Dynamic reprogramming of the kinome in response to targeted MEK inhibition in triple-negative breast cancer.

Kinase inhibitors have limited success in cancer treatment because tumors circumvent their action. Using a quantitative proteomics approach, we assessed kinome activity in response to MEK inhibition in triple-negative breast cancer (TNBC) cells and genetically engineered mice (GEMMs). MEK inhibition caused acute ERK activity loss, resulting in rapid c-Myc degradation that induced expression and activation of several receptor tyrosine kinases (RTKs). RNAi knockdown of ERK or c-Myc mimicked RTK induction by MEK inhibitors, and prevention of proteasomal c-Myc degradation blocked kinome reprogramming. MEK inhibitor-induced RTK stimulation overcame MEK2 inhibition, but not MEK1 inhibition, reactivating ERK and producing drug resistance. The C3Tag GEMM for TNBC similarly induced RTKs in response to MEK inhibition. The inhibitor-induced RTK profile suggested a kinase inhibitor combination therapy that produced GEMM tumor apoptosis and regression where single agents were ineffective. This approach defines mechanisms of drug resistance, allowing rational design of combination therapies for cancer.

Small-molecule inhibition of the archetypal UbiB protein COQ8.

Small-molecule tools have enabled mechanistic investigations and therapeutic targeting of the protein kinase-like (PKL) superfamily. However, such tools are still lacking for many PKL members, including the highly conserved and disease-related UbiB family. Here, we sought to develop and characterize an inhibitor for the archetypal UbiB member COQ8, whose function is essential for coenzyme Q (CoQ) biosynthesis. Guided by crystallography, activity assays and cellular CoQ measurements, we repurposed the 4-anilinoquinoline scaffold to selectively inhibit human COQ8A in cells. Our chemical tool promises to lend mechanistic insights into the activities of these widespread and understudied proteins and to offer potential therapeutic strategies for human diseases connected to their dysfunction.

Effect of next-step antidepressant treatment on suicidal ideation: findings from the VAST-D trial.

BACKGROUND: Major depressive disorder (MDD) contributes to suicide risk. Treating MDD effectively is considered a key suicide prevention intervention. Yet many patients with MDD do not respond to their initial medication and require a 'next-step'. The relationship between next-step treatments and suicidal thoughts and behaviors is uncharted. METHOD: The VA Augmentation and Switching Treatments for Depression trial randomized 1522 participants to one of three next-step treatments: Switching to Bupropion, combining with Bupropion, and augmenting with Aripiprazole. In this secondary analysis, features associated with lifetime suicidal ideation (SI) and attempts (SA) at baseline and current SI during treatment were explored. RESULTS: Compared to those with SI only, those with lifetime SI + SA were more likely to be female, divorced, or separated, unemployed; and to have experienced more childhood adversity. They had a more severe depressive episode and were more likely to respond to 'next-step' treatment. The prevalence of SI decreased from 46.5% (694/1492) at baseline to 21.1% (315/1492) at end-of-treatment. SI during treatment was associated with baseline SI; low positive mental health, more anxiety, greater severity and longer duration of current MDD episode; being male and White; and treatment with S-BUP or C-BUP as compared to A-ARI. CONCLUSION: SI declines for most patients during next-step medication treatments. But about 1 in 5 experienced emergent or worsening SI during treatment, so vigilance for suicide risk through the entire 12-week acute treatment period is necessary. Treatment selection may affect the risk of SI.

Adaptive chromatin remodeling and transcriptional changes of the functional kinome in tumor cells in response to targeted kinase inhibition.

