ALBERT

Description: Background: Sterol glycosyltransferases (SGTs) are ubiquitous but one of the most diverse group of enzymes of glycosyltransferases family. Members of this family modulate physical and chemical properties of secondary plant products important for various physiological processes. The role of SGTs has been demonstrated in the biosynthesis of pharmaceutically important molecules of medicinal plants like Withania somnifera. Results: Analysis suggested conserved behaviour and high similarity in active sites of WsSGTs with other plant GTs. Substrate specificity of WsSGTs were analysed through docking performance of WsSGTs with different substrates (sterols and withanolides). Best docking results of WsSGTL1 in the form of stable enzyme-substrate complex having lowest binding energies were obtained with brassicasterol, transandrosteron and WsSGTL4 with solasodine, stigmasterol and 24-methylene cholesterol. Conclusion: This study reveals topological characters and conserved nature of two SGTs from W. somnifera (WsSGTs) i.e. WsSGTL1 and WsSGTL4. However, besides being ubiquitous in nature and with broad substrate specificity, difference between WsSGTL1 and WsSGTL4 is briefly described by difference in stability (binding energy) of enzyme-substrate complexes through comparative docking.

Description: Background: Banana is one of the most important crop plants grown in the tropics and sub-tropics. It is a climacteric fruit and undergoes ethylene dependent ripening. Once ripening is initiated, it proceeds at a fast rate making postharvest life short, which can result in heavy economic losses. During the fruit ripening process a number of physiological and biochemical changes take place and thousands of genes from various metabolic pathways are recruited to produce a ripe and edible fruit. To better understand the underlying mechanism of ripening, we undertook a study to evaluate global changes in the transcriptome of the fruit during the ripening process. Results: We sequenced the transcriptomes of the unripe and ripe stages of banana (Musa accuminata; Dwarf Cavendish) fruit. The transcriptomes were sequenced using a 454 GSFLX-Titanium platform that resulted in more than 7,00,000 high quality (HQ) reads. The assembly of the reads resulted in 19,410 contigs and 92,823 singletons. A large number of the differentially expressed genes identified were linked to ripening dependent processes including ethylene biosynthesis, perception and signalling, cell wall degradation and production of aromatic volatiles. In the banana fruit transcriptomes, we found transcripts included in 120 pathways described in the KEGG database for rice. The members of the expansin and xyloglucan transglycosylase/hydrolase (XTH) gene families were highly up-regulated during ripening, which suggests that they might play important roles in the softening of the fruit. Several genes involved in the synthesis of aromatic volatiles and members of transcription factor families previously reported to be involved in ripening were also identified. Conclusions: A large number of differentially regulated genes were identified during banana fruit ripening. Many of these are associated with cell wall degradation and synthesis of aromatic volatiles. A large number of differentially expressed genes did not align with any of the databases and might be novel genes in banana. These genes can be good candidates for future studies to establish their role in banana fruit ripening. The datasets developed in this study will help in developing strategies to manipulate banana fruit ripening and reduce post harvest losses.

Description: Internal tandem duplications of the FLT3 gene (FLT3/ITD) portend poor outcome in both adult and pediatric AML and hematopoietic stem cell transplantation (HSCT) is often performed. Unfortunately, approximately 35% of patients will have disease recurrence despite HSCT and curative options are limited in that context. Sorafenib is an oral multi-target tyrosine kinase with demonstrable efficacy in this AML subtype. Moreover, retrospective studies in adults with FLT3/ITD+ AML suggest tolerability and potential clinical benefit of sorafenib when used in the post HSCT setting for treatment of early relapse or minimal residual disease (MRD) emergence. There is limited published data regarding sorafenib’s tolerability and efficacy following HSCT in pediatric FLT3/ITD+ AML. We report here a retrospective review of our experience. We conducted a retrospective study of pediatric FLT3/ITD+ patients treated with allogeneic HSCT followed by sorafenib in the first 18 months following HSCT. Between March 2008 and March 2012, 13 FLT3/ITD+ pediatric patients at 7 HSCT centers met criteria for study inclusion. Median age at time of treatment was 14 years (range 6-21 years) and 6/14 (46%) were male. 9 patients underwent matched family donor HSCT and 4 had a matched unrelated donor. Sorafenib was initiated early after HSCT (median: 66 days, range 44-170 days) as prophylaxis in 5 patients who were considered to have very high risk features including failure to achieve clinical remission (CR) following first course of chemotherapy (N=2), high allelic ratio FLT3/ITD at diagnosis (N=1) and MRD at time of HSCT (N=2). For the remainder, sorafenib was given after sign of relapse (MRD or morphologic) at a median of 90 days (range 45-480 days) following HSCT. 11/13 patients received single agent therapy; 2 patients with morphologic relapse received additional chemotherapy (N=1) or radiotherapy (N=1). Among the entire group, post HSCT sorafenib therapy was initiated a median of 80 days following HSCT (range 44-480 days) at a median dose of 150 mg/m2/day (range 75-340 mg/m2/day) and continued for a median of 12 months (range 0.5-52 months). 