Citations

Abstract BACKGROUND Current recommendations for screening for monoclonal gammopathies include serum protein electrophoresis (PEL), imunofixation electrophoresis (IFE), and free light chain (FLC) ratios to identify or rule out an M-protein. The aim of this study was to examine the feasibility of an assay based on immunoenrichment and MALDI-TOF-MS (MASS-SCREEN) to qualitatively screen for M-proteins. METHODS Serum from 556 patients previously screened for M-proteins by PEL and IFE were immunopurified using a κ/λ-specific nanobody bead mixture. Following purification, light chains (LC) were released from their heavy chains by reduction. MALDI-TOF analysis was performed and the mass-to-charge LC distributions were visually examined for the presence of an M-protein by both unblinded and blinded analysts. RESULTS In unblinded analysis, MASS-SCREEN detected 100% of the PEL-positive samples with an analytical sensitivity and specificity of 96% and 81% using IFE positivity as the standard. In a blinded analysis using 6 different laboratory personnel, consensus was reached in 92% of the samples. Overall analytical sensitivity and specificity were reduced to 92% and 80%, respectively. FLC ratios were found to be abnormal in 28% of MASS-SCREEN–negative samples, suggesting FLC measurements need to be considered in screening. CONCLUSIONS MASS-SCREEN could replace PEL in a panel that would include FLC measurements. Further studies and method development should be performed to validate the clinical sensitivity and specificity and to determine if this panel will suffice as a general screen for monoclonal proteins.

Abstract Purpose: In preclinical studies, the PARP inhibitor veliparib enhanced the antileukemic action of temozolomide through potentiation of DNA damage. Accordingly, we conducted a phase 1 study of temozolomide with escalating doses of veliparib in patients with relapsed, refractory acute myeloid leukemia (AML) or AML arising from aggressive myeloid malignancies. Experimental Design: Patients received veliparib [20–200 mg once a day on day 1 and twice daily on days 4–12 in cycle 1 (days 1–8 in cycle ≥2)] and temozolomide [150–200 mg/m2 daily on days 3–9 in cycle 1 (days 1–5 in cycle ≥2)] every 28 to 56 days. Veliparib pharmacokinetics and pharmacodynamics [ability to inhibit poly(ADP-ribose) polymer (PAR) formation and induce H2AX phosphorylation] were assessed. Pretreatment levels of MGMT and PARP1 protein, methylation of the MGMT promoter, and integrity of the Fanconi anemia pathway were also examined. Results: Forty-eight patients were treated at seven dose levels. Dose-limiting toxicities were oral mucositis and esophagitis lasting >7 days. The MTD was veliparib 150 mg twice daily with temozolomide 200 mg/m2 daily. The complete response (CR) rate was 17% (8/48 patients). Veliparib exposure as well as inhibition of PAR polymer formation increased dose proportionately. A veliparib-induced increase in H2AX phosphorylation in CD34+ cells was observed in responders. Three of 4 patients with MGMT promoter methylation achieved CR. Conclusions: Veliparib plus temozolomide is well tolerated, with activity in advanced AML. Further evaluation of this regimen and of treatment-induced phosphorylation of H2AX and MGMT methylation as potential response predictors appears warranted. Clin Cancer Res; 23(3); 697–706. ©2016 AACR.

Abstract This article is part of the To the Point Series prepared by the Association of Professors of Gynecology and Obstetrics Undergraduate Medical Education Committee. Principles and education in patient safety have been well integrated into academic obstetrics and gynecology practices, although progress in safety profiles has been frustratingly slow. Medical students have not been included in the majority of these ambulatory practice or hospital-based initiatives. Both the Association of American Medical Colleges and Accreditation Council for Graduate Medical Education have recommended incorporating students into safe practices. The Accreditation Council for Graduate Medical Education milestone 1 for entering interns includes competencies in patient safety. We present data and initiatives in patient safety, which have been successfully used in undergraduate and graduate medical education. In addition, this article demonstrates how using student feedback to assess sentinel events can enhance safe practice and quality improvement programs. Resources and implementation tools will be discussed to provide a template for incorporation into educational programs and institutions. Medical student involvement in the culture of safety is necessary for the delivery of both high-quality education and high-quality patient care. It is essential to incorporate students into the ongoing development of patient safety curricula in obstetrics and gynecology.

Abstract Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis, but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112,349 cases and 116,421 controls of European ancestry, all together and in pairs, identified at P < 10−8 seven new cross-cancer loci: three associated with susceptibility to all three cancers (rs17041869/2q13/BCL2L11; rs7937840/11q12/INCENP; rs1469713/19p13/GATAD2A), two breast and ovarian cancer risk loci (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell-type–specific expression quantitative trait locus and enhancer–gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P < 10−5 in the three-cancer meta-analysis. Significance: We demonstrate that combining large-scale GWA meta-analysis findings across cancer types can identify completely new risk loci common to breast, ovarian, and prostate cancers. We show that the identification of such cross-cancer risk loci has the potential to shed new light on the shared biology underlying these hormone-related cancers. Cancer Discov; 6(9); 1052–67. ©2016 AACR. This article is highlighted in the In This Issue feature, p. 932

ABSTRACTRare variants (RVs) have been shown to be significant contributors to complex disease risk. By definition, these variants have very low minor allele frequencies and traditional single‐marker methods for statistical analysis are underpowered for typical sequencing study sample sizes. Multimarker burden‐type approaches attempt to identify aggregation of RVs across case‐control status by analyzing relatively small partitions of the genome, such as genes. However, it is generally the case that the aggregative measure would be a mixture of causal and neutral variants, and these omnibus tests do not directly provide any indication of which RVs may be driving a given association. Recently, Bayesian variable selection approaches have been proposed to identify RV associations from a large set of RVs under consideration. Although these approaches have been shown to be powerful at detecting associations at the RV level, there are often computational limitations on the total quantity of RVs under consideration and compromises are necessary for large‐scale application. Here, we propose a computationally efficient alternative formulation of this method using a probit regression approach specifically capable of simultaneously analyzing hundreds to thousands of RVs. We evaluate our approach to detect causal variation on simulated data and examine sensitivity and specificity in instances of high RV dimensionality as well as apply it to pathway‐level RV analysis results from a prostate cancer (PC) risk case‐control sequencing study. Finally, we discuss potential extensions and future directions of this work.

