Exploring monocyclic core: Discovery of pyrrol-2-one derivatives as a new series of potent MCHR1 antagonists with in vivo efficacy.

With an objective to improve the profiles of the 1st generation non-basic MCHR1 antagonists, a lean design approach of replacing the bicyclic thienopyrimidine core with a monocyclic pyrrol-2-one chemotype was examined in the context of reducing aromatic ring count, while also contemplating enhanced flexibility as a means of decreasing flat character. The new compounds exhibited potent antagonism up to the sub-nanomolar range, thereby implying that the monocyclic ring could effectively serve as an effective bioisostere of the bicyclic system. The prototype compound 2m offered benefits like improved potency, reduced half-life, and enhanced solubility, while also demonstrating >5% reduction in weight gain in rats, thereby providing proof-of-concept for this new class of compounds as anti-obesity agents.

Variation in DCD Liver Transplant Protocols Among Transplant Centers in the United States.

Background: Variation in donation after circulatory death (DCD) organ recovery and liver transplant practices exist among transplant centers. This study aimed to evaluate these practices among centers in the United States. Methods: Scientific Registry of Transplant Recipients data were accessed to identify centers that performed liver transplantation in 2021 and 2022. Surveys were sent to transplant centers that consistently performed ≥5 DCD liver transplants per year. Results: DCD liver transplants were performed by 95 centers (65.1%) of the 146 liver transplant centers in the United States. Survey results were recorded from 42 centers that consistently performed ≥5 DCD liver transplants per year, with a 59.5% response rate. Withdrawal-to-asystole and agonal time were used to define donor warm ischemia time (WIT) in 16% and 84% centers, respectively. Fifty-six percent of the centers did not use oxygen saturation to define donor WIT. Systolic blood pressure cutoffs used to define agonal time varied between 50 and 80 mm Hg, donor age cutoffs ranged between 55 and 75 y, and cold ischemia times varied between 4 and 10 h. Seventy-six percent of centers used normothermic machine perfusion for DCD liver transplantation. Conclusions: This study highlights the wide variation in use, recovery, and definition of donor WIT. Using national data to rigorously define best practices will encourage greater utilization of this important donor resource.

Textbook outcome: A novel metric in heart transplantation outcomes.

OBJECTIVE: Assessing heart transplant program quality using short-term survival is insufficient. We define and validate the composite metric textbook outcome and examine its association with overall survival. METHODS: We identified all primary, isolated adult heart transplants in the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files from May 1, 2005, to December 31, 2017. Textbook outcome was defined as length of stay 30 days or less; ejection fraction greater than 50% during 1-year follow-up; functional status 80% to 100% at 1 year; freedom from acute rejection, dialysis, and stroke during the index hospitalization; and freedom from graft failure, dialysis, rejection, retransplantation, and mortality during the first year post-transplant. Univariate and multivariate analyses were performed. Factors independently associated with textbook outcome were used to create a predictive nomogram. Conditional survival at 1 year was measured. RESULTS: A total of 24,620 patients were identified with 11,169 (45.4%, 95% confidence interval, 44.7-46.0) experiencing textbook outcome. Patients with textbook outcome were more likely free from preoperative mechanical support (odds ratio, 3.504, 95% confidence interval, 2.766 to 4.439, P < .001), free from preoperative dialysis (odds ratio, 2.295, 95% confidence interval, 1.868-2.819, P < .001), to be not hospitalized (odds ratio, 1.264, 95% confidence interval, 1.183-1.349, P < .001), to be nondiabetic (odds ratio, 1.187, 95% confidence interval, 1.113-1.266, P < .001), and to be nonsmokers (odds ratio, 1.160, 95% confidence interval,1.097-1.228, P < .001). Patients with textbook outcome have improved long-term survival relative to patients without textbook outcome who survive at least 1 year (hazard ratio for death, 0.547, 95% confidence interval, 0.504-0.593, P < .001). CONCLUSIONS: Textbook outcome is an alternative means of examining heart transplant outcomes and is associated with long-term survival. The use of textbook outcome as an adjunctive metric provides a holistic view of patient and center outcomes.

Textbook Outcome as a Quality Metric in Living and Deceased Donor Kidney Transplantation.