9/13 patients (69%) experienced toxicity which was felt to be medically significant including thrombocytopenia (N=2), rash (N=3), anorexia (N=1), myelosuppression (N=3), infection (N=2) and life threatening cardiac dysfunction (N=1 in patient treated concomitantly with mitoxantrone). In 8/13 cases (61%) the toxicity resulted in reduction or temporary discontinuation of sorafenib yet all patients tolerated retrial of drug at the same or reduced dosing. One additional patient experienced dose limiting marrow hypoplasia at dosing of 340 mg/m2/day. Sorafenib did not appear to exacerbate GVHD. 8/13 (62%) patients had controlled GHVD at time of sorafenib initiation and only 2 patients had subsequent skin flare that was temporally associated with wean of immune suppression and did not preclude use of further sorafenib. Overall, 10/13 (77%) patients remain alive and 7/13 (54%) are disease free. Of 7 patients in continued CR, the median survival is 3.6 years from HSCT (range 1.75-5.6 years); 6/7 are off sorafenib therapy for a median of 10.5 months (range 7-36 months) after receiving treatment for a median of 19 months (range 8-52 months). 6/13 patients (46%) experienced progressive or recurrent disease while on therapy, 3 of whom have died: 2 from rapid disease progression despite sorafenib initiation and 1 from wild-type FLT3 recurrence. 3 additional patients with recurrent disease are receiving salvage therapy, 1 of whom has achieved a 2nd CR. Of particular interest is the outcome of patients who received sorafenib for MRD in the peri transplant period. All 5 remain alive and disease-free a median of 3.6 years from HSCT (range 1.75-5.6 years) and have been off sorafenib for a median of 12 months (range 7-36 months). Conversely, of the 5 patients who started treatment for morphologic recurrence, only 1/5 (20%) remain in CR. Of 3 additional patients who received prophylactic treatment for high AR or poor induction response, 2/3 have recurred, 1 of whom is now in 2ndCR with higher dose sorafenib in combination with conventional chemotherapy. Our study suggests that sorafenib is tolerable and may improve survival for pediatric patients who undergo HSCT for FLT3/ITD+ AML. Prospective study is necessary to further confirm tolerability and to determine the scope of clinical benefit for this high risk population. Disclosures: Off Label Use: Sorafenib use in AML will be discussed.

Description: Background: Hodgkin's lymphoma (HL) is one of the most common cancers in adolescents and young adults (AYA). Unlike acute lymphoblastic leukemia, few studies have compared AYA HL outcomes between pediatric and adult centers, or pediatric and adult protocols. Recently, a comparison of AYA (17-21 years) treated on a pediatric COG trial vs. an adult ECOG trial demonstrated superior survival in AYA treated on the pediatric trial, but other studies have not demonstrated a treatment center disparity. None of these studies were population-based. We therefore compared treatment patterns, intensity, and outcomes between AYA HL treated at pediatric vs. adult centers using a population-based clinical database. Methods: The IMPACT Cohort comprises all Ontario, Canada AYA aged 15-21 years diagnosed with one of six common cancers (including HL) between 1992-2012. Detailed demographic, disease, treatment, and outcome data were collected through chart abstraction and validated by content experts. Locus of cancer care (pediatric vs. adult cancer center vs. adult community hospital) was based on where the majority of therapy was delivered in the first three months after diagnosis. Linkage to population-based health administrative data identified additional cancer events (second cancers, relapse, death). The treatment modalities received [radiation vs. chemotherapy vs. combined modality treatment (CMT)] were compared by locus of care, as were cumulative doses of doxorubicin, bleomycin, and radiation. Predictors of CMT (vs. chemotherapy only) were examined using logistic regression. Event-free (EFS) and overall survival (OS) were determined using Kaplan-Meier methods. The impact of locus of care on EFS and OS was determined using multivariable Cox proportional hazard models, adjusting for demographic, disease, and treatment variables. Events included disease progression, relapse, death, and second malignancies. Results: Among 954 AYA with HL, 711 (74.5%) received therapy at an adult center (adult regional cancer center or community hospital). The proportion of AYA with limited stage disease did not vary between pediatric centers [90/221 (40.7%)] and adult centers [172/456 (37.7%); p=0.45]. While AYA treated at pediatric centers were more likely to receive radiation, radiation doses were higher at both adult cancer centers and adult community hospitals, as were cumulative doses of doxorubicin and bleomycin (Table 1). When adjusted for age, stage, and histology, AYA treated at pediatric centers were significantly more likely to receive CMT rather than chemotherapy alone as compared to AYA at adult cancer centers [odds ratio (OR) 5.0; 95% confidence interval (CI) 3.0-8.4; p

