Respiratory Effects of Biased Ligand Oliceridine in Older Volunteers: A Pharmacokinetic-Pharmacodynamic Comparison with Morphine.

BACKGROUND: Oliceridine is a G protein-biased µ-opioid, a drug class that is associated with less respiratory depression than nonbiased opioids, such as morphine. The authors quantified the respiratory effects of oliceridine and morphine in elderly volunteers. The authors hypothesized that these opioids differ in their pharmacodynamic behavior, measured as effect on ventilation at an extrapolated end-tidal Pco2 at 55 mmHg, V̇E55. METHODS: This four-arm double-blind, randomized, crossover study examined the respiratory effects of intravenous 0.5 or 2 mg oliceridine and 2 or 8 mg morphine in 18 healthy male and female volunteers, aged 55 to 89 yr, on four separate occasions. Participants' CYP2D6 genotypes were determined, hypercapnic ventilatory responses were obtained, and arterial blood samples were collected before and for 6 h after treatment. A population pharmacokinetic-pharmacodynamic analysis was performed on V̇E55, the primary endpoint; values reported are median ± standard error of the estimate. RESULTS: Oliceridine at low dose was devoid of significant respiratory effects. High-dose oliceridine and both morphine doses caused a rapid onset of respiratory depression with peak effects occurring at 0.5 to 1 h after opioid dosing. After peak effect, compared with morphine, respiratory depression induced by oliceridine returned faster to baseline. The effect-site concentrations causing a 50% depression of V̇E55 were 29.9 ± 3.5 ng/ml (oliceridine) and 21.5 ± 4.6 ng/ml (morphine), the blood effect-site equilibration half-lives differed by a factor of 5: oliceridine 44.3 ± 6.1 min and morphine 214 ± 27 min. Three poor CYP2D6 oliceridine metabolizers exhibited a significant difference in oliceridine clearance by about 50%, causing higher oliceridine plasma concentrations after both low- and high-dose oliceridine, compared with the other participants. CONCLUSIONS: Oliceridine and morphine differ in their respiratory pharmacodynamics with a more rapid onset and offset of respiratory depression for oliceridine and a smaller magnitude of respiratory depression over time.

The effect of TRV027 on coagulation in COVID-19: A pilot randomized, placebo-controlled trial.

COVID-19 causes significant thrombosis and coagulopathy, with elevated D-dimer a predictor of adverse outcome. The precise mechanism of this coagulopathy remains unclear; one hypothesis is that loss of angiotensin-converting enzyme 2 activity during viral endocytosis leads to pro-inflammatory angiotensin-II accumulation, loss of angiotensin-1-7 and subsequent vascular endothelial activation. We undertook a double-blind randomized, placebo-controlled experimental medicine study to assess the effect of TRV027, a synthetic angiotensin-1-7 analogue on D-dimer in 30 patients admitted to hospital with COVID-19. The study showed a similar rate of adverse events in TRV027 and control groups. There was a numerical decrease in D-dimer in the TRV027 group and increase in D-dimer in the placebo group; however, this did not reach statistical significance (P = .15). A Bayesian analysis demonstrated that there was a 92% probability that this change represented a true drug effect.

Benefit and Risk Evaluation of Biased µ-Receptor Agonist Oliceridine versus Morphine.