BACKGROUND: Quality in kidney transplantation is measured using 1-year patient and graft survival. Because 1-year patient and graft survival exceed 95%, this metric fails to measure a spectrum of quality. Textbook outcomes (TO) are a composite quality metric offering greater depth and resolution. We studied TO after living donor (LD) and deceased donor (DD) kidney transplantation. STUDY DESIGN: United Network for Organ Sharing data for 69,165 transplant recipients between 2013 and 2017 were analyzed. TO was defined as patient and graft survival of 1 year or greater, 1-year glomerular filtration rate of greater than 40 mL/min, absence of delayed graft function, length of stay of 5 days or less, no readmissions during the first 6 months, and no episodes of rejection during the first year after transplantation. Bivariate analysis identified characteristics associated with TO, and covariates were incorporated into multivariable models. Five-year conditional survival was measured, and center TO rates were corrected for case complexity to allow center-level comparisons. RESULTS: The national average TO rates were 54.1% and 31.7% for LD and DD transplant recipients. The hazard ratio for death at 5 years for recipients who did not experience TO was 1.92 (95% CI 1.68 to 2.18, p ≤ 0.0001) for LD transplant recipients and 2.08 (95% CI 1.93 to 2.24, p ≤ 0.0001) for DD transplant recipients. Center-level comparisons identify 18% and 24% of centers under-performing in LD and DD transplantation. High rates of TO do not correlate with transplantation center volume. CONCLUSION: Kidney transplant recipients who experience TO have superior long-term survival. Textbook outcomes add value to the current standards of 1-year patient and graft survival.

Textbook Outcome as a Quality Metric in Liver Transplantation.

Quality in liver transplantation (LT) is currently measured using 1-y patient and graft survival. Because patient and graft survival rates now exceed 90%, more informative metrics are needed. Textbook outcomes (TOs) describe ideal patient outcomes after surgery. This study critically evaluates TO as a quality metric in LT. Methods: United Network for Organ Sharing data for 25 887 adult LT recipients were used to define TO as patient and graft survival >1 y, length of stay ≤10 d, 0 readmissions within 6 mo, absence of rejection, and bilirubin <3 mg/dL between months 2 and 12 post-LT. Univariate analysis identified donor and recipient characteristics associated with TO. Covariates were analyzed using purposeful selection to construct a multivariable model, and impactful variables were incorporated as linear predictors into a nomogram. Five-year conditional survival was tested, and center TO rates were corrected for case complexity to allow for center-level comparisons. Results: The national average TO rate is 37.4% (95% confidence interval, 36.8%-38.0%). The hazard ratio for death at 5 y for patients who do not experience TO is 1.22 (95% confidence interval, 1.11-1.34; P ≤ 0.0001). Our nomogram predicts TO with a C-statistic of 0.68. Center-level comparisons identify 31% of centers as high performing and 21% of centers as below average. High rates of TO correlate only weakly with center volume. Conclusions: The composite quality metric of TO after LT incorporates holistic outcome measures and is an important measure of quality in addition to 1-y patient and graft survival.

Dynamic impact of liver allocation policy change on donor utilization.

Liver allocation policy was changed to reduce variance in median MELD scores at transplant (MMaT) in February 2020. "Acuity circles" replaced local allocation. Understanding the impact of policy change on donor utilization is important. Ideal (I), standard (S), and non-ideal (NI) donors were defined. NI donors include older, higher BMI donors with elevated transaminases or bilirubin, history of hepatitis B or C, and all DCD donors. Utilization of I, S, and NI donors was established before and after allocation change and compared between low MELD (LM) centers (MMaT ≤ 28 before allocation change) and high MELD (HM) centers (MMaT > 28). Following reallocation, transplant volume increased nationally (67 transplants/center/year pre, 74 post, p .0006) and increased for both HM and LM centers. LM centers significantly increased use of NI donors and HM centers significantly increased use of I and S donors. Centers further stratify based on donor utilization phenotype. A subset of centers increased transplant volume despite rising MMaT by broadening organ acceptance criteria, increasing use of all donor types including DCD donors (98% increase), increasing living donation, and transplanting more frequently for alcohol associated liver disease. Variance in donor utilization can undermine intended effects of allocation policy change.

A Survey of Current Procurement Travel Practices, Accident Frequency, and Perceptions of Safety.

