Abstract: Abstract 332 PURPOSE : In Multiple Myeloma (MM), the combination of serum beta-2-microglobulin level with serum albumin concentration has been proposed as an outcome predictor in the International Staging System (ISS). More recently, subgroups of MM defined by genetic and cytogenetic abnormalities have been associated with unique biologic, clinical, and prognostic features. PATIENTS AND METHODS: We analyzed the prognostic value of 12 chromosomal abnormalities by fluorescent in situ hybridization (FISH) in a series of 354 MM patients treated within the HOVON-65/GMMG-HD4 trial. Patients with newly diagnosed MM were randomized to receive either three cycles of VAD (arm A; vincristine, adriamycin, dexamethasone) or PAD (arm B; bortezomib, adriamycin, dexamethasone). All patients underwent autologous stem cell transplantation (ASCT) followed by maintenance therapy with thalidomide 50 mg daily (arm A) or bortezomib 1.3 mg/m2 once every 2 weeks (arm B), respectively. In addition, a second cohort of patients was analyzed as a control group (n=462), undergoing ASCT at the University of Heidelberg between September 1994 and December 2010. RESULTS: For the entire group of patients treated within the HOVON-65/GMMG-HD4 trial, we identified 233 patients with 2 copies (67.7%), 95 patients with 3 copies (27.6%) and 16 patients (4.7%) with more than three copies of the chromosomal region 1q21. In addition to del(17p13) and t(4;14), we added +1q21 ( 〉 3 copies) to the group of high-risk aberrations, since the outcome of these patients was almost as poor as it was observed for patients with del(17p13). Subsequently, we analyzed whether combining the ISS score with information on the presence of high-risk aberrations could improve the prognostic value with regard to patients' outcome. A combination of the presence or absence of del(17p13), t(4;14), or +1q21 ( 〉 3 copies) with the ISS score allowed patients to be stratified into three distinct groups: low-risk [absence of del(17p13)/t(4;14)/+1q21 ( 〉 3 copies) and ISS I], high-risk [presence of del(17p13)/t(4;14)/+1q21 ( 〉 3 copies) and ISS II/III], and intermediate-risk (all remaining patients). Most of the patients belonged to the low- (33%) and intermediate-risk (49%) groups, whereas 18% were allocated to the high-risk group. The median PFS times for the low-, intermediate-, and high-risk groups were 41.9 months, 31.1 months (HR=1.7; p=0.0018) and 18.7 months (HR=3.6; p 〈 0.0001), respectively. The 3yr-overall survival (OS) decreased from 94% in the low-risk group to 80% (HR=4.6; p=0.0001) and 43% (HR=12.8; p 〈 0.0001) in the intermediate- and high-risk groups, respectively. These results were confirmed in the independent cohort of patients: From date of first ASCT, the median PFS times for the low-, intermediate-, and high-risk groups were 43.3 months, 23.0 months (HR=1.5; p=0.015) and 13.8 months (HR=2.4; p=0.0003), respectively. The 4yr-OS decreased from 84% in the low-risk group to 71% (HR=2.1; p=0.0043) and 49% (HR=3.84; p 〈 0.0001) in the intermediate- and high-risk groups, respectively. CONCLUSION: In our series, the ISS/FISH-based score/algorithm predicted PFS and OS much better than the ISS alone. Our results with molecular cytogenetic techniques may already have implications for the risk-adapted clinical management of patients with MM particularly in younger patients. Disclosures: van de Velde: Ortho Biotech Oncology Research & Development: Employment. Sonneveld:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium: Membership on an entity's Board of Directors or advisory committees.

Abstract: Abstract 131 Introduction. Autologous stem cell transplantation (ASCT) after cytoreductive induction is considered standard of care for younger patients (pts) with multiple myeloma (MM). The previous standard of induction, the Vincristin-Adriamycin-Dexamethasone (VAD) combination, achieves inferior results compared with induction regimens which combine the proteasome inhibitor Velcade (V = Bortezomib) with Dexamethasone (D)(=VD) and a cytostatic drug such as Doxorubicin (PAD = VD plus Doxorubicin). Velcade-based induction therapy was shown to translate into better myeloma control after high dose melphalan and to lead to prolonged progression-free survival. In order to find a more efficacious and safer drug combination for induction therapy in MM, we tested the combination of Velcade with Cyclophosphamide and Dexamethasone (VCD). Methods. This trial was designed as an open, prospective, multi-center, uncontrolled, combined phase II/III study. As previously reported (Kropff M et al., Ann Hematol 2009), in the first 30 pts the optimal dose of iv Cyclophosphamide in combination with V and D was defined as 900 mg/m2 on d1. Between 03/2006 and 03/2009 we enrolled an additional 370 pts up to 60 years of age with untreated MM to receive three 3-week cycles of induction treatment with V 1.3 mg/m2 iv d1,4,8,11; D 40 mg/d orally d1,2,4,5,8,9,11,12; and C 900mg/m2 iv d1 before scheduled high dose melphalan and ASCT. The primary endpoint of the study is response rate on day 63 after 3 cycles of VCD according to EBMT and IMWG criteria. Results. Final data from 400 pts from 39 German centers will be presented at the meeting. In the currently evaluable 300 pts (mean age 52.3 years; 1.7% stage I, 21.3% stage II, 77.0% stage III) molecular cytogenetic analysis showed a prevalence of 13q- in 38%, of t[4;14] in 13% and of 17p- in 12% of pts (no changes in 35%). All 300 pts (88.3% of whom completed three cycles) were included in the intent-to-treat analysis. Overall response rate (ORR = CR+PR) was 84%, with 10% CR and 74% PR, 5.7% MR, 7.3% NC and 2.3% PD. The negative prognostic impact of 13q- or t[4;14] was abrogated (ORR normal 87.3%, 13q- 83.7%, t[4;14] 90.0%), the unfavorable influence of p53 loss in the 17p- subgroup was still detectable (ORR 69.2%) but this did not reach statistical significance. VGPR rates will be reported at the meeting. Serious adverse events were documented in 78/300 (26.0%) patients. Death rate was remarkably low (1.3%, of which one was not related to the trial medication). 155/300 (52%) of pts experienced grade 3/4 non-serious AEs and of these leucopenia (93/300 pts= 31%), thrombocytopenia (7%), neutropenia (6%), anaemia (5%) were the most frequent events. 80 AEs grade 3 or 4 and 45 SAEs were of infectious origin and occurred in 47/300 pts. 80/130 SAEs (61.5%) were at least possibly related to Velcade. 101/300 pts (34%) developed episodes of peripheral neuropathy. PNP was grade 1 in 62/300 pt (20.7%), grade 2 in 31/300 pt (10.3%) and grade 3 in 7/300 pts (2.3%). Conclusion. This analysis demonstrates that proteasome inhibition by Velcade in combination with Dexamethasone and iv Cyclophosphamide (VCD) is an induction regimen for newly diagnosed MM which is highly effective in a short period of time, has a rather low toxicity profile and is feasible for administration in an outpatient setting. Based on these characteristics, VCD qualifies to become a new standard for MM induction therapy. Disclosures: Einsele: OrthioBiotech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Off Label Use: Bortezomib is licensed as monotherapy for use in relapsed/refractory MM and in combination with melphalan/Prednisone in the first-line treatment of MM pts ineligible for HD-MEL and ASCT. . Liebisch:OrthoBiotech: Consultancy, Honoraria. Langer:OrthoBiotech: Consultancy. Kropff:OrthoBiotech: Consultancy, Honoraria. Kröger:OrthoBiotech: Honoraria. Ostermann:OrthoBiotech: Honoraria. Mügge:OrthoBiotech: Honoraria. Wolf:OrthoBiotech: Honoraria. Gramatzki:OrthoBiotech: Consultancy, Honoraria. Maschmeyer:OrthoBiotech: Travel Grant. Sezer:OrthoBiotech: Consultancy, Honoraria. Heidemann:OrthoBiotech: Honoraria. Jäger:OrthoBiotech: Honoraria. Dechow:Celgene: Research Funding. Simon:OrthoBiotech: Honoraria. Straka:OrthoBiotech: Consultancy, Honoraria, Research Funding. Fingerle-Rowson:orthoBiotech: Employment. Knop:OrthoBiotech: Honoraria.

Abstract: Background: Trisomy 4 is a recurrent but rare cytogenetic abnormality reported in patients with acute myeloid leukemia (AML). The prognostic significance of this abnormality in AML patients is not clear. Prognosis of AML patients with trisomy 4 seems to be poor as compared to that of patients with intermediate-risk cytogenetics. Allogeneic hematopoietic stem cell transplantation (allo-HCT) may improve survival if applied early in first complete remission (CR). However, neither prospective clinical nor larger retrospective cohort studies are available to support these results from small series. Aims: To characterize AML patients with trisomy 4 and compare outcomes according to different treatment strategies. Methods: We retrospectively studied 123 AML patients with trisomy 4 (median age at diagnosis, 58 years; range, 16-76 years) treated between 2000 and 2019 within 2 large study groups. Standard statistical methods were applied. Results: Median white blood cell count at diagnosis was 4.8/nl (range, 0.4-255/nl) and platelets 46/nl (range, 2-330/nl). Type of AML was de novo in 97 (79%), secondary after myelodysplastic syndrome/myeloproliferative neoplasm in 18 (15%), and therapy-related in 8 (6%) patients. Sixty-two (50%) patients were female. Cytogenetic analysis revealed trisomy 4 as the sole abnormality in 28 (23%), additional abnormalities in 95 (77%) patients, most frequently ≥3 (n=66) abnormalities, trisomy 8 (n=41), karyotypes characterized by trisomies only (n=21) and t(8;21) or inv(16) (CBF; n=10). A total of 98 patients (80%) had NPM1 and FLT3-ITD mutation testing. Of those, 21 (21%) and 15 (15%) harbored NPM1 and FLT3-ITD mutations. Only 2 (3%) of 72 patients were CEBPA double mutated. Data on response to intensive anthracycline-based induction therapy were available in 117 patients. Early death rate was 5% (n=6). CR was achieved in 68% (n=79) with 22 (19%) requiring an intensive salvage treatment cycle. Notably, patients with trisomy 4 as sole abnormality had a CR rate of 89% (n=25/28). There was no difference in the CR rate in FLT3-ITD positive (n=10/15) as compared to FLT3 wild type (n=56/83) patients (67% each, P=0.99). Univariable analysis revealed trisomy 4 as sole abnormality (OR, 5.76; P=0.007) and NPM1 (OR, 12.08; P=0.02) as favorable factors. An allo-HCT was performed in 40 (34%) patients, of whom 19 patients were transplanted in first CR after induction therapy. Nine patients achieved CR after salvage chemotherapy and went on to allo-HCT; another 12 patients received allo-HCT with active disease. Type of donor was matched-related in 8, matched-unrelated in 30, and unknown in 2 of the 40 patients, respectively. Median follow-up of the intensively treated cohort was 73 months (95%-CI, 36-91 months). Five-year overall survival (OS) and relapse-free survival (RFS) were 31% (95%-CI, 23-42%) and 27% (95%-CI, 18-42%). OS rates were significantly higher in patients with CBF leukemia or patients with trisomy 4 as compared to all other abnormalities (Figure 1; P & lt;0.001). Cox regression analysis on OS revealed CBF/CEBPA (HR, 0.75; P=0.02) and trisomy 4 as sole abnormality (HR, 0.63; P=0.04) as favorable factors; age with a difference of ten years was an in trend adverse factor (HR, 1.15; P=0.06; not significant: NPM1, FLT3-ITD, complex karyotype with ≥3 abnormalities). There was no difference on OS if patients proceeded to allo-HCT in CR1 or with active disease (P=0.8). Five-year RFS was 26% (95%-CI, 14-50%) in patients proceeding to allo-HCT after induction therapy (n=40), as compared to 28% (95%-CI, 17-46%; P=0.99) in those who received consolidation chemotherapy (n=49). Conclusions: Clinically, patients with trisomy 4 are very heterogeneous in particular with respect to cytogenetic and molecular abnormalities. In our cohort, patients with trisomy 4 as a sole abnormality had a high CR rate and favorable clinical outcome. In the total cohort, allo-HCT did not improve RFS. Figure 1 Figure 1. Disclosures Krause: Siemens: Research Funding; Takeda: Honoraria; Pfizer: Honoraria; art-tempi: Honoraria; Kosmas: Honoraria; Gilead: Other: travel support; Abbvie: Other: travel support. Schliemann: Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Other: travel grants; Astellas: Consultancy; AstraZeneca: Consultancy; Boehringer-Ingelheim: Research Funding; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Haenel: Takeda: Consultancy, Honoraria; Bayer Vital: Honoraria; Jazz: Consultancy, Honoraria; GSK: Consultancy; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Amgen: Consultancy; Celgene: Consultancy, Honoraria. Crysandt: Incyte: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Fransecky: Medac: Honoraria; Amgen: Honoraria; Abbvie: Honoraria, Research Funding; Novartis: Honoraria; Takeda: Honoraria. Martinez-Lopez: Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, 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; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: 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; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: 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. Einsele: Janssen, Celgene/BMS, Amgen, GSK, Sanofi: Consultancy, Honoraria, Research Funding. Platzbecker: AbbVie: Honoraria; Celgene/BMS: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Geron: Honoraria; Takeda: Honoraria. Baldus: Novartis: Honoraria; Amgen: Honoraria; Celgene/BMS: Honoraria; Jazz: Honoraria. Müller-Tidow: Pfizer: Research Funding; Janssen: Consultancy, Research Funding; Bioline: Research Funding. Levis: Astellas and FujiFilm: Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Honoraria; Amgen, Astellas Pharma, Daiichi-Sankyo, FujiFilm, and Menarini: Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria; Takeda: Honoraria. Montesinos: Stemline/Menarini: Consultancy; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Glycomimetics: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Röllig: Roche: Honoraria, Research Funding; Bristol-Meyer-Squibb: Honoraria, Research Funding; Janssen: Honoraria; Jazz: Honoraria; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Amgen: Honoraria; AbbVie: Honoraria, Research Funding. Schlenk: Novartis: Honoraria; Pfizer: Honoraria, Research Funding, Speakers Bureau; Hexal: Honoraria; Neovio Biotech: Honoraria; Daiichi Sankyo: Honoraria, Research Funding; Celgene: Honoraria; Astellas: Honoraria, Research Funding, Speakers Bureau; Abbvie: Honoraria; Agios: Honoraria; Roche: Honoraria, Research Funding; AstraZeneca: Research Funding; Boehringer Ingelheim: Research Funding.

Abstract: Background: Acute myeloid leukemia (AML) is characterized by a high relapse rate, indicating insufficient clearance of leukemia-initiating cells. Depending on genetic risk stratification, consolidating chemotherapy proves to significantly reduce the risk of relapse. In particular, in younger AML patients higher dosage of cytarabine appears to improve long-term outcome, while there is no apparent benefit of multiagent combination, compared to cytarabine monotherapy. However, to this end the optimal dosage of single agent cytarabine in consolidation therapy after 7+3 remission induction remains elusive. Methods: Here, we retrospectively assessed the impact of different dosages of cytarabine consolidation on outcome in a large real-world data set from the German Study Alliance Leukemia-Acute Myeloid Leukemia (SAL-AML) registry. Patients below 65 years of age, registered between April 2005 and September 2020 with non-acute promyelocytic leukemia, who attained complete remission after intensive induction and received at least one consolidation cycle with intermediate (IDAC) or high dose cytarabine (HiDAC) were selected. To account for differences in patient and disease characteristics between both groups, the average treatment effect was estimated by propensity score weighting. Results: 642 patients received HiDAC consolidation with a median dosage of 5794.88 (IQR, 4745.48-5971.56) mg/m 2/d with a median number of 3 cycles (IQR, 2-3), whereas 178 patients received IDAC consolidation with 1946.16 (IQR, 1869.51-2469.15) mg/m 2/d with a median of 2 cycles (IQR, 1-3). IDAC-treated patients showed in average a higher age (median (IQR) 58.5 (49-62) years vs. 50 (41-56) years) and more comorbidities with 43.8% having an HCT-CI score of 2-4, compared to 22.3% among HiDAC-treated patients. Alongside, significantly more secondary (5.1% vs. 3.1%) and therapy-related (12.4% vs. 4.1%) AML as well as more adverse (14.5% vs. 6.5%) and less favorable (40.6% vs. 56%) genetic risk features according to ELN 2017 risk classification were found among IDAC-treated patients. After propensity score weighting for differences in patient and disease characteristics, overall survival after 5 years was comparable between HiDAC-treated (71.1 %) and IDAC-treated (67.7%) patients. Moreover, no