ALBERT

Description: INTRODUCTION: Traditional platinum-based salvage regimens like DHAP, ICE are effective in relapsed Hodgkin's lymphoma (HL), but are more toxic. Gemcitabine based regimens are equally effective in salvage of lymphomas, but are less toxic and allow better stem cell collection for subsequent high dose therapy (HDT). There is limited data on the usefulness of gemcitabine based salvage regimens after the failure of salvage therapies like DHAP and ICE. At our center, we used a combination of gemcitabine, vinorelbine and dexamethasone (GVDexa), a non-platinum containing regimen in those patients who failed DHAP/ ICE based salvage treatment. METHODS: The records of patients with relapsed and refractory Hodgkin's lymphoma, who were treated with GVDexa, were reviewed. The regimen consisted of Gemcitabine 1000mg/m2 IV (D1,8), Vinorelbine 25mg/m2 IV (D1,8) Dexamethasone 40mg oral (D1-4) given as outpatient. It was given for 2-3 cycles until best response or till the patient underwent HDT. RESULTS: Between July 2010 to Jun 2015, 25 patients received GVDexa. The median age was 23 years (Range: 11 to 45 yrs) and 64% were males. Baseline characteristics are summarised in Table 1. Twenty-one patients (84%) had previous exposure to salvage therapy with DHAP/ ICE and GVDexa was given as third line treatment. The overall response rate was 48% (12/25) with complete response in 20% (5/25) and partial response in 28% (7/25). Toxicity: A total of 61 cycles [Median: 2 (Range: 1-6)] were delivered among 25 patients. Grade 3/4 haematological toxicities (neutropenia and thrombocytopenia) occurred in 9/61 (14.7%) cycles and febrile neutropenia occurred in 2 (3.2%) cycles. Grade 3/4 non-haematological toxicities were rare (paralytic ileus in 1 patient). There were no toxic deaths. Stem cell collection: Stem cell harvesting for HDT was attempted in 12 patients and was successful (〉 2 million CD34 positive cells/kg) in 8 (67%) patients. Seven of these patients successfully completed HDT. Two patients who failed stem cell collection underwent reduced intensity conditioning allogeneic transplant. CONCLUSIONS: GVDexa, when used as third line therapy in relapsed and refractory HL shows promising response rates, with minimal toxicity. The high response rates achieved despite failure of first line platinum based salvage, points to the potential usefulness of this regimen as first line salvage therapy in refractory HL. GVDexa could emerge as a safe and effective non-platinum containing alternative regimen for second-line therapy in HL. Table 1. Baseline characteristics (N=25) PARAMETER Number (Range/Percentage) Age (median, range) 23 yrs (10 to 45 yrs) Male sex 16 (64%) Prior exposure to DHAP/ICE chemotherapy 21 (84%) Previous lines of chemotherapy (median, range) 2 (1 to 4) Time from 1st diagnosis to relapse (median, range) 31.5 months (4.3 to 153.7 months) Primary progressivea/refractory 13 (52) Stage III/IV at relapse 20 (80) Haemoglobin 〈 10g/dL at relapse 12 (48) a. Progressed within 3 months of completion of first line chemotherapy Disclosures No relevant conflicts of interest to declare.

