Prediction of the Liver Safety Profile of a First-in-Class Myeloperoxidase Inhibitor Using Quantitative Systems Toxicology Modeling.

The novel myeloperoxidase inhibitor verdiperstat was developed as a treatment for neuroinflammatory and neurodegenerative diseases. During development, a computational prediction of verdiperstat liver safety was performed using DILIsym v8A, a quantitative systems toxicology (QST) model of liver safety.A physiologically-based pharmacokinetic (PBPK) model of verdiperstat was constructed in GastroPlus 9.8, and outputs for liver and plasma time courses of verdiperstat were input into DILIsym. In vitro experiments measured the likelihood that verdiperstat would inhibit mitochondrial function, inhibit bile acid transporters, and generate reactive oxygen species (ROS); these results were used as inputs into DILIsym, with two alternate sets of parameters used in order to fully explore the sensitivity of model predictions. Verdiperstat dosing protocols up to 600 mg BID were simulated for up to 48 weeks using a simulated population (SimPops) in DILIsym.Verdiperstat was predicted to be safe, with only very rare, mild liver enzyme increases as a potential possibility in highly sensitive individuals. Subsequent Phase 3 clinical trials found that ALT elevations in the verdiperstat treatment group were generally similar to those in the placebo group. This validates the DILIsym simulation results and demonstrates the power of QST modeling to predict the liver safety profile of novel therapeutics.

Concentration-QTc and cardiac safety analysis of single and multiple zavegepant nasal spray doses in healthy participants to support approval.

Zavegepant is a novel gepant administered as a nasal spray approved in the United States at a 10 mg dose for the acute treatment of migraine with or without aura in adults. The cardiovascular safety of zavegepant nasal spray was assessed in both single-ascending dose (SAD) and multiple-ascending dose (MAD) studies in healthy participants. The SAD study included 72 participants (54 active/18 placebo) who received 0.1-40 mg zavegepant or placebo. The MAD study included 72 participants (56 active/16 placebo) who received 5-40 mg zavegepant or placebo for 1-14 days. Plasma zavegepant pharmacokinetics and electrocardiographic (ECG) parameters (Fridericia-corrected QT interval [QTcF], heart rate, PR interval, ventricular depolarization [QRS], T-wave morphology, and U-wave presence) were analyzed pre- and post-zavegepant administration. Using pooled data from the SAD and MAD studies, the relationship between time-matched plasma zavegepant concentrations and QTc interval was assessed using a linear mixed-effects model to evaluate the potential for QTc interval prolongation. Results showed that single and multiple doses of zavegepant had no significant impact on ECG parameters versus placebo, and there was no concentration-dependent effect on QTcF interval. The estimated slope of the plasma zavegepant concentration-QTcF model was -0.053 ms per ng/mL with a 90% confidence interval of -0.0955 to -0.0110 (p = 0.0415), which is not considered clinically meaningful. At doses up to four times the recommended daily dose, zavegepant does not prolong the QT interval to any clinically relevant extent.

No clinically relevant electrocardiogram effects in a randomized TQT study of single therapeutic/supratherapeutic rimegepant doses in healthy adults.

A single-center, phase I, partially double-blind (double-blind regarding doses of rimegepant and placebo, and open label with respect to moxifloxacin), randomized, 12-sequence, four-period crossover study of therapeutic (75 mg) and supratherapeutic (300 mg) doses of rimegepant with placebo and moxifloxacin (400 mg) controls was designed to evaluate drug effect on the Fridericia corrected QT (QTcF) interval in healthy fasted adults. A total of 38 participants were randomized and dosed in the study. Electrocardiogram (ECG) data were available from 37 participants in the rimegepant 75-mg group, 38 participants in the rimegepant 300-mg group, and 36 participants in the moxifloxacin and placebo groups. Both the 75- and 300-mg doses of rimegepant had no clinically relevant effect on ECG parameters, including QTcF, heart rate, PR and QRS interval, T-wave morphology, and U-wave presence. All upper 90% confidence intervals for the QTcF effect with rimegepant were less than or equal to 4.69 ms, well below the 10-ms threshold for potential clinical significance. Assay sensitivity was demonstrated by the QT effect of moxifloxacin. Using both by-timepoint and concentration-QTc analysis, a placebo-corrected change-from-baseline QTcF greater than 10 ms could be excluded for rimegepant plasma concentrations up to ~10,000 ng/mL, representing concentrations at least 10.8-fold the maximum observed concentration of the 75-mg therapeutic dose of rimegepant.

