Abstract: Autologous erythrocytes were irradiated at doses of 35,000 to 200,000 rads, chromated, and red cell survival studied. The 24-hour loss of labeled cells and subsequent apparent erythrocyte survival times were found to be functions of the radiation dose. ECIB-produced red cell hemolysis of a mild degree is to be expected during courses of therapy, as demonstrated by clinical findings. However, there is no doubt that acute, severe, hemolysis could be produced by administering large doses to patients over a short period of time.

Abstract: 1. Two patients with acute leukemia had considerable decreases in leukemic cells in the peripheral blood as well as reduction in size of spleen and leukemic masses after 10 injections of 3H-TDR given over a 5-day period. Each injection was 0.25 µc./Gm. body weight. 2. The pertinent aspects of cytotoxic effects of 3H-TDR are reviewed. 3. The radiation doses delivered to the nucleus are estimated from autoradiographic data. 4. Evidence is presented for the observed effects being due to 3H-TDR.

Abstract: The International Prognostic Scoring Sytem (IPSS) is an important standard for ssessing prognosis of primary untreated adult patients with myelodysplastic syndromes (MDS). To refine the IPSS, MDS patient databases from international institutions were coalesced to assemble a much larger combined database (Revised-IPSS [IPSS-R], n = 7012, IPSS, n = 816) for analysis. Multiple statistically weighted clinical features were used to generate a prognostic categorization model. Bone marrow cytogenetics, marrow blast percentage, and cytopenias remained the basis of the new system. Novel components of the current analysis included: 5 rather than 3 cytogenetic prognostic subgroups with specific and new classifications of a number of less common cytogenetic subsets, splitting the low marrow blast percentage value, and depth of cytopenias. This model defined 5 rather than the 4 major prognostic categories that are present in the IPSS. Patient age, performance status, serum ferritin, and lactate dehydrogenase were significant additive features for survival but not for acute myeloid leukemia transformation. This system comprehensively integrated the numerous known clinical features into a method analyzing MDS patient prognosis more precisely than the initial IPSS. As such, this IPSS-R should prove beneficial for predicting the clinical outcomes of untreated MDS patients and aiding design and analysis of clinical trials in this disease.

Abstract: Hazards regarding mortality and leukemic transformation in MDS diminish over time in higher-risk but remain stable in lower-risk patients. This change of hazard indicates time-dependent attenuation of power of basal risk scores, which is relevant for clinical decision making.

Abstract: Background In patients with Myelodysplastic Syndromes (MDS), TP53 mutations associate with high-risk presentation, complex karyotype, acute myeloid leukemia (AML) progression and poor response to hematopoietic stem cell transplantation. These associations highlight the relevance of TP53 as a prognostic and predictive biomarker. Consistent with its role as a tumor suppressor, bi-allelic targeting of the TP53 locus is a frequent but not an obligatory event. Despite the central role of TP53 in MDS, the clinical implications of TP53 mutations in the context of allelic state have not been extensively studied. Methods Under the auspices of the International Working Group for Prognosis in MDS, we sequenced a representative cohort of 3,324 peri-diagnosis MDS patients on a next generation sequencing (NGS) panel optimized for myeloid disease. Conventional G-banding analysis (CBA) was available for 2,931 patients. Focal (~3MB) gains and deletions and regions of NGS-derived copy-neutral loss of heterozygosity (cnLOH) were assessed using an in-house algorithm CNACS. Putative oncogenic mutations in TP53 were characterized by consideration of normal controls and established population databases. A validation cohort of 1,120 samples with independent but comparable molecular and clinical annotation was sourced from a compendium of Japanese MDS data to include JALSG-MDS212, JMDP registry, and regional registries. Results NGS-derived ploidy alterations and CBA show a high genome-wide concordance. From NGS profiles, 11% of patients (n=360) are subject to cnLOH, of which 80 target the TP53 locus. We characterize 490 TP53 mutations in 380 patients, representing 11% of the cohort. Amongst those patients, 22% (n=85) and 21% (n=78) have a deletion or a cnLOH involving the TP53 locus, respectively. Taken together, these segregate patients into two TP53 states: a mono-allelic state where one wild type allele remains (33% of TP53 mutated patients, n=126); and a multi-hit state where TP53 is altered multiple times by either mutations, deletions or cnLOH (67% of TP53 mutated patients, n=254). We find that TP53 state shapes clinical