In 2018, 81% of the 36, 529 solid organs transplanted in the United States came from deceased donors. These organs were recovered through widespread use of aeromedical and emergency ground transportation systems. Urgently scheduled travel to remote hospitals at night and in varied weather conditions carries risk for the transplant professionals involved. A landmark survey conducted in 2007 demonstrated that 80% of respondents had experienced a "near-miss" event while on a procurement trip, and 15% had been involved in at least 1 accident. One decade later, we sought to revisit the issue of procurement related travel safety. METHODS: A 32 question survey designed to interrogate travel practice, accident frequency, and perceptions of safety was sent to the American Society of Transplant Surgeons membership. RESULTS: Our survey response rate was 20.6%. At least 1 travel accident with bodily injury was reported by 23% of respondents and yet only 7% of respondents reported feeling "unsafe" or "very unsafe" during procurement travel. Sixteen percent of respondents participated in a procurement at a dedicated organ procurement facility, and only 53% of procurement surgeons completed at least 1 deceased donor procurement at their own hospital facility within the preceding 12 months. CONCLUSIONS: In a field where increasingly aggressive organ utilization is the norm, the efficiency and safety of procurement travel merits ongoing consideration. Addressing these concerns takes on new significance as organ allocation policies change geographic distribution to expand the extent of travel required for surgical teams.

Mechanisms for Hepatobiliary Toxicity in Rats Treated with an Antagonist of Melanin Concentrating Hormone Receptor 1 (MCHR1).

The objective of this work was to investigate the mechanisms of hepatobiliary toxicity caused by thienopyrimidone MCHR1 antagonists using BMS-773174 as a tool molecule. Co-administration of the pan CYP inhibitor 1-aminobenzotriazole with BMS-773174 prevented hepatobiliary damage, and direct delivery of the diol metabolite BMS-769750 caused hepatobiliary toxicity, identifying the diol and possibly its downstream hydroxyacid (BMS-800754) metabolite as the toxic species. Rat liver gene expression revealed treatment-related changes in hepatic transporters and induction of oval cell-specific genes including deleted malignant tumor 1 (Dmbt1). The metabolites did not alter hepatic transporter activities, suggesting that transporter-mediated cholestasis was not involved. Because injury to biliary epithelium can result in adaptive hyperplasia, rat biliary epithelial cells (BECs) were isolated and exposed to the oxidative metabolites. BMS-769750 was cytotoxic to BECs, but not rat hepatocytes, suggesting a role of the diol in biliary epithelial injury. BMS-800754 was cytotoxic to rat hepatocytes therefore its contribution to hepatocyte injury in rats is a possibility. Induction of Dmbt1 in rat BECs was investigated because of its role in hepatic progenitor cell differentiation/proliferation during injury. Dmbt1 mRNA was induced by BMS-769750, but not BMS-800754 in BECs; this induction and cellular injury was confirmed with diol metabolites formed by other compounds with the same hepatobiliary liability. In conclusion, hepatobiliary injury by thienopyrimidinone MCHR1 antagonists was driven through a CYP-mediated bioactivation pathway. Induction of Dmbt1 mRNA coupled with cellular injury suggests that injury of biliary epithelium may be the first step toward an adaptive proliferative response causing BDH by these compounds.

Synthesis and Antiobesity Properties of 6-(4-Chlorophenyl)-3-(4-((3,3-difluoro-1-hydroxycyclobutyl)methoxy)-3-methoxyphenyl)thieno[3,2-d]pyrimidin-4(3H)-one (BMS-814580): A Highly Efficacious Melanin Concentrating Hormone Receptor 1 (MCHR1) Inhibitor.

The potent MCHR1 in vitro and in vivo antagonist activity of a series of cyclic tertiary alcohols derived from compound 2b is described. Subsequent pharmacokinetic and pharmacodynamic studies identified BMS-814580 (compound 10) as a highly efficacious antiobesity agent with a relatively clean in vitro and in vivo safety profile.

TGF-ß1 promotes acinar to ductal metaplasia of human pancreatic acinar cells.

Animal studies suggest that pancreatitis-induced acinar-to-ductal metaplasia (ADM) is a key event for pancreatic ductal adenocarcinoma (PDAC) initiation. However, there has not been an adequate system to explore the mechanisms of human ADM induction. We have developed a flow cytometry-based, high resolution lineage tracing method and 3D culture system to analyse ADM in human cells. In this system, well-known mouse ADM inducers did not promote ADM in human cells. In contrast, TGF-ß1 efficiently converted human acinar cells to duct-like cells (AD) in a SMAD-dependent manner, highlighting fundamental differences between the species. Functionally, AD cells gained transient proliferative capacity. Furthermore, oncogenic KRAS did not induce acinar cell proliferation, but did sustain the proliferation of AD cells, suggesting that oncogenic KRAS requires ADM-associated-changes to promote PDAC initiation. This ADM model provides a novel platform to explore the mechanisms involved in the development of human pancreatic diseases.

Non-basic azolotriazinone MCHR1 antagonists for the treatment of obesity: An empirical brain-exposures-driven candidate selection for in vivo efficacy studies.

Non-basic azolotriazinones were explored using an empirical free brain exposures-driven approach to identify potent MCHR1 antagonists for evaluation in in vivo efficacy studies. An optimized lead from this series, 1j (rMCHR1 Ki=1.8 nM), demonstrated a 6.9% reduction in weight gain relative to vehicle in a rat model at 30 mg/kg after 4 days of once-daily oral treatment as a glycine prodrug. Despite a promising efficacy profile, an assessment of the biliary toxicity risk of this compound rendered this compound non-progressible.

Dihydropyrrolopyrazol-6-one MCHR1 antagonists for the treatment of obesity: Insights on in vivo efficacy from a novel FLIPR assay setup.

Our investigation of the structure-activity and structure-liability relationships for dihydropyrrolopyrazol-6-one MCHR1 antagonists revealed that off-rate characteristics, inferred from potencies in a FLIPR assay following a 2 h incubation, can impact in vivo efficacy. The in vitro and exposure profiles of dihydropyrrolopyrazol-6-ones 1b and 1e were comparable to that of the thienopyrimidinone counterparts 41 and 43 except for a much faster MCHR1 apparent off-rate. The greatly diminished dihydropyrrolopyrazol-6-one anti-obesity response may be the consequence of this rapid off-rate.

Identification of a nonbasic melanin hormone receptor 1 antagonist as an antiobesity clinical candidate.

Identification of MCHR1 antagonists with a preclinical safety profile to support clinical evaluation as antiobesity agents has been a challenge. Our finding that a basic moiety is not required for MCHR1 antagonists to achieve high affinity allowed us to explore structures less prone to off-target activities such as hERG inhibition. We report the SAR evolution of hydroxylated thienopyrimidinone ethers culminating in the identification of 27 (BMS-819881), which entered obesity clinical trials as the phosphate ester prodrug 35 (BMS-830216).

Differentiating sodium-glucose co-transporter-2 inhibitors in development for the treatment of type 2 diabetes mellitus.

INTRODUCTION: Sodium-glucose co-transporter-2 (SGLT2) inhibitors are a novel class of agents for the treatment of type 2 diabetes mellitus (T2DM). By inhibiting SGLT2, they prevent renal glucose reabsorption, resulting in glucosuria. AREAS COVERED: The rationale for development of SGLT2 inhibitors is reviewed, with particular focus on the nine SGLT2 inhibitors currently in development. The authors compare the potency and SGLT2 selectivity of the agents, as well as the results from both animal and clinical studies, considering the potential implications they may have for clinical use. EXPERT OPINION: Current evidence suggests that SGLT2 inhibitors have similar efficacy in terms of glycemic control and also demonstrate benefits beyond glycemic reductions, including reductions in body weight and modest reductions in blood pressure. Additionally, they appear to preserve beta-cell function and improve insulin sensitivity. Their mechanism of action allows for combination of SGLT2 inhibitors with other antidiabetic drugs and use across the treatment continuum for T2DM. Potential differences in safety and efficacy based on observed differences in potency and selectivity among the SGLT2 inhibitors, particularly versus SGLT1, remain to be seen. Further long-term data, including post-marketing surveillance, are required to fully determine the safety profile of SGLT2 inhibitors in large patient groups.

Sodium glucose co-transporter 2 (SGLT2) inhibitors: novel antidiabetic agents.

INTRODUCTION: Maintenance of glucose homeostasis in healthy individuals involves SGLT2 (sodium glucose co-transporter 2)-mediated recovery of glucose from the glomerular filtrate which otherwise would be excreted in urine. Clinical studies indicate that SGLT2 inhibitors provide an insulin-independent means to reduce the hyperglycemia that is the hallmark of type 2 diabetes mellitus (T2DM) with minimal risk of hypoglycemia. AREAS COVERED: The pharmacophore common to the SGLT2 inhibitors currently in development is a diarylmethane C-glucoside which is discussed in this review. The focus is how this pharmacophore was further modified as inferred from the patents publishing from 2009 to 2011. The emphasis is on the strategy that each group employed to circumvent the constraints imposed by prior art and how the resulting SGLT2 potency and selectivity versus SGLT1 compared with that of the lead clinical compound dapagliflozin. EXPERT OPINION: SGLT2 inhibitors offer a new fundamentally different approach for treatment of diabetes. To date, the clinical results suggest that for non-renally impaired patients this class of inhibitors could be safely used at any stage of T2DM either alone or in combination with other marketed antidiabetic medications.