Bioequivalence of rimegepant, a small molecule CGRP receptor antagonist, administered as an oral tablet, a sublingual orally disintegrating tablet, and a supralingual orally disintegrating tablet: two phase 1 randomized studies in healthy adults.

BACKGROUND: Rimegepant is an orally administered small molecule calcitonin gene-related peptide receptor antagonist indicated for the acute and preventive treatment of migraine. METHODS: Two single-center, phase 1, open-label, randomized bioequivalence studies were conducted in healthy adult non-smokers, aged 18-55 years. One study compared the rate and extent of absorption of the marketed formulation of rimegepant 75 mg orally disintegrating tablet (ODT) administered sublingually with rimegepant 75 mg oral tablet, an earlier development formulation; the second compared the rate and extent of absorption of 75 mg rimegepant ODT administered supralingually with rimegepant oral tablet. RESULTS: The ln-transformed geometric mean ratios for the area under the curve (AUC) from time 0 to the last available concentration time point (time t) (AUC0-t), AUC from time 0 to infinity (AUC0-inf), and maximum observed concentration (Cmax) of sublingual rimegepant ODT vs. rimegepant tablet were 97, 97, and 105%, respectively, and the 90% confidence intervals (CIs) were all within the predefined range (80-125%) for bioequivalence. The ln-transformed geometric mean ratios for the AUC0-t and AUC0-inf of supralingual rimegepant ODT vs. rimegepant tablet were 98%, the 90% CIs were within the predefined range (80-125%), and the geometric mean ratio for Cmax was 103% with the 95% upper confidence bound for the scaled average bioequivalence criterion of -0.0575 (within-participant coefficient of variation for the reference for Cmax > 30%) for bioequivalence. CONCLUSIONS: Rimegepant 75 mg ODT, administered sublingually or supralingually, and rimegepant 75 mg oral tablet were bioequivalent.

A Drug-Drug Interaction Study to Evaluate the Impact of Rimegepant on OCT2- and MATE1-Mediated Transport of Metformin in Healthy Participants.

Rimegepant is a calcitonin gene-related peptide receptor antagonist approved for migraine treatment. This phase 1, open-label, single-center, fixed-sequence study evaluated the effect of rimegepant on the pharmacokinetics (PK) of metformin. Twenty-eight healthy participants received metformin 500 mg twice daily from Days 1 to 4 and Days 7 to 10, and once daily on Days 5 and 11. Rimegepant, 75 mg tablet, was administered once daily from Days 9 to 12. At pre-specified time points, plasma metformin concentration, serum glucose levels, and safety and tolerability were evaluated. A 16% increase in the area under the plasma metformin concentration-time curve (AUC) for 1 dosing interval (AUC0-τ,ss), a statistically insignificant increase in maximum and minimum steady-state metformin concentration (Cmax,ss and Cmin,ss), and a decrease in metformin renal clearance were observed on Day 11 following metformin-rimegepant coadministration compared with metformin alone; however, the changes were not clinically relevant. Additionally, coadministration of rimegepant with metformin did not induce clinically meaningful change in the maximum observed glucose concentration (Gmax) or AUCgluc compared with metformin alone. Overall, rimegepant and metformin coadministration did not result in clinically relevant changes in metformin PK, renal clearance, or the antihyperglycemic effects of metformin. Rimegepant is considered safe for use with metformin.

The Pharmacokinetics, Safety, and Tolerability of Rimegepant 75 mg Are Similar in Elderly and Nonelderly Adults: A Phase 1, Open-Label, Parallel-Group, Single-Dose Study.