BACKGROUND: To improve understanding of the respiratory behavior of oliceridine, a µ-opioid receptor agonist that selectively engages the G-protein-coupled signaling pathway with reduced activation of the ß-arrestin pathway, the authors compared its utility function with that of morphine. It was hypothesized that at equianalgesia, oliceridine will produce less respiratory depression than morphine and that this is reflected in a superior utility. METHODS: Data from a previous trial that compared the respiratory and analgesic effects of oliceridine and morphine in healthy male volunteers (n = 30) were reanalyzed. A population pharmacokinetic-pharmacodynamic analysis was performed and served as basis for construction of utility functions, which are objective functions of probability of analgesia, P(analgesia), and probability of respiratory depression, P(respiratory depression). The utility function = P(analgesia ≥ 0.5) - P(respiratory depression ≥ 0.25), where analgesia ≥ 0.5 is the increase in hand withdrawal latency in the cold pressor test by at least 50%, and respiratory depression ≥ 0.25 is the decrease of the hypercapnic ventilatory response by at least 25%. Values are median ± standard error of the estimate. RESULTS: The two drugs were equianalgesic with similar potency values (oliceridine: 27.9 ± 4.9 ng/ml; morphine 34.3 ± 9.7 ng/ml; potency ratio, 0.81; 95% CI, 0.39 to 1.56). A 50% reduction of the hypercapnic ventilatory response by morphine occurred at an effect-site concentration of 33.7 ± 4.8 ng/ml, while a 25% reduction by oliceridine occurred at 27.4 ± 3.5 ng/ml (potency ratio, 2.48; 95% CI, 1.65 to 3.72; P < 0.01). Over the clinically relevant concentration range of 0 to 35 ng/ml, the oliceridine utility function was positive, indicating that the probability of analgesia exceeds the probability of respiratory depression. In contrast, the morphine function was negative, indicative of a greater probability of respiratory depression than analgesia. CONCLUSIONS: These data indicate a favorable oliceridine safety profile over morphine when considering analgesia and respiratory depression over the clinical concentration range.

Tenofovir Plasma Concentration from Preexposure Prophylaxis at the Time of Potential HIV Exposure: a Population Pharmacokinetic Modeling and Simulation Study Involving Serodiscordant Couples in East Africa.

The Partners Demonstration Project was a prospective, open-label, implementation science-driven study of preexposure prophylaxis (PrEP) among heterosexual HIV serodiscordant couples in Kenya and Uganda. Adherence data were collected using the Medication Event Monitoring System (MEMS), and time of sexual activity was collected using the mobile phone short message service (SMS). Two plasma samples were collected at a single study visit. We integrated adherence, pharmacokinetics, and SMS data using a population pharmacokinetic (PopPK) model to simulate tenofovir plasma concentrations from PrEP at the time of sexual activity. In the first stage of this analysis, we used data from the current study to update a prior PopPK model of tenofovir (TFV) developed with data from the Partners PrEP Study (a phase III clinical trial). The second stage involved simulating plasma concentrations at the time of sexual activity using empirical Bayes estimates (EBEs) derived from the final model. In addition, EBEs from a previously published parent metabolite model of TFV (MTN-001, an open-label 3-way crossover study in healthy women) was used to simulate tenofovir diphosphate (TFV-DP) concentrations. We estimated percent PrEP "coverage" as the number of reported sexual events during which simulated concentrations were above an a priori threshold concentrations associated with a high degree of protection from HIV infection: plasma TFV of >40 ng/ml and peripheral blood mononuclear cell (PBMC) TFV-DP concentration of >36 fmol/million cells. The levels of coverage were 72% for TFV and 81% for TFV-DP. These levels are consistent with a high degree of protection against HIV acquisition in this study of a pragmatic delivery model for antiretroviral-based HIV prevention.

Hospitalized Patients With and Without Hemodialysis Have Markedly Different Vancomycin Pharmacokinetics: A Population Pharmacokinetic Model-Based Analysis.

BACKGROUND: Despite being in clinical use for about 6 decades, vancomycin dosing remains perplexing and complex. METHODS: A population pharmacokinetic modeling and simulation approach was used to evaluate the efficiency of the current nomogram-based dosing of vancomycin. Serum vancomycin concentrations were obtained as a part of routine therapeutic drug monitoring from two 500-bed academic medical centers. A population pharmacokinetic model was first built using these therapeutic drug monitoring data. Population pharmacokinetic modeling was conducted using NONMEM (7.2 and 7.3). The forward addition-backward elimination approach was used to test the covariate effects. Appropriate numerical and visual criteria were used as model diagnostics for checking model appropriateness and model qualification. The current nomogram efficiency was evaluated by determining the percentage of subjects in the therapeutic range (10-20 mg/L). RESULTS: A 2-compartment model with between-subject variability on clearance (CL), central volume of distribution (Vc), and peripheral volume of distribution best fit the data. Blood urea nitrogen, age, creatinine clearance, and hemodialysis status were significant covariates on clearance. Hemodialysis status was a significant covariate on Vc and peripheral volume of distribution. In the final model, creatinine clearance was retained as a covariate on CL whereas hemodialysis status was retained as covariate on both CL and Vc. Using Monte Carlo simulations, the current nomogram was optimized by the addition of a loading dose and reducing the maintenance doses. The current nomogram is suboptimal. Optimization of the nomogram resulted in >40% subjects consistently being in the therapeutic range at troughs collected after the first 6 doses. CONCLUSIONS: CL and Vc differ markedly between patients undergoing hemodialysis and those not undergoing hemodialysis. Dosing nomogram based on these covariate relationships may potentially help in accurate dosing of vancomycin.

