ALBERT

Description: Introduction Epigenetic therapies with azanucleoside DNA hypomethylating agents, alone or in combination with histone deacetylase inhibitors (HDACi), show clinical activity in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), particularly when given at non-cytotoxic doses. They are able to reactivate epigenetically silenced genes including, among others, a number of highly immunogenic proteins dubbed Cancer/testis antigens (CTAs), predominantly the CTAs located on the X chromosome. We have previously shown that decitabine can induce expression of several CTAs, including MAGEB2 and NY-ESO-1, in myeloid cells in vitro and thereby trigger an immune response (Almstedt et al., Leuk. Res. 2010). Induction of a CTA-specific cytotoxic T cell response in vivo was reported also in AML patients treated with azacitidine and sodium valproate (VPA) and correlated with clinical response (Goodyear et al., Blood 2010). To the best of our knowledge, no data have yet been reported on the effect of combination treatment with decitabine and panobinostat or sodium valproate (VPA) on CTA reactivation in myeloid leukemia. Aim We hypothesized that by combining decitabine with HDACi we could further enhance expression of CTAs in myeloid leukemia cells and thereby boost recognition of the malignant cells by the cytotoxic T lymphocytes. Methods The myeloid cell lines U937 and Kasumi-1 were treated with decitabine alone or in combination with the HDACi VPA or panobinostat applied at non-toxic concentrations (〉80% cell viability). Expression of CTAs was analyzed by RT-qPCR and Western blot after 48 hours of HDACi treatment. DNA methylation of NY-ESO-1 and MAGEB2 promoter regions was quantified by pyrosequencing. Bone marrow mononuclear cells from 19 AML patients (treated with or without VPA as add-on to decitabine in the ongoing randomized phase II DECIDER clinical trial, NCT00867672) were collected before and on day 15 of treatment, in some patients also after 2 treatment cycles. CTA mRNA expression and promoter DNA methylation were quantified as described above. Results VPA or panobinostat alone did not induce MAGEB2 or NY-ESO-1 expression in vitro. However the pretreatment of cells with decitabine prior to addition of either HDACi resulted in a synergistic dose-dependent reactivation of MAGEB2 and NY-ESO-1 on the mRNA level (confirmed for the latter on the protein level). Pyrosequencing analysis of the heavily methylated NY-ESO-1 and MAGEB2 promoters revealed, as expected, no methylation changes upon HDACi treatment, but a dose-dependent hypomethylation upon decitabine. In recently initiated in vivo studies (DECIDER trial), until now cells from 19 AML patients receiving epigenetic treatment were sequentially analyzed. Induction of MAGEB2 mRNA was observed in 9 patients (from absent to a median of 0.002 relative to GAPDH, range 0.0004-0.043), with concomitant DNA hypomethylation of the MAGEB2 promoter from median 83% pretreatment methylation (range 63%-90%) to 63% posttreatment (range 44%-74%). In 5 patients modest hypomethylation without changes in MAGEB2 expression was observed (from median pretreatment values of 89% [72%-92%] to 82% [58%-87%] posttreatment). Another 5 patients disclosed neither hypomethylation nor reexpression of MAGEB2 (results as yet blinded to treatment arm and clinical response). Conclusions Combined epigenetic treatment with the hypomethylating agent decitabine and the HDACi VPA or panobinostat synergistically induced a dose-dependent reactivation of the CTAs MAGEB2 and NY-ESO-1 in vitro, accompanied by promoter hypomethylation. First translational results of the DECIDER AML trial also indicate in vivo effects of the epigenetic treatment on CTA induction. The unmasking of CTAs to the immune system by epigenetically active drugs can increase anti-tumor immune responses, and thus has clear implications for future clinical trials combining epigenetic therapy and specific immunotherapy in myeloid neoplasia. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: Treatment of acute myeloid leukemia (AML) in elderly patients remains challenging. Low-dose DNA hypomethylating agents are a therapeutic option in myelodysplastic syndromes and AML. However, the mechanism of action of hypomethylating agents and the role of induction of DNA hypomethylation in the clinical response is still unclear. To unravel the in vivoeffects of sequential cycles of decitabine, we set out to characterize methylomes of leukemic blasts, T cells (presumably not part of the malignant clone) and granulocytes before and during treatment of AML patients enrolled in the randomized phase II DECIDER clinical trial (NCT00867672). We developed a statistical model for longitudinal data analysis to identify the strongest hypomethylation response. Methods: Peripheral blood mononuclear cells (PBMC) from AML patients were collected before and during therapy (i.v. 20 mg/m2 decitabine for 5 days, with or without subsequent oral drug add-on). Leukemic blasts and T-cells were isolated using automatic magnetic sorting of cells (autoMACS) labelled with anti-human CD34, CD117 and CD3 MACS microbeads (Miltenyi Biotec), respectively. Granulocytes were isolated using dextran sedimentation. Cell type specific genome-wide DNA methylation profiles were obtained using Infinium Human Methylation 450 BeadChip arrays. Data were analyzed using R packages RnBeads applying beta mixture quantile dilation for normalization (Teschendorff et al. Bioinformatics, 29:189–196, 2013) and a modified version of NHMMfdr for multiple testing. Results: Peripheral blood blasts (median purity: 92%) were isolated from 20 patients, and T cells (median purity: 94%) from 26 patients before treatment and on days 4 and/or 8 and 15 of treatment cycle 1. From 10 patients, blasts and T cells were also collected during and/or after cycle 2. In total, until now 127 methylomes (46 blasts, 47 T cells, 34 granulocytes) were generated and used for mathematical modelling. Since the trial is still recruiting, genome-wide methylation was interpreted blinded to all clinical data including drug add-on (ATRA, valproic acid). First, the methylation dynamics of each individual CpG site described by a specified summary statistics were identified. Then, inter-probe distance and CpG annotation were incorporated to explain the dependence structure between CpG sites. In order to control the false discovery rate (FDR), we adapted a method proposed for differential DNA methylation (Kuan & Chiang, Biometrics 68: 774–783, 2012). The summary statistics for each CpG site were modelled to follow a non–homogeneous hidden Markov model. Statistical testing was validated by simulations revealing a very high discriminative power for affected CpGs even with very low methylation dynamics. Applying the model to blasts and T cells, extensive differences in the in vivomethylation changes became apparent. In blasts, 13% of CpG (59,920 CpGs of total 460,343 CpGs) showed significant DNA hypomethylation (Δβ〉0.1, FDR

Description: Background: The well-described prognostic impact of tumor characteristics and biology in multiple myeloma (MM), such as the combination of cytogenetics, the International Staging System (ISS) and lactate dehydrogenase (LDH, Moreau et. al., JCO, 2014) as well as frailty (Palumbo et al., Blood, 2015) significantly influence patient outcomes. However, only limited data on the impact of infections during therapy exist (Rajkumar et al., Lancet Oncology, 2010). Therefore, we hypothesized that severe infections during induction therapy (IT) in transplant-eligible MM influence dosage of therapies, treatment responses after IT and survival. Patients and Methods: From 05/2005 until 05/2008, 399 patients were randomly assigned to receive IT with either three cycles of VAD (vincristine, VIN, i.v. 0.4mg, days 1-4; doxorubicine, DOXO, i.v. 9mg/m2, days 1-4; dexamethasone, DEX, p.o. 40mg, days 1-4, 9-12, 17-20; n=201, arm A) or PAD (bortezomib, BTZ, i.v. 1.3mg/m2, days 1, 4, 8, 11; DOXO i.v. 9mg/m2, days 1-4; DEX p.o. 40mg, days 1-4, 9-12, 17-20; n=194, arm B), followed by high-dose melphalan (HDM) and autologous stem cell transplantation (ASCT) and either thalidomide (arm A) or bortezomib (arm B) maintenance within the German part of the joint GMMG-HD4/HOVON65 trial (Sonneveld et al., JCO, 2012). After exclusion of ineligible patients, 395 patients (99.0%) were evaluable for analyses. Any severe infection (equal or greater grade 3, according to the Common Terminology Criteria for Adverse Events, Version 4.0) during IT (at least once, defined from first until last date of application of IT medication) occurred in 105 patients (VAD n=53/198 and PAD n=52/192, 26.9% of all patients, missing data n=5). Results: Among patients with a severe infection during IT in the VAD and PAD arms, total DEX and DOXO doses (equal dosage in VAD/PAD group) were significantly lower (median DEX dose (mg/m2): 689.0 [77.7, 1014.1] vs. 742.3 [0.0, 1324.1], p

Description: Background: The therapeutic effect of DNA-hypomethylating agents (HMAs) in AML/MDS is discussed to be via its effects on aberrant gene silencing by reactivation (e.g. through promoter hypomethylation). While this has been broadly studied in cell line models, only very few studies have addressed the global effects of HMAs in primary blasts serially isolated from AML patients (pts) undergoing HMA treatment (Claus et al., Leuk. Res. 2013, Klco et al., Blood 2013, Welch et al., N. Engl. J. Med. 2016). We therefore conducted prospective serial methylome and transcriptome analyses on AML blasts from pts of the DECIDER trial (NCT00867672), hypothesizing that both random and non-random effects of the HMA may be observed in vivo. Patients, Materials and Methods: Of a total of 200 newly diagnosed AML pts included into the DECIDER randomized phase II trial (Decitabine/DAC treatment, 20 mg/m2 intravenous 1-hour infusion over 5 days, with add-on drugs Valproic acid and/or ATRA added at day 6; Grishina et al., BMC Cancer 2015), serially obtained peripheral blood (pb) samples from a total of 28 pts yielded sufficient numbers of purified blasts at 3 timepoints (days 0, 8 and 15 from DAC treatment start) to allow a "triplet analysis" of these matched samples. Baseline pt characteristics: median WBC 11,900/µl (range 1,200 - 53,800), median pb blasts 37.5% (range 1% - 93%). Blasts were sorted using anti-CD34, CD117 MACS microbeads, respectively (median purity 〉90%). Methylomes were obtained using Infinium Human Methylation 450 BeadChip arrays (Illumina). For expression analyses, GeneChip Human Gene 2.0 ST arrays were used. A linear-model based approach was used to identify the differentially methylated CpGs and expressed genes post vs. prior to treatment. Results: To address in vivo methylation changes occurring at day 8 and 15 from DAC treatment start, complete "triplets" of DNA preparations (thus from purified pb blasts of all 3 time points) were interrogated. Significant hypomethylation at day 8 (Δβ

Description: Background: Novel agents such as IMIDs and proteasome inhibitors have substantially changed the therapeutic landscape in the first line treatment of multiple myeloma (MM). Better response rates and prolonged progression-free survival have lead to an improvement in overall survival (OS) with median values well beyond 5 years. Therefore to assess whether first line therapy strategies have an impact on the prognosis for patients with MM, long-term results of clinical trials with follow up covering 〉10 years are necessary. Methods: The HOVON-65/GMMG-HD4 study is a prospective randomized trial testing bortezomib+adriamycin+dexamethasone (PAD) for 3 cycles as induction prior to high-dose chemotherapy (HDT) and autologous stem cell transplantation compared to vincristine+adriamycin+dexamethasone (VAD) in the control arm. After one (HOVON) or two (GMMG) HDT maintenance was given for 2 years consisting of bortezomib every 2 weeks in the PAD arm and thalidomide 50 mg daily in the VAD arm. The study results were initially reported in 2012 (1) and with a median follow up of 91 months in 2018 (2). In this analysis we present OS results after a median follow up of 137 months. All hazard ratios (HR) are given with 95% confidence intervals (CI). Results: Overall survival at 12 years was 32% (CI 27-37%) in the VAD arm versus 36% (CI 31-41%) in the PAD arm without significant difference in the univariate Cox model (HR 0.87, CI 0.73 - 1.03, p=0. 