Rimegepant is a small-molecule calcitonin gene-related peptide receptor antagonist approved for the acute treatment of migraine ± aura and preventive treatment of migraine in adults. The pharmacokinetics of rimegepant in elderly and nonelderly subjects were evaluated. In an open-label Phase 1 study, 14 elderly (aged 65 years or older) and 14 nonelderly (aged 18 to less than 45 years) subjects each received a single oral dose of rimegepant 75 mg. Blood samples were collected before dosing and through 96 hours after dosing. The pharmacokinetic parameters of rimegepant after a single dose were similar in both age groups. Geometric least-squares mean ratios (elderly/nonelderly) of the natural log-transformed maximum observed plasma concentration and natural log-transformed area under the plasma concentration-time curve from time 0 extrapolated to infinity were 96.6 and 104.6, respectively. Eight (28.6%) subjects (4 elderly, 4 nonelderly) experienced 1 or more adverse events (AEs); all AEs were mild in intensity, and no serious AEs or AEs leading to discontinuation were reported. Following a single 75-mg dose of oral rimegepant, pharmacokinetic parameters were similar in elderly and nonelderly adults; no dose adjustment is warranted in elderly subjects.

A placebo-controlled, randomized, single and multiple dose study to evaluate the safety, tolerability, and pharmacokinetics of rimegepant in healthy participants.

BACKGROUND: Rimegepant is an oral, small molecule calcitonin gene-related peptide receptor antagonist for acute treatment of migraine and migraine prevention. METHODS: This was a single-site, placebo-controlled, sequential, single and multiple ascending dose study in healthy males and females, aged 18-55 years, with no clinically significant medical history. The objectives were to assess the safety, tolerability, and pharmacokinetics of the oral capsule free-base formulation. Single oral doses of rimegepant from 25-1500 mg were evaluated in the single ascending dose phase, and 75-600 mg/day doses administered for 14 days were evaluated in the multiple ascending dose phase. RESULTS: No dose-related trends were observed in orthostatic systolic and diastolic blood pressure or heart rate after rimegepant administration. Rimegepant was rapidly absorbed with the median time of maximum observed plasma concentration from 1-3.5 hours. Rimegepant showed a more than dose-proportional increase in exposure from 25-1500 mg following a single dose and from 75-600 mg/day following multiple doses. CONCLUSIONS: Rimegepant was safe and generally well tolerated at single oral doses up to 1500 mg and multiple doses up to 600 mg/day for 14 days in healthy participants in this study. Median terminal half-life ranged from 8-12 hours across the wide range of single doses studied.

Effects of rimegepant 75 mg daily on the pharmacokinetics of a combined oral contraceptive containing ethinyl estradiol and norgestimate in healthy female participants.

OBJECTIVE: To assess the effect of single and multiple doses of rimegepant 75 mg dose on the pharmacokinetics of an oral contraceptive containing ethinyl estradiol (EE)/norgestimate (NGM) in healthy females of childbearing potential or non-menopausal females with tubal ligation. BACKGROUND: Females of childbearing age experience the highest prevalence of migraine and frequently inquire about the concomitant use of anti-migraine medications and contraceptives. Rimegepant, a calcitonin gene-related peptide receptor antagonist, demonstrated efficacy and safety for treating an acute migraine attack and preventing migraine. METHODS: This open-label, single-center, phase 1, drug-drug interaction study explored the effects of rimegepant 75 mg daily dose on the pharmacokinetics of an oral contraceptive containing EE/NGM 0.035 mg/0.25 mg in healthy females of childbearing potential or non-menopausal females with tubal ligation. During cycles 1 and 2, participants received EE/NGM once daily for 21 days followed by placebo tablets with inactive ingredients for 7 days. Rimegepant was administered during only cycle 2 for 8 days, from days 12 through 19. The primary endpoint was the effect of single and multiple doses of rimegepant on the pharmacokinetics of EE and norelgestromin (NGMN), an active metabolite of NGM, at steady state, including area under the concentration-time curve for 1 dosing interval (AUC0-τ,ss ) and maximum observed concentration (Css[max] ). RESULTS: The study enrolled 25 participants, with pharmacokinetic data assessed for 20 participants. A single 75 mg dose of rimegepant co-administered with EE/NGM increased exposures of EE and NGMN by ≤16% (geometric mean ratio [GMR], 1.03; 90% confidence interval [CI], 1.01-1.06; and GMR, 1.16; 90% CI, 1.13-1.20, respectively). After 8 days of co-administering EE/NGM with rimegepant, EE pharmacokinetic parameters, AUC0-τ,ss and Css(max) , increased by 20% (GMR, 1.20; 90% CI, 1.16-1.25) and 34% (GMR, 1.34; 90% CI, 1.23-1.46), respectively, and NGMN pharmacokinetic parameters increased by 46% (GMR, 1.46; 90% CI, 1.39-1.52) and 40% (GMR, 1.40; 90% CI, 1.30-1.51), respectively. CONCLUSIONS: The study identified modest elevations in overall EE and NGMN exposures after multiple doses of rimegepant, but these elevations are unlikely to be clinically relevant in healthy females with migraine.