presentation and outcomes. Mono-allelic TP53 patients present with more favorable disease than multi-hit TP53 patients: they are less cytopenic, have lower bone marrow blasts (median 4 vs. 9%, p & lt;0.0001) and are enriched in low risk WHO subtypes. We show that the established association between mutated TP53 and complex karyotype is specific to the multi-hit TP53 state (OR=66, CI: 33-141, p & lt;0.0001). Critically, we show that multi-hit TP53 associates with worse overall survival as compared to mono-allelic TP53 (HR=3.7, CI: 2.7-5.1, p & lt;0.0001; Figure 1a) and more pronounced AML transformation (HR=5.3, CI: 3.1-8.9, p & lt;0.0001; Figure 1b). Patients with mono-allelic TP53 mutations have a similar survival to that of wild type TP53 patients and track overall IPSS-R, whereas multi-hit TP53 stratifies adverse prognostic subgroups independent of the IPSS-R. We formally test this using multivariate models that consider age, peripheral blood counts, blasts and IPSS-R cytogenetic score and show that multi-hit TP53 state is an independent prognostic factor for overall survival and AML transformation, whilst mono-allelic TP53 state is not significant. We also observe a significant difference in overall survival between TP53 states in the context of therapy-related MDS (HR=3.1, CI: 1.2-7.9, p=0.03). Last, analyses of 12 serial samples identify multi-hit targeting of the TP53 locus as a critical driver of AML transformation in the context of TP53-mutated MDS. These findings are replicated in the validation cohort. Conclusions TP53 is a natural candidate for incorporation in molecularly informed risk stratification schemas (molecular IPSS-R). We show that TP53 state rather than mutation alone is an independent diagnostic and prognostic biomarker in MDS. We propose that ascertainment of TP53 state is critical in prospective clinical sequencing for risk estimation, disease monitoring and future correlative research into predictors of response to established and investigational therapies. Disclosures Bernard: Celgene: Research Funding. Hasserjian:Jazz Pharmaceuticals: Consultancy; Promedior, Inc.: Consultancy. Germing:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria; Amgen: Honoraria. Cargo:Celgene: Research Funding. Santini:Acceleron: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Menarini: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kotsianidis:Celgene: Research Funding. Takaori-Kondo:Pfizer: Honoraria; Chugai: Research Funding; Janssen: Honoraria; Kyowa Kirin: Research Funding; Takeda: Research Funding; Ono: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria. Savona:Selvita: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Patents & Royalties; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sunesis: Research Funding. Ades:Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Silence Therapeutics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Helsinn Healthcare: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding. Neuberg:Pharmacyclics: Research Funding; Madrigal Pharmaceuticals: Equity Ownership; Celgene: Research Funding. Stevenson:Celgene: Research Funding. Fenaux:Jazz: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Aprea: Research Funding; Celgene Corporation: Honoraria, Research Funding. Platzbecker:Novartis: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Heuser:Synimmune: Research Funding; Bayer Pharma AG, Berlin: Research Funding. Valent:Blueprint: Research Funding; Pfizer: Honoraria; Celgene: Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Deciphera: Honoraria, Research Funding. Miyazaki:Nippon-Shinyaku: Honoraria; Dainippon-Sumitomo: Honoraria; Otsuka: Honoraria; Chugai: Research Funding; Novartis: Honoraria; Kyowa-Kirin: Honoraria. Finelli:Novartis: Consultancy, Speakers Bureau; Celgene Corporation: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Speakers Bureau. Atsuta:CHUGAI PHARMACEUTICAL CO., LTD.: Honoraria; Kyowa Kirin Co., Ltd: Honoraria. Gattermann:Novartis: Honoraria; Takeda: Research Funding; Alexion: Research Funding. Ebert:Broad Institute: Other: Contributor to a patent filing on this technology that is held by the Broad Institute.; Celgene: Research Funding; Deerfield: Research Funding. Bejar:Celgene: Consultancy; Takeda Pharmaceuticals: Research Funding; AbbVie/Genentech: Consultancy, Honoraria; Astex/Otsuka: Consultancy; Modus Outcomes: Consultancy; Daiichi-Sankyo: Consultancy. Greenberg:Notable Labs: Research Funding; Celgene: Research Funding; Genentech: Research Funding; H3 Biotech: Research Funding; Aprea: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Ogawa:Qiagen Corporation: Patents & Royalties; ChordiaTherapeutics, Inc.: Consultancy, Equity Ownership; RegCell Corporation: Equity Ownership; Dainippon-Sumitomo Pharmaceutical, Inc.: Research Funding; Kan Research Laboratory, Inc.: Consultancy; Asahi Genomics: Equity Ownership. Papaemmanuil:Celgene: Research Funding.