11 or in multivariate Cox model including ISS stage and treatment arm (HR 0.87, CI 0.73 - 1.04, p=0.12; the primary analysis) as specified in the study protocol. When other factors including age, sex, ISS stage, WHO performance status, Immunoglobulin-type, Durie and Salmon-stage, LDH, del 13q, study group and renal impairment (RI, defined as serum creatinine ≥ 2 mg/dl) were added to the Cox model, treatment in the PAD arm was a significant factor for improved OS (HR 0.84, CI 0.7 - 1.0, p=0.048). Of the remaining factors age (HR 1.02, CI 1.01 - 1.03, p=0.002), female sex (HR 0.83, CI 0.69 - 0.99, p=0.044), ISS stage (HR 1.19, CI 1.04 - 1.35, p=0.01), WHO performance status (HR 1.32, CI 1.17 - 1.48, pULN (HR 1.44, CI 1.14 - 1.82, p=0.002), del 13q (HR 1.42, CI 1.17 - 1.73, p

Description: Introduction In older patients (pts), host factors such as functional deficits, comorbidities and other age-related factors are increasingly recognized as predictors for outcome of leukemia treatment. Thus, prospective clinical trials increasingly implement functional studies (often termed geriatric assessment) in their pretreatment diagnostic workup. In older, fit AML pts receiving standard chemotherapy, Klepin et al. demonstrated a predictive value of this approach for overall survival (OS) in a single-center study (Blood 2013). We also developed a Frailty Score, assessed at 3 study centers and predicting OS of elderly AML/MDS pts receiving either hypomethylating agents (n=66) or sole best supportive care (n=35; Deschler et al., Haematologica 2013). To validate this score, which is composed of performance status (PS), activities of daily living (ADL) and fatigue, we prospectively assessed these parameters in the DECIDER trial (AMLSG 14-09, NCT00867672). Methods In the DECIDER trial, 200 non-fit AML pts aged 〉60 years (yr) were randomized between four treatment arms with either decitabine (DAC) alone, or DAC plus all-trans retinoid acid (ATRA) or DAC plus valproic acid (VPA) or DAC plus ATRA and VPA. We assessed PS via ECOG, ADL via Barthel index and fatigue via the EORTC QLQ-C30 questionnaire, which were available for 200, 175 and 156 pts, respectively. Pts with missing ADL and/or fatigue assessments tended to have a lower PS than those with complete data, which may explain at least in part why the assessments could not be performed. The Frailty Score was calculated using ECOG PS as a substitute for the Karnofsky Index (KI, as applied when establishing this score), with ECOG 0-1 taken as corresponding to KI ≥80, and ECOG 2-3 to KI

Description: Background: We reported better PFS and OS in transplant eligible patients with newly diagnosed Multiple Myeloma (MM) who were treated with bortezomib during induction and maintenance, when compared with standard treatment in the HOVON-65/GMMG-HD4 trial. (P. Sonneveld et al., J Clin Oncol 30:2946-2955, 2012). Here the long-term follow up data are presented. Methods: 827 eligible patients were randomized to induction therapy with VAD (vincristine, doxorubicin, dexamethasone) or PAD (bortezomib, doxorubicin, dexamethasone) followed by high-dose melphalan (once or twice) and autologous stem cell transplant. Maintenance consisted of daily thalidomide (T) 50 mg (VAD arm) or 2-weekly bortezomib (B) 1.3 mg/m2 (PAD arm) for 2 years. The primary endpoint was progression-free survival (PFS) adjusted for ISS stage. Results: After a median follow up of 91.4 months (maximum 119) 410 patients are alive. Response rates were VAD/HDM/T: CR 25%, ≥VGPR 56%, ≥PR 83%; PAD/HDM/B: CR 37%, ≥VGPR 76%%, ≥PR 91%, The median duration of maintenance therapy was 14 months (thalidomide) and 23 months (bortezomib), respectively. Main reasons for discontinuation were toxicity (T: 31%; B: 11%), disease progression (T: 33%; B: 36%) or normal completion (T: 28%; B: 48%). Of 827 patients in the analysis, 206 are alive without progression/relapse. PFS was significantly better in the bortezomib arm, i.e. median 34 versus 28 