Rimegepant 75 mg in Subjects With Hepatic Impairment: Results of a Phase 1, Open-Label, Single-Dose, Parallel-Group Study.

Rimegepant is a small-molecule calcitonin gene-related peptide receptor antagonist (gepant) with demonstrated efficacy and safety in the acute and preventive treatment of migraine. Here, we report the pharmacokinetics and safety of a single 75-mg oral dose of rimegepant in subjects with severe, moderate, or mild hepatic impairment and matched healthy subjects from an open-label, single-dose, 4-group phase 1 study. Thirty-six subjects aged 41-71 years were enrolled, including 6 each with severe, moderate, or mild hepatic impairment and 18 healthy subjects. All subjects completed the study. A <20% increase in total and unbound pharmacokinetics was observed in subjects with mild hepatic impairment and ≤65% increase with moderate hepatic impairment versus matched healthy controls. Total and unbound systemic exposure increased 2.0- and 3.9-fold in the severe hepatic impairment group. In subjects with severe hepatic impairment, geometric mean ratios (severe impairment/controls) for total concentrations were 202.2% for area under the plasma concentration-time curve from time 0 to the last quantifiable concentration, 202.2% for area under the plasma concentration-time curve from time 0 to infinity, and 189.1% for maximum observed plasma concentration. Corresponding geometric mean ratios using unbound concentrations were 388.8% and 388.7%, respectively. Three (8.3%) subjects reported 4 treatment-emergent adverse events. Rimegepant is not recommended for use in adults with severe hepatic impairment.

Pharmacokinetics and Safety of Single and Multiple Daily Dosing of 75-mg Rimegepant Orally Disintegrating Tablets in Healthy Chinese Adults: A Randomized Placebo-Controlled Trial.

Rimegepant is an oral small-molecule calcitonin gene-related peptide antagonist for acute migraine treatment with or without aura and prevention of episodic migraine in adults. This was a rimegepant single- and multiple-dose phase 1, randomized, placebo-controlled, double-blind study to evaluate the pharmacokinetics and confirm safety in healthy Chinese participants. Participants received a 75-mg rimegepant orally disintegrating tablet (ODT) (N = 12) or matching placebo (N = 4) ODT on days 1 and 3-7 after fasting for pharmacokinetic assessments. Safety assessments included 12-lead electrocardiograms, vital signs, clinical laboratory data, and adverse events (AEs). After a single dose (9 females, 7 males) median time to maximum plasma concentration was 1.5 hours; mean values were 937 ng/mL (maximum concentration), 4582 h*ng/mL (area under the concentration-time curve, 0 to infinity), 7.7 hours (terminal elimination half-life), and 19.9 L/h (apparent clearance). Similar results were seen after 5 daily doses, with minimal accumulation. Six (37.5%) participants experienced ≥1 treatment-emergent AE: 4 (33.3%) had received rimegepant and 2 (50.0%) had received placebo. All AEs were grade 1 and resolved by the end of the study with no deaths, serious/significant AEs, or AEs leading to discontinuation. Overall, single- and multiple-dose rimegepant ODT 75 mg was safe and well-tolerated in healthy Chinese adults with similar pharmacokinetics to non-Asian healthy participants. Trial registration: This trial is registered with the China Center for Drug Evaluation (CDE): CTR20210569.

