ALBERT

Description: Introduction: Black patients with acute myeloid leukemia (AML) have inferior overall survival relative to White patients. Few studies have evaluated differences in induction mortality and none has assessed the contribution of severity of illness at presentation to the disparity in survival. Our primary objectives were to compare induction mortality and acuity of presentation among Black relative to White patients and to assess whether any disparity in induction mortality is the consequence of differences in presentation acuity. In addition, we explored the interaction between Black race and public insurance on induction mortality with use of single referent models. Methods: Using a retrospective cohort of children (ages 0 to 18 years) from 2004 to 2014 with new-onset AML diagnosed and treated at free-standing pediatric hospitals who contribute inpatient information to the Pediatric Health Information System administrative database (PHIS), we evaluated inpatient mortality over two courses of standard induction chemotherapy. We examined race (Black versus White) as the primary exposure and insurance was considered with race using a common reference group. We also considered Intensive Care Unit (ICU)-level resource use during the first 72 hours following the initial AML admission as a surrogate for acuity at presentation and a potential mediator of the association between race and induction mortality. Results: 1,122 patients (183 Black, 939 White) with AML who received standard induction chemotherapy were included. Induction mortality for Blacks was substantially higher than for Whites (cHR= 2.31, 95% CI: 1.01, 5.42). Blacks also had a significantly higher risk of requiring any ICU-level care within the first 72 hours after initial presentation compared with Whites (cHR= 1.52, 95% CI: 1.02, 2.24).The association between race and induction mortality was attenuated following adjustment for ICU-level care within the initial 72 hours after admission, (aHR=1.42, 95% CI: 0.67, 2.99). Publicly insured patients experienced greater induction mortality than privately insured patients regardless of race. Induction mortality rates for Black and White patients were more similar among the privately insured and were increasingly disparate among the publicly insured. Conclusion: Our findings suggest that Black patients with AML present with more acute illness at initial diagnosis, accounting for up to 63% of the relative excess induction mortality. Identifying factors impacting acuity of illness at presentation and associated with public insurance may help to identify opportunities for intervention and thus narrow the current racial disparities in pediatric AML survival. Table 1. Inpatient Induction Mortality and ICU level Care by Race Outcome, Follow-up Period Overall (N=1122) n (%) Black (n=183) n (%) White (n=939) n (%) cHR (95% CI) aHRa (95% CI) Induction Death 27 (2.4%) 8 (4.4%) 19 (2.0%) 2.31 (1.01, 5.42) 1.42 (0.67, 2.99) Any ICU Level Care in first 72 hrs 135 (12.0%) 31 (16.9%) 104 (11.1%) 1.52 (1.04, 2.24) ICU involving 〉1 system in first 72 hrs 47 (4.2%) 18 (9.8%) 29 (3.1%) 3.35 (1.84, 6.12) Any ICU Level Care in Induction 237 (21.1%) 48 (26.2%) 189 (20.1%) 1.30 (0.99, 1.71) 1.09 (0.74, 1.61) ICU involving 〉1 system in Induction 99 (8.8%) 22 (12.0%) 77 (8.2%) 1.42 (0.85, 2.38) 0.92 (0.54, 1.57) a adjusted for ICU acuity score within the first 72 hours of index admission Figure 1. Independent and joint effects of Black race and public insurance on induction mortality Figure 1. Independent and joint effects of Black race and public insurance on induction mortality Disclosures Wilkes: Alex's Lemonade Stand Foundation: Research Funding; Healthcare Research and Quality: Research Funding. Fisher:Merck: Research Funding; Pfizer: Research Funding. Epstein:Medicus Economics: Consultancy. Aplenc:Sigma Tau: Consultancy.