Abstract: Abstract 2772 Poster Board II-748 Introduction: The IPSS-Score, published by Greenberg et al. (1997), defines the gold standard in risk stratification of patients with MDS. Since its implementation in 1997 based on 816 patients with primary MDS, the knowledge concerning the prognostic impact of distinct abnormalities increased extensively. The present study proposes a new and comprehensive cytogenetic scoring system based on an international data collection of 3803 patients, originating from the German-Austrian (GA)-, the International Risk analysis workshop (IMRAW)- and the Spanish Cytogenetics working group (GCECGH). Additionally, 53 cases of rare abnormalities were contributed by the International Cytogenetics Working Group of the MDS Foundation (ICWG), resulting in total number of 3856 pts. As compared to our previous reports, the data set was substantially enlarged by adding the GCECGH cases and data quality was improved by updating the clinical and survival data; allowing the analysis of the prognostic impact for isolated abnormalities exclusively to assure a maximum accurateness. Furthermore, multivariate analysis was refined by including peripheral cytopenias. Materials and Methods: Inclusion criteria were defined as follows: Primary MDS, age 〉 =16, and bone marrow blasts 〈 =30%. Regarding therapy, exclusively patients with primary MDS and supportive care, only allowing short courses of oral chemotherapy or hemopoietic growth factors were included. Based on these criteria, 958 pts. were excluded resulting in 2901 pts. available for final analysis. Univariate and multivariate analysis concerning overall survival (OS) and 25% AML-transformation (AML-t) was performed. In multivariate analysis, age, gender, bone marrow blast count and number of peripheral cytopenias were defined as co-variables. OS and AML-t in distinct cytogenetic abnormalities was only calculated when the abnormality occurred as an isolated aberration with a minimal frequency of n=10. Median observation time was 19.0 months. Clinical follow-up was performed until April 2009. Results: In total, 20 cytogenetic subgroups matching the inclusion criteria were detected. Abnormalities were grouped as normal (n=1522, 52.5% of all cases), single (1 abnormality), double (2 abnormalities) or complex ( 〉 =3 abnormalities). Single abnormalities found were: del(5q) (176, 6.1%); -7/7q- (59, 2.0%); +8 (130, 4.5%); del(20q) (48, 1.7%), -Y (46, 2.1%); der(1;7)(q10;p10)/t(1;7)(var;var) (10, 0.3%); der(3)(q21)/der(3)(q26) (10, 0.3%); del(11q) (19, 0.7%); del(12p) (17, 0.6%); i(17)(q10) (11, 0.4%); +19 (10, 0.3%), +21 (10, 0.3%) and any other single (150, 5.2%). Double abnormalities were stratified into 3 subgroups: double including del(5q) (45, 1.6%); double including -7/7q- (31; 1.1%) and any other double (98, 3.4%). As reported (Haase et al. Blood 2008), complex karyotypes were sub-divided into 2 groups: Karyotypes with 3 abnormalities (59, 2.0%) vs. 〉 3 abnormalities (188, 6.5%). Finally, 20 pts. (0.7%) displayed cytogenetically unrelated clones. According to OS and AML-t, abnormalities were classified to 4 prognostic subgroups: good (normal, del(5q), double incl. del(5q), der(1;7)(q10;p10)/t(1;7)(var;var), del(11q), del(12p), +19, del(20q), -Y); int-1 (any other double, +8, i(17)(q10), +21, any other single, independent clones); int-2 (double incl. -7/7q-, der(3)(q21)/der(3)(q26), -7/7q-, complex 3 abnormalities) and poor (complex 〉 3 abnormalities). Median survival was 50.6 months for good (n=1936), 25.7 months for int-1 (n=451), 16.0 months for int-2 (n=177) and 5.7 months for poor (n=188) and AML-t was 71.9 months for good (n=1681), 14.7 months for int-1 (n=384), 9.8 months for int-2 (n=148) and 3.4 months for poor (n=159). Differences in OS and AML-t were highly significant (p 〈 0.0001). Multivariate analysis resulted in a Hazard Ratio of 1.0 for good (reference category), 1.8 for int-1, 2.1 for int-2 and 4.8 for poor concerning OS. Regarding AML-t, HR was 1.0 for good, 2.6 for int-1, 3.1 for int-2 and 5.2 for poor (all p 〈 0.0001 for OS and AML-t). Conclusions: In summary, we were able to generate a solid database for a revised cytogenetic scoring system, which can serve as the cytogenetic model for the upcoming revision of the IPSS. Acknowledgments: The authors like to thank the MDS-Foundation for its support. Disclosures: No relevant conflicts of interest to declare.