P-Glycoprotein and Breast Cancer Resistance Protein Transporter Inhibition by Cyclosporine and Quinidine on the Pharmacokinetics of Oral Rimegepant in Healthy Subjects.

Rimegepant (Nurtec ODT)-an orally administered, small-molecule calcitonin gene-related peptide receptor antagonist indicated for the acute and preventive treatment of migraine-is a substrate for both the P-glycoprotein and breast cancer resistance protein transporters in vitro. We evaluated the effects of concomitant administration of strong inhibitors of these transporters on the pharmacokinetics of rimegepant in healthy subjects. This single-center, open-label, randomized study was conducted in 2 parts, both of which were 2-period, 2-sequence, crossover studies. Part 1 (n = 15) evaluated the effect of a single oral dose of 200-mg cyclosporine, a strong inhibitor of the P-glycoprotein and breast cancer resistance protein transporters, on the pharmacokinetics of rimegepant 75 mg. Part 2 (n = 12) evaluated the effect of a single oral dose of 600-mg quinidine, a strong selective P-glycoprotein transporter, on the pharmacokinetics of rimegepant 75 mg. Coadministration with cyclosporine showed an increase in rimegepant area under the plasma concentration-time curve from time 0 to infinity and maximum observed concentration based on geometric mean ratios (90% confidence intervals [CIs]) of 1.6 (1.49-1.72) and 1.41 (1.27-1.57), respectively, versus rimegepant alone. Coadministration with quinidine showed an increase in rimegepant area under the plasma concentration-time curve from time 0 to infinity and maximum observed concentration geometric mean ratios (90% CIs) of 1.55 (1.40-1.72) and 1.67 (1.46-1.91), respectively, versus rimegepant alone. Strong P-glycoprotein inhibitors (cyclosporine, quinidine) increased rimegepant exposures (>50%, <2-fold). In parts 1 and 2, rimegepant coadministration was well tolerated and safe. The similar effect of cyclosporine and quinidine coadministration on rimegepant exposure suggests that inhibition of breast cancer resistance protein inhibition may have less influence on rimegepant exposure.

Human Milk and Plasma Pharmacokinetics of Single-Dose Rimegepant 75 mg in Healthy Lactating Women.

Objective: Investigate whether rimegepant-an oral small molecule calcitonin gene-related peptide receptor antagonist for the treatment of migraine-is excreted in human milk after a single 75 mg dose and characterize its concentration-time profile in the plasma and milk of healthy lactating women to determine the relative infant dose (RID). Methods: This open-label, single-center study enrolled healthy lactating women aged 18-40 years with a gestation of 37-42 weeks and uncomplicated delivery of a single healthy child ≥2 weeks (14 days) and ≤6 months before study drug administration. Plasma samples were collected 0, 1, 2, 4, and 8 hours postdose; human milk samples were collected at 0, 1, 2, 4, 8, 12, 16, 24, 32, and 36 hours. The milk:plasma drug concentration ratio was estimated as the ratio of the human milk:plasma areas under the curve. The RID (%) was calculated as 100 times the quotient of the body weight-normalized infant and maternal doses. Results: Subjects (N = 12) were enrolled between 25 January and 15 September 2020. The mean (standard deviation [SD]) age was 29.8 (3.6) years; mean (SD) body mass index was 26.8 (4.9) kg/m2. The mean (SD) RID of rimegepant was 0.51% (0.14). The mean (SD) body-weight normalized infant dose was 0.005 (0.001) mg/kg/day, the mean (SD) body-weight normalized maternal dose was 1.04 (0.18) mg/kg/day, and mean (SD) maternal body weight was 74.0 (13.3) kg. Conclusion: On a weight-adjusted basis, the mean RID of rimegepant was <1% of the maternal dose.

