 2nd generation tyrosine kinase inhibitors. Results After a median observation time of 9.5 years, 10-year overall survival was 82%, 10-year progression-free survival 80% and 10-year relative survival 92%. In spite of a faster response with IM800mg, the survival difference between IM400mg and IM800mg was only 3% at 5 years. In a multivariate analysis, the influence on survival of risk-group, major-route chromosomal aberrations, comorbidities, smoking and treatment center (academic vs. other) was significant in contrast to any form of initial treatment optimization. Patients that reached the response milestones 3, 6 and 12 months, had a significant survival advantage of about 6% after 10 years regardless of therapy. The progression probability to blast crisis was 5.8%. Blast crisis was proceeded by high-risk additional chromosomal aberrations. Conclusions For responders, monotherapy with IM400mg provides a close to normal life expectancy independent of the time to response. Survival is more determined by patients' and disease factors than by initial treatment selection. Although improvements are also needed for refractory disease and blast crisis, more life-time can currently be gained by carefully addressing non-CML determinants of survival. Disclosures Hehlmann: Novartis: Research Funding; BMS: Consultancy. Saussele: Pfizer: Honoraria; Incyte: Honoraria; Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Pfirrmann: BMS: Honoraria; Novartis: Honoraria. Krause: Novartis: Honoraria. Baerlocher: Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria. Bruemmendorf: Novartis: Research Funding. Müller: Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Ariad: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Jeromin: MLL Munich Leukemia Laboratory: Employment. Hänel: Roche: Honoraria; Novartis: Honoraria. Burchert: BMS: Honoraria. Waller: Mylan: Consultancy, Honoraria. Mayer: Eisai: Research Funding; Novartis: Research Funding. Link: Novartis: Honoraria. Scheid: Novartis: Honoraria. Schafhausen: Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria; Ariad: Honoraria. Hochhaus: Incyte: Research Funding; MSD: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; BMS: Research Funding; ARIAD: Research Funding.

Abstract: Introduction MDR1 gene expression has recently been reported to be associated with clinical outcome in imatinib-resistant patients with chronic myeloid leukemia (CML) on second-line nilotinib treatment (Agrawal et al., Leukemia 2014). High MDR1 expression was predictive for achieving deeper cytogenetic and molecular responses as well as duration of chronic phase. We thus prospectively evaluated the value of MDR1 expression analysis in the first-line situation within a large European, multicenter trial of CML patients under treatment with nilotinib. Methods 305 patients enrolled on the ENEST1st study (Evaluating Nilotinib Efficacy and Safety in clinical Trials as First-Line Treatment, NCT01061177) consented to participate in this substudy. Of these, 225 patients were evaluable due to sample availability and presence of typical e14a2 and/or e13a2 BCR-ABL1 transcripts. The median age was 52 (range 18-83), 39% were female. Prior to therapy, the expression of MDR1, BCR-ABL1, and GUSB were determined using a serial dilution of a plasmid constructs harboring MDR1 and GUSB and BCR-ABL1 and GUSB sequences. Ratios MDR1/GUSB and BCR-ABL1/GUSB were calculated. ROC curves were established using initial MDR1 and BCR-ABL1 expression levels aiming to achieve the primary endpoint of MR4 (defined as BCR-ABL1 ≤ 0.01% on the International Scale [BCR-ABL1IS] or undetectable BCR-ABL1 in cDNA with ≥ 10,000 ABL1 transcripts) at 18 months or to achieve a MMR (≤ 0.1% BCR-ABL1IS) at 9 months. Mann-Whitney tests have been applied using a significance level of 0.05. Results At 9 months, 161 patients (72%) achieved MMR and at 18 months 111 patients (49%) a MR4. The median ratio MDR1/GUSB among all evaluable patients was 11.4% (range, 0.6-318.1), the median ratio BCR-ABL1/GUSB was 22.2% (range 0.09-198.7). Initial BCR-ABL1/GUSB levels did not predict MMR or MR4 at 9 or 18 months. However, initial ratios MDR1/GUSB were predictive for the achievement of MMR at 9 months (best cut-off 3.8%, sensitivity 88.8%, specificity 26.6%, AUC 0.598, p=0.022) and for reaching MR4 at 18 months (best cut-off 7.90%, sensitivity 72.1%, specificity 51.8%, AUC 0.624, p=0.001). Conclusions High MDR1 expression levels in newly diagnosed CML patients appear to be associated with deeper molecular responses within the first 18 months of nilotinib treatment. These data merit further exploration and if validated would justify the investigation of frontline CML therapy guided by baseline MDR1 expression levels. Disclosures Dietz: Novartis: Research Funding. Hanfstein:Bristol-Myers Squibb: Honoraria; Novartis: Research Funding. Rousselot:Novartis: Research Funding. Lange:Novartis: Consultancy, Honoraria, Research Funding. Maier:Novartis: Research Funding. Foroni:Novartis: Research Funding. Gerrard:Novartis: Research Funding. Talmaci:Novartis: Research Funding. Janssen:Novartis: Research Funding. Frank:Novartis: Employment. Saussele:Pfizer: Honoraria, Travel, Travel Other; Bristol-Myers Squibb: Honoraria, Research Funding, Travel, Travel Other; Novartis: Honoraria, Research Funding, Travel Other. Giles:Novartis: Honoraria, Research Funding. Hochhaus:Novartis: Research Funding. Müller:Novartis: Honoraria, Research Funding.