Pharmacological inhibition of protein kinases induces adaptive reprogramming of tumor cell regulatory networks by altering expression of genes that regulate signaling, including protein kinases. Adaptive responses are dependent on transcriptional changes resulting from remodeling of enhancer and promoter landscapes. Enhancer and promoter remodeling in response to targeted kinase inhibition is controlled by changes in open chromatin state and by activity of specific transcription factors, such as c-MYC. This review focuses on the dynamic plasticity of protein kinase expression of the tumor cell kinome and the resulting adaptive resistance to targeted kinase inhibition. Plasticity of the functional kinome has been shown in patient window trials where triple-negative and human epidermal growth factor receptor 2-positive breast cancer patient tumors were characterized by RNAseq after biopsies before and after 1 week of therapy. The expressed kinome changed dramatically during drug treatment, and these changes in kinase expression were shown in cell lines and xenografts in mice to be correlated with adaptive tumor cell drug resistance. The dynamic transcriptional nature of the kinome also differs for inhibitors targeting different kinase signaling pathways (e.g., BRAF-MEK-ERK versus PI3K-AKT) that are commonly activated in cancers. Heterogeneity arising from differences in gene regulation and mutations represents a challenge to therapeutic durability and prevention of clinical drug resistance with drug-tolerant tumor cell populations developing and persisting through treatment. We conclude that understanding the heterogeneity of kinase expression at baseline and in response to therapy is imperative for development of combinations and timing intervals of therapies making interventions durable.

Variants in FtsJ RNA 2'-O-Methyltransferase 3 and Growth Hormone 1 are associated with small body size and a dental anomaly in dogs.

Domesticated dogs show unparalleled diversity in body size across breeds, but within breeds variation is limited by selective breeding. Many heritable diseases of dogs are found among breeds of similar sizes, suggesting that as in humans, alleles governing growth have pleiotropic effects. Here, we conducted independent genome-wide association studies in the small Shetland Sheepdog breed and discovered a locus on chromosome 9 that is associated with a dental abnormality called maxillary canine-tooth mesioversion (MCM) (P = 1.53 × 10-7) as well as two body size traits: height (P = 1.67 × 10-5) and weight (P = 1.16 × 10-7). Using whole-genome resequencing data, we identified variants in two proximal genes: FTSJ3, encoding an RNA methyltransferase, and GH1, encoding growth hormone. A substitution in FTSJ3 and a splice donor insertion in GH1 are strongly associated with MCM and reduced body size in Shetland Sheepdogs. We demonstrated in vitro that the GH1 variant leads to exon 3 skipping, predicting a mutant protein known to cause human pituitary dwarfism. Statistical modeling, however, indicates that the FTSJ3 variant is the stronger predictor of MCM and that each derived allele reduces body size by about 1 inch and 5 pounds. In a survey of 224 breeds, both FTSJ3 and GH1 variants are frequent among very small "toy" breeds and absent from larger breeds. Our findings indicate that a chromosome 9 locus harboring tightly linked variants in FTSJ3 and GH1 reduces growth in the Shetland Sheepdog and toy breed dogs and confers risk for MCM through vertical pleiotropy.

Association of in-competition injury risk and the degree of rapid weight cutting prior to competition in division I collegiate wrestlers.

OBJECTIVES: Weight cutting is thought to offer a competitive advantage in wrestling. Dehydration has deleterious effects on physical and cognitive function, which may increase the risk of injury. The purpose of the study was to investigate whether the degree of weight cutting was associated with injury risk. METHODS: Data were collected prospectively in a cohort of collegiate wrestlers over seven seasons. Changes in weight, body fat and lean mass were measured during the preseason, at midseason and before competition. Cox proportional-hazard ratios were calculated for risk of in-competition injury. RESULTS: Among 67 unique division 1 collegiate wrestlers (163 athlete seasons), there were 53 unique injuries affecting 46 athletes. There was no difference in absolute weight change, per cent weight change, per cent body fat change or per cent lean mass change between injured and non-injured wrestlers from the preseason to midseason measurements. From midseason to competition weight, change in body weight was -7.0%±3.2% (-5.3 kg±2.6) in injured athletes compared with -5.7%±3.3% (-4.3 kg±2.5) in non-injured athletes. For every kilogram of body weight lost, wrestlers had a 14% increased hazard of injury (HR 1.14, 95% CI 1.04 to 1.25, p=0.004). For every 1% of body weight lost, wrestlers had an 11% increased hazard of injury (HR 1.11, 95% CI 1.03 to 1.19, p=0.005). CONCLUSION: Rapid weight cutting was associated with a higher risk of in-competition injuries in division 1 collegiate wrestlers. For every per cent in body weight lost, wrestlers had an 11% increased hazard of injury during competition.