Description: Background: Minimal residual disease (MRD) assessment after initial therapy is integral to modern risk stratification in both precursor B and T lineage acute lymphoblastic leukemia (B-ALL and T-ALL). While MRD is used to determine depth of remission, remission is still defined, both in clinical practice and clinical trials, according to morphological assessment. We aimed to determine the outcomes of children, adolescents and young adults with discordant assessments of remission by morphology vs. by MRD, and in doing so, the extent to which morphologic assessment of remission contributes to risk assessment in this population. Methods: We identified a cohort of patients age 1-30.99 years enrolled on frontline COG trials for B-ALL [standard risk (SR): AALL0331; high risk (HR) AALL0232] and T-ALL (AALL0434) that underwent bone marrow assessment of remission at the end of induction therapy (Day 29). Morphologic response was assessed by local centers and was categorized according to traditional criteria: M1 (25%). MRD was measured by flow cytometry at one of two central laboratories. We determined predictors of MRD discordance and compared event free survival (EFS) between those with discordant vs. concordant morphology/MRD remission assessments. Results: Day 29 remission assessments and central MRD data were available on 9,350 patients, 7,857 (84%) with B-ALL (AALL0331: N=5049; AALL0232: N=2808) and 1,493 (16%) with T-ALL. Table 1 shows the distribution of end induction marrow morphology vs. flow cytometry results. Few patients with M2/M3 marrows had discordant low MRD values. For example, of 84 patients with M3 morphology, only 2 (2.4%) had MRD =50,000/microliter (OR=2.1, CI 1.3-3.6; p=0.004), and unfavorable compared to favorable cytogenetics (OR=31, CI 8.9-109; p=5%) had modestly superior 5-year EFS when compared to those with M2 morphology and MRD 〉=5% (33.1%±6.2% vs. 22.0%±6.9%; p=0.03), but EFS was significantly inferior to those with M1 morphology and concordant MRD (=5% have outcomes similar to those who fail to achieve morphological remission. These results suggest that, in addition to measuring depth of remission, MRD should replace morphology in defining remission in subjects with ALL, with consequent implications for risk stratification, treatment assignment and eligibility for experimental agents. Disclosures Loh: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding. Borowitz:HTG Molecular: Consultancy; Bristol-Myers Squibb: Research Funding; MedImmune: Research Funding; BD Biosciences: Research Funding. Wood:Juno: Other: Laboratory Services Agreement; Pfizer: Honoraria, Other: Laboratory Services Agreement; Amgen: Honoraria, Other: Laboratory Services Agreement; Seattle Genetics: Honoraria, Other: Laboratory Services Agreement.

Description: Introduction: Systems to quantify and incentivize quality of care (QoC) have been developed in multiple healthcare settings. In pediatric oncology, lists of QoC metrics or recommendations have been procured through consensus methodologies such as the Delphi process. To date, no QoC metrics have been developed for outpatient pediatric oncology. Objectives: The aim of this study was to develop a list of QoC metrics for the leukeumia-lymphoma (LL) clinic at the Hospital for Sick Children in Toronto, using a consensus process that could be adapted to other clinic settings. Methods: A modified Delphi process following the American Society of Clinical Oncology (ASCO) guidelines was used to generate consensus on a list of QoC metrics (Loblaw et al., 2012). A Medline-Ovid search was conducted for quality indicators, metrics and recommendations relevant to pediatric oncology. Results were screened for (a) system-level metrics that could be translated to a clinic level and (b) clinic-level recommendations that could be converted to measurable quantities. Additional metrics outside the literature search were considered. A provisional list was compiled and circulated electronically to local stakeholders, including medical and nursing staff (n=10). Stakeholders ranked each metric on a 5-point Likert scale based on importance and feasibility of measurement (round 1). Stakeholders provided feedback on the metrics and suggested additional metrics. Median, interquartile range and full ranges were calculated for each metric. A metric was considered to reach consensus if the percent of respondents ranking within two consecutive scores was ≥70%. Results and comments from round 1 were re-circulated to stakeholders in personalized reports. This allowed each stakeholder to compare his or her previous scores with overall scores for each