Evaluating the coding accuracy of type 2 diabetes mellitus among patients with non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) describes a spectrum of chronic fattening of liver that can lead to fibrosis and cirrhosis. Diabetes has been identified as a major comorbidity that contributes to NAFLD progression. Health systems around the world make use of administrative data to conduct population-based prevalence studies. To that end, we sought to assess the accuracy of diabetes International Classification of Diseases (ICD) coding in administrative databases among a cohort of confirmed NAFLD patients in Calgary, Alberta, Canada. METHODS: The Calgary NAFLD Pathway Database was linked to the following databases: Physician Claims, Discharge Abstract Database, National Ambulatory Care Reporting System, Pharmaceutical Information Network database, Laboratory, and Electronic Medical Records. Hemoglobin A1c and diabetes medication details were used to classify diabetes groups into absent, prediabetes, meeting glycemic targets, and not meeting glycemic targets. The performance of ICD codes among these groups was compared to this standard. Within each group, the total numbers of true positives, false positives, false negatives, and true negatives were calculated. Descriptive statistics and bivariate analysis were conducted on identified covariates, including demographics and types of interacted physicians. RESULTS: A total of 12,012 NAFLD patients were registered through the Calgary NAFLD Pathway Database and 100% were successfully linked to the administrative databases. Overall, diabetes coding showed a sensitivity of 0.81 and a positive predictive value of 0.87. False negative rates in the absent and not meeting glycemic control groups were 4.5% and 6.4%, respectively, whereas the meeting glycemic control group had a 42.2% coding error. Visits to primary and outpatient services were associated with most encounters. CONCLUSION: Diabetes ICD coding in administrative databases can accurately detect true diabetic cases. However, patients with diabetes who meets glycemic control targets are less likely to be coded in administrative databases. A detailed understanding of the clinical context will require additional data linkage from primary care settings.

Epigenetic Regulation of Corneal Epithelial Differentiation by TET2.

Epigenetic DNA modification by 5-hydroxymethylcytosine (5hmC), generated by the Ten-eleven translocation (TET) dioxygenases, regulates diverse biological functions in many organ tissues, including the mammalian eye. For example, 5hmC has been shown to be involved in epigenetic regulation of retinal gene expression. However, a functional role of 5hmC in corneal differentiation has not been investigated to date. Here, we examined 5hmC and TET function in the human cornea. We found 5hmC highly expressed in MUC16-positive terminally differentiated cells that also co-expressed the 5hmC-generating enzyme TET2. TET2 knockdown (KD) in cultured corneal epithelial cells led to significant reductions of 5hmC peak distributions and resulted in transcriptional repression of molecular pathways involved in corneal differentiation, as evidenced by downregulation of MUC4, MUC16, and Keratin 12. Additionally, integrated TET2 KD RNA-seq and genome-wide Reduced Representation Hydroxymethylation Profiling revealed novel epigenetically regulated genes expressed by terminally differentiated cells, including KRT78, MYEOV, and MAL. In aggregate, our findings reveal a novel function of TET2 in the epigenetic regulation of corneal epithelial gene expression and identify novel TET2-controlled genes expressed in differentiated corneal epithelial cells. These results point to potential roles for TET2 induction strategies to enhance treatment of corneal diseases associated with abnormal epithelial maturation.

Quantitative norovirus viral load is not affected by home storage of stool.

In preparation of a clinical trial of norovirus treatment, there were concerns raised by FDA about risk of self-storage of stool from patients infected with norovirus affecting quantitative assessments of norovirus RNA. Specifically, most home freezers are frost-free and may expose the samples to multiple rounds of freeze-thaw. Stool samples collected by the study team were stored at different lengths in a frost-free freezer and at -80°C. Quantitative PCRs of norovirus were performed on all samples using the same assay. By all measures, there was no significant change in measured viral load with home storage.

Turalio risk evaluation and mitigation strategy for treatment of tenosynovial giant cell tumor: framework and experience.