Treatment of spontaneous preterm labour with retosiban: a phase II pilot dose-ranging study.

AIMS: The aims of the present study were to investigate the maternal, fetal and neonatal safety and tolerability, pharmacodynamics and pharmacokinetics of intravenous (IV) retosiban in pregnant women with spontaneous preterm labour (PTL) between 340/7 and 356/7  weeks' gestation. METHODS: In parts A and B of a three-part, double-blind, placebo-controlled, multicentre study, women were randomized 3:1 (Part A) or 2:1 (Part B) to either 12-h IV retosiban followed by a single dose of oral placebo (R-P) or 12-h IV placebo followed by single-dose oral retosiban (P-R). RESULTS: A total of 29 women were randomized; 20 to R-P and nine to P-R. An integrated analysis found that adverse events were infrequent in mothers/newborns and consistent with events expected in the population under study or associated with confounding factors. Retosiban was rapidly absorbed after oral administration, with an observed half-life of 1.45 h. Efficacy analyses included 19 women. While not statistically significant, those receiving R-P more frequently achieved uterine quiescence in 6 h (R-P, 63%; 95% credible interval [CrI]: 38, 84; P-R, 43%; 95% CrI: 12, 78) and more achieved a reduction of ≥50% in uterine contractions in 6 h (R-P, 63%; 95% CrI: 38, 84; P-R, 29%; 95% CrI: 4, 64). The number of days to delivery was increased in women receiving R-P (median 26 days for R-P vs. 13 days for P-R). CONCLUSIONS: Intravenous retosiban has a favourable safety and tolerability profile and might prolong pregnancies in women with PTL. The study provides the rationale and dosing strategy for further evaluation of the efficacy of retosiban in the treatment of PTL.

Population Pharmacokinetics of Tenofovir in HIV-1-Uninfected Members of Serodiscordant Couples and Effect of Dose Reporting Methods.

Antiretroviral preexposure prophylaxis (PrEP) with once-daily dosing of tenofovir and tenofovir-emtricitabine was shown to be effective for preventing HIV-1 infection in individuals who had HIV-1-seropositive partners (the Partners PrEP Study). We developed a population pharmacokinetic model for tenofovir and investigated the impacts of different dose reporting methods. Dosing information was collected as patient-reported dosing information (PRDI) from 404 subjects (corresponding to 1,280 drug concentration records) from the main trial and electronic monitoring-based adherence data collected from 211 subjects (corresponding to 327 drug concentration records) in an ancillary adherence study. Model development was conducted with NONMEM (7.2), using PRDI with a steady-state assumption or using PRDI replaced with electronic monitoring records where available. A two-compartment model with first-order absorption was the best model in both modeling approaches, with the need for an absorption lag time when electronic monitoring-based dosing records were included in the analysis. Age, body weight, and creatinine clearance were significant covariates on clearance, but only creatinine clearance was retained in the final models per stepwise selection. Sex was not a significant covariate on clearance. Tenofovir population pharmacokinetic parameter estimates and the precisions of the parameters from the two final models were comparable with the point estimates of the parameters, differing from 0% to 35%, and bootstrap confidence intervals widely overlapped. These findings indicate that PRDI was sufficient for population pharmacokinetic model development in this study, with a high level of adherence per multiple measures.