metric. Stakeholders were asked to re-rank each metric (round 2). Results: The literature search yielded 2 relevant publications from which a provisional list of 27 metrics was generated. Metrics were grouped into 7 categories (Table 1). In round 1, 19/27 (70%) metrics reached consensus. Stakeholders’ comments resulted in 4 new metrics and edits to 8 original metrics. All metrics were included in round 2 for a total of 31. Twenty-four of 31 (77%) metrics reached consensus after round 2 (Table 1). Thirteen were chosen for the final list based on highest consensus scores, highest interquartile and full ranges, and minimizing redundancy. Conclusion: This study demonstrates the feasibility of using a modified Delphi process to generate QoC metrics for a pediatric hematology oncology clinic, and provides a model other clinics may employ for local use. The final metrics will be used to evaluate the quality of care in the LL clinic, and to identify areas for improvement in clinic function. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Description: Background: Chimeric antigen receptor T-cells (CAR-T) have emerged as a promising treatment for children with relapsed/refractory acute lymphoblastic leukemia (ALL). While CAR-T outcomes have been published, little data exist on how to manage these patients for the weeks to months between T-cell collection and CAR-T infusion. Unlike stem cell transplant (SCT), where higher burden of disease is associated with poor outcomes and is often a contraindication, successful outcomes for children with high disease burden pre-CAR-T have been demonstrated. Thus, traditional high-intensity chemotherapy for relapsed ALL that aims to minimize disease burden but carries significant morbidity may not be the best option for pre-CAR-T populations. We thus compared our population-based experience in using high vs. low-intensity chemotherapy regimens to bridge patients in terms of toxicity, inpatient days, and success in reaching CAR-T infusion. Methods: The Hospital for Sick Children (Sickkids) is the provincial referral centre for cellular therapy for children in Ontario, Canada. All Ontario children referred to Sickkids between 2014-2018 for first T-cell collection with intent to proceed to CAR-T therapy were included and followed until CAR-T infusion, decision to pursue alternative therapy, or death. Bridging regimen details were collected and classified as low vs. high intensity based on whether such therapy was likely associated with 〉7 days of neutropenia. Disease and outcome variables were compared between high vs. low intensity regimens using Chi squared, Fisher's exact, or Wilcoxon tests. Results: The cohort included 32 patients with a median age of 9.7 years at the time of first T-cell collection [interquartile range (IQR) 6.0-12.3]. The median number of previous relapses was 2 (IQR 1-2), 14 (44.0%) had undergone prior SCT, and 4 (12.5%) had Down syndrome. The vast majority of patients (28, 87.5%) were successfully bridged to receive CAR-T therapy with a median time to infusion of 81 days (IQR 60-105). Two patients experienced manufacturing failure and pursued SCT instead, 1 died of toxicity, and 1 was still awaiting infusion at the end of the study period. Low-intensity bridging regimens were used following collection for 19 (59.4%) patients, most often based on low-dose intravenous methotrexate, 3-drug induction (vincristine/steroids/asparaginase), or maintenance therapy. The most common high-intensity regimens included cyclophosphamide/etoposide, high dose cytarabine, or 4-drug induction (vincristine/steroids/asparaginase/anthracycline). Patients receiving high-intensity therapy did not seem to have more aggressive disease prior to starting bridging treatment (as indicated by peripheral blasts, number of previous relapses, prior SCT) that would have justified choosing high-intensity treatments. Patients receiving initial high-intensity regimens were however more likely to have been collected in first half of the study period (Table 1). Patients receiving initial high-intensity regimens also developed more microbiologically documented infections and experienced a greater number of inpatient days (Table 1). Excluding patients experiencing manufacturing failure or still awaiting CAR-T at the end of the study period, the likelihood of receiving CAR-T also did not vary [high-intensity regimen - 11/12 (91.7%) vs. low-intensity regimen - 17/17 (100%); p=0.41]. Conclusions: We demonstrate in our population-based cohort of heavily pre-treated and high-risk patients that initial low-intensity chemotherapy had a very high likelihood of successfully bridging children to CAR-T infusion. Low-intensity bridging regimens were associated with lower rates of toxicity and higher quality of life as indicated by fewer inpatient days. Low-intensity regimens should be considered the first line option in this population. Disclosures Grupp: Jazz Pharmaceuticals: Consultancy; Adaptimmune: Consultancy; University of Pennsylvania: Patents & Royalties; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding. Maude:Novartis Pharmaceuticals Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees.