Quantification of clesrovimab, an investigational, half-life extended, anti-respiratory syncytial virus protein F human monoclonal antibody in the nasal epithelial lining fluid of healthy adults.

BACKGROUND: Clesrovimab (MK-1654) is an investigational, half-life extended human monoclonal antibody (mAb) against RSV F glycoprotein in clinical trials as a prophylactic agent against RSV infection for infants. METHODS: This adult study measured clesrovimab concentrations in the serum and nasal epithelial lining fluid (ELF) to establish the partitioning of the antibody after dosing. Clesrovimab concentrations in the nasal ELF were normalized for sampling dilution using urea concentrations from ELF and serum. Furthermore, in vitro RSV neutralization of human nasal ELF following dosing was also measured to examine the activity of clesrovimab in the nasal compartment. FINDINGS: mAbs with YTE mutations are reported in literature to partition ∼1-2 % of serum antibodies into nasal mucosa. Nasal: serum ratios of 1:69-1:30 were observed for clesrovimab in two separate adult human trials after urea normalization, translating to 1.4-3.3 % of serum concentrations. The nasal PK and estimates of peripheral volume of distribution correlated with higher extravascular distribution of clesrovimab. These higher concentration of the antibody in the nasal ELF corroborated with the nasal sample's ability to neutralize RSV ex vivo. An overall trend of decreased viral plaque AUC was also noted with increasing availability of clesrovimab in the nasal ELF from a human RSV challenge study. INTERPRETATION: Along with its extended half-life, the higher penetration of clesrovimab into the nasal epithelial lining fluid and the associated local increase in RSV neutralization activity could offer infants better protection against RSV infection.

Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy.

Developmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients' primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy.

Liver-specific androgen receptor knockout attenuates early liver tumor development in zebrafish.

Hepatocellular carcinoma (HCC) is one of the most severe cancer types and many genetic and environmental factors contribute to the development of HCC. Androgen receptor (AR) signaling is increasingly recognized as one of the important factors associated with HCC. Previously, we have developed an inducible HCC model in kras transgenic zebrafish. In the present study, to investigate the role of AR in liver tumor development, we specifically knocked out ar gene in the liver of zebrafish via the CRISPR/Cas9 system and the knockout zebrafish was named L-ARKO for liver-specific ar knockout. We observed that liver-specific knockout of ar attenuated liver tumor development in kras transgenic zebrafish at the early stage (one week of tumor induction). However, at the late stage (two weeks of tumor induction), essentially all kras transgenic fish continue to develop HCC irrespective of the absence or presence of ar gene, indicating an overwhelming role of the driver oncogene kras over ar knockout. Consistently, cell proliferation was reduced at the early stage, but not the late stage, of liver tumor induction in the kras/L-ARKO fish, indicating that the attenuant effect of ar knockout was at least in part via cell proliferation. Furthermore, androgen treatment showed acceleration of HCC progression in kras fish but not in kras/L-ARKO fish, further indicating the abolishment of ar signalling. Therefore, we have established a tissue-specific ar knockout zebrafish and it should be a valuable tool to investigate AR signalling in the liver in future.

Effects of sex hormones on liver tumor progression and regression in Myc/xmrk double oncogene transgenic zebrafish.

Hepatocellular carcinoma (HCC) shows clear sex disparity with men being more prone to developing HCC and having higher mortality than women. Previous studies have indicated that sex hormones play important roles in HCC initiation and development, but the effects of sex hormones on HCC in clinical trials remain inconsistent. Using zebrafish liver tumor model co-induced by oncogenes Myc and xmrk, we observed similar sex disparity between male and female zebrafish in liver tumor progression and regression; i.e. male Myc/xmrk transgenic zebrafish developed HCC significantly faster and regressed HCC significantly slower than female Myc/xmrk transgenic zebrtafish. To investigate the effects of sex hormones on liver tumor progression and regression, Myc/xmrk fish were treated with either androgen or estrogen, we observed that androgen promoted HCC progression and retarded HCC regression in females, while estrogen attenuated HCC progression and accelerated HCC regression in males. Furthermore, androgen promoted cell proliferation while estrogen inhibited it. Overall, the present study suggested that sex hormones affected liver tumor progression and regression in the Myc/xmrk transgenic zebrafish.

Transcriptomic analyses of oncogenic hepatocytes reveal common and different molecular pathways of hepatocarcinogenesis in different developmental stages and genders in krasG12V transgenic zebrafish.

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is mainly due to genetic changes in hepatocytes. However, molecular expression in hepatocytes during hepatocarcinogenesis has not been characterized. In this study, using an inducible kras transgenic zebrafish models for HCC, transcriptomic profiles of oncogenic hepatocytes from larvae, male and female adult fish following a brief induction of oncogenic kras were investigated. We found that oncogenic hepatocytes from all the three sources possess most of the cancer hallmarks at molecular level, including Sustaining proliferative signaling, Evading growth suppressors, Resisting cell death, Avoiding immune destruction, Inflammation, Reprogramming of energy metabolism, Angiogenesis, and Activating invasion and metastasis, suggesting the malignant transformation at molecular level could occur at the early stage of hepatocarcinogensis and can be captured in hepatocytes. However, each group of oncogenic hepatocytes also had their own characteristics. Larval oncogenic hepatocytes have cancer stem cell features. Female oncogenic hepatocytes showed resemblance to a mild human HCC subtype while male oncogenic hepatocytes resembled a severe HCC subtype, consistent with the observed sex disparity of HCC in both zebrafish and human. Finally, the two adult groups were more similar to each other than to the larval group, indicating an overwhelming effect of development over the gender.

Transcriptomic profiles of tumor-associated neutrophils reveal prominent roles in enhancing angiogenesis in liver tumorigenesis in zebrafish.

We have previously demonstrated the pro-tumoral role of neutrophils using a kras-induced zebrafish hepatocarcinogenesis model. To further illustrate the molecular basis of the pro-tumoral role, Tumor-associated neutrophils (TANs) were isolated by fluorescence-activated cell sorting (FACS) and transcriptomic analyses were carried out by RNA-Seq. Differentially expressed gene profiles of TANs from larvae, male and female livers indicate great variations during liver tumorigenesis, but the common responsive canonical pathways included an immune pathway (Acute Phase Response Signaling), a liver metabolism-related pathway (LXR/RXR Activation) and Thrombin Signaling. Consistent with the pro-tumoral role of TANs, gene module analysis identified a consistent down-regulation of Cytotoxicity module, which may allow continued proliferation of malignant cells. Gene Set Enrichment Analysis indicated up-regulation of several genes promoting angiogenesis. Consistent with this, we found decreased density of blood vessels accompanied with decreased oncogenic liver sizes in neutrophil-depleted larvae. Collectively, our study has indicated some molecular mechanisms of the pro-tumoral roles of TANs in hepatocarcinogenesis, including weakened immune clearance against tumor cells and enhanced function in angiogenesis.

Immune response induced by major environmental pollutants through altering neutrophils in zebrafish larvae.

Environmental pollutants may cause adverse effects on the immune system of aquatic organisms. However, the cellular effects of pollutants on fish immune system are largely unknown. Here, we exploited the transgenic zebrafish Tg(lysC:DsRed2) larva as a preliminary screening system to evaluate the potential inflammatory effects of environmental pollutants. Tg(lysC:DsRED2) larvae aged 7-day-postfertilization (7 dpf) were treated with selected environmental chemicals for 24 h (24 h) and the number of neutrophils were quantified using both image analysis and fluorescence activated cell sorting (FACS). We found that the numbers of neutrophils in the Tg(lysC:DsRED2) larvae were significantly increased by most of the organic chemicals tested, including E2 (17ß-estradiol), BPA (Bisphenol-A), NDEA (N-nitrosodiethylamine), 4-NP (4-Nitrophenol) and Lindane (γ-hexachlorocyclohexane). Neutrophil numbers were also increased by all the metals tested (Na2HAsO4· 7H2O, Pb(NO3)2, HgCl2, CdCl2, CuSO4·5H2O, ZnSO4, and K2Cr2O7). The only exception was TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), which significantly reduced the number of neutrophils after exposure. Additionally, the transcription of genes (lyz, mpo, tnfα and il8) related to fish immune system were significantly modulated upon exposure to some of the selected chemicals such as E2, TCDD, Cu and Cd. This study revealed that representatives of major categories of environmental pollutants could cause an acute inflammatory response in zebrafish larvae as shown by alterations in the neutrophils, which may imply a common immunotoxicity mechanism for most environmental pollutants. This study has also demonstrated that Tg(lyz:DsRed2) transgenic zebrafish is an excellent tool for screening environmental chemicals with potential inflammatory effects through FACS-facilitated neutrophil counting.

Chemical inhibition reveals differential requirements of signaling pathways in krasV12- and Myc-induced liver tumors in transgenic zebrafish.

Previously we have generated inducible liver tumor models by transgenic expression of an oncogene and robust tumorigenesis can be rapidly induced by activation of the oncogene in both juvenile and adult fish. In the present study, we aimed at chemical intervention of tumorigenesis for understanding molecular pathways of tumorigenesis and for potential development of a chemical screening tool for anti-cancer drug discovery. Thus, we evaluated the roles of several major signaling pathways in krasV12- or Myc-induced liver tumors by using several small molecule inhibitors: SU5402 and SU6668 for VEGF/FGF signaling; IWR1 and cardionogen 1 for Wnt signaling; and cyclopamine and Gant61 for Hedgehog signaling. Inhibition of VEGF/FGF signaling was found to deter both Myc- and krasV12-induced liver tumorigenesis while suppression of Wnt signaling relaxed only Myc- but not krasV12-induced liver tumorigenesis. Inhibiting Hedgehog signaling did not suppress either krasV12 or Myc-induced tumors. The suppression of liver tumorigenesis was accompanied with a decrease of cell proliferation, increase of apoptosis, distorted liver histology. Collectively, our observations suggested the requirement of VEGF/FGF signaling but not the hedgehog signaling in liver tumorigenesis in both transgenic fry. However, Wnt signaling appeared to be required for liver tumorigenesis only in Myc but not krasV12 transgenic zebrafish.

Males develop faster and more severe hepatocellular carcinoma than females in krasV12 transgenic zebrafish.

Hepatocellular carcinoma (HCC) is more prevalent in men than women, but the reason for this gender disparity is not well understood. To investigate whether zebrafish could be used to study the gender disparity of HCC, we compared the difference of liver tumorigenesis between female and male fish during early tumorigenesis and long-term tumor progression in our previously established inducible and reversible HCC model - the krasV12 transgenic zebrafish. We found that male fish developed HCC faster than females. The male tumors were more severe from the initiation stage, characteristic of higher proliferation, activation of WNT/ß-catenin pathway and loss of cell adhesion. During long-term tumor progression, the male tumors developed into more advanced multi-nodular tumors, whereas the female tumors remain uniform and homogenous. Moreover, regression of male tumors required longer time. We further investigated the role of sex hormones in krasV12 transgenic fish. Estrogen treatment showed tumor suppressing effect during early tumorigenesis through inhibiting cell proliferation, whereas androgen accelerated tumor growth by promoting cell proliferation. Overall, our study presented the zebrafish as a useful animal model for study of gender disparity of HCC.

Application of in vitro transmucosal permeability, dose number, and maximum absorbable dose for biopharmaceutics assessment during early drug development for intraoral delivery.

Intraoral (IO) administration is a unique route that takes advantage of transmucosal absorption in the oral cavity to deliver a drug substance locally or systemically. IO delivery can also enhance or enable oral administration, providing a better therapeutic benefit/safety risk profile for patient compliance. However, there are relatively few systematic biopharmaceutics assessments for IO delivery to date. Therefore, the goals of this study were to i) identify the most relevant in vitro permeability models as alternatives to porcine oral tissues (gold standard) for predicting human IO absorption and ii) establish guidelines for biopharmaceutics assessment during early drug development for IO delivery. Porcine kidney LLC-PK1 cells provided the strongest correlation of transmucosal permeability with porcine oral tissues followed by human Caco-2 cells. Furthermore, cultured human buccal tissues predicted high/low permeability classification and correlated well with porcine oral tissues, which are used for predicting clinical IO absorption. In the meantime, we introduced maximum absorbable dose and dose number in the oral cavity for IO delivery assessment as well as a decision tree to provide guidance for biopharmaceutics assessment during early drug development for IO delivery.

Synergistic Induction of Potential Warburg Effect in Zebrafish Hepatocellular Carcinoma by Co-Transgenic Expression of Myc and xmrk Oncogenes.

Previously we have generated inducible liver tumor models by transgenic expression of Myc or xmrk (activated EGFR homolog) oncogenes in zebrafish. To investigate the interaction of the two oncogenes, we crossed the two transgenic lines and observed more severe and faster hepatocarcinogenesis in Myc/xmrk double transgenic zebrafish than either single transgenic fish. RNA-Seq analyses revealed distinct changes in many molecular pathways among the three types of liver tumors. In particular, we found dramatic alteration of cancer metabolism based on the uniquely enriched pathways in the Myc/xmrk tumors. Critical glycolytic genes including hk2, pkm and ldha were significantly up-regulated in Myc/xmrk tumors but not in either single oncogene-induced tumors, suggesting a potential Warburg effect. In RT-qPCR analyses, the specific pkm2 isoformin Warburg effect was found to be highly enriched in the Myc/xmrk tumors but not in Myc or xmrk tumors, consistent with the observations in many human cancers with Warburg effect. Moreover, the splicing factor genes (hnrnpa1, ptbp1a, ptbp1b and sfrs3b) responsible for generating the pkm isoform were also greatly up-regulated in the Myc/xmrk tumors. As Pkm2 isoform is generally inactive and causes incomplete glycolysis to favor anabolism and tumor growth, by treatment with a Pkm2-specific activator, TEPP-46, we further demonstrated that activation of Pkm2 suppressed the growth of oncogenic liver as well as proliferation of liver cells. Collectively, our Myc/xmrk zebrafish model suggests synergetic effect of EGFR and MYC in triggering Warburg effect in the HCC formation and may provide a promising in vivo model for Warburg effect.

Characterization and high cross-species transferability of microsatellite markers from the floral transcriptome of Aspidistra saxicola (Asparagaceae).

Recent studies utilizing transcriptome sequences generated by next-generation sequencing (NGS) technologies have demonstrated the ability to rapidly detect and characterize thousands of gene-based microsatellites from different plants. However, these simple sequence repeats (SSRs) were seldom used directly to test interspecific transferability in the populations of closely related species. Aspidistra Ker-Gawl. is a monocot genus with high species richness and diversity in flower structure, but its fresh floral materials are not easy to obtain. Until now, little is known about genetic background in the species of Aspidistra, quite apart from the fearful reduction of their natural habitats. In this study, the floral transcriptome of Aspidistra saxicola was obtained using NGS. Based on these data, a total of 5527 SSRs were identified in the unigenes. Among these SSRs, the proportions of di- and tri-nucleotide repeats were quite close (49.6% verse 46.8%), and the most tri-nucleotide repeats were AGG/CCT followed by AAG/CTT and AGC/GCT in A. saxicola, showing distinct differences with other angiosperm species. To assess genetic diversity in the species of Aspidistra, 48 SSR loci were tested in four available populations of A. elatior. The results revealed that more than a third of the loci were polymorphic. The majority of these primers could be amplified in 24 species representing the main clades of Aspidistra. The primer subsets from transcriptome data proved highly useful for detecting polymorphisms in the related species, supporting the finding that NGS is an efficient approach to molecular marker development at both intra- and interspecies levels, especially in endangered nonmodel species.

Ultrasensitive liquid chromatography-tandem mass spectrometric methodologies for quantification of five HIV-1 integrase inhibitors in plasma for a microdose clinical trial.

