ALBERT

Description: © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biology Open 5 (2016): 436-442, doi:10.1242/bio.017251.

Description: The accurate estimation of field metabolic rates (FMR) in wild animals is a key component of bioenergetic models, and is important for understanding the routine limitations for survival as well as individual responses to disturbances or environmental changes. Several methods have been used to estimate FMR, including accelerometer-derived activity budgets, isotope dilution techniques, and proxies from heart rate. Counting the number of breaths is another method used to assess FMR in cetaceans, which is attractive in its simplicity and the ability to measure respiration frequency from visual cues or data loggers. This method hinges on the assumption that over time a constant tidal volume (VT) and O2 exchange fraction (ΔO2) can be used to predict FMR. To test whether this method of estimating FMR is valid, we measured breath-by-breath tidal volumes and expired O2 levels of bottlenose dolphins, and computed the O2 consumption rate (V̇O2) before and after a pre-determined duration of exercise. The measured V̇O2 was compared with three methods to estimate FMR. Each method to estimate V̇O2 included variable VT and/or ΔO2. Two assumption-based methods overestimated V̇O2 by 216-501%. Once the temporal changes in cardio-respiratory physiology, such as variation in VT and ΔO2, were taken into account, pre-exercise resting V̇O2 was predicted to within 2%, and post-exercise V̇O2 was overestimated by 12%. Our data show that a better understanding of cardiorespiratory physiology significantly improves the ability to estimate metabolic rate from respiratory frequency, and further emphasizes the importance of eco-physiology for conservation management efforts.

Description: Funding for this project was provided by the Office of Naval Research [ONR YIP Award # N000141410563]. M.J.M. received funding from National Oceanographic Partnership Program [9N00014-11-1-0113].

Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biology Open 6 (2017): 307-308, doi:10.1242/bio.023143.

Description: We are grateful for the interest in our paper by two eminent physiologists and hope this response to their comments will clarify the objectives of our paper. The analysis in Fahlman et al. (2016) was not intended to provide an accurate method to estimate field metabolic rate (FMR) in large mysticetes; the objective was to measure the dynamic changes in physiology associated with recovery from exercise and show that they are important to consider when estimating FMR. While static averages can provide useful estimates of FMR for a variety of situations, these need to be appropriately selected. For example, we illustrate that it is not possible to use selected average values chosen from excised tissues or resting animals (as in Blix and Folkow, 1995) to provide meaningful estimates of FMR for animals at different activities (i.e. the dolphins in our study). Our study highlights the importance of temporal variation in physiological models: the Blix and Folkow (1995) estimates rely on the assumption that only breathing frequency (fR) changes with activity, while we argue that both the tidal volume (VT) and mixed lung O2 content also vary with activity and recovery from a dive (Ridgway et al., 1969). Including this variation in all three parameters reduces temporal uncertainty in the same conceptual model (see Eqn. 1 in Fahlman et al., 2016).