significant differences in relapse-free survival were observed after 5 years (47.4 vs. 45.2%). Notably, more patients treated with IDAC received allogeneic stem cell transplantation in first remission (37.6 vs. 19.8%) while significantly more HiDAC-treated patients underwent allogeneic stem cell transplantation in relapse (30.8 vs. 20.2%). Censoring for allogeneic stem cell transplantation in first remission revealed no significant survival difference with regard to cytarabine dosage. Considering only ELN favorable risk AML patients, there was no difference in 5-years overall (80.5% vs. 83.9%) nor relapse-free (57.7% vs. 56.8%) survival. Of note, significantly more patients treated with HiDAC suffered from ≥3 CTCAE infectious complications (56.7 vs. 44.1%), which was more striking in patients above 50 years of age. The rate of other ≥3 CTCAE non-hematological toxicities and secondary malignancies was comparable in both treatment groups. Conclusion: This retrospective analysis suggests no significant benefit of high dose cytarabine compared to intermediate dosages in consolidation for AML patients under 65 years of age, independent of ELN risk group. Disclosures Krause: Siemens: Research Funding; Takeda: Honoraria; Pfizer: Honoraria; art-tempi: Honoraria; Kosmas: Honoraria; Gilead: Other: travel support; Abbvie: Other: travel support. Schliemann: Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Other: travel grants; Astellas: Consultancy; AstraZeneca: Consultancy; Boehringer-Ingelheim: Research Funding; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Haenel: Jazz: Consultancy, Honoraria; GSK: Consultancy; Bayer Vital: Honoraria; Takeda: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Amgen: Consultancy; Celgene: Consultancy, Honoraria. Brummendorf: Takepart Media: Honoraria; Repeat Diagnostics: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Patents & Royalties, Research Funding; Janssen: Honoraria; Bristol Myers: Research Funding. Fransecky: Abbvie: Honoraria, Research Funding; Medac: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Takeda: Honoraria. Einsele: Janssen, Celgene/BMS, Amgen, GSK, Sanofi: Consultancy, Honoraria, Research Funding. Held: MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Roche: Research Funding; Acortech Biopharma: Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Platzbecker: Janssen: Honoraria; Celgene/BMS: Honoraria; AbbVie: Honoraria; Geron: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Baldus: Amgen: Honoraria; Celgene/BMS: Honoraria; Novartis: Honoraria; Jazz: Honoraria. Mueller-Tidow: Janssen Cilag: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Bioline: Consultancy, Research Funding.

Abstract: Introduction Aberrant DNA methylation is a common feature of acute myeloid leukemia (AML) and increases with age. DNMT inhibitors such as Azacitidine (AZA) can induce meaningful responses and remissions in AML as monotherapy. The combination of AZA with standard chemotherapy (7+3) has not been tested in a randomized trial. Patients and study design The AML-AZA trial compared AZA directly followed by standard induction therapy, AZA followed by standard consolidation, and further Azacitdine maintenance with standard induction and consolidation without AZA in older patients with AML. All patients received standard Cytarabine (100 mg/sqm) and Daunorubicin (60 mg/sqm) induction (“7+3”) and up to two cycles of intermediate dose Cytarabine (1 g/sqm q12hr days 1, 3, 5) as consolidation therapy. AZA (75 mg/sqm for 5 days) preceded each therapy cycle in the AZA arm. In addition, AZA maintenance for up to 1 year was also scheduled for patients in the AZA arm. 105 patients were randomized to receive AZA plus Cytarabine plus Daunorubicin as induction therapy (AZA + 7+3) and 109 patients to receive 7+3 only (control group). Median age was 70 years in both treatment arms. Patient cohorts were well balanced with regard to blast counts in bone marrow, secondary versus de novo AML and molecular genetics risk group. More patients in the AZA + 7+3 arm (39/105; 37.1%) than in the control group (25/109; 22.9%) showed high risk cytogenetics (p=0.057). Event free survival (EFS) was the primary end point. Secondary endpoints were overall survival (OS), complete remission (CR) rate, toxicity and different treatment response according to molecular markers. Results Overall, 214 of 216 planned patients were enrolled into the