Maternofetal pharmacokinetics and fetal lung responses in chronically catheterized sheep receiving constant, low-dose infusions of betamethasone phosphate.

BACKGROUND: Antenatal steroids are standard of care for cases of anticipated preterm labor to improve neonatal outcomes. However, steroids are potent drugs, and their use in pregnancy remains largely unoptimized. OBJECTIVE: The objective of the study was to measure the maternofetal pharmacokinetics of constant, low-dose intravenous betamethasone phosphate infusions and correlate these data with the transcriptional effect exerted by subclinical betamethasone exposures on the ovine fetal lung. STUDY DESIGN: Thirty-two ewes carrying a single fetus had surgery to catheterize fetal and maternal jugular veins at 116 days of gestation (term, 150 days). Animals were recovered for 2 days and then were randomized to receive 2 sequential maternal intravenous infusions of either (n = 4/group) of the following: 1) saline, 0.125, 0.04, or 0.0125 mg/kg betamethasone phosphate over 3 hours; or 2) saline, 0.25, 0.08, or 0.025 mg/kg betamethasone phosphate over 12 hours. Each infusion was separated by 2 days. Fetal lung tissue was collected for analysis using quantitative polymerase chain reaction and an ovine-specific microarray. Plasma betamethasone levels from time-course catheter samples were determined by mass spectrometry. Data were assessed for distribution, variance, and tested by an analysis of variance. RESULTS: Betamethasone was detectable (>1 ng/mL) in fetal plasma only in animals randomized to 0.125 mg/kg 3 hour or 0.250 mg/kg 12 hour infusions. Fetal betamethasone half-lives were 1.7-2.8 times greater than maternal values. At maximum concentration, fetal plasma betamethasone levels were approximately 10% of maternal levels. Compared with saline control, all animals, other than those receiving 0.0125 mg/kg 3 hour betamethasone phosphate infusions, had evidence of dose-dependent glucocorticoid transcriptional responses in the fetal lung. CONCLUSION: Constant maternal betamethasone infusions delivering substantially lower fetal and maternal betamethasone maximal concentrations than those achieved with current clinical treatment protocols were associated with dose-dependent changes in glucocorticoid-response markers in the fetal lung. Further studies to determine the minimally efficacious dose of steroids for improving outcomes in preterm infants should be viewed as a priority.

Treatment of spontaneous preterm labour with retosiban: a phase 2 proof-of-concept study.

AIM: The aim was to investigate the efficacy and safety of intravenous retosiban in women with spontaneous preterm labour. METHODS: This was a randomized, double-blind, placebo-controlled, phase 2 trial. Retosiban was administered intravenously for 48 h to women in spontaneous preterm labour between 30(0/7) and 35(6/7) weeks' gestation with an uncomplicated singleton pregnancy in an in-patient obstetric unit. Outcome measures were uterine quiescence (primary endpoint), days to delivery, preterm delivery and safety. RESULTS: Uterine quiescence was achieved in 62% of women who received retosiban (n = 30) compared with 41% who received placebo (n = 34). The relative risk (RR) was 1.53 (95% credible interval [CrI] 0.98, 2.48; NS). Retosiban resulted in a significant increase in time to delivery compared with placebo (mean difference 8.2 days, 95% CrI 2.7, 13.74). This difference was consistent across all gestational ages. The proportion of preterm births in the retosiban and placebo groups was 18.7% (95% CrI 7.4%, 33.7%) and 47.2% (95% CrI 31.4%, 63.4%), respectively. The RR of preterm birth in women treated with retosiban was 0.38 (95% CrI 0.15, 0.81). There were no deliveries within 7 days in the retosiban group, but there were six (17.6%) births in the placebo group. The maternal, fetal and neonatal adverse events were comparable in the retosiban and placebo groups. CONCLUSIONS: Intravenous administration of retosiban in women with spontaneous preterm labour was associated with a greater than 1 week increase in time to delivery compared with placebo, a significant reduction in preterm deliveries, a non-significant increase in uterine quiescence and a favourable safety profile.

Safety, tolerability, pharmacokinetics and pharmacodynamics of losmapimod following a single intravenous or oral dose in healthy volunteers.