Description: The increased survival of children with cancer is largely credited to treatment on clinical trials. As such there is interest in determining factors associated with trial enrollment. Adult oncology studies suggest non-Whites are less likely to enroll than Whites on clinical trials. Additional factors, such as insurance and geographic region, have been associated with adolescent and adult trial enrollment. Data describing factors associated with pediatric trial enrollment is limited. This study sought to evaluate whether race and other patient factors were associated with enrollment on the recently completed Children's Oncology Group (COG) acute myeloid leukemia (AML) chemotherapy trial AAML0531. A retrospective cohort study was conducted using data from the Pediatric Health Information System (PHIS) and trial data from COG AAML0531. PHIS is an administrative database containing inpatient data from Child Health Corporation of America-affiliated hospitals. Data from a previously assembled and validated PHIS AML cohort was merged with data from the AAML0531 trial for the period of time that the COG trial was open and PHIS data was available (2006 to 2010). Patients that were identified in both the PHIS and COG datasets were labeled as enrolled patients and those only in the PHIS database were labeled as not enrolled patients. Enrolled and not enrolled patients were compared by race, gender, age, insurance type, illness severity at AML presentation (defined by need for an ICU intervention in the first or second day of index admission) and geographic region of hospitalization. Chi-square test and logistic regression analyses were used for unadjusted and adjusted comparisons, respectively. The PHIS AML cohort contained 874 patients of which 312 (36%) were enrolled on AAML0531. Table 1 displays the comparison of enrolled versus not enrolled patients by each of the demographic and clinical variables of interest. In adjusted analyses patients were less likely to enroll if they had government insurance (compared to private insurance). Patients were more likely to enroll if they were hospitalized in the West (compared to the South). Trial enrollment percentage was higher than reported in adult cooperative group trials but still comprised a minority of potentially eligible patients. Unlike adult clinical trials, race was not associated with enrollment on the AAML0531 trial. However, patients who did enroll on AAML0531 were less likely to have government insurance and more likely to be hospitalized in the West. Work is ongoing to refine estimates of enrollment eligible patients, to define patient socio-economic status more precisely than insurance status, and to evaluate the impact of insurance status beyond socio-economic status. Such analyses should provide additional data to guide efforts to increase trial enrollment and ensure equitable access to COG AML clinical trials for all pediatric patients. Disclosures No relevant conflicts of interest to declare.

Description: Treatment for pediatric acute myeloid leukemia (AML) involves multiple courses of intensive chemotherapy leading to prolonged neutropenia with substantive infection risks. Patients are typically hospitalized at each course for the duration of chemotherapy and associated marrow aplasia. Evaluations of early discharge and outpatient supportive care in adult AML patients demonstrate comparable mortality and shorter lengths of stay compared to standard discharge. Similar data in the pediatric setting are limited. We used data from the Pediatric Health Information System (PHIS) to evaluate course-specific mortality and resource utilization in AML patients who were discharged prior to count recovery relative to comparable patients who remained hospitalized. We used a cohort of children treated for new onset AML at children's hospitals in the US contributing to PHIS. Analyses were restricted to patients considered eligible for discharge prior to count recovery. Patients were categorized at each course as early or standard discharge. Discharges within 3 days after chemotherapy completion were considered early. Course-specific follow-up started on the last day of chemotherapy and continued until the earliest of: start of the subsequent course, death, or 50 days after commencement of chemotherapy. Resource utilization was determined based on daily billing data and reported as days of use per 100 hospital days. Case fatality rates and duration of hospitalization were compared using chi-square and Wilcoxon rank sum tests. Poisson regression with inpatient days as offset was used to compare resource use by discharge status. The study population included 996 patients representing 2358 courses. Fewer patients were discharged early following Induction I (7%) compared to subsequent courses (22-24%). Rates of early discharge varied greatly by hospital ranging from 0% to 100%. Across courses, patients discharged early experienced 8-12 fewer inpatient days (all p90%. Case fatality rates were low across courses (0-1.3%) and did not differ significantly by discharge status. However, more early discharge patients required ICU level care at each course (7.2-18.1%) compared to standard discharge patients (2.0%-8.7%; all p