Abstract: Introduction New, refined prognostic scoring systems have been established for MDS. Most scores assess prognosis at time of diagnosis assuming stable prediction over time. Earlier studies have shown moderate loss of prognostic power over time in scores using clinical parameters whereas cytogenetic scores maintained prognostic power, scores including comorbidity had shown gain of prognostic power (Pfeilstöcker et al, 2012). The aim of this multicenter retrospective study was to assess the relative stability of the newly developed scoring systems over time, to compare and explain observed time-related losses of prognostic power, and to discuss their clinical implications. Methods This study is based on 7212 untreated (no disease modifying treatment) MDS patients from multiple institutional databases of the IWG-PM, which generated the IPSS-R (Greenberg et al, 2012). Patient characteristics were well comparable with other populations: median age 71 years, male gender 60 %, median overall survival 3.8 years (range 3.7-4.0), median time to AML transformation not reached with 25% of patients transforming to AML after 6.8 years. Patients were diagnosed and classified by FAB and WHO; cytogenetics were classified by original IPSS subtypes and by the recently refined proposal integrated into the IPSS-R (Schanz et al, 2012). The following scores were analysed for their stability over time: IPSS, IPSS-R, WPSS variants, cytogenetic scores, age, performance status and other differentiating features of the IPSS-R. Time variations were described by the Cox-zph-test, and by applying Dxy, a measure of concordance, for censored data at separate observation periods. Results In line with previous observations, loss of prognostic power occurred over time after diagnosis in all scoring systems. While for the entire population the risk between adjacent IPSS-R risk categories differs by ∼80%, for patients observed at least 1 year the increase is ∼66%, and for those observed 4 years it is only ∼25%. The IPSS-R and particularly its age-including version (the IPSS-RA) retained the highest prognostic values compared to all other scoring systems at all time points. Dxy for IPSS-R: at diagnosis 0.43, 1 year 0.35, 2 years 0.27, 4 years 0.14. Including age, as in the IPSS-RA, was associated with less loss of prognostic power over time: Dxy at diagnosis 0.46, 1 year 0.38, 2 years 0.31, 4 years 0.22. For the IPSS and WPSS (available for the latter in only 33% cases), these values were: 0.37, 0.30, 0.22, 0.11 and 0.44, 0.36, 0.29, 0.18 respectively. Considering risk categories, the risk remained fairly constant over time for the lower risk categories in every analyzed scoring system, while the risks in the higher risk categories were especially high in the second half of the first year after diagnosis, diminishing thereafter, thus reducing the prognostic value of these categories over time. To determine whether statistical weights optimized for each time period would alter these results, time-specific weights were applied, which did not demonstrate substantially different prognostic values from the basic model analysis. Particularly good retention of prognostic power was found in the lower risk categories over time. The lesser retention of prognostic power in the higher risk categories appeared related to loss of a larger portion of these patients over time due to their deaths or being censored by their beginning treatment. For the IPSS-R intermediate risk category patients, the prognosis for survival approached the “high” category ∼3 years after diagnosis, while it remained intermediate regarding their risk of AML transformation. Conclusions These data demonstrate that a degree of attrition of prognostic value occurred over time from diagnosis for all of the assessed MDS prognostic scoring systems. The IPSS-R, particularly the age-inclusive IPSS-RA, best retained such prognostic capability over time for the untreated patients analyzed. Disclosures: No relevant conflicts of interest to declare.