Estimation of the extent of in vivo formation of a mutagenic aromatic amine from a potent thyromimetic compound: correlation of in vitro and in vivo findings.

The development of compounds with the potential for genotoxicity poses significant safety risks as well as risks of attrition. Although genotoxicity evaluation of the parent molecule is routine and reasonably predictive, assessing the risk of commercialization when release of a genotoxic degradant and/or metabolite from a nongenotoxic parent molecule is suspected is much more challenging and resource intensive. Much of the risk of the formation of a genotoxic degradant/metabolite can be discharged with the conduct of carcinogenicity studies in models where the compound is formed, but this approach requires a great deal of time and resources. In this manuscript, we investigated the contribution of various factors (pH, serum instability, and hepatic metabolism) to the formation of a mutagenic aromatic amine from a potent and highly selective thyromimetic compound ([3-(3,5-dibromo-4-(4-hydroxy-3-isopropyl-5-methylphenoxy)-2-methylphenylamino)-3-oxopropanoic acid], compound 1), under in vitro conditions. The kinetic parameters obtained from in vitro experiments combined with the pharmacokinetics of 1in vivo (e.g., plasma concentration-time profile and clearance) were used to estimate the extent of in vivo formation of [4-(4-amino-2,6-dibromo-3-methylphenoxy)-2-isopropyl-6-methylphenol] (compound 2), in rats upon administration of a single oral dose of 1. The agreement between the predicted values (1.9% conversion of total administered dose) with the observed levels of 2 in rats (0.2%-2.2% of the 10 mg/kg dose, 10 mg/kg) further prompted the utilization of this approach to predict the extent of release of this mutagen in humans upon administration of 1. The projection of 0.13% conversion to 2 from an efficacious daily dose of 15 mg of 1 translated to the generation of 20 µg of 2 and provided the basis for the decision to terminate the development of 1.

Sirolimus plus sorafenib in treating HCC recurrence after liver transplantation: a case report.

A case of hepatocellular carcinoma (HCC) with pulmonary recurrence after liver transplantation for HCC is presented in this report. The patient showed disease progression on sorafenib therapy demonstrated by computed tomography scans as well as serial serum α-fetoprotein (AFP) elevation. After his immunosuppression therapy was successfully transitioned to sirolimus and a continuation of sorafenib, he achieved partial remission based on RECIST criteria and normalization of AFP. Mammalian target of rapamycin inhibitors including sirolimus alone or in conjunction with sorafenib may be useful in the treatment of post transplant HCC.

Evolution of sodium glucose co-transporter 2 inhibitors as anti-diabetic agents.

BACKGROUND: A critical factor for maintenance of glucose balance is the renal recovery of glucose from the glomerular filtrate mediated primarily by sodium glucose co-transporter 2 (SGLT2). This capacity can be modulated by SGLT2 inhibitors thereby providing a unique insulin independent method of treatment of diabetes. OBJECTIVE/METHOD: A discussion of the evolution of SGLT inhibitors as inferred from patents published from 2005 to 2009 is prefaced by a brief review of the role of SGLT in glucose transport and the clinical findings illustrating the therapeutic potential of SGLT inhibitors as anti-diabetic agents. These compounds comprise O, C and N-glycosides generated by attachment of an appropriate lipophilic aglycone component to a suitable glucose analogue. CONCLUSION: The realization that the in vivo potency of O-glucosides was markedly less than that of C-glucosides necessitated a shift in medicinal chemistry focus of the pharmaceutical companies pursuing SGLT2 inhibitors. Particular emphasis is placed on the strategy that each used to circumvent the constraints imposed by prior art while utilizing a common pharmacophore. The role of SGLT2 inhibitors for treatment of diabetes will be established by the outcome of the five compounds in advanced clinical trials.

Surgical treatment of an extrarenal pseudoaneurysm after kidney transplantation.

A 69-year-old man who underwent a kidney transplantation developed a large pseudoaneurysm at the anastomosis between the right external iliac artery and renal transplant artery. After an unsuccessful attempt using percutaneous thrombin injection, the patient underwent open exploratory laparotomy and surgical ligation of the pseudoaneurysm with preservation of renal graft function.