For drugs with enhanced serious safety risks, Risk Evaluation and Mitigation Strategy (REMS) may be required. Pexidartinib is approved for treatment of adult symptomatic tenosynovial giant cell tumor (TGCT) associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Its approval was conditional on its prescription via a mandatory REMS due to serious and potentially fatal liver injury seen in clinical trials. Turalio® REMS aims to mitigate this risk by ensuring provider education on pexidartinib use and required REMS components, prescriber adherence to baseline and periodic monitoring, and enrolling patients in a registry to further assess safe use and acute, chronic and irreversible hepatotoxicity. Through Turalio REMS, benefits of treating patients with pexidartinib may be preserved.

For drugs with serious side effects, specific safety measures may be put in place to manage these serious side effects in the form of Risk Evaluation and Mitigation Strategy (REMS) programs. Pexidartinib (Turalio^®) is approved for treatment of adults who have symptoms of severe tenosynovial giant cell tumor or have limitations in function that do not improve with surgery. Turalio^® has an REMS program because liver injuries that can be serious or fatal were seen in Pexidartinib clinical trials. This program aims to decrease the seriousness of the liver injuries by assuring doctors and pharmacists are educated on how to use the drug, patients are advised of this potential risk and that baseline and periodic monitoring of patients are conducted.

Direct visualization of cAMP signaling in primary cilia reveals up-regulation of ciliary GPCR activity following Hedgehog activation.

The primary cilium permits compartmentalization of specific signaling pathways, including elements of the Hedgehog (Hh) pathway. Hh transcriptional activity is thought to be negatively regulated by constitutively high ciliary cAMP maintained by the Gα(s)-coupled GPCR, GPR161. However, cilia also sequester many other Gα(s)-coupled GPCRs with unknown potential to regulate Hh. Here we used biosensors optimized for ciliary cAMP and strategies to isolate signals in the cilium from the cell body and neighboring cells. We found that ciliary cAMP was not elevated relative to cellular cAMP, inconsistent with constitutive cAMP production. Gα(s)-coupled GPCRs (e.g., the 5-HT6 serotonin and D1R dopamine receptor) had reduced ability to generate cAMP upon trafficking to the ciliary membrane. However, activation of the Hh pathway restored or amplified GPCR function to permit cAMP elevation selectively in the cilium. Hh therefore enables its own local GPCR-dependent cAMP regulatory circuit. Considering that GPCRs comprise much of the druggable genome, these data suggest alternative strategies to modify Hh signaling.

Enhancing ICD-Code-Based Case Definition for Heart Failure Using Electronic Medical Record Data.

BACKGROUND: Surveillance and outcome studies for heart failure (HF) require accurate identification of patients with HF. Algorithms based on International Classification of Diseases (ICD) codes to identify HF from administrative data are inadequate owing to their relatively low sensitivity. Detailed clinical information from electronic medical records (EMRs) is potentially useful for improving ICD algorithms. This study aimed to enhance the ICD algorithm for HF definition by incorporating comprehensive information from EMRs. METHODS: The study included 2106 inpatients in Calgary, Alberta, Canada. Medical chart review was used as the reference gold standard for evaluating developed algorithms. The commonly used ICD codes for defining HF were used (namely, the ICD algorithm). The performance of different algorithms using the free text discharge summaries from a population-based EMR were compared with the ICD algorithm. These algorithms included a keyword search algorithm looking for HF-specific terms, a machine learning-based HF concept (HFC) algorithm, an EMR structured data based algorithm, and combined algorithms (the ICD and HFC combined algorithm). RESULTS: Of 2106 patients, 296 (14.1%) were patients with HF as determined by chart review. The ICD algorithm had 92.4% positive predictive value (PPV) but low sensitivity (57.4%). The EMR keyword search algorithm achieved a higher sensitivity (65.5%) than the ICD algorithm, but with a lower PPV (77.6%). The HFC algorithm achieved a better sensitivity (80.0%) and maintained a reasonable PPV (88.9%) compared with the ICD algorithm and the keyword algorithm. An even higher sensitivity (83.3%) was reached by combining the HFC and ICD algorithms, with a lower PPV (83.3%). The structured EMR data algorithm reached a sensitivity of 78% and a PPV of 54.2%. The combined EMR structured data and ICD algorithm had a higher sensitivity (82.4%), but the PPV remained low at 54.8%. All algorithms had a specificity ranging from 87.5% to 99.2%. CONCLUSIONS: Applying natural language processing and machine learning on the discharge summaries of inpatient EMR data can improve the capture of cases of HF compared with the widely used ICD algorithm. The utility of the HFC algorithm is straightforward, making it easily applied for HF case identification.