Description: Introduction: We previously demonstrated Black patients with acute myeloid leukemia (AML) are more likely to require ICU-level resources at initial presentation. This disparity in acuity at presentation explained 62% of the two-fold racial disparity in early mortality (Winestone Am J Hematol 2017). We sought to expand these findings using a more detailed data source that leverages electronic medical record (EMR) data from two large institutions. We hypothesized that disparities in severity at presentation by race, ethnicity, and socioeconomic status would be identified in granular EMR data for children with acute lymphoblastic leukemia (ALL) and AML. Methods: Acute leukemia patients who were diagnosed at Children's Hospital of Philadelphia or Texas Children's Hospital (2006-2014) were included. Patients who transferred from a referring hospital or whose race was specified as Asian, other, or unknown were excluded. Race and ethnicity were combined into 3 mutually exclusive categories: Hispanic, non-Hispanic White, and non-Hispanic Black. The first set of vital signs (blood pressure, heart rate, respiratory rate, and temperature) and the timing of key diagnostic evaluations were manually abstracted. Patient age, sex, race/ethnicity, residential address, and results of selected laboratory tests from the first 72 hours after admission underwent automated extraction from the EMR. Residential addresses were batch-matched to geo-coordinates linking each patient to a census-derived block group. The following measures of socioeconomic status (SES) were evaluated: median household income, education, unemployment, and crowding. Vital signs were interpreted using age-specific American Heart Association reference ranges. Individual and composite lab-based definitions created a priori were used to identify high disease burden, risk of infection, renal dysfunction, abnormal coagulation (prothrombin time 〉17 or fibrinogen 200 or bilirubin 〉2.5 or GGT〉150). Log-binomial regression was used to compute unadjusted prevalence ratios (PR) and corresponding 95% confidence intervals (CI) comparing incidence of vital sign and laboratory abnormalities by race/ethnicity and block group SES. Stratification by leukemia type (AML vs. ALL) allowed for assessment of heterogeneity in associations of interest. Covariates that were associated with race and thus were potential confounders were also included in multivariable models to obtain adjusted PRs. Results: A total of 899 acute leukemia patients (474 non-Hispanic White, 318 Hispanic, and 107 non-Hispanic Black) were included. Figure 1 shows patient characteristics including patients' geo-coordinates mapped onto census block group median household income. Vital signs at presentation were generally similar across racial/ethnic groups with the exception of heart rate among Hispanic patients (62% vs. 53%, p=0.03). Black patients with AML had an increased prevalence of elevated white blood cell (WBC) count and uric acid and Black patients with ALL demonstrated increased prevalence of coagulopathy compared to White non-Hispanic patients (Table 1). For both AML and ALL, Black patients were more likely to have more than 2 lab abnormalities relative to White non-Hispanic patients. There were no clinically significant differences in time to key diagnostic evaluations by race/ethnicity; median time to CBC was under 2 hours for all racial/ethnic groups, median times to bone marrow biopsy and lumbar puncture ranged from 25-39 hours, and median time to chemotherapy was between 2-3 days. None of the measures of SES were significantly associated with abnormal vital signs, abnormal labs, or prolonged time to key diagnostic evaluations. Conclusions: Black patients with newly diagnosed AML present with increased prevalence of high disease burden as evidenced by elevated WBC and uric acid. Across acute leukemia types, Black patients are more likely to present with more than 2 lab abnormalities; these lab abnormalities likely represent physiologic dysfunction at diagnosis and may compound one another to explain the previously observed racial disparity in ICU-level care requirement. Similar ethnic differences were not observed among Hispanic patients with AML or ALL. We are conducting ongoing investigation into the impact that rurality and distance to the hospital have on initial presentation. Disclosures Fisher: Merck: Research Funding; Pfizer: Research Funding.

Description: Introduction: Hepatotoxicity is a frequent and challenging adverse event in children with acute lymphoblastic leukemia (ALL), but patient factors that are predictive of hepatotoxicity are not well understood. We leveraged a data repository jointly developed by two pediatric oncology centers within the Leukemia Electronic Abstraction of Records [LEARN] Consortium to assess the landscape and determinants of liver dysfunction throughout ALL therapy in patients who were risk-stratified to receive either standard- or high-intensity treatment blocks. Methods: The subjects were children ages 1-21 years who were treated for ALL between 2006-2014 at either Children's Hospital of Philadelphia or Texas Children's Hospital. Demographics, disease-related data, and every laboratory value collected during treatment were obtained by targeted manual abstraction and extensive semi-automated extraction of patient electronic medical record (EMR) data. To reduce cohort heterogeneity, we excluded patients who received non-standard ALL therapies. Patients were categorized as receiving either standard-intensity or high-intensity