Description: Introduction: The treatment of acute myeloid leukaemia (AML) with intensive induction regimens remains a challenge in low and middle incomes countries. Early induction related deaths particularly due to infectious complications are a major problem. This is in stark contrast to high-income countries where induction mortality has declined significantly over the last 2 decades with improved antibiotic use and supportive care. In this study we assess induction mortality (all cause and infection related) in AML patients who received intensive induction therapy in a tertiary cancer centre in India over a 10-year period (2008-2017). Methods: We included patients with newly diagnosed AML treated at Cancer Institute, Chennai in South India who received intensive induction therapy. Intensive therapy was defined as use of any anthracycline with cytarabine (3+7/ADE/others). We assessed baseline demographics including age, gender, cytogenetic risk status, and type of induction regimen used. We also assessed key clinical outcomes including patterns of antimicrobial prophylaxis and treatment, infectious complications, cause of death, ICU stay, and length of hospital stay. Induction mortality was defined as deaths occurring within 45 days of initiating treatment for AML or start of 2nd induction. Results: Between January 2008 and December 2017, 510 patients with AML were evaluated at Cancer Institute, Chennai and accepted for treatment. Excluding 51 patients with APML and 55 patients who were unfit for intensive induction, 404 patients received treatment with an intensive induction regimen. Median age was 23 years (Range: 1-74 years) and 219 (54.2%) were male patients. 165(40.8%) patients were less than 18 years of age. Among those who had cytogenetic and/ molecular data for risk stratification [N=341 (84.7%)], 101 (29.6%) were low risk, 166 (48.7%) intermediate risk and 74 (21.7%) high risk. Therapy details: 318 (78.7%) patients received daunorubicin and cytarabine ('3+7'), 52 (12.9%) received ADE, and 38 (8.4%) received other combinations ofdaunorubicin and cytarabine. 87(21.5%) of the cases had infection at the time of presentation. 389(96.8%) had an episode of febrile neutropenia with 184(45.5%) requiring management in Intensive Care Unit (ICU). Focus of infection could be identified in 294(72.7%) of the patients with 207(51.2%) having a positive culture. The overall incidence of induction mortality over the entire study period was 15.6%(n=63)and 14.8% for the most recent year included (2017). The majority of the deaths (n=53; 84.1%) were due to infectious complications (fig1). Median time to death from start of induction was 19 days. The incidence of fungal pneumonia significantly reduced since 2012 when thethe antifungal prophylaxis was switched from fluconazole to voriconazole (p=0.03). Starting in 2012, an increase in the incidence of multi-drug resistance (MDR) gram negative septicaemia and mortality (MDR: carbapenem resistant enterobacteriacea sensitive only to colistin and tigecycline) was noted. This led to proactive use of colistin in patients with febrile neutropenia and septic shock, a GI focus or baseline stool colonisation by MDR gram negative organisms.Despite this, during the last 4 years(2014-2017), there has been a significant rise in the incidence of sepsis and death due to MDR gram negative organisms (fig2). The proportion of deaths attributable to MDR sepsis is 23.8%. The early use of colistin, tigecycline and carbapenems did not significantly decrease the mortality. Conclusions: The induction mortality remains high at 15.6% and is in contrast to the declining induction mortality in high-income countries. While the morbidity and mortality due to specific infections (specifically fungal pneumonia) have changed over time, there is no signfiicant decline in infectious or all cause induction mortality over the 10 years. In the last four years, MDR gram negative sepsis has been a major cause of morbidity and mortality. The early and increased use of broad spectrum antibiotics like tigecycline, colistin and carbapenems has not led to a decrease in MDR gram negative sepsis. Overall, despite improvements in supportive care and early use of broad spectrum antimicrobial agents, infection related morbidity and mortality remains a substantial challenge in treating acute myeloid leukaemia in low- and middle-income countries. Disclosures No relevant conflicts of interest to declare.

Description: Background: The use of PET CT has become instrumental in the management of Hodgkin's lymphoma (HL), with multiple studies favoring PET adapted therapies. Current guidelines recommend using the Deauville score (DS) for assessment of end therapy PET-CT scans. We looked at the predictive ability of end therapy PET CT DS in a cohort of HL. Methods: Adult patients diagnosed with, and treated for, Hodgkin's lymphoma between 2007 and 2015 with end-of-treatment PET CT scans were included in this retrospective analysis. Results: One hundred and ninety-eight patients [median age- 35 (18-74) years, advanced disease: 147 (74%); bulky disease: 54 (27%)] underwent end-of-therapy PET CT scanning with Deauville scoring. The chemotherapy regimens used were as follows: ABVD in 167 patients (84%); COPP/AVD in 20 patients (10%) and other regimens in 11 patients (6%). The end of therapy Deauville score (DS) was 1 or 2 in 160 patients (81%), 3 in 9 patients (5%) and 4 or 5 in 29 patients (14%). The median follow-up was 62 months. The 5-year DFS for patients with DS 1 or 2 was 85%, DS 3 was 65% and DS 4 or 5 was 40% (p

Description: Introduction Acute lymphoblastic leukemia (ALL) diagnosed in adolescent and young adults (AYA) poses unique challenges. Despite using more intensive "pediatric-type" protocols, outcomes are generally inferior to those seen in children. The reasons are wide ranging, but when compared to pediatric ALL, AYA ALL has higher-risk biology, poorer tolerance to intensive treatments, and worse compliance with treatment regimens. India has one of the largest AYA populations in the world and AYA-ALL form a significant proportion of leukemias. The Indian acute leukemia research database [INwARD] was established in 2018 and had reported outcomes of ALLs from various centers of all age groups (Korula A, et al. Blood 2018 132:1374). Here, we present data focused on AYA-ALL from this database. Methods Retrospective data of AYA (15-29 years) patients with ALL (diagnosed between January 2012 to December 2017) from 9 centers were entered into an independent centralized online data capture system and analyzed for presenting characteristics, treatment and survival outcomes. Protocol choice was based on individual-center preference. For the purpose of this analysis, patients with WBC ≥30000 (B cell) and ≥100,000 (T-cell and other subtypes) were considered as high risk. Intensive protocols (MCP-841, BFM-95, COG), predominantly meant for children were labeled as "pediatric-type" and less intense protocols (GMALL, Hyper CVAD, UKALL) were considered as "adult-type". Results In the 6-year period, 1454 patients were registered [Males: 1114(76%), Median age: 20 years (15-29), Fig. 1.B; Subtype: B -ALL: 916(63%), T-ALL: 396 (27%); Fig. 1.C; High risk disease: 406 (28%)]. Of these,1100 (75%) underwent treatment. Poor financial support was the major reason for not taking treatment (Fig. 1.A). "Pediatric-type" protocols were used in 881 (81%) patients. After induction, 72% achieved complete remission (CR), 11% were refractory, 4% died during induction and 14% were not evaluable. Minimal residual disease was assessed in 581 and was present in 356 (61%). Attainment of CR, induction mortality, or MRD achievement was not affected by the type of regimen. Among these 1100 patients, 138 (12%) were lost to follow up and did not complete treatment. BCR ABL was tested in 636 and was positive in 112 (17%) [19% among patients with B-ALL (107/557)]and 106 of these were treated with additional tyrosine kinase inhibitors [imatinib (N=83) and dasatinib (N=23)]. Survival analysis: After a median follow up of 21 months, 270 patients relapsed [median time to relapse: 24 months (73% medullary, 17% CNS or testis, and 10% had a combined relapse) and 259 had died. The estimated 2-year event-free (EFS), relapse-free (RFS) and overall survival (OS) were 64%, 75% and 75% respectively. On univariate analysis the factors associated with inferior survival were as follows: EFS: WBC count ≥30,000/cmm, and ECOG PS 2-4; RFS: WBC count ≥30,000/cmm and ECOG PS 2-4; OS: use of "adult-type" protocols, ECOG PS 2-4, and BCR-ABL positive disease. On multivariate cox regression analysis, the only factors associated with inferior OS were: use of "adult" protocols (HR: 1.6), and BCR -ABL positive status (HR1.56) (Fig. 1.D). High WBC count at presentation predicted for inferior RFS while no factor could predict EFS on multivariate analysis. Conclusions In a multicenter analysis of AYA-ALL from different parts of India, we found that a quarter of newly diagnosed patients do not start treatment and another 12% are lost from follow up before treatment completion. Majority (80%) of the centers used "pediatric-type" protocols to treat AYA-ALL. Though superior survival was achieved with "pediatric-type" protocols, results must be interpreted with caution as these regimens were likely to be used more often in in younger patients. Variations in treatment protocols used between centers and the retrospective nature of the data are other caveats. Despite these limitations, this is one of the largest reports of AYA ALL from any part of the world and serves as a benchmark for planning prospective studies. Disclosures No relevant conflicts of interest to declare.