Phase I Trial of a Tablet Formulation of Pilaralisib, a Pan-Class I PI3K Inhibitor, in Patients with Advanced Solid Tumors.

LESSONS LEARNED: A phase I study of the pan-class I phosphoinositide 3-kinase inhibitor pilaralisib (in capsule formulation) in advanced solid tumors established the maximum tolerated dose as 600 mg once daily.The current study investigated pilaralisib in tablet formulation.Pilaralisib tablets were associated with a favorable safety profile and preliminary antitumor activity.Based on pharmacokinetic data, the recommended phase II dose of pilaralisib tablets was established as 400 mg once daily. BACKGROUND: A phase I trial of pilaralisib, an oral pan-class I phosphoinositide 3-kinase (PI3K) inhibitor, established the maximum tolerated dose (MTD) of the capsule formulation in patients with advanced solid tumors as 600 mg once daily. This phase I study investigated pilaralisib in tablet formulation. MATERIALS AND METHODS: Patients with advanced solid tumors received pilaralisib tablets (100-600 mg once daily). Primary endpoints were MTD and safety; secondary and exploratory endpoints included pharmacokinetics (PK), pharmacodynamics, and efficacy. RESULTS: Twenty-two patients were enrolled. No dose-limiting toxicities (DLTs) were reported. The most common treatment-related adverse events were diarrhea (40.9%), fatigue (40.9%), decreased appetite (22.7%), and hyperglycemia (22.7%). Pilaralisib plasma exposure did not appear to increase dose-proportionally. Steady-state exposure was higher with pilaralisib tablet formulation at 400 mg than with pilaralisib capsule formulation at 400 or 600 mg (mean area under the curve [AUC0-24] 2,820,000 ng × h/mL vs. 2,653,000 and 1,930,000 ng × h/mL, respectively). Of 18 evaluable patients, 2 (11.1%) had a partial response (PR). CONCLUSION: Pilaralisib tablets were associated with a favorable safety profile and preliminary antitumor activity. MTD was not determined. The recommended phase II dose for pilaralisib tablets, based on PK data, was 400 mg once daily.

Strategies for improving physician documentation in the emergency department: a systematic review.

BACKGROUND: Physician chart documentation can facilitate patient care decisions, reduce treatment errors, and inform health system planning and resource allocation activities. Although accurate and complete patient chart data supports quality and continuity of patient care, physician documentation often varies in terms of timeliness, legibility, clarity and completeness. While many educational and other approaches have been implemented in hospital settings, the extent to which these interventions can improve the quality of documentation in emergency departments (EDs) is unknown. METHODS: We conducted a systematic review to assess the effectiveness of approaches to improve ED physician documentation. Peer reviewed electronic databases, grey literature sources, and reference lists of included studies were searched to March 2015. Studies were included if they reported on outcomes associated with interventions designed to enhance the quality of physician documentation. RESULTS: Nineteen studies were identified that report on the effectiveness of interventions to improve physician documentation in EDs. Interventions included audit/feedback, dictation, education, facilitation, reminders, templates, and multi-interventions. While ten studies found that audit/feedback, dictation, pharmacist facilitation, reminders, templates, and multi-pronged approaches did improve the quality of physician documentation across multiple outcome measures, the remaining nine studies reported mixed results. CONCLUSIONS: Promising approaches to improving physician documentation in emergency department settings include audit/feedback, reminders, templates, and multi-pronged education interventions. Future research should focus on exploring the impact of implementing these interventions in EDs with and without emergency medical record systems (EMRs), and investigating the potential of emerging technologies, including EMR-based machine-learning, to promote improvements in the quality of ED documentation.

Phase I Dose-Escalation Study of Pilaralisib (SAR245408, XL147) in Combination with Paclitaxel and Carboplatin in Patients with Solid Tumors.