New strategies for targeting kinase networks in cancer.

Targeted strategies against specific driver molecules of cancer have brought about many advances in cancer treatment since the early success of the first small-molecule inhibitor Gleevec. Today, there are a multitude of targeted therapies approved by the Food and Drug Administration for the treatment of cancer. However, the initial efficacy of virtually every targeted treatment is often reversed by tumor resistance to the inhibitor through acquisition of new mutations in the target molecule, or reprogramming of the epigenome, transcriptome, or kinome of the tumor cells. At the core of this clinical problem lies the assumption that targeted treatments will only be efficacious if the inhibitors are used at their maximum tolerated doses. Such aggressive regimens create strong selective pressure on the evolutionary progression of the tumor, resulting in resistant cells. High-dose single agent treatments activate alternative mechanisms that bypass the inhibitor, while high-dose combinatorial treatments suffer from increased toxicity resulting in treatment cessation. Although there is an arsenal of targeted agents being tested clinically and preclinically, identifying the most effective combination treatment plan remains a challenge. In this review, we discuss novel targeted strategies with an emphasis on the recent cross-disciplinary studies demonstrating that it is possible to achieve antitumor efficacy without increasing toxicity by adopting low-dose multitarget approaches to treatment of cancer and metastasis.

Open versus Endovascular Repair of Abdominal Aortic Aneurysm.

BACKGROUND: Elective endovascular repair of an abdominal aortic aneurysm results in lower perioperative mortality than traditional open repair, but after 4 years this survival advantage is not seen; in addition, results of two European trials have shown worse long-term outcomes with endovascular repair than with open repair. Long-term results of a study we conducted more than a decade ago to compare endovascular repair with open repair are unknown. METHODS: We randomly assigned patients with asymptomatic abdominal aortic aneurysms to either endovascular repair or open repair of the aneurysm. All the patients were candidates for either procedure. Patients were followed for up to 14 years. RESULTS: A total of 881 patients underwent randomization: 444 were assigned to endovascular repair and 437 to open repair. The primary outcome was all-cause mortality. A total of 302 patients (68.0%) in the endovascular-repair group and 306 (70.0%) in the open-repair group died (hazard ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.13). During the first 4 years of follow-up, overall survival appeared to be higher with endovascular repair than with open repair; from year 4 through year 8, overall survival was higher in the open-repair group; and after 8 years, overall survival was once again higher in the endovascular-repair group (hazard ratio for death, 0.94; 95% CI, 0.74 to 1.18). None of these trends were significant. There were 12 aneurysm-related deaths (2.7%) in the endovascular-repair group and 16 (3.7%) in the open-repair group (between-group difference, -1.0 percentage point; 95% CI, -3.3 to 1.4); most deaths occurred during the perioperative period. Aneurysm rupture occurred in 7 patients (1.6%) in the endovascular-repair group, and rupture of a thoracic aneurysm occurred in 1 patient (0.2%) in the open-repair group (between-group difference, 1.3 percentage points; 95% CI, 0.1 to 2.6). Death from chronic obstructive lung disease was just over 50% more common with open repair (5.4% of patients in the endovascular-repair group and 8.2% in the open-repair group died from chronic obstructive lung disease; between-group difference, -2.8 percentage points; 95% CI, -6.2 to 0.5). More patients in the endovascular-repair group underwent secondary procedures. CONCLUSIONS: Long-term overall survival was similar among patients who underwent endovascular repair and those who underwent open repair. A difference between groups was noted in the number of patients who underwent secondary therapeutic procedures. Our results were not consistent with the findings of worse performance of endovascular repair with respect to long-term survival that was seen in the two European trials. (Funded by the Department of Veteran Affairs Office of Research and Development; OVER ClinicalTrials.gov number, NCT00094575.).