Abstract: Digital PCR (dPCR) generates an absolute read out that is largely tolerant to variations in PCR efficiency, reducing the requirement for standardisation like the conversion of the BCR-ABL/ABL ratio to international scale (IS). The aim of this study was to compare the results of dPCR to qPCR in blinded samples from two independent laboratories with respect to the observed rates of molecular response (MR) in CML patients (pts) having undergone 18 months of nilotinib treatment in the ENEST1st trial. A total of 230 cDNA samples from CML pts treated within the ENEST1st trial with e13 or e14/a2 BCR-ABL fusion genes were analysed in Leipzig (L, n=75) or Mannheim (M, n=155) with qPCR between 2012 and 2013. BCR-ABL levels were determined relative to those of ABL and standardization was achieved using plasmid DNA. Both labs are accredited by the European Treatment Outcome Study (EUTOS) collaboration. The cDNA samples were blinded for the qPCR results and re-analysed in L with a duplex dPCR using a QX200 Droplet Digital PCR System (BIO-RAD). In line with the manufacturer's recommendations, samples yielding a minimum of 3 positive droplets in duplicates from the 12-19.000 routinely analysed were scored as positive (+). Depth of MR was scored using the EUTOS definitions used in the ENEST1st trial. For the whole cohort, the median copy number (CN) of BCR-ABL and ABL was 12 and 59350 by dPCR and 10 and 53537 by qPCR, respectively. Both methods detected similar numbers of BCR- ABL+ samples (dPCR 186, qPCR 189) with a median % BCR-ABL 0.022 by dPCR compared 0.013 by qPCR after conversion to IS. 90% of the BCR-ABL+ samples with dPCR were within an deviation of 4.06 -fold (median 1.22 fold) from qPCR for BCR-ABL, 1.77 fold (median 1.06 fold) for ABL and 6.43 fold (median 1.72 fold) for %BCR-ABLIS. Samples from L showed median CN with dPCR and qPCR for BCR-ABL (9 and 10) and ABL (29670 and 30734) with a correlation R2 = 0.95 and 0.84. The median % BCR-ABL was 0.02% by dPCR and 0.03% before and 0.01% after conversion to IS with qPCR. 90% of the BCR-ABL+ samples by dPCR were within a range of 2.9 -fold deviation (median 0.66 fold) from qPCR for BCR-ABL, 1.9 fold (median 0.91 fold) for ABL, 2.6 fold (median 0.74 fold) for %BCR-ABL and 7.5 fold (median 1.96 fold) for %BCR-ABLIS. Samples from M had higher median CN for BCR-ABL and ABL (16 and 80000) by dPCR compared to qPCR (10 and 66570). Correlation was better for BCR-ABL compared to ABL with R2=0.95 and R2 = 0.74. The median % BCR-ABL was 0.022 by dPCR compared to 0.017 and 0.015 with qPCR after conversion to IS. 90% of the BCR-ABL positive samples with dPCR were within a deviation of 4.7 -fold (median 1.6 fold) from qPCR for BCR-ABL, 1.7 fold (median 1.1 fold) for ABL, 4.9 fold (median 1.5 fold) for %BCR-ABL and 5.6 fold (median 1.4 fold) for %BCR-ABLIS. The cumulative rates of MR3, MR4 and MR4.5 or better @ 18 months of treatment in the ENEST1st trial were 83, 43 and 29% with qPCR. The distribution in MR classes was significantly different between dPCR and qPCR (p 〈 0.001). MR scoring by dPCR resulted in decreased cumulative rates of MR3 (-6%), MR4 (-10%) and MR4.5 or better (-11%). Significantly fewer pts achieved 〉 =MR4 when analysed by dPCR compared to qPCR (n=77 vs. 100, p 〈 0.05). Of the 91, 33, 44 and 23 samples scored MR3, MR4, MR4.5 or MR5 with qPCR, 71 (37%) were one (n=49), two (n=21) or three (n=1) MR classes higher with dPCR. In contrast, only 13% were scored one (n=20) or more (n=5) MR classes deeper, most likely as a result of the cut-off of 3 positive droplets. 51% of the samples were concordant (Table 1). Comparison of samples for which MR was deeper by dPCR against those for which MR was worse by dPCR than by qPCR showed no difference in ABL levels (p=0.6). Conclusions: dPCR tends to read out higher levels of BCR-ABL/ABL than standard qPCR, resulting in the placement of pts in worse MR classes. This effect does not appear to be associated with the amount or quality of material and was observed in two independent pt cohorts. Therefore, dPCR should not be used without careful evaluation and comparison to RT-qPCR. Table 1. Depth of MR according to method of quantification and lab dPCR (n) qPCR 〉 MR3 (M/L) MR3 (M/L) MR4 (M/L) MR4.5 (M/L) MR5 (M/L) n (M/L) 〉 MR3 37 (26/11) 1 (0/1) 1 (1/0) 0 0 39 (27/12) MR3 16 (7/9) 68 (48/20) 6 (4/2) 0 1 (1/0) 91 (60/31) qPCR (n) MR4 0 15 (10/5) 10 (6/4) 5 (3/2) 3 (3/0) 33 (22/11) MR4.5 0 15 (7/8) 12 (7/5) 9 (4/5) 8 (7/1) 44 (25/19) MR5 0 1 (1/0) 6 (5/1) 6 (6/0) 10 (9/1) 23 (21/2) dPCR n (M/L) 53 (33/20) 100 (66/34) 35 (23/12) 20 (13/7) 22 (20/2) 230 Disclosures Franke: Novartis: Other: Travel Costs; BMS: Honoraria; MSD: Other: Travel Costs. Frank:Novartis: Employment. Giles:Novartis: Consultancy, Honoraria, Research Funding. Hochhaus:ARIAD: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Müller:Novartis: Honoraria, Other: CONSULTING OR ADVISORY ROLE, Research Funding; BMS: Honoraria, Other: Consulting or Advisory Role, Research Funding; ARIAD Pharmaceuticals Inc.: Honoraria, Other: Consulting & Advisory Role, Research Funding. Niederwieser:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Lange:Novartis: Research Funding.

Abstract: Introduction: Mutations (muts) in JAK2, MPL, and CALR are genetic hallmarks in myeloproliferative neoplasms such as myelofibrosis (MF). Prognostication in MF is predominantly based on clinical parameters according to the Dynamic International Prognostic Scoring System (DIPSS). However, gene mutations become increasingly important allowing for a more precised assessment of prognosis. For instance, CALR mutated MF is associated with favorable prognosis, while mutations in distinct high molecular-risk (HMR) genes are considered adverse. Our multicenter phase-Ib/II MPNSG-0212 trial (NCT01644110) investigating ruxolitinib plus pomalidomide in a total cohort of 92 patients with advanced MF and anemia provides an ideal basis for investigating the genomic landscape and molecular risk in a well-defined study population. Aims & Methods: To assess the genomic landscape in MF patients treated within the MPNSG-0212 trial and to correlate the results with clinical parameters and overall survival (OS). So far, targeted next generation sequencing (NGS) of 269 candidate genes was performed in peripheral blood or bone marrow from 81/92 patients using libraries prepared with SureSelectXT HS (Agilent, Santa Clara, USA). NGS was carried out on a NextSeq550 (Illumina, San Diego, USA). Results: At study entry, median age of the 81 patients was 71 years (range 52-86), median Hb 8.6 g/dL (range 5.4-11.7 g/dl); 30% of patients were RBC transfusion-dependent; 67% had primary MF (PMF) and 33% secondary MF (SMF), respectively. According to DIPSS, the vast majority of the patients were categorized as intermediate-2 (63%) or high-risk (26%) MF; 11% were low- and intermediate-1 risk patients. Overall, 315 muts were identified in 80/81 (99%) patients with a median of 3 muts/patient (range 0-9). Recurrent muts (≥5%) were identified in JAK2 (60%), ASXL1 (30%), SRSF2 (21%), CALR (20%; type-1: 75% [n=12], type-2 and non-type-1/2: 12.5% [n=2] each), MPL (19%), SF3B1 (19%), TET2 (16%), U2AF1 (15%), CBL and EZH2 (10% each), IDH2 and DNMT3A (7% each), PHF6, ZRSR2, and CUX1 (5% each). The majority of the patients (95%) was characterized by the presence of a driver mut in JAK2, CALR, or MPL; 4/81 patients (5%) were triple negative (Figure 1). JAK2mut was associated with TET2mut (p=.047), whereas muts in CALR and TET2 were mutually exclusive (p=.05). CALRmut patients had less co-muts than patients with JAK2/MPL muts (mean 2.5 vs. 4.1, p=.007) and were mutually exclusive with muts in the spliceosome regulating genes SRSF2, SF3B1, U2AF1, and ZRSR2 (p=.009). Compared to MF with mutated JAK2 or MPL, MF patients with mutated CALR had a longer median OS (not reached vs. 3.1 years; p=.04). With regard to high molecular risk (HMR) muts, n=56 were detected in 38 patients (47%), with 40% (15/38) of the patients harboring ≥2 HMR muts. The most commonly mutated HMR genes were ASXL1 (43%; 24/56), followed by SRSF2 (30%), EZH2 (14%), IDH2 (11%), and IDH1 (2%). MPLmut but not JAK2mut or CALRmut were significantly associated with HMR mut (p=.023). HMR mut patients harbored more co-muts than HMR wt patients (median 5 vs. 3; p & lt;.0001). There were no significant differences in the variables age, sex, WBC, Hb, PLT, or LDH level between patients with HMR mut and HMR wt MF. In univariate