AIMS: The purpose of this study was to establish safety and tolerability of a single intravenous (IV) infusion of a p38 mitogen-activated protein kinase inhibitor, losmapimod, to obtain therapeutic levels rapidly for a potential acute coronary syndrome indication. Pharmacokinetics (PK) following IV dosing were characterized, and pharmacokinetic/pharmacodynamic (PK/PD) relationships between losmapimod and phosphorylated heat shock protein 27 (pHSP27) and high-sensitivity C-reactive protein were explored. METHODS: Healthy volunteers received 1 mg losmapimod IV over 15 min (n = 4) or 3 mg IV over 15 min followed by a washout period and then 15 mg orally (PO; n = 12). Pharmacokinetic parameters were calculated by noncompartmental methods. The PK/PD relationships were explored using modelling and simulation. RESULTS: There were no deaths, nonfatal serious adverse events or adverse events leading to withdrawal. Headache was the only adverse event reported more than once (n = 3 following oral dosing). Following 3 mg IV and 15 mg PO, Cmax was 59.4 and 45.9 µg l(-1) and AUC0-∞ was 171.1 and 528.0 µg h l(-1) , respectively. Absolute oral bioavailability was 0.62 [90% confidence interval (CI) 0.56, 0.68]. Following 3 mg IV and 15 mg PO, maximal reductions in pHSP27 were 44% (95% CI 38%, 50%) and 55% (95% CI 50%, 59%) occurring at 30 min and 4 h, respectively. There was a 17% decrease (95% CI 9%, 24%) in high-sensitivity C-reactive protein 24 h following oral dosing. A direct-link maximal inhibitory effect model related plasma concentrations to pHSP27 concentrations. CONCLUSIONS: A single IV infusion of losmapimod in healthy volunteers was safe and well tolerated, and may potentially serve as an initial loading dose in acute coronary syndrome as rapid exposure is achieved.

Budget impact and pharmacy costs with targeted use of oliceridine for postsurgical pain in patients at high risk of opioid-related adverse events.

BACKGROUND: Oliceridine, a new class of µ-opioid receptor agonist, may be associated with fewer opioid-related adverse events (ORAEs) due to its unique mechanism of action. Thus, it may provide a cost-effective alternative to conventional opioids such as morphine. PATIENTS AND METHODS: Using a decision tree with a 24-hour time horizon, we calculated costs for medication and management of the three most common AEs (oxygen saturation <90%, vomiting, somnolence) following postoperative oliceridine or morphine in high-risk patients. Costs were enumerated as differences in cost of analgesics and resource utilization in the first 24 hours post-surgery. An economic model compared expected AEs and costs in a blended cohort where elderly/obese patients at higher risk for ORAEs received oliceridine while those presumed to be at lower risk received morphine with a cohort that received morphine alone. RESULTS: In high-risk patients, use of oliceridine resulted in overall savings of $363,944 (in 1,000 patients). Implementing a targeted approach of oliceridine utilization in patients with high risk for ORAEs can save a typical hospital system $122,296 in total cost of care. CONCLUSION: Use of oliceridine in postoperative care among patients at high risk provides a favorable health economic benefit compared to the use of morphine.

Oliceridine, a new class of opioid analgesics, administered directly into a vein, is a unique medication in that it provides pain relief equivalent to morphine and may have less costly side effects. It is given in a hospital/clinic or surgery center for the treatment of postoperative pain and can reduce costs compared to other opioid analgesics, possibly due to less side effects. An economic model was developed that compares morphine to oliceridine in patients more likely to experience sides effects due to traditional pain medications, comparing common side effects and pain relief following surgery. Although oliceridine costs more than morphine, in our economic model, the use of oliceridine resulted in cost savings ($363,944 US 2020 Dollars in 1,000 patients), and a positive return of investment of over 7 times, when compared to morphine.

Two-Part Phase 1 Multiple-Ascending-Dose Study to Evaluate the Safety, Tolerability, Pharmacodynamics, and Pharmacokinetics of TRV734 in Healthy Adults.