Pathologic characterization of canine multiple system degeneration in the Ibizan hound.

Canine multiple system degeneration (CMSD) is a progressive hereditary neurodegenerative disorder commonly characterized by neuronal degeneration and loss in the cerebellum, olivary nuclei, substantia nigra, and caudate nuclei. In this article, we describe 3 cases of CMSD in Ibizan hounds. All patients exhibited marked cerebellar ataxia and had cerebellar atrophy on magnetic resonance imaging. At necropsy, all cases showed varying degrees of cerebellar atrophy, and 2 cases had gross cavitation of the caudate nuclei. Histologic findings included severe degeneration and loss of all layers of the cerebellum and neuronal loss and degeneration within the olivary nuclei, substantia nigra, and caudate nuclei. Pedigree analysis indicated an autosomal recessive mode of inheritance, but the causative gene in this breed is yet to be identified. CMSD resembles human multiple system atrophy and warrants further investigation.

Kinome profiling of non-Hodgkin lymphoma identifies Tyro3 as a therapeutic target in primary effusion lymphoma.

Non-Hodgkin lymphomas (NHLs) make up the majority of lymphoma diagnoses and represent a very diverse set of malignancies. We sought to identify kinases uniquely up-regulated in different NHL subtypes. Using multiplexed inhibitor bead-mass spectrometry (MIB/MS), we found Tyro3 was uniquely up-regulated and important for cell survival in primary effusion lymphoma (PEL), which is a viral lymphoma infected with Kaposi's sarcoma-associated herpesvirus (KSHV). Tyro3 was also highly expressed in PEL cell lines as well as in primary PEL exudates. Based on this discovery, we developed an inhibitor against Tyro3 named UNC3810A, which hindered cell growth in PEL, but not in other NHL subtypes where Tyro3 was not highly expressed. UNC3810A also significantly inhibited tumor progression in a PEL xenograft mouse model that was not seen in a non-PEL NHL model. Taken together, our data suggest Tyro3 is a therapeutic target for PEL.

Chromosome-length genome assembly and structural variations of the primal Basenji dog (Canis lupus familiaris) genome.

BACKGROUND: Basenjis are considered an ancient dog breed of central African origins that still live and hunt with tribesmen in the African Congo. Nicknamed the barkless dog, Basenjis possess unique phylogeny, geographical origins and traits, making their genome structure of great interest. The increasing number of available canid reference genomes allows us to examine the impact the choice of reference genome makes with regard to reference genome quality and breed relatedness. RESULTS: Here, we report two high quality de novo Basenji genome assemblies: a female, China (CanFam_Bas), and a male, Wags. We conduct pairwise comparisons and report structural variations between assembled genomes of three dog breeds: Basenji (CanFam_Bas), Boxer (CanFam3.1) and German Shepherd Dog (GSD) (CanFam_GSD). CanFam_Bas is superior to CanFam3.1 in terms of genome contiguity and comparable overall to the high quality CanFam_GSD assembly. By aligning short read data from 58 representative dog breeds to three reference genomes, we demonstrate how the choice of reference genome significantly impacts both read mapping and variant detection. CONCLUSIONS: The growing number of high-quality canid reference genomes means the choice of reference genome is an increasingly critical decision in subsequent canid variant analyses. The basal position of the Basenji makes it suitable for variant analysis for targeted applications of specific dog breeds. However, we believe more comprehensive analyses across the entire family of canids is more suited to a pangenome approach. Collectively this work highlights the importance the choice of reference genome makes in all variation studies.

A proteasome-resistant fragment of NIK mediates oncogenic NF-κB signaling in schwannomas.