months (HR=0.77, 95% CI=0.65-0.90, p=0.001). Median overall survival (OS) was 90 months in the bortezomib arm vs 83 months in the control arm, but 42% at 9 years in both arms. We used the restricted mean survival time (RMST) method to compare OS between the two treatment arms In univariate analysis. The difference in RMST8y was 4.8 months (95% CI 0.2-9.5, p=0.04) in favor of the bortezomib arm. A landmark analysis in patients who had received HDM starting at 12 months showed a significant PFS advantage of bortezomib in all patients (p=0.02), in patients in VGPR/PR (p=0.02) but not in CR (p=0.19). For OS there was no advantage for bortezomib in either group. PFS at 60 months in bortezomib treated patients was not different when single vs double HDM/ASCT was administered, i.e. 28% vs 27%. However, OS at 60 months was 71% vs 60% in favor of double HDM/ASCT (p=0.04). Subgroup analysis was performed based on presence/absence of adverse FISH (CA) in 395 patients treated with double HDM/ASCT. PFS at 60 months for each abnormality (CA or no CA) in bortezomib vs standard arm is given in Table 1 Table 1.PFS at 60 months, %OS at 60 months, %FISHnBortezomib armpStandard armBortezomib armpStandard Armt(4;14) yes/no50/29516% vs 27%0.048% vs 24%52% vs 75%0.0133% vs 64%add(1q) yes/no113/23116% vs 32%0.00510% vs 28%57% vs 79%0.00143% vs 70%del(17p) yes/no39/31222% vs 27%0.475% vs 24%65% vs 72%0.4818% vs 66% These data show that bortezomib treatment combined with double HDM/ASCT significantly improves PFS and OS in patients with del(17p) and almost abrogates the negative impact of this CA. In t(4;14) and add(1q) some improvement is observed, however the negative impact remains significant. In high-risk patients presenting with elevated creatinine 〉2 mg/dL bortezomib significantly improved PFS at 60 months (32% vs 5%) (p=0.001) and OS at 60 months (66% vs 21% months (p

Description: Introduction Salvage high dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is used in fit patients with relapsed multiple myeloma (RMM) in clinical practice. However, the role of this approach in the era of continuous novel agent based treatment has not been defined in randomized trials. The ReLApsE trial compared lenalidomide/dexamethasone (Rd) re-induction, salvage HDCT/ASCT and lenalidomide (R) maintenance with standard continuous Rd in a randomized controlled multicenter trial. Methods Between 2010 and 2016, 282 patients were randomized of whom 277 constituted the intention-to-treat (ITT) population (arm B/A n=139/138). Arm B received 3 cycles of Rd (lenalidomide 25 mg, day 1-21; dexamethasone 40 mg, day 1, 8, 15, 22; 4 week cycles) re-induction, HDCT (melphalan 200 mg/m2), ASCT and R maintenance (10 mg daily) until progression (PD). Arm A was treated with Rd until PD. In both arms stem cells were harvested after the 3rd Rd cycle if no back-up transplant was available. Key inclusion criteria were 1-3 prior therapy lines, age ≤ 75 years, time to PD ≥ 12 months in case of front-line HDCT/ASCT and WHO PS ≤ 2. The primary endpoint was progression free survival (PFS). Secondary endpoints included overall survival (OS), response rates and toxicity. ISRCTN16345835, Eudra CT-No: 2009-013856-61. Results Arm B and A were balanced regarding age (median 61.3 vs. 62.2 years), ISS (I/II/III in 62.6/24.4/13% vs. 59.7/31/9.3%) and WHO PS (0/1/2 in 69.1/30.9/0% vs. 76.1/23.2/0.7%). Almost all patients had only 1 prior therapy line (arm B: 94.2% vs. arm A: 93.5%) and had received front-line HDCT/ASCT (92.8% vs. 94.2%). More patients in arm B had high risk cytogenetic aberrations (HR-CA; 42.9% vs. 31.6%) based on a higher frequency of t(4;14) (20.2% vs. 10.1%). The overall response rate (≥ partial response; ORR) for arm B and A was 77.9% and 74.6% (p=0.57) with 49.3% and 47.1% (p=0.81) achieving ≥ very good partial response as best response. Within a median follow up of 36.3 months, 183 PFS events and 76 deaths occurred. Median PFS in the ITT population was 20.7 months in arm B and 18.8 months in arm A without a statistically significant difference (HR 0.87; 95% CI 0.65-1.16; p=0.34). Median OS was