LESSONS LEARNED: Despite involvement of PI3K pathway activation in tumorigenesis of solid tumors, single-agent PI3K inhibitors have shown modest clinical activity.Preclinical evidence suggests that combining PI3K pathway inhibitors and chemotherapy can enhance antitumor effects.In patients with solid tumors, the PI3K inhibitor pilaralisib had a favorable safety profile but did not enhance the antitumor activity of paclitaxel plus carboplatin.Further clinical evaluation is warranted to identify effective combination strategies with PI3K pathway inhibitors. BACKGROUND: Pilaralisib (SAR245408) is an oral, pan-class I phosphoinositide 3-kinase (PI3K) inhibitor. This phase I dose-escalation study evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics (PK), and pharmacodynamics of pilaralisib in capsule and tablet formulations, administered in combination with paclitaxel and carboplatin in patients with advanced solid tumors. METHODS: A 3 + 3 design was used. Pilaralisib was administered once daily (QD); paclitaxel (up to 175 mg/m2) and carboplatin (up to area under the curve [AUC] of 6) were administered on day 1 of 21-day cycles. An MTD expansion cohort of patients with endometrial carcinoma was included. RESULTS: Fifty-eight patients were enrolled. Six patients (10.3%) had dose-limiting toxicities, of which only rash (two patients, 3.4%) occurred in more than one patient. The MTD of pilaralisib tablets in combination with paclitaxel and carboplatin was determined to be 200 mg QD. The most frequently reported adverse events (AEs) of any grade were neutropenia (67.2%) and thrombocytopenia (67.2%). PK data showed no interaction between pilaralisib and paclitaxel/carboplatin. Tumor tissue showed moderate inhibition of PI3K and mitogen-activated protein kinase (MAPK) pathways. Seven of 52 evaluable patients had a partial response (PR; 13.5%). CONCLUSION: Pilaralisib had a favorable safety profile but did not enhance the antitumor activity of paclitaxel plus carboplatin in solid tumors. The Oncologist 2017;22:377-378.

Molecular Basis for Modulation of Metabotropic Glutamate Receptors and Their Drug Actions by Extracellular Ca2.

Metabotropic glutamate receptors (mGluRs) associated with the slow phase of the glutamatergic signaling pathway in neurons of the central nervous system have gained importance as drug targets for chronic neurodegenerative diseases. While extracellular Ca2+ was reported to exhibit direct activation and modulation via an allosteric site, the identification of those binding sites was challenged by weak binding. Herein, we review the discovery of extracellular Ca2+ in regulation of mGluRs, summarize the recent developments in probing Ca2+ binding and its co-regulation of the receptor based on structural and biochemical analysis, and discuss the molecular basis for Ca2+ to regulate various classes of drug action as well as its importance as an allosteric modulator in mGluRs.

Shiga Toxin-Producing Escherichia coli Infection, Antibiotics, and Risk of Developing Hemolytic Uremic Syndrome: A Meta-analysis.

BACKGROUND: Antibiotic administration to individuals with Shiga toxin-producing Escherichia coli (STEC) infection remains controversial. We assessed if antibiotic administration to individuals with STEC infection is associated with development of hemolytic uremic syndrome (HUS). METHODS: The analysis included studies published up to 29 April 2015, that provided data from patients (1) with STEC infection, (2) who received antibiotics, (3) who developed HUS, and (4) for whom data reported timing of antibiotic administration in relation to HUS. Risk of bias was assessed; strength of evidence was adjudicated. HUS was the primary outcome. Secondary outcomes restricted the analysis to low-risk-of-bias studies employing commonly used HUS criteria. Pooled estimates of the odds ratio (OR) were obtained using random-effects models. RESULTS: Seventeen reports and 1896 patients met eligibility; 8 (47%) studies were retrospective, 5 (29%) were prospective cohort, 3 (18%) were case-control, and 1 was a trial. The pooled OR, including all studies, associating antibiotic administration and development of HUS was 1.33 (95% confidence interval [CI], .89-1.99; I(2) = 42%). The repeat analysis including only studies with a low risk of bias and those employing an appropriate definition of HUS yielded an OR of 2.24 (95% CI, 1.45-3.46; I(2) = 0%). CONCLUSIONS: Overall, use of antibiotics was not associated with an increased risk of developing HUS; however, after excluding studies at high risk of bias and those that did not employ an acceptable definition of HUS, there was a significant association. Consequently, the use of antibiotics in individuals with STEC infections is not recommended.