Schwannomas are common, highly morbid and medically untreatable tumors that can arise in patients with germ line as well as somatic mutations in neurofibromatosis type 2 (NF2). These mutations most commonly result in the loss of function of the NF2-encoded protein, Merlin. Little is known about how Merlin functions endogenously as a tumor suppressor and how its loss leads to oncogenic transformation in Schwann cells (SCs). Here, we identify nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-inducing kinase (NIK) as a potential drug target driving NF-κB signaling and Merlin-deficient schwannoma genesis. Using a genomic approach to profile aberrant tumor signaling pathways, we describe multiple upregulated NF-κB signaling elements in human and murine schwannomas, leading us to identify a caspase-cleaved, proteasome-resistant NIK kinase domain fragment that amplifies pathogenic NF-κB signaling. Lentiviral-mediated transduction of this NIK fragment into normal SCs promotes proliferation, survival, and adhesion while inducing schwannoma formation in a novel in vivo orthotopic transplant model. Furthermore, we describe an NF-κB-potentiated hepatocyte growth factor (HGF) to MET proto-oncogene receptor tyrosine kinase (c-Met) autocrine feed-forward loop promoting SC proliferation. These innovative studies identify a novel signaling axis underlying schwannoma formation, revealing new and potentially druggable schwannoma vulnerabilities with future therapeutic potential.

Epigenetic Mechanisms Regulating Adaptive Responses to Targeted Kinase Inhibitors in Cancer.

Although targeted inhibition of oncogenic kinase drivers has achieved remarkable patient responses in many cancers, the development of resistance has remained a significant challenge. Numerous mechanisms have been identified, including the acquisition of gatekeeper mutations, activating pathway mutations, and copy number loss or gain of the driver or alternate nodes. These changes have prompted the development of kinase inhibitors with increased selectivity, use of second-line therapeutics to overcome primary resistance, and combination treatment to forestall resistance. In addition to genomic resistance mechanisms, adaptive transcriptional and signaling responses seen in tumors are gaining appreciation as alterations that lead to a phenotypic state change-often observed as an epithelial-to-mesenchymal shift or reversion to a cancer stem cell-like phenotype underpinned by remodeling of the epigenetic landscape. This epigenomic modulation driving cell state change is multifaceted and includes modulation of repressive and activating histone modifications, DNA methylation, enhancer remodeling, and noncoding RNA species. Consequently, the combination of kinase inhibitors with drugs targeting components of the transcriptional machinery and histone-modifying enzymes has shown promise in preclinical and clinical studies. Here, we review mechanisms of resistance to kinase inhibition in cancer, with special emphasis on the rewired kinome and transcriptional signaling networks and the potential vulnerabilities that may be exploited to overcome these adaptive signaling changes.

PRM-LIVE with Trapped Ion Mobility Spectrometry and Its Application in Selectivity Profiling of Kinase Inhibitors.

Parallel reaction monitoring (PRM) has emerged as a popular approach for targeted protein quantification. With high ion utilization efficiency and first-in-class acquisition speed, the timsTOF Pro provides a powerful platform for PRM analysis. However, sporadic chromatographic drift in peptide retention time represents a fundamental limitation for the reproducible multiplexing of targets across PRM acquisitions. Here, we present PRM-LIVE, an extensible, Python-based acquisition engine for the timsTOF Pro, which dynamically adjusts detection windows for reproducible target scheduling. In this initial implementation, we used iRT peptides as retention time standards and demonstrated reproducible detection and quantification of 1857 tryptic peptides from the cell lysate in a 60 min PRM-LIVE acquisition. As an application in functional proteomics, we use PRM-LIVE in an activity-based protein profiling platform to assess binding selectivity of small-molecule inhibitors against 220 endogenous human kinases.

Far away from the lamppost.

This Formal Comment responds to a recent Meta-Research Article by identifying initiatives that are already in place for funding risky exploratory research that illuminate mysteries of the dark genome.

Continuation phase treatment outcomes for switching, combining, or augmenting strategies for treatment-resistant major depressive disorder: A VAST-D report.

BACKGROUND: This secondary analysis of the VA Augmentation and Switching Treatments for Depression study compared the continuation phase treatment outcomes of three commonly used second-step treatment strategies following at least one prior failed medication treatment attempt. METHODS: In total, 1522 outpatients with MDD were randomized to switching to bupropion-SR (S-BUP), combining with bupropion-SR (C-BUP), or augmenting with aripiprazole (A-ARI). Following 12 weeks of acute phase treatment, 725 entered the 24-week continuation treatment phase. Depressive symptom severity, relapse, "emergent" remission, anxiety, suicidal ideation, quality of life, health status, and side effects were compared. RESULTS: We did not find clinically significant differential treatment effects with the exception that A-ARI was associated with less anxiety than S-BUP or C-BUP. Participants who entered continuation treatment as remitters had milder depressive symptom severity and lower relapse rates than those not in remission; they also experienced more improvement on most other outcomes. A-ARI was associated with less anxiety, insomnia, and dry mouth but more somnolence, extrapyramidal effects, akathisia, abnormal laboratory values, and appetite and weight gain. CONCLUSIONS: Continuation treatment is a dynamic period. Regardless of the treatment, participants who entered continuation treatment at Week 12 in full remission continued to have better outcomes over the subsequent 24 weeks than those who were not in remission at the start of the continuation phase.

Synthesis and Evaluation of Novel 1,2,6-Thiadiazinone Kinase Inhibitors as Potent Inhibitors of Solid Tumors.

A focused series of substituted 4H-1,2,6-thiadiazin-4-ones was designed and synthesized to probe the anti-cancer properties of this scaffold. Insights from previous kinase inhibitor programs were used to carefully select several different substitution patterns. Compounds were tested on bladder, prostate, pancreatic, breast, chordoma, and lung cancer cell lines with an additional skin fibroblast cell line as a toxicity control. This resulted in the identification of several low single digit micro molar compounds with promising therapeutic windows, particularly for bladder and prostate cancer. A number of key structural features of the 4H-1,2,6-thiadiazin-4-one scaffold are discussed that show promising scope for future improvement.

Applying cumulative effects to strategically advance large-scale ecosystem restoration.

International efforts to restore degraded ecosystems will continue to expand over the coming decades, yet the factors contributing to the effectiveness of long-term restoration across large areas remain largely unexplored. At large scales, outcomes are more complex and synergistic than the additive impacts of individual restoration projects. Here, we propose a cumulative-effects conceptual framework to inform restoration design and implementation and to comprehensively measure ecological outcomes. To evaluate and illustrate this approach, we reviewed long-term restoration in several large coastal and riverine areas across the US: the greater Florida Everglades; Gulf of Mexico coast; lower Columbia River and estuary; Puget Sound; San Francisco Bay and Sacramento-San Joaquin Delta; Missouri River; and northeastern coastal states. Evidence supported eight modes of cumulative effects of interacting restoration projects, which improved outcomes for species and ecosystems at landscape and regional scales. We conclude that cumulative effects, usually measured for ecosystem degradation, are also measurable for ecosystem restoration. The consideration of evidence-based cumulative effects will help managers of large-scale restoration capitalize on positive feedback and reduce countervailing effects.

A mixed breed dog with neuronal ceroid lipofuscinosis is homozygous for a CLN5 nonsense mutation previously identified in Border Collies and Australian Cattle Dogs.