analysis, patients with HMR mut MF had shorter median OS (2.3 vs 3.7 years, p=.007). In multivariate analysis (HMR mut, age, DIPSS-category, SMF vs. PMF) a higher DIPSS-score (HR, 3.2; 95% CI, 1.5-7.0; p=.004) and muts in HMR genes (HR, 3.5; 95% CI, 1.5-8.1; p=.003) were significant adverse prognostic factors for OS. Conclusions: Our NGS data underline the genomic complexity of advanced MF. CALR mutations were only found in 20% of the patients that were characterized by less co-mutations, mutual exclusivity with spliceosome mutations, and with more favorable outcome suggesting a distinct disease biology. Almost 50% of patients showed mutations in HMR genes which were associated with an inferior OS in univariate and multivariate analyses. §Frank Stegelmann and Konstanze Döhner contributed equally to this work. Figure 1 Figure 1. Disclosures Koschmieder: Shire: Honoraria, Other; Alexion: Other: Travel support; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Geron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; AOP Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Baxalta: Membership on an entity's Board of Directors or advisory committees, Other; Abbvie: Other: Travel support; CTI: Membership on an entity's Board of Directors or advisory committees, Other; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Image Biosciences: Other: Travel support; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karthos: Other: Travel support. Heidel: Incyte: Consultancy, 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; CTI: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene/BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AOP: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Hochhaus: Bristol-Myers Squibb: Research Funding; Pfizer: Research Funding; Incyte: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Hebart: AbbVie: Honoraria; AstraZeneca: Honoraria; BMS: Honoraria; Janssen: Honoraria; Roche: Honoraria. Isfort: Alexion: Other: Travel reimbursement; Roche: Other: Travel reimbursement; Amgen: Other: Travel reimbursement; Mundipharma: Other: Travel reimbursement; Hexal: Other: Travel reimbursement; BMS: Honoraria; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel reimbursement; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel reimbursement. Reiter: AOP Orphan Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Deciphera: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Incyte: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Blueprint Medicines: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding. Waller: Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Mylan: Consultancy; Alvotech: Consultancy; Takeda: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees; Lilly: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Chugai: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Amgen: Membership on an entity's Board of Directors or advisory committees; IPSEN: Other: travel grant. Scheid: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Goethert: Pfizer: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Travel support; Incyte: Consultancy, Honoraria, Other: Travel support; zr pharma & : Honoraria; BMS: Consultancy, Honoraria, Other: Travel support; AOP Orphan Pharmaceuticals: Honoraria, Other: travel support; Proteros Biostructures: Consultancy. Schafhausen: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Swedish Orphan Biovitrum AB: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Blueprint Medicines: Membership on an entity's Board of Directors or advisory committees. Radsak: Otsuka: Consultancy, Honoraria; Abbvie: Other: e.g. travel support; Astellas: Other: e.g. travel support; TEVA: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: e.g. travel support; Daiichi Sankyo: Consultancy, Honoraria, Other: e.g. travel support; Celgene/BMS: Consultancy, Honoraria, Other: e.g. travel support; Amgen: Other: e.g. travel support; Takeda: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Corat: Consultancy, Honoraria; Cogent Biosciences: Consultancy, Honoraria; JAZZ: Other: e.g. travel support. Gattermann: Takeda: Research Funding; Novartis: Honoraria; Celgene: Honoraria. von Bubnoff: Novartis: Honoraria; Takeda: Honoraria. Brümmendorf: Bristol Myers: Research Funding; Janssen: Honoraria; Novartis: Honoraria, Patents & Royalties, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Repeat Diagnostics: Research Funding; Takepart Media: Honoraria. Döhner: Celgene: Honoraria, Research Funding; Agios: Honoraria, Research Funding; GEMoaB: Honoraria; Astex Pharmaceuticals: Honoraria; Astellas: Honoraria, Research Funding; Oxford Biomedica: Honoraria; Novartis: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Janssen: Honoraria; Helsinn: Honoraria; Gilead: Honoraria; AstraZeneca: Honoraria; Abbvie: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Berlin-Chemie: Honoraria; Roche: Honoraria; Pfizer: Research Funding. Griesshammer: Amgen: Consultancy, Honoraria; AOP Orphan: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; CTI: Consultancy, Honoraria; Shire: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria. Stegelmann: BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Döhner: Abbvie: Consultancy, Honoraria; Janssen: Honoraria, Other: Advisory Board; Jazz Roche: Consultancy, Honoraria; Daiichi Sankyo: Honoraria, Other: Advisory Board; Astellas: Research Funding; Celgene/BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Agios and Astex: Research Funding. OffLabel Disclosure: Pomalidomide was shown to be active in patients with myelofibrosis in particular in the treatment of anemia (Tefferi et al 2009, Begna et al 2011, Mesa et al 2010)

Abstract: 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 〈 65y) for cytogenetic, and 600 (143 and 457, respectively) for molecular responses. Median age was 70y vs. 49y for IM400 and 69y vs. 46y for IM800. The median dose per day was lower for elderly patients with IM800 (517mg vs. 666mg) and the same with IM400 (400mg each). Patients' characteristics at baseline were evenly distributed in all groups regarding gender, follow-up, hemoglobin, platelet count and spleen size. Leukocyte counts were significantly lower in elderly patients (IM400: 50/nl vs. 78/nl, IM800: 36/nl vs. 94/nl). EURO score was different due to age in elderly patients (low risk: IM400: 11% vs. 43%, IM800: 14% vs. 42%; intermediate risk: IM400: 79% vs. 44% and IM800: 73% and 43%). There was no difference in cytogenetic and molecular analyses between treatment groups. With regard to efficacy, there was no difference for older patients in achieving a complete cytogenetic remission (CCR) and major molecular remission (MMR) if IM400 and IM800 were compared together. If treatment groups were analyzed separately, older patients treated with IM400 reached CCR and MMR statistically significant slower than younger patients (CCR: median 14.2 months vs. 12.1 months, p=0.019; MMR: median 18.7 months vs. 17.5 months, p=0.006). There was no difference with IM800 (CCR: median 7.7 months vs. 8.9 months, MMR: median 9.9 months vs. 10.0 months). 3y-OS for older patients 〉 65y was 94.7% and for patients 〈 65y was 96.1%. Some differences were observed in the safety analyses. 530 patients (IM400: 278, IM800: 252) were evaluated on common toxicity criteria (WHO). Some hematologic AEs were documented slightly more often in the elderly than in the younger patients: for IM400 anemia grade 1–2 (60 vs. 42%) and leukopenia grade 3–4 (5.6 vs. 1.4%) and for IM800 anemia grade 1–4 (64 vs.47% and 7.2 vs. 5.7%) and thrombocytopenia grade 3–4 (9.3 vs. 7.1%). Non hematologic AEs were more prominent in IM800 and were mainly gastrointestinal symptoms (IM400: 33 vs. 31%, IM800: 48 and 44%) and edema (IM400: 28 vs. 29%, IM800: 35 vs. 50%). There was no difference for grade 3/4 non-hematological AEs in older patients in both groups. Conclusions: Imatinib 400 mg and 800 mg are well tolerated also in the elderly. The IM800 dosage was more tolerability-adapted for the elderly, but there was no difference in reaching a CCR and MMR in contrast to the IM400 where a significantly slower response was detected in the elderly. Whether this difference is clinically relevant has yet to be determined. Updated results will be presented. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership, Research Funding. German CML-Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; Roche: Research Funding; BMBF: Research Funding; Essex: Research Funding.