Extracellular calcium modulates actions of orthosteric and allosteric ligands on metabotropic glutamate receptor 1α.

Metabotropic glutamate receptor 1α (mGluR1α), a member of the family C G protein-coupled receptors, is emerging as a potential drug target for various disorders, including chronic neuronal degenerative diseases. In addition to being activated by glutamate, mGluR1α is also modulated by extracellular Ca(2+). However, the underlying mechanism is unknown. Moreover, it has long been challenging to develop receptor-specific agonists due to homologies within the mGluR family, and the Ca(2+)-binding site(s) on mGluR1α may provide an opportunity for receptor-selective targeting by therapeutics. In the present study, we show that our previously predicted Ca(2+)-binding site in the hinge region of mGluR1α is adjacent to the site where orthosteric agonists and antagonists bind on the extracellular domain of the receptor. Moreover, we found that extracellular Ca(2+) enhanced mGluR1α-mediated intracellular Ca(2+) responses evoked by the orthosteric agonist l-quisqualate. Conversely, extracellular Ca(2+) diminished the inhibitory effect of the mGluR1α orthosteric antagonist (S)-α-methyl-4-carboxyphenylglycine. In addition, selective positive (Ro 67-4853) and negative (7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester) allosteric modulators of mGluR1α potentiated and inhibited responses to extracellular Ca(2+), respectively, in a manner similar to their effects on the response of mGluR1α to glutamate. Mutations at residues predicted to be involved in Ca(2+) binding, including E325I, had significant effects on the modulation of responses to the orthosteric agonist l-quisqualate and the allosteric modulator Ro 67-4853 by extracellular Ca(2+). These studies reveal that binding of extracellular Ca(2+) to the predicted Ca(2+)-binding site in the extracellular domain of mGluR1α modulates not only glutamate-evoked signaling but also the actions of both orthosteric ligands and allosteric modulators on mGluR1α.

Phase I dose-escalation study of pilaralisib (SAR245408, XL147), a pan-class I PI3K inhibitor, in combination with erlotinib in patients with solid tumors.

BACKGROUND: This phase I study evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics (PK), and pharmacodynamics of pilaralisib (SAR245408), an oral pan-class I phosphoinositide 3-kinase (PI3K) inhibitor, in combination with erlotinib, an epidermal growth factor receptor (EGFR) inhibitor. METHODS: In a 3 + 3 dose-escalation study, patients with advanced solid tumors received pilaralisib capsules once daily (21 days per 28-day cycle; 50-600 mg) plus erlotinib tablets once daily (28 days per 28-day cycle; 100 or 150 mg). An MTD expansion cohort of patients with non-small cell lung cancer who had previously received treatment with an EGFR inhibitor was included. RESULTS: Thirty-five patients were enrolled. Only one patient had an EGFR activating mutation. One dose-limiting toxicity was reported (grade 4 drug reaction or rash with eosinophilia and systemic symptoms). MTD was pilaralisib 400 mg plus erlotinib 150 mg. The most commonly reported treatment-related adverse events were rash (62.9%), diarrhea (42.9%), and fatigue (40.0%). Pilaralisib PK findings were consistent with previous studies, suggesting erlotinib had no effect on pilaralisib pharmacokinetics. Pharmacodynamic analyses indicated moderate inhibition of PI3K, mitogen-activated protein kinase, and EGFR pathways. Of 27 evaluable patients, one had a partial response (3.7%) and 14 (51.9%) had stable disease. There was no association between molecular alterations of PI3K pathway components and clinical activity. CONCLUSION: Pilaralisib plus erlotinib had limited antitumor activity. Safety findings were similar to recent studies of single-agent pilaralisib or other PI3K inhibitors.

Phase I/II dose-escalation study of PI3K inhibitors pilaralisib or voxtalisib in combination with letrozole in patients with hormone-receptor-positive and HER2-negative metastatic breast cancer refractory to a non-steroidal aromatase inhibitor.