The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders characterized by progressive declines in neurological functions following normal development. The NCLs are distinguished from similar disorders by the accumulation of autofluorescent lysosomal storage bodies in neurons and many other cell types, and are classified as lysosomal storage diseases. At least 13 genes contain pathogenic sequence variants that underlie different forms of NCL. Naturally occurring canine NCLs can serve as models to develop better understanding of the disease pathologies and for preclinical evaluation of therapeutic interventions for these disorders. To date 14 sequence variants in 8 canine orthologs of human NCL genes have been found to cause progressive neurological disorders similar to human NCLs in 12 different dog breeds. A mixed breed dog with parents of uncertain breed background developed progressive neurological signs consistent with NCL starting at approximately 11 to 12 months of age, and when evaluated with magnetic resonance imaging at 21 months of age exhibited diffuse brain atrophy. Due to the severity of neurological decline the dog was euthanized at 23 months of age. Cerebellar and cerebral cortical neurons contained massive accumulations of autofluorescent storage bodies the contents of which had the appearance of tightly packed membranes. A whole genome sequence, generated with DNA from the affected dog contained a homozygous C-to-T transition at position 30,574,637 on chromosome 22 which is reflected in the mature CLN5 transcript (CLN5: c.619C > T) and converts a glutamine codon to a termination codon (p.Gln207Ter). The identical nonsense mutation has been previously associated with NCL in Border Collies, Australian Cattle Dogs, and a German Shepherd-Australian Cattle Dog mix. The current whole genome sequence and a previously generated whole genome sequence for an Australian Cattle Dog with NCL share a rare homozygous haplotype that extends for 87 kb surrounding 22: 30, 574, 637 and includes 21 polymorphic sites. When genotyped at 7 of these polymorphic sites, DNA samples from the German Shepherd-Australian Cattle Dog mix and from 5 Border Collies with NCL that were homozygous for the CLN5: c.619 T allele also shared this homozygous haplotype, suggesting that the NCL in all of these dogs stems from the same founding mutation event that may have predated the establishment of the modern dog breeds. If so, the CLN5 nonsence allele is probably segregating in other, as yet unidentified, breeds. Thus, dogs exhibiting similar NCL-like signs should be screened for this CLN5 nonsense allele regardless of breed.

Automated safety event monitoring using electronic medical records in a clinical trial setting: Validation study using the VA NEPHRON-D trial.

BACKGROUND/AIMS: Electronic medical records are now frequently used for capturing patient-level data in clinical trials. Within the Veterans Affairs health care system, electronic medical record data have been widely used in clinical trials to assess eligibility, facilitate referrals for recruitment, and conduct follow-up and safety monitoring. Despite the potential for increased efficiency in using electronic medical records to capture safety data via a centralized algorithm, it is important to evaluate the integrity and accuracy of electronic medical record-captured data. To this end, this investigation assesses data collection, both for general and study-specific safety endpoints, by comparing electronic medical record-based safety monitoring versus safety data collected during the course of the Veterans Affairs Nephropathy in Diabetes (VA NEPHRON-D) clinical trial. METHODS: The VA NEPHRON-D study was a multicenter, double-blind, randomized clinical trial designed to compare the effect of combination therapy (losartan plus lisinopril) versus monotherapy (losartan) on the progression of kidney disease in individuals with diabetes and proteinuria. The trial's safety outcomes included serious adverse events, hyperkalemia, and acute kidney injury. A subset of the participants (~62%, n = 895) enrolled in the trial's long-term follow-up sub-study and consented to electronic medical record data collection. We applied an automated algorithm to search and capture safety data using the VA Corporate Data Warehouse which houses electronic medical record data. Using study safety data reported during the trial as the gold standard, we evaluated the sensitivity and precision of electronic medical record-based safety data and related treatment effects. RESULTS: The sensitivity of the electronic medical record-based safety for hospitalizations was 65.3% without non-VA hospitalization events and 92.3% with the non-VA hospitalization events included. The sensitivity was only 54.3% for acute kidney injury and 87.3% for hyperkalemia. The precision of electronic medical record-based safety data was 89.4%, 38%, and 63.2% for hospitalization, acute kidney injury, and hyperkalemia, respectively. Relative treatment differences under the study and electronic medical record settings were 15% and 3% for hospitalization, 123% and 29% for acute kidney injury, and 238% and 140% for hyperkalemia, respectively. CONCLUSION: The accuracy of using automated electronic medical record safety data depends on the events of interest. Identification of all-cause hospitalizations would be reliable if search methods could, in addition to VA hospitalizations, also capture non-VA hospitalizations. However, hospitalization is different from a cause-specific serious adverse event that could be more sensitive to treatment effects. In addition, some study-specific safety events were not easily identified using the electronic medical records. This limits the effectiveness of the automated central database search for purposes of safety monitoring. Hence, this data captured approach should be carefully considered when implementing endpoint data collection in future pragmatic trials.