treatment for their first three blocks of therapy (Induction, Consolidation, Interim Maintenance 1 [IM1]) based on chemotherapeutic agents delivered in those blocks. Differences in laboratory value-determined hepatoxicity were then analyzed based on this categorization for all remaining phases of therapy. Hepatic lab values (AST [SGOT], ALT [SGPT], total bilirubin [t. bili], and conjugated bilirubin [c. bili]) were first normalized to the age-based upper limit of normal (ULN), and the median value was then determined. A multivariate mixed-effects linear regression model with random effects was used to identify differences in the treatment group medians and the following covariates: age, race/ethnicity, sex, BMI, and ALL immunophenotype. Laboratory values were classified by the CTCAE v5.0 grading system, with grade ≥ 3 considered 'elevated.' Results: 805 pediatric ALL patients were included in the analysis, representing 114,095 hepatic lab values (Table 1). Less than 10% of patients had elevated lab values at diagnosis. Throughout treatment, the majority of lab values fell within 1-2x ULN for age for both standard- and high-intensity treatment groups (Fig. 1a-d). The median hepatic lab values for the high-intensity group were slightly higher than the standard risk group across all treatment phases, and this difference was most consistently significant in Consolidation and Delayed Intensification. Among the four hepatic labs that were assessed, ALT had the most significant deviation above normal (up to 30x ULN, Fig 1a). Patients were more likely to have elevated transaminases during maintenance than prior to maintenance (Fig. 1e). Similarly, but to a lesser degree, patients were more likely to have elevated t. or c. bili during maintenance than prior to maintenance. Age, race, and BMI were correlated with elevated hepatic labs, with Hispanic and/or overweight patients more likely to have elevations in 3 or more phases of therapy (Table 2). However, no hepatic lab abnormalities were correlated with either overall or relapse-free survival. Conclusions: This is the first comprehensive study of measures of hepatotoxicity in a large and uniformly-treated cohort of pediatric ALL. While significantly elevated hepatic labs are rare at diagnosis, they are common during ALL treatment and are seen more commonly in maintenance than in prior phases. Patients who are overweight and/or Hispanic are more likely to experience grade 3 or higher hepatoxicity. We observed no relationship between hepatotoxicity and relapse or survival. Further studies are ongoing to delineate the temporal correlation of liver function and chemotherapy dosing and administration. Disclosures No relevant conflicts of interest to declare.

Description: Introduction Advances in pediatric Acute Lymphoblastic Leukemia (ALL) have led to substantial improvement in remission rates. However, there is a lack of data characterizing morbidity during induction. During this period, patients are stratified into "standard risk," receiving a 3 drug induction regimen of steroids, vincristine, and asparaginase, or "high risk" receiving anthracycline as a fourth chemotherapeutic agent. An understanding of adverse events (AEs) may facilitate supportive care and predict and guide hospitalization needs during this phase of treatment. There is potential benefit in comparing AE rates between the two treatment groups. This study aimed to identify rates of clinically significant AEs, hospital readmissions, and intensive care unit (ICU) admissions in pediatric patients with ALL during induction. Methods This retrospective cohort included patients ages 1 through 21 who initiated induction therapy for ALL between January 1, 2013 and May 13, 2018 at Children's Healthcare of Atlanta (CHOA). Algorithms to identify and grade AEs according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 definitions were determined a priori. Using these algorithms, manual chart abstraction to identify AEs occurring from diagnosis to day 34 after the start of induction was performed for 19 AEs: pancreatitis, hepatotoxicity, hypoxia, adult respiratory distress syndrome (ARDS), hyperglycemia, thromboembolic event, stroke, infection, sepsis, fever, hypertension, hypotension, seizure, ileus, anaphylaxis, hyponatremia, and constipation. Chart abstraction additionally identified ALL risk classification, admissions to the intensive care unit (ICU), and readmissions. Demographic data were extracted in an automated fashion from the electronic health record. Rates of each AE, readmissions, and ICU admissions were calculated for the induction period. The highest grade of each AE was captured for these analyses and clinically relevant grade 2-5 AEs are reported. Development of each AE, readmission, and ICU admission were stratified by therapy risk group and analyzed by chi square, Fisher's exact, or Kruskal Wallis tests as appropriate. Results AE grading and abstraction are complete and reported on 286 of 512 eligible patients; median age at diagnosis was 5.7 years; 45.1% were female, 47.6% were non-Hispanic white, 20.5% were black, and 23.6% were Hispanic. Among those discharged before the end of induction (283/286), 36.0% were readmitted. Additionally, 12.9% of all patients were admitted to the ICU at some point during induction. Overall, 72.4% of patients had at least one AE 〉 grade 3 during induction. The most common