HIV-1 integrase strand transfer inhibitors are an important class of compounds targeted for the treatment of HIV-1 infection. Microdosing has emerged as an attractive tool to assist in drug candidate screening for clinical development, but necessitates extremely sensitive bioanalytical assays, typically in the pg/mL concentration range. Currently, accelerator mass spectrometry is the predominant tool for microdosing support, which requires a specialized facility and synthesis of radiolabeled compounds. There have been few studies attempted to comprehensively assess a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach in the context of microdosing applications. Herein, we describe the development of automated LC-MS/MS methods to quantify five integrase inhibitors in plasma with the limits of quantification at 1 pg/mL for raltegravir and 2 pg/mL for four proprietary compounds. The assays involved double extractions followed by UPLC coupled with negative ion electrospray MS/MS analysis. All methods were fully validated to the rigor of regulated bioanalysis requirements, with intraday precision between 1.20 and 14.1% and accuracy between 93.8 and 107% at the standard curve concentration range. These methods were successfully applied to a human microdose study and demonstrated to be accurate, reproducible, and cost-effective. Results of the study indicate that raltegravir displayed linear pharmacokinetics between a microdose and a pharmacologically active dose.

Metabolism and excretion of [14C]taranabant, a cannabinoid-1 inverse agonist, in humans.

Taranabant (N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-{[5-(trifluoromethyl)pyridin-2-yl]oxy}propanamide or MK-0364) is an orally active inverse agonist of the cannabinoid 1 (CB-1) receptor that was under development for the management of obesity. The metabolism and excretion of taranabant were investigated following a single oral dose of 5 mg/201 µCi [14C]taranabant to six healthy male subjects. The overall excretion recovery of the administered radioactivity was nearly quantitative (∼92%), with the majority of the dose (∼87%) excreted into faeces and a much smaller fraction (∼5%) into urine. Taranabant was absorbed rapidly, with C(max) of radioactivity attained at 1-2-h postdose. The parent compound and its monohydroxylated metabolite, M1, were the major radioactive components circulating in plasma and comprised ∼12-24% and 33-42%, respectively, of the plasma radioactivity for up to 48 h. A second monohydroxylated metabolite, designated as M1a, represented ∼10-12% of the radioactivity in the 2- and 8-h postdose plasma profiles. Metabolite profiles of the faeces samples consisted mainly of the (unabsorbed) parent compound and multiple diastereomeric carboxylic acid derivatives derived from oxidation of the geminal methyl group of the parent compound and of the hydroxylated metabolite/s. These data suggest that, similar to rats and monkeys, taranabant is primarily eliminated in humans via oxidative metabolism and excretion of metabolites via the biliary/faecal route.

Development of a population pharmacokinetic model for taranabant, a cannibinoid-1 receptor inverse agonist.

Taranabant is a cannabinoid-1 receptor inverse agonist developed for the treatment of obesity. A population model was constructed to facilitate the estimation of pharmacokinetic parameters and to identify the influence of selected covariates. Data from 12 phase 1 studies and one phase 2 study were pooled from subjects administered single and multiple oral doses of taranabant ranging from 0.5 to 8 mg. A total of 6,834 taranabant plasma concentrations from 187 healthy and 385 obese subjects were used to develop the population model in NONMEM. A standard covariate analysis using forward selection (α = 0.05) and backward elimination (α = 0.001) was conducted. A three-compartment model with first-order absorption and elimination adequately described plasma taranabant concentrations. The population mean estimates for apparent clearance and apparent steady-state volume of distribution were 25.4 L/h and 2,578 L, respectively. Statistically significant covariate effects were modest in magnitude and not considered clinically relevant (the effects of body mass index (BMI) and creatinine clearance (CrCL) on apparent clearance; BMI, age, CrCL, and gender on apparent volume of the peripheral compartment and age on apparent intercompartmental clearance). The pharmacokinetic profile of taranabant can adequately be described by a three-compartment model with first-order absorption and elimination. Clinical dose adjustment based on covariates effects is not warranted.