Description: Introduction:Breast Implant Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) is an indolent subtype of ALCL, arising in the space between the implant and the capsule. BIA-ALCL seems to be directly related to the exposure to breast implants, and usually happens more than 7 years from implant placement. In 2011 the Food and Drug administration released the first safety communication on the risk of BIA-ALCL for women with breast implants, raising awareness of the disease. In 60-70% of the cases BIA-ALCL presents as a delayed seroma, a non-resolving fluid collection around breast implants arising after at least 1 year from implant placement. In previous studies, the risk of developing a late seroma ranged between 0.05% to 0.1% for people with textured surface breast implants. Among those with delayed seromas, the risk of BIA-ALCL has been estimated from retrospective cohorts to be 10%. (McGuire 2017, Clemens 2017, Maxwell 2015, Di Napoli 2017). Methods:A prospective cohort study was conducted in the population that underwent breast reconstruction with textured breast implants after mastectomy for breast cancer by a single surgeon at Memorial Sloan Kettering Cancer Center (MSKCC). Patients were enrolled from December 1992 to December 2017 at the time of tissue expander insertion, underwent long-term follow up and major events related to implants were prospectively recorded. We actively started looking for BIA-ALCL in late seromas in early 2011. All cases of BIA-ALCL were analyzed by our hematopathology service at MSKCC. We identified all late seromas sent to hematopathology to exclude BIA-ALCL by cross checking all the pathology reports containing the words "lymphoma" or "anaplastic" or "ALCL" in this population. We calculated the cumulative incidence of clinically relevant late seromas, considering death as a competing risk with the statistical program R version 3.5.1. Results:Between 1992 and 2017, 3521 women underwent breast reconstruction with textured surface expanders followed by permanent textured breast implants. Median age at surgery was 48 years (range 18-88), 1056 (30.0%) underwent unilateral reconstruction and 2464 (70.0%) bilateral reconstruction. Reason for mastectomy was lobular carcinoma in 675 (19.1%), 116 in situ, ductal carcinoma in 2529 (71.8%), 591 in situ, other histology in 59 (1.7%), unknown in 257 (7.3%). Besides surgery, additional treatments for breast cancer were: chemotherapy in 1015 (28.8%), radiotherapy in 285 (8.1%), chemo and radiotherapy in 706 (20.0%), none in 1514 (43.0%). Median follow up of the cohort was 8.2 years (range 3.4 months - 26.4 years). After a median exposure of 9 years (range 1.8 - 15.8 years), 28 women developed a clinically relevant delayed seroma, and 8 were diagnosed with BIA-ALCL (28.5% of the late seromas). The first late seroma was analyzed with flow cytometry in February 2011. All seromas sent to pathology were clinically relevant (main symptom was swelling of the breast - in 15 patients, tenderness/fullness of the breast - in 5 patients, asymmetry - in 3 patients, capsule contracture - in 5 patients). Three patients had previous drainage of peri-implant fluid that was not analyzed in pathology. 2 additional cases of BIA-ALCL were diagnosed in this population, one on an internal mammary chain lymph node biopsy, without fluid collection, and another with a capsular mass and lymph node involvement. Rate of late seroma accounting for the varying follow-up and death as a competing event was 1.6% at 15 years. Rough percentage getting a seroma was 0.79%, 1/126 women exposed. All the 28 samples were analyzed with cytology, and 22/28 with flow cytometry including CD30. 14/28 (50%) of these women removed the implants for several reasons, 3/28 (10.7%) immediately exchanged the implants with another textured surface device. Conclusions:in this population of breast cancer patients receiving textured breast implant reconstructions, the incidence of clinically relevant seromas and BIA-ALCL seems higher than previously reported. Similarly, the ratio of patients testing positive for BIA-ALCL on the total number of seromas analyzed higher than previously estimated. We believe these results will be informative for people with breast reconstructions after breast cancer and their surgeons, to better estimate the risk of seroma and BIA-ALCL with textured implants. Disclosures Cordeiro: Inamed: Research Funding; Acelity: Research Funding; Allergan: Research Funding. Dogan:Takeda: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Seattle Genetics: Consultancy; Corvus Pharmaceuticals: Consultancy; Roche: Consultancy, Research Funding. Horwitz:Seattle Genetics: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Trillium: Research Funding; Kyowa Hakko Kirin: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Astex: Consultancy; Portola: Consultancy; Affimed: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Kura: Consultancy; Celgene: Consultancy, Research Funding; Affimed: Consultancy; Trillium: Research Funding; Forty-Seven: Research Funding; Miragen: Consultancy; Mundipharma: Consultancy; Aileron: Research Funding; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Trillium: Research Funding; ADCT Therapeutics: Research Funding; Innate Pharma: Consultancy; Affimed: Consultancy; Forty-Seven: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Portola: Consultancy; Portola: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Mundipharma: Consultancy; Mundipharma: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Innate Pharma: Consultancy; Aileron: Research Funding; Innate Pharma: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Miragen: Consultancy; Miragen: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy; Kura: Consultancy; Kura: Consultancy; Aileron: Research Funding; ADCT Therapeutics: Research Funding; Innate Pharma: Consultancy; Astex: Consultancy; ADCT Therapeutics: Research Funding; Astex: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Miragen: Consultancy; Astex: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Aileron: Research Funding; Kura: Consultancy; Trillium: Research Funding; Portola: Consultancy; Forty-Seven: Research Funding.