clinically relevant AEs were: ALT elevation (36.3%); hypertension (33.9%); and infection (17.8%) (Table 1). Four of the 286 patients died during induction; 3 deaths were attributed to respiratory failure, and 1 to sepsis. Overall, 36% of patients required readmission with no difference in readmission rates by treatment group. However, patients with high risk treatment were significantly more likely to have an ICU course (18.0% vs 8.2%, p=0.01). A larger proportion of high risk patients experienced sepsis (6.3% vs 3.8%, p=0.05) or hypotension requiring medical intervention (6.6% vs 3.5%, p=0.05). Conclusions This study demonstrates that AEs ≥ grade 3 are common in induction and that more than a third of patients require readmission during induction after initial discharge. While capture of grade 3-5 AEs indicate severe events, several grade 2 AEs are clinically relevant to morbidity and patient management, such as thromboembolism and fever. These results highlight the AEs driving morbidity during induction therapy, and can be used to guide patients regarding expected AEs. Work is ongoing to analyze the full cohort. Further analyses will compare rates of the highest grade AEs, length of hospitalization, readmission, and ICU admission by chemotherapy regimen. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Adverse events (AEs) are often under- or misreported on clinical trials, leading to an incomplete understanding of therapy-associated toxicities. We previously demonstrated that laboratory result data can be extracted from the electronic health record (EHR), cleaned, and processed to ascertain laboratory AEs with high accuracy compared to gold standard chart abstraction at a single institution. We sought to employ this methodology at three large children's hospitals to demonstrate scalability and describe laboratory AE rates during therapy for pediatric acute myeloid and acute lymphoblastic leukemia (AML, ALL). Methods: The Leukemia Electronic Abstraction of Records Network (LEARN) comprises data from patients with AML and ALL treated at the Children's Hospital of Philadelphia (CHOP) from 2006 to 2014, Children's Healthcare of Atlanta from 2010 to 2018, and Texas Children's Hospital from 2008 to 2014. Risk classification, clinical trial enrollment status, and chemotherapy course start and end dates for all patients were collected via manual chart abstraction. After manual input of medical record numbers and course dates, a package we developed in the R programming language (ExtractEHR) was employed to extract laboratory results from the Epic EHR at each site. De-identified laboratory result data were cleaned centrally at CHOP to remove falsely abnormal results, including hemolyzed specimens and results that normalized within 1 hour for electrolytes and hematology tests and within 12 hours for liver function tests (LFTs). Laboratory results were processed and graded according to Common Terminology Criteria for Adverse Events (CTCAE) v5 definitions for 22 AEs. The highest grade of each AE in each course was calculated and results were tabulated by chemotherapy course for ALL and AML separately. Only chemotherapy courses with complete start and end dates were included; courses that were ongoing at time of abstraction were excluded. Highest grades for each AE over all chemotherapy courses combined were stratified by leukemia risk classification and trial enrollment status and were compared using chi square tests. CTCAE grade 5 definitions are not numerically based, so were excluded. Results: Laboratory result data on 1687 patients (AML: 282, ALL: 1405) who experienced 6652 courses (AML: 909, ALL: 5743) were extracted, processed and graded. For the purposes of these results, AEs indicate grades 3-4. More than 95% of AML courses had anemia, neutropenia and thrombocytopenia (Table). AML patients experienced the most laboratory AEs during Induction I and Intensification III (prevalence of grade 3-4 AEs was ≥10% for 10 AEs evaluated). Apart from hematologic AEs, hypokalemia (17.9-44.9% of courses) and increased LFTs (7.7-18.6% of courses) were the most common AEs in AML courses. While AML patients experienced higher rates of hematologic AEs, ALL patients had higher rates of electrolyte and LFT AEs over all courses. These AEs were distributed across all courses; in each course there were 7-9 AEs with a prevalence of ≥10%. Increased alanine aminotransferase was common in every ALL course (17.4-66.2%). For both for AML and ALL, AE rates were similar among patients enrolled on trials and those who were not. AE rates were similar for all AML risk classifications. In contrast, for ALL there were significantly higher rates (p