Abstract Therapeutic monoclonal immunoglobulins (mAbs) are used to treat patients with a wide range of disorders including autoimmune diseases. As pharmaceutical companies bring more fully humanized therapeutic mAb drugs to the healthcare market analytical platforms that perform therapeutic drug monitoring (TDM) without relying on mAb specific reagents will be needed. In this study we demonstrate that liquid-chromatography?mass spectrometry (LC?MS) can be used to perform TDM of mAbs in the same manner as smaller nonbiologic drugs. The assay uses commercially available reagents combined with heavy and light chain disulfide bond reduction followed by light chain analysis by microflow-LC?electrospray ionization-quadrupole-time-of-flight mass spectrometry (ESI-Q-TOF MS). Quantification is performed using the peak areas from multiply charged mAb light chain ions using an in-house developed software package developed for TDM of mAbs. The data presented here demonstrate the ability of an LC?MS assay to quantify a therapeutic mAb in a large cohort of patients in a clinical trial. The ability to quantify any mAb in serum via the reduced light chain without the need for reagents specific for each mAb demonstrates the unique capabilities of LC?MS. This fact, coupled with the ability to phenotype a patient?s polyclonal repertoire in the same analysis further shows the potential of this approach to mAb analysis.

Abstract Pinometostat is a highly selective first in class DOT1L inhibitor currently in Phase 1 clinical trials in adult and pediatric leukemia patients (pts) with MLL rearrangements (MLL-r or MLL-PTD). Preliminary results of the adult trial have demonstrated clinical activity including complete remissions in a subset of patients (Stein, 2014). Investigation and identification of candidate molecular correlates of pinometostat response in both pt samples and cell lines are reported. RNA and DNA were isolated from PBMCs and/or bone marrow collected prior to treatment from 18 pts enrolled in the adult pinometostat Phase 1 study (CT.gov: NCT01684150), at the following doses 24 (n = 2), 36 (n = 3), 54 (n = 6), 80 (n = 3) and 90 mg/m2/day doses (n = 4). mRNA transcript abundance was assessed using whole genome RNASeq and DNA variants were determined using a 194 gene panel, MyAML (Genection Inc.). Correlations of transcript abundance and DNA variants detected with categorical (responder = CR or PR [n = 3], or no response [n = 16]) and continuous response parameters (time on study [TOS], mean = 59 days: range = 8-196 days) were performed. For cell lines, whole genome RNASeq data was generated from 14 cell lines (MLL-r or MLL-PTD) with a range of in vitro sensitivity to pinometostat (cell proliferation IC50 2 nM to > 10 μM) and RNA transcripts identified as correlated with IC50 were submitted for pathway analysis. Univariate analyses revealed no DNA variants to be associated with either response category (FDR adjusted P < 0.05), however, a statistical association (unadjusted P = 0.05) was identified between increased TOS and those pts harboring t(11:19). Indicating that specific MLL fusion partners may elicit differential sensitivity to pinometostat therapy (2/2 CR pts had t(11:19)). Analysis of the baseline PBMC RNASeq data revealed 201 genes as significantly correlated with TOS (FDR adjusted P<0.05), these data were further analyzed using the Selventa causal modelling platform to identify pathways associated with TOS. Increased activity in pathways leading to differentiation, oxidative stress, inflammation, ras activation and decreased activities of PPAR-γ, DNA methylation and stem cell renewal were associated with increased TOS. Independent analysis of the cell line response data identified pathways that significantly overlapped with those observed in pt samples, with 4/7 of the pt derived mechanisms identified (PPAR-γ activity, inflammation, stem cell renewal and ras activation). In all cases directionality of pathway activity relative to pinometostat sensitivity were concordant between pt and cell line data. Based on these results the effect of a PPAR-γ agonist e.g. rosiglitazone, would be predicted to be antagonistic to pinometostat activity. Results of experiments investigating the effects of combination of rosiglitazone and pinometostat in MOLM-13 cell lines demonstrated that the combination was significantly less effective at inhibiting cell proliferation than pinometostat alone (IC50 shift of 2 fold (n = 2)). MLL-r fusion partner (e.g. t(11:19)) may influence clinical response to pinometostat. In addition RNASeq based characterization of patient samples and cell lines revealed candidate pathways that may cooperate with or antagonize pinometostat activity that warrant further investigation. Citation Format: Scott Daigle, Alice McDonald, Ty M. Thomson, David A. Drubin, Michael Maria, A. Carson, Brad Patay, Jeff Keats, Christine Klaus, Alejandra Raimondi, G. Garcia-Manero, D. A. Rizzieri, Raoul Tibes, Jesus Berdeja, Eytan M. Stein, Blythe Thomson, Stephen J. Blakemore. Identification of biomarkers and pathways associated with response to the DOT1L inhibitor Pinometostat (EPZ-5676) in MLL-r leukemia. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C12.