Description: Background: Minimal Residual Disease (MRD) is a powerful predictor of event-free survival in acute lymphoblastic leukemia (ALL). However, as T-ALL is less common, MRD studies are limited, often with small cohorts, and even fewer have been done by flowcytometry-based MRD (FC-MRD). There have also been different time-points such as Post-Induction (PI-MRD), and late or Post-Consolidation (PC-MRD) that have shown significant correlation with overall, event, and relapse-free survival (OS, EFS & RFS). As the available literature is still not conclusive, we investigated the impact of FC-MRD on survival in childhood T-ALL at a large tertiary cancer care centre in India. Methods: Children less than 15-years age diagnosed with T-ALL from Jan-2014 to May 2018 were treated uniformly on a modified MCP-841 protocol that included a 4-drug induction (vincristine, prednisolone, l-asparaginase, daunomycin), and consolidation with high-dose cytarabine (24gm/m2 in 3 equal legs for children below 3-years, and 16gm/m2 in two equal legs, for 3 or more years age). Post-consolidation therapy followed the pattern of Interim Maintenance, two Delayed Intensification cycles, and 18 months of Maintenance. Central Nervous System (CNS)-directed therapy consisted of intrathecal methotrexate in all cycles, and those with CNS involvement received additional Cranial Radiation of 18Gy. In early-thymic-precursor (ETP-ALL) immunophenotype patients, dexamethasone replaced prednisolone in Induction. The protocol did not include High-Dose Methotrexate. FC-MRD was estimated by 10-color FC-MRD assay on Navios flow-cytometer (Beckman Coulter, Inc.) at Post-Induction(day-35), and Post-Consolidation(day-78) for those PI-MRD positive(+ve). FC-MRD was analyzed on Kaluza® software v-1.3. Any detectable value was taken as positive. Statistical analysis was performed using MedCalc Statistical Software®. Results: Of 368 eligible patients diagnosed at our centre in the study period, 81 did not undergo PI-MRD (14- Induction deaths, 13- treatment abandonment, 54- referral to other institute/ time-point missed/ did not consent/ other reasons). Another 18 abandoned treatment within 100 days of diagnosis and were also excluded. In the remaining 269, median age was 10-years (range:1-15), M:F-3.8:1. Median presenting WBC was 96.7 x 103/cmm (range:1.14-849), and thirteen patients had ETP. PI-MRD was positive in 125(46%) patients (median MRD -0.3%, range:0.0007-43.6%) of which 58(46.4%) developed medullary relapse, compared to 17 of 144(11.6%) for PI-MRD negative(-ve) patients, with Hazard Ratio (HR) for risk of medullary-relapse for PI-MRD+ve being 5.02(95% CI:3.16-7.96; p

Description: Introduction: Core binding factor acute myeloid leukemia (CBF-AML) is one of the commonest subtypes of AML characterized presence of t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22). It is characterised by a high frequency of somatic mutations especially in RAS and tyrosine kinase signalling pathways. Here we investigated the feasibility of improving risk prediction of CBF-AML using machine learning algorithms. Methods: We developed a next generation sequencing panel that targeted 50 genes implicated in the pathogenesis of myeloid malignancies using single molecule molecular inversion probes. This panel was used to sequence 106 patients of CBF-AML accrued over a six year period (March 2012 - December 2018) treated with conventional "3 + 7" chemotherapy. Post data analysis, we devised a supervised machine learning (ML) approach for identification of mutations most likely to predict for favorable outcome in CBF-AML. We included somatic mutations in genes occurring in CBF-AML at a frequency of 〉5%. A total of 11 variables were included for feature selection to predict for favorable outcome (including mutations in ASXL2, CSF3R,FLT3, KIT, NF1, NRAS, RAD21, TET2 and WT1 genes as well as mutation burden). Approaches for supervised ML were naïve bayes, generalized linear model, logistic regression, deep learning and random forest methods. Based on the ML results top 6 selected variables were allotted an individual score. A final score for that case was devised as a sum total of the individual scores. These sum were used to generate a genetic risk for a patient. Overall survival (OS) was calculated from date of diagnosis to time of last follow up or death. Relapse free survival (RFS) was calculated from date of CR till time to relapse or death or last follow up if in CR. Results of the genetic risk were analyzed for their impact on OS and RFS using log rank test. Multivariate analysis was performed using cox proportional hazards regression model. Results: The median follow up of the cohort was 27.6 months. A total of 181 somatic mutations were identified in this subset of AML with 86.7% harbouring at least one somatic mutation (median = 2). Based on ML data, a genetic score was formulated that incorporated mutations in RAD21, FLT3, KIT D816, ASXL2, NRAS genes as well as high mutation burden (≥2) into two genetic risk classes (favorable risk and poor ML derived genetic genetic risk). Patients classified as