Description: Background: In general, modern clinical trials for pediatric acute lymphoblastic leukemia (ALL) have intensified therapy compared with therapy in prior decades. While survival rates now approach 90%, increased treatment intensity has heightened the risk of complications such as serious infections or organ toxicities, which may in turn lead to dose modifications and/or treatment delays. There is a paucity of data on the prognostic impact of cumulative delays during the intensive phases of ALL therapy. Methods: We performed a retrospective chart review of patients between the ages of 1-21 years with newly diagnosed ALL who were treated at two large academic pediatric hospitals that are part of the Leukemia Electronic Abstraction of Records Network (LEARN). Eligible patients were those diagnosed with B- or T-lineage ALL who received chemotherapy treatment at least through the start of maintenance therapy. Exclusion criteria included disease relapse prior to start of maintenance, Down syndrome, or clinical features requiring highly intensified frontline therapy. The primary study objective was to determine the impact of treatment delays on relapse-free survival (RFS) and overall survival (OS). A secondary objective was to investigate associations between delays and patient clinical characteristics. Results: A total of 537 patients were eligible for analysis. Of these 537, 32 were analyzed separately as an "extreme toxicity" subgroup, due to excessive treatment-related morbidities prior to the start of maintenance requiring significant therapy modification. The remaining 505 were divided into quartiles based on their duration of delay, with the highest quartile experiencing 〉64 days of delay to start of maintenance. Most patients experienced some delay (median 40 days, range 0-154 days). Patients in the highest quartile were characterized by an older mean age at diagnosis (7.8 versus 6.7 years, p=0.0254), treatment on a more intensified regimen (p

Description: Introduction Cooperative group oncology trials have led to dramatic improvements in outcomes for children with cancer, but the current method of reporting adverse events (AEs) is inefficient and potentially ineffective. Like all cooperative oncology groups, AEs on Children's Oncology Group (COG) clinical trials are reported by clinical research associates via case report forms using the National Cancer Institute Common Terminology Criteria system. Despite the extensive resources needed for AE reporting, there is evidence that AEs may not be accurately reported. However, there are no data on the sensitivity, specificity and positive and negative predictive values (PPV, NPV) of AE reporting on pediatric or adult cooperative group oncology trials. This study sought to determine these operating characteristics for AE reporting for COG clinical trial AAML0531, the most recently completed clinical trial for de novo acute myeloid leukemia (AML) in children. Methods Chart abstraction was performed by a single pediatric oncologist on patients enrolled on COG clinical trial AAML0531 at 5 hospitals in the United States. Presence or absence of the following 12 grade III or higher AEs was determined for each hospital day: hypertension, hypotension, hypoxia, adult respiratory distress syndrome (ARDS), anorexia, typhlitis, disseminated intravascular coagulation (DIC), microbiologically proven viridans group streptococcal bacteremia (VGS), microbiologically proven invasive fungal infection (IFI), pain, seizure, and acute renal failure. The definitions for the gold standard of chart abstraction were defined a priori. Using the daily AE assessments based on chart review, the presence or absence of each toxicity was determined for each chemotherapy course. These data were then merged with COG adverse event data that includes grade III or higher toxicities for each patient by chemotherapy course. The percentages of chemotherapy courses with each toxicity were determined for chart abstraction and COG data. Sensitivity, specificity, PPV and NPV for COG AE reporting of the 12 toxicities were determined by comparing to the gold standard of chart abstraction data. Age, gender, race and ethnicity were determined from COG data. Results COG clinical trial AAML0531 enrolled 1028 patients between August 14, 2006 and June 15, 2010. Chart abstraction was performed on 99 of these patients (373 courses). Compared to all patients enrolled on AAML0531, the 99 patients were younger (mean age 8.0 vs. 9.3 years, p = 0.04), and a larger percentage was African American (18.2% vs. 11.5%, p = 0.05). No differences were observed in gender (female: 48.5% vs. 50.4%, p = 0.72) or ethnicity (Hispanic: 18.2% vs. 18.4%, p = 0.96). In the COG AE report, the rates of toxicities ranged from 0.3% of courses (seizure) to 18.8% of courses (anorexia). In the chart abstraction data the rates of toxicities ranged from 0% of courses (seizure) to 37.0% of courses (pain). Table 1 shows the sensitivity, specificity, PPV and NPV for the 12 targeted toxicities. For toxicities with 10 or more identified events, the sensitivity of COG data ranged from 18.2% (DIC) to 70.0% (hypotension). Of significant concern, sensitivity was less than or equal to 50% for eight toxicities, including hypertension (38.5%), hypoxia (25.3%), anorexia (49.6%), VGS (49.2%), and pain (21.7%). The PPV ranged from 50% (IFI and ARDS) to 100% (DIC and renal failure). Conclusions In this cohort of 99 patients treated on COG clinical trial AAML0531, the sensitivity of COG adverse event reporting was relatively low for all but one AE and was less than or equal to 50% for eight of the 12 targeted toxicities. Although PPV was high for most toxicities, it was not 100% for many, indicating that false positive results occur for nearly all of the evaluated AEs. This data demonstrates that the current system of AE reporting on cooperative group oncology trials has modest sensitivity and a demonstrable false positive rate. Work is ongoing to further refine these estimates and to develop improved AE reporting methodologies. Disclosures: No relevant conflicts of interest to declare.