TRV734, an oral G-protein biased ligand at the µ-opioid receptor has demonstrated differentiated pharmacology in preclinical studies compared to unbiased ligands. First-time-in-human data suggested that TRV734 was safe and well tolerated and caused effective pain relief after single doses of 150 to 250 mg. In this study, safety and tolerability of multiple ascending doses of TRV734, and single doses of TRV734 125 mg following various administration paradigms, in healthy subjects were evaluated. In both parts of the study, TRV734 was generally well tolerated with no serious adverse events. Pharmacokinetics of TRV734 were similar when TRV734 125 mg was administered following a high-fat or standard meal. Compared to either of the fed conditions, maximum concentration and area under the plasma concentration-time curve did not change, and time to maximum concentration was 1.5 hours later when TRV734 125 mg was administered as 3 split portions over 120 minutes under fasted conditions. Split doses of TRV734 delayed time to peak decrease in pupil diameter. Following multiple-dose administration of TRV734 60 to 175 mg every 6 hours, there was a trend of slightly less-than-dose proportional increase of maximum concentration, and area under the plasma concentration-time curve and accumulation was modest. Time to maximum concentration was ≈1 to 2 hours and elimination half-life ≈1.9 to 2.5 hours. The analgesic effect of TRV734 on the cold pain test was generally dose proportional and similar to that of oxycodone 10 mg immediate release, after both the first and last doses. There was a dose-related decrease in pupil diameter following administration of TRV734 up to TRV734 125 mg every 6 hours. A favorable trend in bowel function index for TRV734 warrants continued study.

Cost-effectiveness and cost-benefit analysis of oliceridine in the treatment of acute pain.

Aim: Oliceridine, a new class of µ-opioid receptor agonist, is selective for G-protein signaling (analgesia) with limited recruitment of ß-arrestin (associated with adverse outcomes) and may provide a cost-effective alternative versus conventional opioid morphine for postoperative pain. Patients & methods: Using a decision tree with a 24-h time horizon, we calculated costs for medication and management of three most common adverse events (AEs; oxygen saturation <90%, vomiting and somnolence) following postoperative oliceridine or morphine use. Results: Using oliceridine, the cost for managing AEs was US$528,424 versus $852,429 for morphine, with a net cost savings of $324,005. Conclusion: Oliceridine has a favorable overall impact on the total cost of postoperative care compared with the use of the conventional opioid morphine.

Lay abstract Oliceridine, a new class of opioid pain medication, given in a vein, is a unique medication in that it provides pain relief comparable to morphine and may have less costly side effects. It is given in a hospital or surgery center for the treatment of postoperative pain and can save money compared with other opioid pain medicines due to fewer side effects. An economic model was developed to compare morphine to oliceridine for common side effects and pain relief following surgery. Oliceridine use resulted in a cost saving (US$324,005; 2020 US dollars) when compared with morphine.

Oliceridine Exhibits Improved Tolerability Compared to Morphine at Equianalgesic Conditions: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials.