Pharmacokinetics, safety, and tolerability of phentermine in healthy participants receiving taranabant, a novel cannabinoid-1 receptor (CB1R) inverse agonist.

This study assessed the potential pharmacokinetic interaction and safety/tolerability of taranabant and phentermine coadministration. This was a randomized, double-blind, 3-panel, fixed-sequence study in healthy participants. Panels A, B, and C evaluated the safety/tolerability of phentermine 15 mg coadministered with taranabant 0.5, 1, and 2 mg for 7 days (panel A) and 28 days (panels B and C). In panels A and C, phentermine 15 mg was administered both with (7 days, panel A; 28 days, panel C) and without (7 days) taranabant 0.5 mg or 2 mg to evaluate pharmacokinetics. The primary endpoint was phentermine AUC(0-24 h) in panels A and C. Secondary endpoints were changes from baseline in blood pressure and heart rate for all panels. The geometric mean ratios and 90% confidence intervals for phentermine AUC(0-24 h) in the presence/absence of taranabant 0.5 mg and 2 mg were 1.08 (0.99, 1.17) and 1.04 (0.98, 1.10), respectively. No significant differences in blood pressure and heart rate were observed with any treatment versus placebo. Coadministration of taranabant 0.5 mg, 1 mg, and 2 mg with phentermine was well tolerated with no pharmacokinetic interaction and did not result in meaningful changes in blood pressure or heart rate versus placebo.

Multiple-dose pharmacokinetics, pharmacodynamics, and safety of taranabant, a novel selective cannabinoid-1 receptor inverse agonist, in healthy male volunteers.

Taranabant is a cannabinoid-1 receptor inverse agonist for the treatment of obesity. This study evaluated the safety, pharmacokinetics, and pharmacodynamics of taranabant (5, 7.5, 10, or 25 mg once daily for 14 days) in 60 healthy male subjects. Taranabant was rapidly absorbed, with a median t(max) of 1.0 to 2.0 hours and a t(1/2) of approximately 74 to 104 hours. Moderate accumulation was observed in C(max) (1.18- to 1.40-fold) and AUC(0-24 h) (1.5- to 1.8-fold) over 14 days for the 5-, 7.5-, and 10-mg doses, with an accumulation half-life ranging from 15 to 21 hours. Steady state was reached after 13 days. After multiple-dose administration, plasma AUC(0-24 h) and C(max) of taranabant increased dose proportionally (5-10 mg) and increased somewhat less than dose proportionally for 25 mg. Taranabant was generally well tolerated up to doses of 10 mg and exhibited multiple-dose pharmacokinetics consistent with once-daily dosing.

Safety, tolerability, pharmacokinetics, and pharmacodynamic properties of taranabant, a novel selective cannabinoid-1 receptor inverse agonist, for the treatment of obesity: results from a double-blind, placebo-controlled, single oral dose study in healthy volunteers.

Taranabant is a novel cannabinoid CB-1 receptor (CB1R) inverse agonist in clinical development for the treatment of obesity. This double-blind, randomized, placebo-controlled, single oral dose study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of taranabant (0.5-600 mg) in 24 healthy male volunteers. Single-dose AUC(0-infinity) and C(max) values for taranabant increased approximately linearly with dose up to 200 mg, with slightly less than dose-proportional increases in AUC(0-infinity) and C(max) values for doses >200 mg. Plasma taranabant had a biphasic disposition, with a median t(max) of 1 to 2.5 hours and a terminal elimination t((1/2)) of 38 to 69 hours. Coadministration of taranabant with a high-fat meal led to a 14% increase in C(max) and a 74% increase in AUC(0-infinity). Clinical adverse experiences associated with single doses of taranabant were generally mild and transient. Of the 198 clinical adverse experiences reported, the most common drug-related ones were nausea (36), headache (22), drowsiness (14), abdominal discomfort/abdominal pain/stomachache (14), hiccups (9), dizziness (8), decreased appetite (7), increased bowel movement (7), mood change (6), tiredness (4), vomiting (4), and sweating increased (4). Taranabant has pharmacokinetic characteristics suitable for a once-daily dosing regimen.