AML-AZA trial. Due to a higher number of severe adverse events (SAE), AZA administration was stopped after recruitment of 214 patients whereas chemotherapy was continued as planned. Percentages of patients in the AZA arm with AZA doses as initially planned were as follows: 99% for first induction cycle, 72% for the second induction cycle. AZA as maintenance therapy for at least one cycle was delivered to 18% of patients in the AZA group. At least one SAE occurred in 51% of AZA + 7+3 patients compared to 31% of 7+3 patients (p=0.005). Cardiac disorders with CTCAE grade 3-5 occurred more frequently in the AZA + 7+3 arm (n = 15) than in the 7+3 arm (n = 6) (not significant). Leukopenia was prolonged by one day (median 23 vs 22 days) in the AZA + 7+3 group (p=0.043), whereas time of thrombocytopenia was not different. The early death rates at 30, 60 and 90 days did not differ significantly between treatment groups. Efficacy analyses were performed on an intention-to-treat basis. Median EFS as the primary endpoint was 6 months in both treatment arms (p=0.96). Median OS was 16 months for patients treated with AZA + 7+3 and 21 months for 7+3 (p=0.35). Median relapse free survival was 12 months in both treatment arms (p=0.95). 48 of 100 patients (48%) in the AZA + 7+3 arm achieved complete remission (CR) after induction therapy versus 57 of 109 patients (52%) in the 7+3 arm (p=0.58). DNMT3A exon 23 mutations were detected in 30 out of 162 analyzed patients. Exploratory analyses were performed to detect a potential interaction between AZA + 7+3 response and DNMT3A mutation status. Trends for improved EFS and OS were noted for AZA + 7+3 treatment in DNMT3A mutated patients. Conclusion AZA as addition prior to standard induction and consolidation chemotherapy does not prolong EFS and OS in unselected older AML patients and it is more toxic. However, a trend towards better efficacy in patients with DNMT3A mutation was observed and should be further explored. Disclosures Müller-Tidow: Celgene: Honoraria, Research Funding. Thiede:AgenDix GmbH: Equity Ownership, Research Funding; Illumina: Research Support, Research Support Other. Kiehl:Roche: Membership on an entity's Board of Directors or advisory committees. Brümmendorf:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Ehninger:GEMoaB GmbH: Consultancy, Patents & Royalties.

Abstract: The major limitation of allogeneic stem cell transplantatiopn (SCT) in patients (pts) with myelofibrosis is the high treatment related mortality. We performed a prospective multicenter trial of a dose-reduced conditioning regimen, consisting of busulfan (10 mg/kg orally or 8mg/kg i.v), fludarabine (180 mg/m2) and anti-thymocyte globulin (ATG Fresenius: 30–60 mg/kg) followed by allogeneic SCT in pts with myelofibrosis. From 2002 to 2006, 104 pts with a median age of 55 years (range: 32–68) andlow risk with constitutional symptoms (18%) or intermediate risk (n= 58%) and high risk (n=19%) were included. Cytogenetic abnormalities and JAK2 mutation were noted in 22% and 48%, respectively. Bone marrow histology showed advanced fibrosis (MF 2 and 3) in all pts. All but 3 pts received peripheral blood stem cells as graft source either from related (n=33) or unrelated donor (n=71). All but one (1%) pts showed leukocyte and platelet engraftment after a median of 18 and 21 days, respectively. The median duration of leukocyte aplasia was 9 days (range: 3–21). Acute GvHD grade II to IV occurred in 19% and severe aGvHD III/IV in 7%, while chronic GvHD was seen in 32% of the pts. Non-relapse mortality at 1 year was 19% (95% CI: 11–27%) and significantly lower for pts younger than 50 years of age (0% vs 27%, p=0.004) and for pts with low risk vs intermediate/high risk disease (0% vs 27%, p= 0.02). The cumulative incidence of relapse at 3 years was 29% (95%CI: 15–43%). The 3 year overall (OS) and event-free survival (EFS) was 70% (95% CI 60–80%) and 55% (95% CI 42–68%). Significant factors for improved 3 year OS and EFS were age less than 50 years (92% vs 62%, p=0.003 and 79% vs 46%, p= 0,004) and low vs intermediate/high risk (100% vs 62%, p=0.01 and 72% vs 48%, p= 0.02), while no impact on survival was seen for cytogenetic abnormalities, JAK2 mutation status and donor (related vs unrelated). These prospective multicenter study show excellent outcome of an busulafan/fludarabine based reduced conditioning regimen followed by allogeneic SCT in pts with myelofibrosis.

