Differentiating infection from inflammation in acute pancreatitis is difficult, leading to overuse of antibiotics. Procalcitonin (PCT) measurement is a means of distinguishing infection from ...inflammation as levels rise rapidly in response to a pro-inflammatory stimulus of bacterial origin and normally fall after successful treatment. Algorithms based on PCT measurement can differentiate bacterial sepsis from a systemic inflammatory response. The PROCalcitonin-based algorithm for antibiotic use in Acute Pancreatitis (PROCAP) trial tests the hypothesis that a PCT-based algorithm to guide initiation, continuation and discontinuation of antibiotics will lead to reduced antibiotic use in patients with acute pancreatitis and without an adverse effect on outcome.
This is a single-centre, randomised, controlled, single-blind, two-arm pragmatic clinical and cost-effectiveness trial. Patients with a clinical diagnosis of acute pancreatitis will be allocated on a 1:1 basis to intervention or standard care. Intervention will involve the use of a PCT-based algorithm to guide antibiotic use. The primary outcome measure will be the binary outcome of antibiotic use during index admission. Secondary outcome measures include: safety non-inferiority endpoint all-cause mortality; days of antibiotic use; clinical infections; new isolates of multiresistant bacteria; duration of inpatient stay; episode-related mortality and cause; quality of life (EuroQol EQ-5D); and cost analysis. A 20% absolute change in antibiotic use would be a clinically important difference. A study with 80% power and 5% significance (two-sided) would require 97 patients in each arm (194 patients in total): the study will aim to recruit 200 patients. Analysis will follow intention-to-treat principles.
When complete, PROCAP will be the largest randomised trial of the use of a PCT algorithm to guide initiation, continuation and cessation of antibiotics in acute pancreatitis. PROCAP is the only randomised trial to date to compare standard care of acute pancreatitis as defined by the International Association of Pancreatology/American Pancreatic Association guidelines to patients having standard care but with all antibiotic prescribing decisions based on PCT measurement.
International Standard Randomised Controlled Trial Number, ISRCTN50584992. Registered on 7 February 2018.
Idiosyncratic adverse drug reactions (IADRs) represent an important human health problem, yet animal models for preclinical prediction of these reactions are lacking. Recent evidence in animals ...suggests that some IADRs arise from drug interaction with an inflammatory episode that renders the liver sensitive to injury. Diclofenac (DCLF) is one of those drugs for which the clinical use is limited by idiosyncratic liver injury. We tested the hypothesis that modest inflammation triggered in rats by a small dose of lipopolysaccharide (LPS) renders a nonhepatotoxic dose of DCLF injurious to liver. Cotreatment of rats with nonhepatotoxic doses of LPS and DCLF resulted in elevated serum alanine aminotransferase activity and liver histopathologic changes 6 h after DCLF administration. Neither LPS nor DCLF alone had such an effect. Gene array analysis of livers revealed a unique gene expression pattern in the LPS/DCLF-cotreated group compared with groups given either agent alone. Antiserum-induced neutrophil (PMN) depletion in LPS/DCLF-cotreated rats protected against liver injury, demonstrating a role for PMNs in the pathogenesis of this LPS/DCLF interaction. Gut sterilization of LPS/DCLF-treated rats did not protect against liver injury. In contrast, gut sterilization did attenuate liver injury caused by a large, hepatotoxic dose of DCLF, suggesting that hepatotoxicity induced by large doses of DCLF is caused in part by its ability to increase intestinal permeability to endotoxin or other bacterial products. These results demonstrate that inflammation-DCLF interaction precipitates hepatotoxicity in rats and raise the possibility of creating animal models that predict human IADRs.
Pharmaceutical discovery and development is a long and expensive process that, unfortunately, still results in a low success rate, with drug safety continuing to be a major impedance. Improved safety ...screening strategies and methods are needed to more effectively fill this critical gap. Recent advances in informatics are now making it possible to manage bigger data sets and integrate multiple sources of screening data in a manner that can potentially improve the selection of higher-quality drug candidates. Integrated screening paradigms have become the norm in Pharma, both in discovery screening and in the identification of off-target toxicity mechanisms during later-stage development. Furthermore, advances in computational methods are making in silico screens more relevant and suggest that they may represent a feasible option for augmenting the current screening paradigm. This paper outlines several fundamental methods of the current drug screening processes across Pharma and emerging techniques/technologies that promise to improve molecule selection. In addition, the authors discuss integrated screening strategies and provide examples of advanced screening paradigms.