Abstract: 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 〈 0,01 on the International Scale. From July 2002 – April 30, 2009 1022 newly diagnosed patients with CML in chronic phase were randomized, 1012 were evaluable (338 with imatinib 800 mg, 324 with imatinib 400 mg, 350 with imatinib plus IFN). Median observation time was 40 months. The median average daily imatinib doses were 628 mg in the 800 mg arm and 400 mg in the 400 mg based arms. The actual median daily doses in the 800 mg arm per 3-months periods were: 555 mg, 737 mg, 613 mg, 600 mg, and 600 mg thereafter, reflecting the run–in period with imatinib 400 mg for 6 weeks in the first period and the adaptation to tolerability from the third 3-months period onwards. Median daily imatinib doses in the 400 mg arms were 400 mg throughout. Adaptation of imatinib dose in the 800 mg arm according to tolerability is reflected by similar higher-grade adverse events rates (WHO grades 3 and 4) with all treatments. Significantly higher remission rates were achieved with imatinib 800 mg by 12 months. The cumulative incidences of CCR by 12 months were 63% [95%CI:56.4-67.9] with imatinib 800 mg vs 50% [95%CI:43.0-54.5] with the two 400 mg arms. The cumulative incidences of MMR by 12 months were 54.8% [95%CI:48.7-59.7] with imatinib 800 mg vs 30.8% [95%CI:26.6-36.1] with imatinib 400 mg vs 34.7% [95%CI:29.0-39.2] with imatinib + IFN. The cumulative incidences of CMR4 compared with the MMR incidences over the first 36 months are shown in Table 1. Imatinib 800 mg shows superior CMR4 rates over the entire 36 months period, CMR4 is reached significantly faster with imatinib 800 mg as compared to the 400 mg arms. The CMR4 rates reach 56.8% by 36 months [95%CI:49.4-63.5] as compared to 45.5% with imatinib 400 mg [95%CI:38.7-51.0] and 40.5% with imatinib plus IFN [95%CI:34.6-46.3] . Most patients have stable CMR4 over the entire period. Time after start of treat-ment (months) Cumulative incidences MMR(%) CMR4 (%) IM400 n=306 D IM800 n=328 D IM400 +IFN n=336 IM400 n=306 D IM800 n=328 D IM400 +IFN n=336 6 8.6 9.5 18.1 9.7 8.4 3 0.7 3.7 1.3 2.4 12 30.8 24.0 54.8 20.1 34.7 7.5 12.3 19.8 7.4 12.4 18 50.3 18.1 68.4 14.3 54.1 21.2 12.2 33.4 9.8 23.6 24 63 13.0 76.0 13.2 62.8 30.7 12.3 43 13 30.0 36 79.3 2.3 81.6 10.9 70.7 45.5 11.3 56.8 16.3 40.5 In summary, superior CMR4 rates are achieved with high-dose imatinib adapted to good tolerability, and more patients in the tolerability-adapted 800 mg arm have stable CMR4 qualifying for treatment discontinuation as compared to the 400 mg based arms. With improved application imatinib remains first choice for early CML. Disclosures: Koschmieder: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. German CML-Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; Roche: Research Funding; BMBF: Research Funding; Essex: Research Funding.