This phase I/II dose-escalation study evaluated the efficacy, safety, and pharmacokinetics of pilaralisib (SAR245408), a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor, or voxtalisib (SAR245409), a PI3K and mammalian target of rapamycin inhibitor, in combination with letrozole in hormone-receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative, non-steroidal aromatase inhibitor-refractory, recurrent or metastatic breast cancer. Maximum tolerated doses (MTDs) were determined using a 3 + 3 design in phase I. Efficacy was evaluated at the MTDs in phase II. Twenty-one patients were enrolled in phase I; MTDs were determined to be pilaralisib tablets 400 mg once daily (QD) or voxtalisib capsules 50 mg twice daily in combination with letrozole tablets 2.5 mg QD. Fifty-one patients were enrolled in phase II; one patient had a partial response in the pilaralisib arm. Rates of progression-free survival at 6 months were 17 and 8 % in the pilaralisib and voxtalisib arms, respectively. The most frequently reported treatment-related grade ≥ 3 adverse events were aspartate aminotransferase increased (5 %) and rash (5 %) in the pilaralisib arm, and alanine aminotransferase increased (11 %) and rash (9 %) in the voxtalisib arm. Pilaralisib and voxtalisib did not interact pharmacokinetically with letrozole. Pilaralisib had a greater pharmacodynamic impact than voxtalisib, as demonstrated by its impact on glucose homeostasis. There was no association between molecular alterations in the PI3K pathway and efficacy. In summary, pilaralisib or voxtalisib, in combination with letrozole, was associated with an acceptable safety profile and limited efficacy in endocrine therapy-resistant HR+ , HER2-negative metastatic breast cancer.

Phase I/II study of pilaralisib (SAR245408) in combination with trastuzumab or trastuzumab plus paclitaxel in trastuzumab-refractory HER2-positive metastatic breast cancer.

This phase I/II dose-escalation study investigated the maximum tolerated dose (MTD), safety, pharmacokinetics, and efficacy of the pan-class I phosphoinositide 3-kinase inhibitor pilaralisib in combination with trastuzumab (Arm 1) or trastuzumab plus paclitaxel (Arm 2) in patients with HER2-positive metastatic breast cancer. Patients had progressed on prior trastuzumab (Arms 1 and 2) and received prior taxane (Arm 2). The MTD of pilaralisib was determined using a 3 + 3 dose-escalation design (starting dose 200 mg once daily). Forty-two patients were enrolled (21 in each arm). Five patients had a dose-limiting toxicity (DLT; three in Arm 1 and two in Arm 2). Dose-limiting toxicities were rash (three patients) and neutropenia (two patients). The MTD of pilaralisib was determined at 400 mg once daily in both arms. The most frequently reported treatment-related adverse events (AEs) were diarrhea (23.8 % in Arm 1 vs. 66.7 % in Arm 2), fatigue (14.3 vs. 42.9 %), and rash (33.3 vs. 38.1 %). The most frequently reported treatment-related grade ≥3 AEs were erythematous rash (9.5 %) in Arm 1 and diarrhea, peripheral neuropathy, and neutropenia (14.3 % each) in Arm 2. Steady-state pilaralisib exposure was similar to previous studies with pilaralisib monotherapy. No responses occurred in Arm 1; four of 20 evaluable patients (20 %) in Arm 2 had a partial response. Observed PIK3CA mutations in cell-free circulating DNA did not correlate with response. Pilaralisib in combination with trastuzumab with or without paclitaxel had an acceptable safety profile in metastatic HER2-positive breast cancer, with clinical activity in the paclitaxel arm.

Industry Review of Best Practices for Risk Management of Drug-Induced Liver Injury from Development to Real-World Use.