Effect of ondansetron on reducing ICU mortality in patients with acute kidney injury.

The purpose of this study is to identify medications with potentially beneficial effects on decreasing mortality in patients with acute kidney injury (AKI) while in the intensive care unit (ICU). We used logistic regression to investigate associations between medications received and ICU mortality in patients with AKI in the MIMIC III database. Drugs associated with reduced mortality were then validated using the eICU database. Propensity score matching (PSM) was used for matching the patients' baseline severity of illness followed by a chi-square test to calculate the significance of drug use and mortality. Finally, we examined gene expression signatures to explore the drug's molecular mechanism on AKI. While several drugs demonstrated potential beneficial effects on reducing mortality, most were used for potentially fatal illnesses (e.g. antibiotics, cardiac medications). One exception was found, ondansetron, a drug without previously identified life-saving effects, has correlation with lower mortality among AKI patients. This association was confirmed in a subsequent analysis using the eICU database. Based on the comparison of gene expression signatures, the presumed therapeutic effect of ondansetron may be elicited through the NF-KB pathway and JAK-STAT pathway. Our findings provide real-world evidence to support clinical trials of ondansetron for treatment of AKI.

Pain Chemogenomics Knowledgebase (Pain-CKB) for Systems Pharmacology Target Mapping and Physiologically Based Pharmacokinetic Modeling Investigation of Opioid Drug-Drug Interactions.

More than 50 million adults in America suffer from chronic pain. Opioids are commonly prescribed for their effectiveness in relieving many types of pain. However, excessive prescribing of opioids can lead to abuse, addiction, and death. Non-steroidal anti-inflammatory drugs (NSAIDs), another major class of analgesic, also have many problematic side effects including headache, dizziness, vomiting, diarrhea, nausea, constipation, reduced appetite, and drowsiness. There is an urgent need for the understanding of molecular mechanisms that underlie drug abuse and addiction to aid in the design of new preventive or therapeutic agents for pain management. To facilitate pain related small-molecule signaling pathway studies and the prediction of potential therapeutic target(s) for the treatment of pain, we have constructed a comprehensive platform of a pain domain-specific chemogenomics knowledgebase (Pain-CKB) with integrated data mining computing tools. Our new computing platform describes the chemical molecules, genes, proteins, and signaling pathways involved in pain regulation. Pain-CKB is implemented with a friendly user interface for the prediction of the relevant protein targets and analysis and visualization of the outputs, including HTDocking, TargetHunter, BBB predictor, and Spider Plot. Combining these with other novel tools, we performed three case studies to systematically demonstrate how further studies can be conducted based on the data generated from Pain-CKB and its algorithms and tools. First, systems pharmacology target mapping was carried out for four FDA approved analgesics in order to identify the known target and predict off-target interactions. Subsequently, the target mapping outcomes were applied to build physiologically based pharmacokinetic (PBPK) models for acetaminophen and fentanyl to explore the drug-drug interaction (DDI) between this pair of drugs. Finally, pharmaco-analytics was conducted to explore the detailed interaction pattern of acetaminophen reactive metabolite and its hepatotoxicity target, thioredoxin reductase.

Pharmacological Optimization for Successful Traumatic Brain Injury Drug Development.

The purpose of this review is to highlight the pharmacological barrier to drug development for traumatic brain injury (TBI) and to discuss best practice strategies to overcome such barriers. Specifically, this article will review the pharmacological considerations of moving from the disease target "hit" to the "lead" compound with drug-like and central nervous system (CNS) penetrant properties. In vitro assessment of drug-like properties will be detailed, followed by pre-clinical studies to ensure adequate pharmacokinetic and pharmacodynamic characteristics of response. The importance of biomarker development and utilization in both pre-clinical and clinical studies will be detailed, along with the importance of identifying diagnostic, pharmacodynamic/response, and prognostic biomarkers of injury type or severity, drug target engagement, and disease progression. This review will detail the important considerations in determining in vivo pre-clinical dose selection, as well as cross-species and human equivalent dose selection. Specific use of allometric scaling, pharmacokinetic and pharmacodynamic criteria, as well as incorporation of biomarker assessments in human dose selection for clinical trial design will also be discussed. The overarching goal of this review is to detail the pharmacological considerations in the drug development process as a method to improve both pre-clinical and clinical study design as we evaluate novel therapies to improve outcomes in patients with TBI.