INTRODUCTION: In the management of postoperative acute moderate-to-severe pain, opioids remain an important component. However, conventional opioids have a narrow therapeutic index and are associated with dose-limiting opioid-related adverse events (ORAEs) that can result in worse patient outcomes. Oliceridine, a new intravenous µ-opioid receptor agonist, is shown in nonclinical studies to be biased for G protein signaling (achieving analgesia) with limited recruitment of ß-arrestin (associated with ORAEs). In two phase 3 randomized controlled studies of patients with moderate-to-severe acute pain following hard or soft tissue surgery, in which analgesia was measured using Sum of Pain Intensity Differences (SPID) from baseline over 48 and 24 h (SPID-48 and -24 respectively, oliceridine at demand doses of 0.1, 0.35, or 0.5 mg was highly effective compared to placebo, with a favorable safety profile compared to morphine. This exploratory analysis was conducted to determine whether the safety benefits seen with oliceridine persisted when adjusted for equal levels of analgesia compared to morphine. METHODS: Presence of at least one treatment-emergent ORAE (based on Medical Dictionary for Regulatory Activities [MedDRA]-coded events: hypoxemia, nausea, vomiting, sedation, pruritus, or dizziness) was used as the composite safety endpoint. A logistic regression model was utilized to compare oliceridine (pooled regimens) versus morphine, after controlling for analgesia (using SPID-48 or SPID-24 with pre-rescue scores carried forward 6 h). This analysis excluded patients receiving placebo and was repeated for each study and for pooled data. RESULTS: At a given level of SPID-48 or SPID-24, patients receiving oliceridine were less likely to experience the composite safety endpoint. Although not statistically significant at the 0.05 level in the soft tissue model, the odds ratio (OR) showed a consistent numerical trend for oliceridine, being approximately half that observed with morphine in both the hard (OR 0.499; 95% confidence interval [CI] 0.255, 0.976; p = 0.042) and soft (OR 0.542; 95% CI 0.250, 1.175; p = 0.121) tissue studies. Results from the pooled data were consistent with those observed in the individual studies (OR 0.507; 95% CI 0.304, 0.844; p = 0.009). CONCLUSION: Findings from this exploratory analysis suggest that at comparable levels of analgesia, patients receiving oliceridine were less likely to experience the composite safety endpoint consisting of ORAEs compared to patients treated with morphine. Oliceridine Exhibits Improved Tolerability Compared to Morphine at Equianalgesic Conditions: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials- A Video (MP4 99188 kb).

Intracellular uptake of agents that block the hERG channel can confound the assessment of QT interval prolongation and arrhythmic risk.

BACKGROUND: Oliceridine is a biased ligand at the µ-opioid receptor recently approved for the treatment of acute pain. In a thorough QT study, corrected QT (QTc) prolongation displayed peaks at 2.5 and 60 minutes after a supratherapeutic dose. The mean plasma concentration peaked at 5 minutes, declining rapidly thereafter. OBJECTIVE: The purpose of this study was to examine the basis for the delayed effect of oliceridine to prolong the QTc interval. METHODS: Repolarization parameters and tissue accumulation of oliceridine were evaluated in rabbit left ventricular wedge preparations over a period of 5 hours. The effects of oliceridine on ion channel currents were evaluated in human embryonic kidney and Chinese hamster ovary cells. Quinidine was used as a control. RESULTS: Oliceridine and quinidine produced a progressive prolongation of the QTc interval and action potential duration over a period of 5 hours, paralleling slow progressive tissue uptake of the drugs. Oliceridine caused modest prolongation of these parameters, whereas quinidine produced a prominent prolongation of action potential duration and QTc interval as well as development of early afterdepolarization (after 2 hours), resulting in a high torsades de pointes score. The 50% inhibitory concentration values for the oliceridine inhibition of the rapidly activating delayed rectifier current (human ether a-go-go current) and late sodium channel current were 2.2 and 3.45 µM when assessed after traditional acute exposure but much lower after 3 hours of drug exposure. CONCLUSION: Our findings suggest that a gradual increase of intracellular access of drugs to the hERG channels as a result of their intracellular uptake and accumulation can significantly delay effects on repolarization, thus confounding the assessment of QT interval prolongation and arrhythmic risk when studied acutely. The multi-ion channel effects of oliceridine, late sodium channel current inhibition in particular, point to a low risk of devloping torsades de pointes.

Oliceridine is Associated with Reduced Risk of Vomiting and Need for Rescue Antiemetics Compared to Morphine: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials.