poor genetic risk had a significantly lower OS [median OS: 34.8 months; 95% confidence interval (CI) (14.2-34.8); p=0.0086] and RFS [median RFS: 17.9 months; 95%CI (12.7-33.6); p=0.0043] as compared to patients with favorable genetic risk (median OS and RFS not reached). These results can be seen in Figure 1. On multivariate analysis poor genetic risk was the most important independent risk factor that predicted for inferior OS [hazard ratio(HR), 2.7; 95% CI 1.3 to 5.7] and RFS (HR, 2.6; 95% CI:1.3 to 5.1). Conclusions In a proof of concept, we describe a novel ML derived genomics scoring model that provides a mechanism to risk stratify CBF-AML, a seemingly homogeneous disease entity. This study, to the best of our knowledge represents a novel application of ML to CBF mutated AML. Our data indicates that this scoring system will be useful in identifying CBF mutated AML patients who are at higher risk of relapse and distinguishes them from patients who are truly good risk. Figure 1 Disclosures No relevant conflicts of interest to declare.

Description: Multicenter large collaborative research groups have been the cornerstone for advances that have been made in multiple disciplines in medicine. These collaborative groups are specifically useful in situation where no single center based dataset is large enough to effectively address biological and clinical relevant questions that could advance the field. Most such collaborative groups exist in the developed countries and have contributed significantly to the development of the current standards of care in leukemia. The challenges in the developing countries or low middle income countries (LMIC) are distinctly different and often algorithms that have evolved in the developed world may not be applicable, relevant or accessible in the LMIC. It is imperative that these challenges be addressed through large multicenter studies that are located within the LMIC and appropriate local data driven solutions be implemented in response. The 'Hematological Cancer Consortium' is a collaborative group from India currently compromising twelve institutions spread across the country that have come together to collaborate in the field of leukemia. As an initial exercise, to establish denominators a retrospective data analysis was undertaken (Indian acute leukemia research database [INwARD]). Here we present the retrospective analysis of the acute myeloid leukemia (AML) data. Retrospective data from January 2013 to December 2017 was collected from 10 large tertiary centers from across the country (in one center data was available only from January 2017). A central online data capture and management system was in place which was independent of all the participating centers (Clinical Data Management Center [CDMC], Vellore, which is compliant with standard ICH-GCP regulations). In this initial phase some centers contributed data offline to the data management center. A total of 3848 were confirmed to have had a diagnosis of AML in this period of which it was noted that 1766 (46%) received definitive treatment (Fig 1 a). The median age of the patients was 40 years (range: 0-89) and there were 59% males. The age distribution of patients by each decade is illustrated in Fig 1b. 399 (10.4%) were ≤ 18 years). A sample for karyotyping was sent in 2609 (68%) however of these an evaluable karyotype was noted in only 1477 (57%) (Fig 1c), the reasons for lack of evaluable metaphases was not clear. A FLT3 and NPM1 mutation status was evaluated in 1338 (35%) and 1401 (36%) respectively. Of the evaluated patients 20.6% and 21.9% had FLT3-ITD and NPM1 mutated respectively (Fig 1d). Of the 1766 patients that were treated 858 (48.6%) received a conventional 7/3 induction, 170 (9.6%) received hypo-methylating agents while the rest received various abbreviated dose regimens and a small proportion (2.8%) received high dose cytosine based regimens as induction therapy. Antifungal prophylaxis was used by 82% of patients that received therapy. Of those that received induction therapy there were 18% induction deaths and 12.9% subsequently received an allogeneic SCT as part of their consolidation therapy (Fig 1a). The 5 year KM estimate for overall and event free survival for the patient that received treatment was 56.2±2.6% and 33.8±2.4% respectively. The data illustrates significant challenges and opportunities with the management of AML in India. A significant proportion of cases do not receive definitive therapy nor do they have conventional tests such as karyotyping or molecular tests done as part of the baseline diagnostic tests, various social and financial constraints could contribute to these and these need to be evaluated in more detail. Strategies to increase access to care and laboratory facilities along with an effort to reduce early induction deaths need relatively urgent attention. The relatively young age of the cohort and large number of cases would allow us to address relevant biological and clinically challenges effectively, in the future, in this cooperative setting. Disclosures No relevant conflicts of interest to declare.

Description: The focus of ATO resistance in acute promyelocytic leukemia (APL) has centered on mutations in PML-RARA gene (Blood 2011, NEJM 2014). However such mutations are rare and cannot explain the majority of relapses seen in the clinic. To evaluate the mechanisms of ATO resistance, we generated ATO resistant NB4 sub clone NB4-EVAsR1 (A216V - VAF-91.7%) in our laboratory. We also had another ATO resistant cell line (UF1) which does not have the A216V mutation. In an expression array we noted that redox signaling, AMPK signaling and energy metabolism pathways were significantly dysregulated in the ATO resistant cell lines compared to naïve NB4 cells. Towards validating the microarray data and to characterize the ATO resistant cell lines we measured the basal levels of reactive oxygen species (ROS), glutathione(GSH), mitochondrial membrane potential (MMP), glucose uptake and their sensitivity to glycolytic inhibitor 2-Deoxy glucose (2-DG) in comparison to naïve NB4 cells. We observed that resistant cell lines have significantly lower ROS, MMP, glucose uptake (Fig 1a) and increased GSH. We also observed that the resistant cell lines were significantly less susceptible to treatment with 2-DG in comparison to naïve NB4 cells (Fig 1b) suggesting that resistant cell lines were less dependent on glycolysis. ATO has been reported to directly inhibit the glycolytic pathway, this effect is believed to contribute to its cytotoxic effect (PNAS 2015). However, we did not observe any cytotoxic synergy between ATO and 2-DG on naïve NB4 cells and neither did this combination restore sensitivity to ATO in the resistant cell lines (Fig 1b). Next we assessed the sensitivity of these resistant cell lines to oxidative phosphorylation (OXPHOS) inhibitors. We used an uncoupler (FCCP at 10uM) of OXPHOS which promotes uncoupled respiration by deregulating the proton gradient which drives ATP synthesis via ATP synthase. We observed that the FCCP treatment alone did not reduced the viability of naïve NB4 cells. Similarly, viability of ATO resistant cell lines also did not reduce significantly suggesting the ability of these cells to uncouple their metabolic pathway from OXPHOS to glycolysis when inhibited. However, when FCCP was combined with ATO it significantly restored the sensitivity of the resistant cell lines to ATO (Fig 1c). The same combination did not have any additive effect on naïve NB4 cells. The combination not only restored the sensitivity of the ATO resistant cell lines but also sensitized the conventionally ATO resistant cell lines such U937 (Fig 1c) and THP1. In spite of the profound effect on leukemic cells we also observed a significant bystander effect on the normal peripheral blood mononuclear cells (Fig 1c). The data suggests that the sensitivity of these resistant cell lines could be potentially restored by combining ATO with an OXPHOS uncoupler. A number of molecules that are FDA approved and used in the clinic also have OXPHOS uncoupling activity and could potentially be evaluated for their synergistic activity with ATO in leukemia. This data also draws attention to possible severe systemic off-target toxicity of such combinations which may be inadvertently used in the clinic. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Mainstay of chemotherapy in acute myeloid leukemia (AML) is induction with a goal to achieve morphological complete remission (CR) as evident by less than 5% blasts. Post remission strategies then focus on either consolidation chemotherapy or allogeneic bone marrow transplantation (aBMT). However, not all patients by this remission criterion achieve long term remission and a subset of patients' relapse. This relapse originates from further expansion chemoresistant clones. Detection of minimal residual disease (MRD) following chemotherapy, early in the course of treatment, is highly predictive of outcome and