Abstract: Abstract 4022 Introduction: The occurrence of cytogenetically-unrelated clones is a rare but recognized event in haematological malignancies that may appear at either presentation or in further progression of disease. As yet, little is known about the composition and prognostic relevance of unrelated clones in MDS and AML. The aim of this retrospective study was to analyze cases of unrelated clones in a large, multicentric and international study to further characterize their clinical relevance in myeloid disorders. Patients/Methods: A total of 95 patients with unrelated clones and their corresponding clinical data were collected from 10 different databases: MLL (n=30), German-Austrian-Swiss (16), Athens (11), City of Hope (10), Bobigny (6), Lund (5), Tokyo (5), Spanish (4), IMRAW (3), and Dortmund (2). 77 pts. (81.1%) had a diagnosis of primary MDS, 5 (5.3%) t-MDS, 9 (9.5%) de novo AML, and 4 (4.2%) AML following MDS. Abnormalities detected FISH only were excluded. Unrelated clones were defined as two abnormal clones that were not evolvable from each other. Overall survival and the risk of AML transformation was calculated. For comparison MDS cases without unrelated clones were included from the international MDS database, including 2901 pts. with primary MDS. Result: Two unrelated clones were seen in 80 pts. (84%), three in 14 (15%) and five in 1 patient (1%). The majority of cases showed one aberration per clone (84.5%). The most frequent single aberration was +8 (43.2%), followed by del(5q) (28.4%). Other anomalies were -7/del(7q) (14.7%), -Y (12.6%), del(20q) (9.5%), +21 (7.4%), i(17q) (5.3%) and del(9q) (5.3%). Complex aberrations were identified in 3/95 cases (3.2%) only. Patients with unrelated clones showed an overrepresentation of +8 (p 〈 0.0001), -Y (p=0.031) and i(17q) (p=0.013) in comparison to patients without unrelated clones. A combination of del(5q) and +8 was observed in 13/95 (13.7%) cases. Other recurrent combinations were: -7/+8 (n=2; 2.1%), -Y/del(5q) (n=2; 2.1%) and del(5q)/20q- (n=2; 2.1%). Translocations occurred only in single cases. The median survival of all patients with unrelated clones was 26.5 months, a finding consistent with an intermediate prognosis. Patients with a +8 clone and a clone with any other aberration showed a median survival of 21.0 months. Combinations of del(5q)/+8 (median 45.8 months) as compared to isolated del(5q) showed no significant difference in survival and in comparison to cases with +8 plus a clone with any other aberration, led to a significantly better survival (p=0.004). Summary: Our data presents the largest series of MDS/AML patients showing unrelated clones published to date. While the most frequent combination del(5q)/+8 is associated with a favourable outcome, all other combinations have to be assigned to the intermediate risk group until further distinct combinations can be evaluated. Further data will be presented in detail. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Slovak:PerkinElmer: Employment. Ohyashiki:Nippon Shinyaku Co., Ltd.: Research Funding. Giagounidis:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Bennett:Johnson & Johnson: Consultancy.