Description: Background Therapy-related myelodysplastic syndrome (MDS) and acute leukemias represent a major cause of non-relapse morbidity and mortality in childhood cancer survivors, and have been associated with exposure to cytotoxic therapies (e.g. radiation, alkylators, topoisomerase inhibitors). Neuroblastoma (NB) patients receive multimodality therapy with intensive chemotherapy, radiation, and immunotherapy, and have had high rates of treatment-related leukemias (Kushner, Cheung et al. 1998). Whilst specific therapeutic modalities have been associated with distinct cytogenetic and molecular abnormalities, our understanding of the relationships between timing of mutation acquisition, dynamics of clonal selection in relation to specific therapeutic modalities, and how these in unison result in overt leukemia, remains limited. Motivated to study these relationships and inform future screening guidelines, we characterized serial bone marrow (BM) samples obtained during surveillance for NB recurrence and therapy-related leukemias. Methods We studied a total of 219 serial samples from 55 NB patients treated at MSKCC over a 21-year period. These included 19 patients with MDS or leukemic transformation (median time following NB diagnosis 4.4 years), 15 with transient cytogenetic abnormalities (median time to abnormality 3.1 years), and 21 matched controls (median disease-free follow-up 8.1 years). On average, we analyzed 4 samples per transformation patient, representative of pre-treatment timepoints at NB diagnosis, during NB treatment, and throughout follow-up, with a lead time of 18 years - 1 month prior to transformation, and at time of leukemic transformation. Comprehensive genomic profiling with targeted gene sequencing (MSK-IMPACT Heme), RNA-seq, and Archer FusionPlex was performed to capture acquired gene mutations, chromosome-level copy number alterations (CNA), and fusion genes at the time of diagnosis. Backtracking studies were performed in longitudinal samples with complete molecular and clonal characterization. Results We detected at least one disease-defining alteration in all cases with MDS or leukemic transformation at time of diagnosis, with a total of 61 putative oncogenic events across all patients (median 3 alterations per patient, range 1-12). As expected, the most frequent events were MLL fusions (n=6 patients), and mutations in TP53 (n=5 patients). The remaining cases harbored chromosomal aneuploidies or acquired gene mutations in NPM1, IDH1, PTPN11, NRAS, BCOR, CUX1, STAG2, WT1, amongst other genes, at a median variant allele frequency 24% (range 4-68%). Backtracking studies identified at least one of these mutations in 81% of patients at a sampling time point prior to diagnosis. In contrast, only two patients (2/15) from the cohort with transient cytogenetic abnormalities had acquired somatic mutations detected at a median VAF of 3%, with resolution of the molecular alterations in subsequent samples. One of the control cases also had an identified mutation, though this patient died of NB with limited hematologic follow-up. The median time of detection of a putative driver alteration was 6 months prior to leukemic transformation, with the earliest identified at 2.8 years prior to disease transformation. At least 3 cases of MLL fusions were detected 2.2, 14.5, and 20.9 months prior to diagnosis. Mutations in TP53 co-occurred with CNAs in all patients in our cohort, and has been shown to be predictive of chemoresistant disease. Mutations in TP53 were also identified in at least 2 pre-leukemic samples per patient in 4 of 5 cases, at a median VAF 5% (range 5-20%). In all of these cases, TP53 mutations preceded clinically detectable CNA. Genetic evolution led clonal dominance, which, intriguingly, often preceded disease presentation in the context of normal hematopoeisis. We also found evidence of clonal drifts, possibly as a consequence of treatment effects. Conclusions Our preliminary data demonstrate that NB patients at risk of developing secondary leukemia can be identified by molecular profiling of BM aspirates obtained during routine disease surveillance for NB. These findings present an opportunity for the development of early detection studies for patients with pediatric malignancies undergoing intensive therapy and importantly inform studies into mechanisms of leukemic transformation and specific gene-treatment effects. Disclosures Cheung: Ymabs: Patents & Royalties.

Description: Background: CTL019 is an investigational therapy derived from autologous T-cells expressing a CD19-specific chimeric antigen receptor (CAR). A single center, phase I/IIa trial of CTL019 showed complete and durable remissions in pediatric/young adult patients (pts) with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL) (Maude et al NEJM 2014); these results have yet to be reproduced in a multicenter setting. Here, we report results from a 6-month interim analysis of the first multicenter phase II trial of an engineered cell therapy in leukemia. Methods: 9 US sites participated in this single-arm phase II study in pediatric/young adult pts with R/R B-ALL. Leukapheresis products were shipped for centralized manufacturing according to the University of Pennsylvania (Penn) process in an academic-industry collaboration. T cells were transduced with a lentiviral vector encoding a CAR composed of anti-CD19 scFv, CD3ζ and 4-1BB domains. Following lymphodepletion with fludarabine and cyclophosphamide, a single dose of CTL019 cells was administered (target dose 2.0-5.0×106 cells/kg for ≤50 kg and 1.0-2.5×108 cells for 〉50 kg). The primary endpoint was overall remission rate (ORR = CR + CRi [CRi, complete remission with incomplete blood count recovery] maintained at 2 evaluations ≥28 days apart) as determined by an Independent Review Committee. Secondary objectives included minimal residual disease (MRD), relapse-free survival (RFS), overall survival (OS) and safety. All analyses were performed on infused patient set. Results: 29/35 pts enrolled (82.9%) were infused with CTL019; 6 withdrew prior to infusion (2 manufacturing failures [1 lack of growth, 1 contamination]; 4 deaths [median, 48 days from enrollment; 2 progressive disease, 1 multi-organ failure, 1 pneumonia]). Mean bone marrow involvement at enrollment was 68.2% (SD, 27.3%; Table 1). 2 pts did not receive lymphodepleting chemotherapy due to leukopenia. Collection, manufacturing and infusion were feasible in a multicenter setting with a median time from enrollment to infusion of 37 days. Target cell dose was met in 24/33 (72.7%) manufactured products. ORR in all infused pts was 69.0% (20/29 pts; 98.95% CI 43.6, 88.1). Of the 5 pts who received CTL019 below the target dose, 2 achieved CR/CRi. Of note, deep remission with no evidence of MRD (

Description: Background: Value is defined as health outcomes achieved per dollar spent. While risk-stratified AL HCT survival estimates are made possible by the Stem Cell Therapeutic Outcomes Database (SCTOD), an assessment of healthcare value is not possible as they do not include cost adjustments based upon clinical risk. We report a risk-based cost analysis, modeled on AL pts undergoing HCT at our institution that can potentially serve as a simple, statistically significant risk-based comparison tool. Methods: All AL pts who underwent HCT at City of Hope between 1/1/2010 and 12/31/2014 were included. Detailed data were captured from multiple electronic record sources in our database. Total direct costs were assessed for each pt from 14 days prior to 100 days post HCT. Categorical data were tested for associations by Chi-square; continuous data that were normally distributed were tested by T-test, while non-normal data were tested by Wilcoxon rank sum test. Univariate and multivariable logistic regression models were used to identify predictors associated with HCT costs ≥ median and ≥ 80th percentile. Univariate and multivariable Cox proportional hazards regression were used to identify predictors of overall survival (OS). All p-values were 2-sided with alpha level of 0.05. Results: This analysis included 389 pts (AML 352; ALL 37); median age was 52.5 years (yr) [range 1-74; 107 (27.5%) age ≥ 60]; 48% were female. At the time of HCT 204 (52%) were in 1st complete remission [CR], 87 (22%) in 1st relapse (rel)/2nd CR, and 98 (25%) 〉2nd CR/Induction Failure [IF]; ECOG performance status was ≥1 in 29.5% and Sorrer comorbidity score ≥1 in 56%. 214 (55%) and 175 (45%) received myeloablative (MAC) or reduced intensity (RIC) conditioning regimen, respectively; 231 (59%) had matched unrelated donor [MUD] or mismatched related donor (MRD) HCT. Graft-versus-host prophylactic (GVHD) regimen consisted of tacrolimus/sirolimus for 80% pts. 207 pts were enrolled on a therapeutic intervention trials and 121 had Medicare and/or Medicaid (Medi-Cal) as payer. Median follow-up was 12.9 months. The estimated 1- yr unadjusted OS for the entire group post-HCT was 71% (95% CI 66%-75%), 80% (74%-85%) for pts in 1st CR, 68% (57%-77%) for pts in 1st rel/2nd CR, and 56% (45%-65%) for pts 〉2nd CR/ IF. OS was similar for sibling matched and MUD/MRD transplants (1-yr OS 73% vs. 70%). In a multivariable analyses, disease status, MUD/MRD donor, MAC regimen, GVHD prophylaxis other than tacrolimus/sirolimus, ECOG ≥1, and Medicare and/or Medicaid as payer significantly predicted for cost ≥ median (Figure1A). Using Akaike Information Criterion (AIC) scores, donor type and disease status at HCT were found to be more informative variables with regard to higher cost of HCT. Disease status, MUD/MRD, MAC regimen, Medicare and/or Medicaid as payer and ECOG ≥1 also significantly predicted cost ≥ 80th percentile (Figure1B). In a multivariable analysis for OS (Figure 1C) , only 〉2nd CR/IF and HCT cost exceeding median had significantly higher hazard of death. Of note, despite reaching statistical significance in univariate analysis age, cytogenetics, treatment on protocol, and Sorrer score lost significance in adjusted higher costs and OS multivariable models. Conclusions: Our data suggest that: 1. Higher levels of care complexity drive higher costs, 2. Patients with more advanced disease status and inferior performance status have higher costs, 3. Statistically significant drivers of higher care costs are predictable prior to HCT. These risk factors are easily abstractable from medical records and provide prospective, equitably comparisons of risk-based costs between transplant centers. These data compliment the outcomes data available from the SCTOD and may enable providers and payers to make meaningful value comparisons between transplant centers. They may also help establish alternative models for payer contracting that include consideration of clinical risk-stratification. Of note, given the favorable survival outcomes of pts with higher cost-risk features (i.e., advanced disease status at HCT and MUD/MRD), the higher care costs associated with effective care of higher complexity pts are justified. While validation of this model is necessary using large payer or multi-institutional databases, we propose that similar clinical-economic models can be created for pts with other blood cancers requiring high complexity care. Figure 1 Figure 1. Figure 2 Figure 2. Figure 3 Figure 3. Disclosures Forman: Mustang Therpapeutics: Other: Construct licensed by City of Hope.