offers a window of opportunity to intensify treatment and prevent relapse as seen in ALL. Here, we describe assessment of immunophenotypic MRD using a 10-colour two tube assay and a combination of difference from normal and leukemia associated immunophenotype (LAIP) approach in patients of adult AML. Methods: We accrued 310 patients of adult (〉18 years) AML, other than with t(15;17), over a 66-month period (1st July 2012- 31st December 2017) after obtaining informed consent. All patients received standard induction chemotherapy. MRD testing was done post induction and after first consolidation with high dose cytarabine. Patients accrued from 1st July 2012 to 28th February 2015 (85 patients) were processed using a three tube 8 colour MRD assay. Subsequently samples of 225 patients were processed using a two tube 10 colour MRD assay. Identical panel was used for diagnostic sample, post induction and post consolidation. 500,000 events were acquired per tube with the 3-tube assay and 1.6 million events per tube obtained per tube with the 2 tube, 10 colour assay. Analysis of MRD was done using Kaluza 1.3 by a combination of difference from normal approach that focused on the development of Myeloid progenitors to mature cells and LAIP approaches. Cytogenetic studies by conventional karyotyping and FISH was done as per NCCN version 2 2014 recommendations. Patients were classified into favorable, intermediate and poor cytogenetic risk. The presence of FLT3-ITD, NPM1 and CEBPA mutations were detected by a fragment length analysis-based assay. Overall survival (OS) was calculated from date of diagnosis to time of last follow up or death. Relapse free survival (RFS) was calculated from date of CR till time to relapse or death or last follow up if in CR. Results of the MRD assays, cytogenetic and molecular risk groups were analyzed for their impact on OS and RFS using log rank test. Results: The median age of entire cohort was 33 years (M : F = 1.6 : 1). Based on cytogenetics, 35.1% were classified as favorable risk whereas 52.5% and 12.2% were intermediate and poor risk respectively. FLT3-ITD, NPM1 and CEBPA mutations were detected in 21.9%, 29.0% and 7.7% of patients respectively. Post induction MRD was assessed in 298 patients of which 114 (38.3%) had detectable residual disease (range 0.004-22.6%, median:0.9%). Post consolidation MRD was assessed in 186 patients of which 49 (26.4%) were MRD positive (range 0.002-19.8%, median: 0.37%).The 3 year OS, RFS and median RFS of the entire cohort was 59.0%, 44.8% and 18.7 months respectively. Poor risk cytogenetics as expected was predictive of inferior OS (median OS = 14.6 months vs not reached, p=0.05) as well as RFS (median RFS = 9.3 months vs 18.6 months, p=0.003 respectively). FLT3, NPM1 and CEBPA mutations were not informative as predictors of outcome.The presence of MRD at post induction time point predicted an inferior OS [(p=0.08), HR:1.53; 95% CI (0.93-2.51)] & RFS [(p=0.0002), HR:2.14; 95% CI (1.4-3.3)] as compared to the MRD negative group. Similarly, patients harboring MRD at the end of consolidation had an inferior OS [(p=0.04), HR:1.83; 95% CI (0.94-3.6)] & RFS [(p=0.02), HR:1.79; 95% CI (1.04-3.09)] as compared to the MRD negative group. On multivariate analysis post induction FCM MRD emerged as the most important independent prognostic factor predictive of inferior outcome for RFS [(p=0.01); HR:2.14; 95% CI (1.17 - 3.4)] followed by poor cytogenetic risk [(p=0.05); HR:1.8; 95% CI (1.0 to 3.26)]. Conclusion: Our data demonstrates that MRD by flow cytometry at end of induction as well as consolidation are important prognostic factors together with known factors such as high risk cytogenetics. AML MRD is a very useful guide for post remission strategies in AML and should be incorporated into routine treatment algorithms. Figure. Figure. Disclosures No relevant conflicts of interest to declare.