The relative treatment benefit of a drug for patients during development, marketing authorization review, or after approval includes an assessment of the risk of drug-induced liver injury (DILI). In this article, the Pharmacovigilance and Risk Mitigation Working Group of the IQ-DILI Initiative launched in June 2016 within the International Consortium for Innovation and Quality in Pharmaceutical Development presents and reviews three key topics for essential risk management activities to identify, characterize, monitor, mitigate, and communicate DILI risk associated with small molecules during drug development. The three topics are: (1) Current best practices for characterizing the DILI phenotype and the severity and incidence of DILI in the treatment population, including DILI identification, prediction and recovery. (2) Characterization of the relative treatment benefit for patients who will be exposed to a drug and the attendant risk of DILI in conjunction with existing global risk mitigation strategies. (3) Implementation of risk mitigation strategies during drug development highlighting patient factors, healthcare settings and site of product administration, and prescriber and healthcare provider factors. Industry guidance is provided for assessing whether the product labeling is sufficient to minimize the risk of DILI or whether a United States Food and Drug Administration (FDA) Risk Evaluation and Mitigation Strategy (REMS) or European Medicines Agency (EMA) Risk Management Plan (RMP) with additional Risk Minimization Measures (aRMM) is needed.

The relative treatment benefit of a drug for patients during development, marketing authorization review or after approval includes an assessment of the risk of drug-induced liver injury (DILI). Reported incidences of DILI range from 0.74 to 19 per 100,000, and laboratory criteria and/or clinical outcome determine the severity of DILI. At least 10% of patients who develop jaundice caused by DILI (Hy's Law cases) develop liver failure (i.e., severe DILI). A drug's liver safety profile can be assessed using Evaluation of Drug-Induced Serious Hepatotoxicity Plots. Specific recommendations for monitoring DILI in the post-marketing setting depend on characterization of the phenotype during drug development. Risk mitigation tools include additional educational mechanisms, and risk minimization measures include Elements To Assure Safe Use (ETASU) for healthcare professionals, administration sites, and patients. The overall aim of risk management is to ensure that the benefit of a particular product exceeds the risks as far as possible for the individual patient and for the target population.

Dosing Recommendation Based on the Effects of Different Meal Types on Pexidartinib Pharmacokinetics in Healthy Subjects: Implementation of Model-informed Drug Development Strategy.

Pexidartinib, an oral small molecule inhibitor of the colony-stimulating factor 1 receptor, is approved for treatment of adults with symptomatic tenosynovial giant cell tumor associated with severe morbidity or functional limitations and not amenable to improvement with surgery. The original dosing regimen is 400 mg of pexidartinib (2 × 200-mg capsules) twice daily, administered on an empty stomach at least 1 hour before or 2 hours after a meal or snack. Because pexidartinib is likely to be taken over an extended period of time, the ability to take pexidartinib with a meal would simplify timing of administration and potentially improve compliance. Since administering 400 mg of pexidartinib with a low-fat meal increases exposure by ≈60% relative to the fasted state, administering 250 mg of pexidartinib with a low-fat meal (low-fat meal dosing regimen) was predicted to achieve an exposure similar to 400 mg administered during a fasted state (original dosing regimen). Based on clinical trial simulations with two one-sided t-tests and bootstrapping (ie, resampling) analyses, a bioequivalence study (n = 24) would have >90% power to conclude that the original dosing regimen (400 mg fasted twice daily) and the low-fat meal dosing regimen (250 mg with a low-fat meal twice daily) are bioequivalent. This report provides the outcome of the implementation of the model-informed drug development strategy to recommend and justify a low-fat meal dosing regimen for pexidartinib that has the potential to improve patient compliance while maintaining drug exposure.

Gp05, a Prophage-Encoded Virulence Factor, Contributes to Persistent Methicillin-Resistant Staphylococcus aureus Endovascular Infection.

Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a serious public health threat. We recently demonstrated that the presence of a novel prophage ϕSA169 was associated with vancomycin (VAN) treatment failure in experimental MRSA endocarditis. In this study, we assessed the role of a ϕSA169 gene, ϕ80α_gp05 (gp05), in VAN-persistent outcome using gp05 isogenic MRSA strain sets. Of note, Gp05 significantly influences the intersection of MRSA virulence factors, host immune responses, and antibiotic treatment efficacy, including the following: (i) activity of the significant energy-yielding metabolic pathway (e.g., tricarboxylic acid cycle); (ii) carotenoid pigment production; (iii) (p)ppGpp (guanosine tetra- and pentaphosphate) production, which activates the stringent response and subsequent downstream functional factors (e.g., phenol-soluble modulins and polymorphonuclear neutrophil bactericidal activity); and (iv) persistence to VAN treatment in an experimental infective endocarditis model. These data suggest that Gp05 is a significant virulence factor which contributes to the persistent outcomes in MRSA endovascular infection by multiple pathways. IMPORTANCE Persistent endovascular infections are often caused by MRSA strains that are susceptible to anti-MRSA antibiotics in vitro by CLSI breakpoints. Thus, the persistent outcome represents a unique variant of traditional antibiotic resistance mechanisms and a significant therapeutic challenge. Prophage, a critical mobile genetic element carried by most MRSA isolates, provides their bacterial host with metabolic advantages and resistance mechanisms. However, how prophage-encoded virulence factors interact with the host defense system and antibiotics, driving the persistent outcome, is not well known. In the current study, we demonstrated that a novel prophage gene, gp05, significantly impacts tricarboxylic acid cycle activity, stringent response, and pigmentation, as well as vancomycin treatment outcome in an experimental endocarditis model using isogenic gp05 overexpression and chromosomal deletion mutant MRSA strain sets. The findings significantly advance our understanding of the role of Gp05 in persistent MRSA endovascular infection and provide a potential target for development of novel drugs against these life-threatening infections.

Single-cell transcriptomics identifies a WNT7A-FZD5 signaling axis that maintains fallopian tube stem cells in patient-derived organoids.

The study of fallopian tube (FT) function in health and disease has been hampered by limited knowledge of FT stem cells and lack of in vitro models of stem cell renewal and differentiation. Using optimized organoid culture conditions to address these limitations, we find that FT stem cell renewal is highly dependent on WNT/ß-catenin signaling and engineer endogenous WNT/ß-catenin signaling reporter organoids to biomark, isolate, and characterize these cells. Using functional approaches, as well as bulk and single-cell transcriptomics analyses, we show that an endogenous hormonally regulated WNT7A-FZD5 signaling axis is critical for stem cell renewal and that WNT/ß-catenin pathway-activated cells form a distinct transcriptomic cluster of FT cells enriched in extracellular matrix (ECM) remodeling and integrin signaling pathways. Overall, we provide a deep characterization of FT stem cells and their molecular requirements for self-renewal, paving the way for mechanistic work investigating the role of stem cells in FT health and disease.

Generation of a Microsporidia Species Attribute Database and Analysis of the Extensive Ecological and Phenotypic Diversity of Microsporidia.

Microsporidia are a large group of fungus-related obligate intracellular parasites. Though many microsporidia species have been identified over the past 160 years, depiction of the full diversity of this phylum is lacking. To systematically describe the characteristics of these parasites, we created a database of 1,440 species and their attributes, including the hosts they infect and spore characteristics. We find that microsporidia have been reported to infect 16 metazoan and 4 protozoan phyla, with smaller phyla being underrepresented. Most species are reported to infect only a single host, but those that are generalists are also more likely to infect a broader set of host tissues. Strikingly, polar tubes are threefold longer in species that infect tissues besides the intestine, suggesting that polar tube length is a determinant of tissue specificity. Phylogenetic analysis revealed four clades which each contain microsporidia that infect hosts from all major habitats. Although related species are more likely to infect similar hosts, we observe examples of changes in host specificity and convergent evolution. Taken together, our results show that microsporidia display vast diversity in their morphology and the hosts they infect, illustrating the flexibility of these parasites to evolve new traits. IMPORTANCE Microsporidia are a large group of parasites that cause death and disease in humans and many agriculturally important animal species. To fully understand the diverse properties of these parasites, we curated species reports from the last 160 years. Using these data, we describe when and where microsporidia were identified and what types of animals and host tissues these parasites infect. Microsporidia infect hosts using a conserved apparatus known as the polar tube. We observe that the length of this tube is correlated with the tissues that are being infected, suggesting that the polar tube controls where within the animals that the parasite infects. Finally, we show that microsporidia species often exist in multiple environments and are flexible in their ability to evolve new traits. Our study provides insight into the ecology and evolution of microsporidia and provides a useful resource to further understand these fascinating parasites.