not reached (NR) in arm B vs. 62.7 months in arm A (HR 0.81; 95% CI 0.52-1.28; p=0.37). In arm B, 41 patients (29.5%) did not receive the planned HDCT/ASCT. Thus, exploratory landmark (LM) analyses from HDCT and the contemporaneous Rd cycle 5 in arm A were performed (median interval from randomization to HDCT/Rd cycle 5: 117/122 days; n=103[B]/114[A]). They showed a trend towards superior PFS (23.3 vs. 20.1 months; HR 0.74; p=0.09) and significantly superior OS (NR vs. 57 months; HR 0.56; p=0.046) in arm B vs. A. Multivariate analyses revealed significant associations of treatment in arm B with superior LM PFS (HR 0.6; p=0.01) and LM OS (HR 0.39; p=0.006). Other factors in the LM multivariate models showing significant associations with survival were HR-CA (PFS, OS), number of prior therapy lines (PFS), and age (PFS). The ORR in arm B after HDCT/ASCT was significantly higher than in arm A after Rd cycle 5 (82.3% vs. 69.6%; p=0.04). Grade ≥3 adverse events were reported in 83% (arm B) and 74.5% (arm A; p=0.11). Grade ≥3 leukopenia/neutropenia was reported in 61.5 vs. 24.8% (p

Description: Background: Despite the recent approval of DNA-hypomethylating agents (HMAs) for treatment of elderly AML patients (pts) ineligible for induction, their prognosis is still poor, and rational, effective HMA-based combination treatments are under study. Histone deacetylase inhibitors (HDACi) show synergism with HMAs in vitro. ATRA - as single agent clinically ineffective in non-M3 AML - in combination with HMAs also shows in vitro synergistic antileukemic activity in non-M3 AML cells. We previously conducted a non-randomized phase II trial in elderly non-fit AML pts with DAC (3-dy schedule), given alone or combined with ATRA (45 mg/m2 dy 4-28, only during course 2), with encouraging results (Lübbert et al., Haematologica 2012). We now expanded this approach to a 4-arm randomized phase II study (2x2 factorial design) asking whether the addition of either VPA (HDACi activity) or ATRA or both to DAC as first-line treatment of elderly AML pts might improve the effect of DAC monotherapy (NCT00867672). Patients and Methods: Inclusion criteria: newly diagnosed pts 〉60 yr unfit for induction (reasons for treatment decision prospectively captured) with non-M3 AML (WHO, de novo or after antecedent hematologic disorder [AHD], therapy-associated [t]AML), ECOG performance status (PS) 0-2. Pts with 〉30,000 WBC/µl were to receive a short course of hydroxyurea. Treatment: DAC 20 mg/m2 dy 1-5 (treatment arms A/B/C/D), VPA p.o. continuously (target serum levels: 50-110 mg/l) from dy 6 (arms B/D), ATRA p.o. dy 6-28 (arms C/D) of each 28-dy course (repeated until relapse/progression, prohibitive toxicity, withdrawal or death). Key endpoints: objective response rate (ORR): CR/CRi/PR (ELN criteria), overall survival (OS). Sample size calculation was based on the primary endpoint ORR, assuming an ORR of 25% in arm A (Lübbert et al., Haematologica 2012). For a power of 80% (test in this phase II study at 1-sided alpha=0.1) for an increase of ORR to 40% with VPA or ATRA, 176 pts were necessary, planned sample size 200. Efficacy analyses were performed in the intention-to-treat (ITT) population including all randomized pts for whom treatment was started. VPA was investigated by comparing arms B+D vs arms A+C, ATRA by comparing arms C+D vs arms A+B. ORR was analyzed with logistic regression, OS with Cox regression, without adjustment for prognostic factors. Odds ratios (OR) for the effect on ORR and hazard ratios (HR) for the effect on death with 95% confidence intervals (CI), and two-sided p values of the tests of no treatment effect are presented. Central hematopathological review by an independent morphologist was conducted in a blinded fashion as to treatment arms. Results: Between 12/2011 and 2/2015, 204 pts were randomized (4 were excluded from the analysis because no treatment was administered). Median age: 76 yrs (interquartile range 72-79, range 61-92), ECOG PS 0/1/2-3: 19/61/20%: 52% had an HCT-CI 〉3, 16.5% WBC 〉30.000/µl, 31.5% poor cytogenetics (ELN), 51% had an AHD, 13.5% tAML (characteristics overall balanced across all 4 treatment arms). A median of 3 DAC courses were administered (per arm: 2/3/5.5/4), however 53 pts (26.5%), who were older, with reduced PS and a higher HCT-CI compared to the other 147 pts, received only a single course. The ORR (usually achieved only after 〉3 courses) was 17.5%, median OS 6.2 mths (arm A: 8.5% and 4.8 CI [2.8,7.6] mths, arm B: 17.5% and 6.1 CI [3.7,7.2] mths, arm C: 26.1% and 8.4 CI [4.0,14.0] mths, arm D: 18% and 7.7 CI [4.6,11.2] mths, respectively). Effect on ORR of VPA vs no VPA (17.8 vs 17.2%): OR 1.06, CI [0.51,2.21], p=0.88; of ATRA vs no ATRA (21.9 vs 13.5%): OR 1.80, CI [0.86,3.79], p=0.12. Effect on OS of VPA vs no VPA (6.2 vs 6.4 mths median OS): HR 0.94, CI [0.70,1.28], p=0.70; of ATRA vs no ATRA (8.2 vs 5.1 months median OS): HR 0.65, CI [0.48,0.88], p=0.006 (after adjustment for PS, HCT-CI, WBC, LDH: HR 0.59, CI [0.43,0.82], p=0.002). Improved survival with ATRA was also seen in pts with poor cytogenetics. Toxicities (predominantly hematologic) did not show relevant differences between the 4 treatment arms. Conclusions: Based on this ITT analysis of a randomized trial, the addition of ATRA to standard-dose DAC resulted in a higher ORR and in a clinically relevant extension of OS, without additional (hematologic and non-hematologic) toxicity. In contrast, the addition of VPA did not affect ORR or OS. Disclosures Lübbert: Celgene: Other: Travel Funding; Janssen-Cilag: Other: Travel Funding, Research Funding; Ratiopharm: Other: Study drug valproic acid. Schlenk:Pfizer: Honoraria, Research Funding; Amgen: Research Funding. Heuser:Pfizer: Research Funding; Tetralogic: Research Funding; BerGenBio: Research Funding; Karyopharm Therapeutics Inc: Research Funding; Bayer Pharma AG: Research Funding; Celgene: Honoraria; Novartis: Consultancy, Research Funding. Bug:Janssen: Other: Travel Grant; Astellas: Other: Travel Grant; Teva Oncology: Other: Travel Grant; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Other: Travel Grant; Nord Medica: Consultancy. Giagounidis:Celgene Corporation: Consultancy. Brugger:Astrazeneca: Employment. Niederwieser:Amgen: Speakers Bureau; Novartis Oncology Europe: Research Funding, Speakers Bureau.

Description: During the course of chronic myeloid leukemia (CML) progression to blast crisis (BC) is thought to be caused by genetic instability such as cytogenetic aberrations in addition to the translocation t(9;22)(q34;q11). We have shown previously that major route ACA indicate an unfavorable outcome (Fabarius et al., Blood 2011). We now investigate whether there is a correlation in time between appearance of major route ACA and increase in blast count. Methods: Cytogenetic data and blast count in the peripheral blood were available from 1,290 CML patients recruited to the German CML-studies III (621 patients) and IIIa (669 patients) from January 1995 to January 2004. Treatments were interferon-alpha-based or related allogeneic stem cell transplantation (HSCT). Presence of ACA and major route ACA was considered as a time-dependent covariate. Multivariate proportional hazards models were estimated taking Euro CML score, study III vs. IIIa and stem cell transplantability into account. Cumulative incidences of blast increases were calculated starting at the date of the first ACA or major route ACA, respectively, regarding death as a competing risk. Patients were censored at the date of HSCT with an unrelated donor. Results: 1,287 patients were evaluable with median observation times of 13 and 12 years and a 10-year survival of 48% and 61% in CML studies III and IIIa, respectively. 258 patients progressed to BC with a cumulative 10-year incidence of 20%. 195 patients displayed ACA during the course of disease. 45 patients (15.7%) showed ACA already at diagnosis. 44 patients showed unbalanced minor route, 29 balanced minor route aberrations, 23 -Y. 109 patients showed major route aberrations including 10 with other prior ACA. In a multivariate analysis on 1,257 patients, patients with ACA had a hazard ratio (HR) for a blast increase of between 2.0-2.2 (p