In drug discovery, during the lead optimization and candidate characterization stages, novel small molecules are frequently evaluated in a battery of in vitro pharmacology assays to identify ...potential unintended, off-target interactions with various receptors, transporters, ion channels, and enzymes, including kinases. Furthermore, these screening panels may also provide utility at later stages of development to provide a mechanistic understanding of unexpected safety findings. Here, we present a compendium of the most likely functional and pathological outcomes associated with interaction(s) to a panel of 95 kinases based on an extensive curation of the scientific literature. This panel of kinases was designed by AbbVie based on safety-related data extracted from the literature, as well as from over 20 years of institutional knowledge generated from discovery efforts. For each kinase, the scientific literature was reviewed using online databases and the most often reported functional and pathological effects were summarized. This work should serve as a practical guide for small molecule drug discovery scientists and clinical investigators to predict and/or interpret adverse effects related to pharmacological interactions with these kinases.
High levels of hepcidin, the main regulator of systemic iron metabolism, lead to various diseases. Targeting hepcidin and lowering its concentration is a possible form of intervention in order to ...treat these diseases. High turnover rate of hepcidin is a major drawback of therapies directly targeting this peptide. We developed two monoclonal antibodies ABT-207 and h5F9-AM8 which inhibit hemojuvelin/repulsive guidance molecule C (RGMc) and downregulate hepcidin. We conducted single-application and dose response studies to understand the antibodies’ mechanism and subchronic toxicology studies to exclude safety-related concerns. Investigation was carried out at different biological levels through qPCR, Affymetrix, liquid chromatography coupled with mass spectrometry (LC-MS/MS), histopathology, serum iron, unsaturated iron binding capacity (UIBC), and drug concentration measurements. After a single application of these antibodies, hepcidin expression in liver and its serum protein levels were reduced. Serum iron increased for several weeks. The RGMc antibodies show a pronounced dose response relationship in rats with h5F9-AM8 having an IC
50
(UIBC) of approximately 80-fold higher than ABT-207. When hepcidin levels were downregulated, iron deposition in the liver was visible histologically 1 week post application. These antibody-mediated iron depositions were not associated with any adverse toxicologically relevant effect at the doses and time points evaluated. Iron depositions seen after 14 weekly treatments with ABT-207 were reversible in rats and in cynomolgus monkeys. Due to their long-lasting effects and excellent safety profile, both RGMc-blocking antibodies ABT-207 and h5F9-AM8 are favorable clinical candidates for diseases characterized by high serum hepcidin levels like anemia of chronic disease.
The antibiotic trovafloxacin (TVX) has caused severe idiosyncratic hepatotoxicity in people, whereas levofloxacin (LVX) has not. Mice cotreated with TVX and lipopolysaccharide (LPS), but not with LVX ...and LPS, develop severe hepatocellular necrosis. Mice were treated with TVX and/or LPS, and hepatic gene expression changes were measured before liver injury using gene array. Hepatic gene expression profiles from mice treated with TVX/LPS clustered differently from those treated with LPS or TVX alone. Several of the probe sets expressed differently in TVX/LPS–treated mice were involved in interferon (IFN) signaling and the janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. A time course of plasma concentrations of IFN-γ and interleukin (IL)-18, which directly induces IFN-γ production, revealed that both cytokines were selectively increased in TVX/LPS–treated mice. Both IL-18−/− and IFN-γ−/− mice were significantly protected from TVX/LPS–induced liver injury. In addition, IFN-γ−/− mice had decreased plasma concentrations of tumor necrosis factor-α, IL-18, and IL-1β when compared to wild-type mice. In conclusion, the altered expression of genes involved in IFN signaling in TVX/LPS–treated mice led to the finding that IL-18 and IFN-γ play a critical role in TVX/LPS–induced liver injury.
Idiosyncratic drug toxicity, defined as toxicity that is dose independent, host dependent, and usually cannot be predicted during preclinical or early phases of clinical trials, is a particularly ...confounding complication of drug development. An understanding of the mechanisms that lead to idiosyncratic liver toxicity would be extremely beneficial for the development of new compounds. We used microarray analysis on isolated human hepatocytes to understand the mechanisms underlying the idiosyncratic toxicity induced by trovafloxacin. Our results clearly distinguish trovafloxacin from other marketed quinolone agents and identify unique gene changes induced by trovafloxacin that are involved in mitochondrial damage, RNA processing, transcription, and inflammation that may suggest a mechanism for the hepatotoxicity induced by this agent. In conclusion, this work establishes the basis for future microarray analysis of new compounds to determine the presence of these expression changes and their usefulness in predicting idiosyncratic hepatotoxicity. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience. Wiley.com/jpages/0270-9139/suppmat/index.htnd).
Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is ...commonly used as a surrogate for human hepatocytes, but its use in absorption, distribution, metabolism, and excretion and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite the widespread use of HepG2 cells, a comparison of their transcriptomes with those of PHH has not been well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the naive HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin (TVX), which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. Although TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity.
The liver is an important target for drug-induced toxicities. Early detection of hepatotoxic drugs requires use of well-characterized test systems, yet current knowledge, gaps and limitations of ...tests employed remains an important issue for drug development. Areas Covered: The current state of the science, understanding and application of test systems in use for the detection of drug-induced cytotoxicity, mitochondrial toxicity, cholestasis and inflammation is summarized. The test systems highlighted herein cover mostly in vitro and some in vivo models and endpoint measurements used in the assessment of small molecule toxic liabilities. Opportunities for research efforts in areas necessitating the development of specific tests and improved mechanistic understanding are highlighted. Expert Opinion: Use of in vitro test systems for safety optimization will remain a core activity in drug discovery. Substantial inroads have been made with a number of assays established for human Drug-induced Liver Injury. There nevertheless remain significant gaps with a need for improved in vitro tools and novel tests to address specific mechanisms of human Drug-Induced Liver Injury. Progress in these areas will necessitate not only models fit for application, but also mechanistic understanding of how chemical insult on the liver occurs in order to identify translational and quantifiable readouts for decision-making.
Differentiating inflammation from bacterial infection in patients with acute pancreatitis can be difficult. Procalcitonin can distinguish infection from inflammation, and algorithms based on ...procalcitonin measurement can differentiate bacterial sepsis from a systemic inflammatory response. We aimed to test the hypothesis that a procalcitonin-based algorithm to guide initiation, continuation, and discontinuation of antibiotics could lead to reduced antibiotic use without an adverse effect on outcome in acute pancreatitis.
PROCAP was a single-centre, patient-blinded, randomised controlled trial done at the Manchester Royal Infirmary (Manchester, UK). Eligible participants were aged 18 years or older and had a clinical diagnosis of acute pancreatitis. Participants were randomly assigned (1:1) to procalcitonin-guided care or usual care using web-based randomisation software. The randomisation sequence was stratified by disease severity and admission pathway, using variable block sizes of 4, 6, or 8. Patients, but not clinicians, were masked to group assignment. In the procalcitonin-guided care group, procalcitonin testing was conducted on days 0, 4, 7, and weekly thereafter. Guidance was to stop or not start antibiotics following a test value of less than 1·0 ng/mL and to start or continue antibiotics following a test value of 1·0 ng/mL or more. In the intervention group, any empirical clinical decision to use antibiotics was preceded by measurement of procalcitonin. Otherwise, both groups received standard care. The primary outcome was use of antibiotics during the index admission to hospital. All analyses were done in the intention-to-treat population. This study was registered with the International Standard Randomised Controlled Trial registry, ISRCTN 50584992.
Between July 29, 2018, and Nov 13, 2020, 369 patients were screened, of whom 260 were enrolled and randomly assigned to a treatment group (132 to procalcitonin-guided care and 128 to usual care). 59 (45%) of patients in the procalcitonin-guided care group were prescribed antibiotics compared with 79 (63%) in the usual care group (adjusted risk difference -15·6% 95% CI -27·0 to -4·2; p=0·0071). The odds ratio for the treatment effect was 0·49 (95% CI 0·29 to 0·83; p=0·0077). There was no significant difference between groups in terms of the number of clinical infections or hospital-acquired infections per patient. Four (3%) patients in the procalcitonin-guided care group and three (2%) patients in the usual care group died; all deaths were related to underlying severe pancreatitis. There was no difference in adverse events between the groups.
Our findings suggest that procalcitonin-guided care can reduce antibiotic use without increasing infection or harm in patients with acute pancreatitis. Procalcitonin-based algorithms to guide antibiotic use should be considered in the care of this group of patients and be incorporated into future guidelines on the management of acute pancreatitis.
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