A Systematic Review of Gastric Acid-Reducing Agent-Mediated Drug-Drug Interactions with Orally Administered Medications.

BACKGROUND AND OBJECTIVE: Several review articles have been published discussing gastric acid-related drug-drug interactions (DDIs) mediated by coadministration of antacids, histamine H2 receptor antagonists, or proton pump inhibitors, but are not sufficiently comprehensive in capturing all documented DDIs with acid-reducing agents (ARAs) and tend to focus on gastric pH-dependent DDIs and/or basic drugs. Subsequently, several new drugs have been approved, and new information is available in the literature. The objective of this systematic review is to comprehensively identify oral medications that have clinically meaningful DDIs, including loss of efficacy or adverse effects, with gastric ARAs, and categorize these medications according to mechanism of interaction. METHODS: An indepth search of clinical data in the PDR3D: Reed Tech Navigator™ for Drug Labels, University of Washington Drug-Drug Interaction Database, DailyMed, Drugs@FDA.gov, and UpToDate®/Lexicomp® Drug and Drug Interaction screening tool was conducted from 1 June to 1 August 2018. The PDR3D, University of Washington Drug-Drug Interaction Database, and DailyMed were searched with terms associated with gastric acid and ARAs. Conflicting findings were further investigated using the UpToDate®/Lexicomp® screening tool. Clinical relevance was assessed on whether an intervention was needed, and prescribing information and/or literature supporting the DDI. RESULTS: Through the search strategy, 121 medications were found to clinically meaningfully interact with ARAs. For 38 medications the mechanism of interaction with ARAs was identified as gastric pH dependent, and for 83 medications the interaction was found to be not gastric pH mediated, with mechanisms involving metabolic enzymes, transporters, chelation, and urine alkalization. Additionally, 109 medications were studied and did not have a clinically meaningful interaction with ARAs. CONCLUSION: This review may provide a resource to healthcare professionals in aiding the care of patients by increasing awareness of interactions with ARAs and may also identify and potentially aid in avoiding clinically relevant DDIs and preventing risk of treatment failure and/or adverse effects. Advances in non-clinical predictions of gastric pH-mediated DDIs may guide the need for a future clinical evaluation.

Challenges and Opportunities With Oncology Drug Development in China.

Cancer is a growing public health problem in China. Despite the high unmet medical need of patients with cancer in China, oncology drug approvals have historically lagged behind those in the West, mainly the United States and Europe. China is currently undertaking regulatory reforms at a fast pace in order to mitigate this lag.

Population Pharmacokinetic Analysis of Asunaprevir in Subjects with Hepatitis C Virus Infection.

INTRODUCTION: Asunaprevir (ASV) is a potent, pangenotypic, twice-daily hepatitis C virus (HCV) NS3 inhibitor indicated for the treatment of chronic HCV infection. METHODS: A population pharmacokinetic (PPK) model was developed using pooled ASV concentration data from 1239 HCV-infected subjects who received ASV either as part of the DUAL regimen with daclatasvir or as part of the QUAD regimen with daclatasvir and peg-interferon/ribavirin. RESULTS: A two-compartment model with first-order elimination from the central compartment, an induction effect on clearance, and an absorption model consisted of zero-order release followed by first-order absorption adequately described ASV PK after oral administration. A typical value for ASV clearance (CL/F) was 50.8 L/h, increasing by 43% after 2 days to a CL/F of 72.5 L/h at steady-state, likely due to auto-induction of cytochrome P450 3A4 (CYP3A4). Factors indicative of hepatic function were identified as key influential covariates on ASV exposures. Subjects with cirrhosis had an 84% increase in ASV area under the concentration time curve (AUC) and subjects with baseline aspartate aminotransferase (AST) above 78 IU/L had a 58% increase in area under the concentration time curve (AUC). Asians subjects had a 46% higher steady-state AUC relative to White/Caucasian subjects. Other significant covariates were formulation, age, and gender. CONCLUSION: The current PPK model provided a parsimonious description of ASV concentration data in HCV-infected subjects. Key covariates identified in the model help explain the observed variability in ASV exposures and may guide clinical use of the drug. FUNDING: Bristol-Myers Squibb.