Abstract: Background: Lenalidomide with low-dose dexamethasone (Rd) is an emerging treatment option for newly diagnosed multiple myeloma patients with higher age. However, many older patients also remain candidates for autologous transplantation especially with age-adjustment of high-dose melphalan. Potentially, high-dose therapy could add to the benefit of Rd, alternatively the effect of high-dose therapy could be more or less redundant in this setting. The DSMM XIII trial is a multicenter, open-label, phase III trial comparing the safety and efficacy of continuous Rd versus Rd induction followed by age-adjusted tandem high-dose melphalan with autologous transplantation and lenalidomide maintenance. Methods: Patients with newly diagnosed multiple myeloma with symptomatic and measurable disease of age 60-75 years were randomly assigned to either (A1) lenalidomide (25 mg po d1-21/28d) with low-dose dexamethasone (Rd) (40 mg po d1, d8, d15, d22/d28) for 3 cycles followed by stem cell mobilization and continued Rd until progression or (A2) 3 cycles of Rd, followed by stem cell mobilization, tandem high-dose melphalan 140 mg2 (MEL140) with autologous blood stem cell transplantation and lenalidomide maintenance 10 mg daily until progression. At randomization, patients were stratified according to age (≤70 years vs 〉 70 years) and ISS stage (I, II vs III). Antithrombotic prophylaxis with low molecular weight (LMW) heparin or aspirin was recommended. The primary endpoint was progression-free survival (PFS), and secondary endpoints included safety, responses, overall survival and others. We report the results of the planned first interim analysis after occurrence of one third of events as pre-specified. Results: Since March 2010, 253 patients have been randomized and data of 251 patients were available for analysis. The median age was 68 years (range 59-75), 30% were older than 70 years, 34% had ISS stage I, 37% ISS stage II, and 29% ISS stage III. The median PFS for the whole study population (A1 and A2) was 37.3 months. The comparison of PFS by randomization arm did not meet the formal criteria for early termination of the trial. The overall response rate after 3 cycles of Rd (A1 and A2) was 75%, with 2% demonstrating complete response (CR), 21% very good partial response (VGPR) and 52% partial response (PR). A further 20% of patients had stable disease and 6% of patients progressive disease. The 3-year-survival rate is 75% (95% confidence interval, 68-84) for all patients and with respect to ISS stage amounted to 90% (CI: 81-99, ISS stage I), 78% (CI: 66-91, ISS stage II) and 51% (CI: 35-74, ISS stage III). For the two age groups, the 3-year-survival was 73% (CI: 64-84) in patients with age ≤70 years and 80% (CI: 68-94) in patients with age 〉 70 years. So far, 8 (3%) second primary malignancies (SPM) were observed, 4 skin tumors and 4 other solid tumors, but no hematological SPM was documented. Conclusion: In our trial, lenalidomide with low-dose dexamethasone (Rd) was found to be associated with a favorable median progression-free survival at 3 years. The survival in patients 〉 70 years was not inferior compared to younger patients. The potential advantages and disadvantages of combining lenalidomide with high-dose melphalan and autologous transplantation in comparison to continous Rd are addressed by this ongoing trial and further data will be presented at the meeting. Disclosures Straka: Celgene: Consultancy, Honoraria, Research Funding. Off Label Use: Lenalidomide for first-line treatment.

Abstract: We retrospectively studied 97 acute myeloid leukemia patients with trisomy 19 (median age at diagnosis 57 years; range, 17- 83 years) treated between 2001 and 2019 within two multicenter study groups. Trisomy 19 occurred alone in ten (10.5%) patients, with additional abnormalities being present in non-complex karyotypes in eight (8%) patients and in complex karyotypes in 79 (82%) patients. Altogether, karyotypes characterized by trisomies only were present in 27 (28%) patients. Data on response and outcome of intensively treated patients were available for 92 cases. The median follow-up was 6.4 years (95% confidence interval [95% CI]: 2.9-9.0 years). The complete remission (CR) rate after induction therapy was 52% (48 patients); the early death rate was 10% (n=9). Notably, patients with trisomy 19 as the sole abnormality had a CR rate of 89%. Allogeneic hematopoietic stem cell transplantation (allo-HCT) was performed in 34 (35%) patients (CR, n=19; active disease, n=15). Five-year relapse-free and overall survival rates were 26% (95% CI: 16-43%) and 20% (95% CI: 13-31%), respectively. Overall survival rates were significantly higher in patients with trisomy 19 as the sole abnormality or within karyotypes characterized by trisomies only (P=0.05). An Andersen-Gill model including allo-HCT as a time-dependent covariable on overall survival revealed that trisomy 19 as the sole abno rmality or within karyotypes characterized by trisomies only was a favorable factor (hazard ratio [HR]=0.47; P=0.021); higher age at diagnosis had an adverse impact (10 years difference; HR=1.29; P=0.002), whereas allo-HCT did not have a beneficial impact (odds ratio=1.45; P=0.21). In our cohort, patients with trisomy 19 as the sole abnormality or within karyotypes characterized by trisomies only had a high CR rate and better clinical outcome.