Daclatasvir: A Review of Preclinical and Clinical Pharmacokinetics.

Daclatasvir is a first-in-class, highly selective, hepatitis C virus, non-structural protein 5a polymerase replication complex inhibitor with picomolar potency and broad genotypic coverage in vitro. Daclatasvir undergoes rapid absorption, with a time to reach maximum plasma concentration of 1-2 h and an elimination half-life of ~ 10 to 14 h observed in single-ascending dose studies. Steady state was achieved by day 4 in multiple-ascending dose studies. Daclatasvir can be administered without regard to food or pH modifiers. Daclatasvir exposure is similar between healthy subjects and subjects infected with hepatitis C virus. Intrinsic factors such as age, race, or sex do not impact daclatasvir exposure. No dose adjustment is necessary for patients with any degree of hepatic or renal impairment. Daclatasvir has low-to-moderate clearance with the predominant route of elimination via cytochrome P450 3A4-mediated metabolism and P-glycoprotein excretion and intestinal secretion. Renal clearance is a minor route of elimination for daclatasvir. As a result, the dose of daclatasvir should be reduced from 60 to 30 mg once daily when co-administered with strong inhibitors of cytochrome P450 3A4. No dose adjustment is required when daclatasvir is co-administered with moderate inhibitors of cytochrome P450 3A4. The dose of daclatasvir should be increased from 60 to 90 mg once daily when co-administered with moderate inducers of cytochrome P450 3A4. Co-administration of daclatasvir with strong inducers of cytochrome P450 3A4 is contraindicated. Concurrent medications with inhibitory effects on P-glycoprotein without concurrent inhibition of cytochrome P450 3A4 are unlikely to cause marked changes in daclatasvir exposure, as the clearance of daclatasvir is through both cytochrome P450 3A4 and P-glycoprotein. The potential for daclatasvir to affect the pharmacokinetics of concomitantly administered drugs that are substrates of the cytochrome P450 enzyme system is low. In vitro, daclatasvir is a weak-to-moderate inhibitor of transporters including organic cation transporter 1, P-glycoprotein, organic transporting polypeptide 1B1, organic transporting polypeptide 1B3, and breast cancer resistance protein, although in clinical studies, daclatasvir has not altered the pharmacokinetics of concomitantly administered drugs that are substrates of these transporters to an appreciable degree, except for rosuvastatin. In summary, daclatasvir is a hepatitis C virus, non-structural protein 5a-selective inhibitor with a well-characterized pharmacokinetic profile that forms part of potent and well-tolerated all-oral treatment regimens for chronic hepatitis C virus infection.

Asunaprevir: An HCV Protease Inhibitor With Preferential Liver Distribution.

Asunaprevir is an inhibitor of the hepatitis C virus (HCV) NS3/4A protease, demonstrating efficacy in clinical studies in patients infected with HCV genotype 1 or 4, with either peginterferon/ribavirin or combinations of direct-acting antivirals. Because of preferential distribution of asunaprevir to the liver via organic anion-transporting polypeptide (OATP)-mediated transport, asunaprevir demonstrates high apparent oral clearance and very low plasma concentrations. Asunaprevir plasma concentrations are markedly increased by single-dose rifampin (an OATP inhibitor) and in subjects with moderate to severe hepatic impairment. In addition, modestly higher plasma concentrations of asunaprevir have been noted in subjects infected with HCV relative to healthy subjects and in Asian subjects relative to whites. At the marketed dose, infrequent hepatic transaminase abnormalities were poorly predicted by plasma concentrations. For a compound with these characteristics, hepatic concentrations may have provided an improved understanding of the in vivo pharmacokinetic and pharmacodynamic data to support decision making during development.