INTRODUCTION: Use of parenteral opioids is a major risk factor for postoperative nausea and vomiting. Conventional opioids bind to µ-opioid receptors (MOR), stimulate both the G-protein signaling (achieving analgesia); and the ß-arrestin pathway (associated with opioid-related adverse effects). Oliceridine, a next-generation IV opioid, is a G-protein selective MOR agonist, with limited recruitment of ß-arrestin. In two randomized, placebo- and morphine-controlled phase 3 studies of patients with moderate-to-severe acute pain following bunionectomy or abdominoplasty, oliceridine at demand doses of 0.1, 0.35, and 0.5 mg provided rapid and sustained analgesia vs. placebo with favorable gastrointestinal (GI) tolerability. In this exploratory analysis, we utilized a clinical endpoint assessing gastrointestinal tolerability, "complete GI response" defined as the proportion of patients with no vomiting and no use of rescue antiemetic to characterize the GI tolerability profile of oliceridine vs. morphine. METHODS: A logistic regression model was utilized to compare oliceridine (pooled regimens) vs. morphine, after controlling for analgesia (using the sum of pain intensity difference [SPID]-48/24 [bunionectomy/abdominoplasty] with pre-rescue scores carried forward for 6 h). This analysis excluded patients receiving placebo and was performed for each study separately and for pooled data from both studies. RESULTS: In the unadjusted analysis, a significantly greater proportion of patients in the placebo (76.4%), oliceridine 0.1 mg (68.0%), and 0.35 mg (46.2%) demand dose achieved complete GI response vs. morphine 1 mg (30.8%), p ≤ 0.005. In the adjusted analysis, after controlling for analgesia, the odds ratio of experiencing a complete GI response with oliceridine (pooled regimens) vs. morphine was 3.14 (95% CI: 1.78, 5.56; p < 0.0001) in bunionectomy study and 1.92 (95% CI: 1.09, 3.36; p = 0.024) in abdominoplasty study. CONCLUSIONS: When controlled for the analgesic effects (constant SPID-48/24), the odds ratio for complete GI response was higher with oliceridine than morphine, suggesting better GI tolerability with oliceridine.

Functionally Selective Inhibition of the Oxytocin Receptor by Retosiban in Human Myometrial Smooth Muscle.

Novel small molecule inhibitors of the oxytocin receptor (OTR) may have distinct pharmacology and mode of action when compared with first-generation oxytocin antagonists when used for the prevention of preterm birth. The aim was to determine the mechanism of action of small molecule OTR antagonists retosiban and epelsiban compared with the currently used peptide-based compound atosiban. Human myometrial samples were obtained at cesarean section and subjected to pharmacological manipulations to establish the effect of antagonist binding to OTR on downstream signaling. Retosiban antagonism of oxytocin action in human myometrium was potent, rapid, and reversible. Inhibition of inositol 1,4,5-trisphosphate (IP3) production followed single-site competitive binding kinetics for epelsiban, retosiban, and atosiban. Retosiban inhibited basal production of IP3 in the absence of oxytocin. Oxytocin and atosiban but not retosiban inhibited forskolin, and calcitonin stimulated 3',5'-cyclic adenosine 5'-mono-phosphate (cAMP) production. Inhibition of cAMP was reversed by pertussis toxin. Oxytocin and atosiban, but not retosiban and epelsiban, stimulated extracellular regulated kinase (ERK)1/2 activity in a time- and concentration-dependent manner. Oxytocin and atosiban stimulated cyclo-oxygenase 2 activity and subsequent production of prostaglandin E2 and F2α. Prostaglandin production was inhibited by rofecoxib, pertussin toxin, and ERK inhibitor U0126. Oxytocin but not retosiban or atosiban stimulated coupling of the OTR to Gα q G-proteins. Oxytocin and atosiban but not retosiban stimulated coupling of the OTR to Gα i G-proteins. Retosiban and epelsiban demonstrate distinct pharmacology when compared with atosiban in human myometrial smooth muscle. Atosiban displays agonist activity at micromolar concentrations leading to stimulation of prostaglandin production.

A Phase I, Randomized, Single­Blind, Placebo­Controlled, Single Ascending Dose Study of the Safety, Tolerability, and Pharmacokinetics of Subcutaneous and Oral TRV250, a G Protein-Selective Delta Receptor Agonist, in Healthy Subjects.

BACKGROUND: The delta opioid receptor (DOR) has been identified as a therapeutic target for migraine, with DOR agonists exhibiting low abuse potential compared with conventional µ-opioid agonists. TRV250 is a novel small molecule agonist of the DOR that is preferentially selective for G-protein signaling, with relatively little activation of the ß-arrestin2 post-receptor signaling pathway. This selectivity provides reduced susceptibility to proconvulsant activity seen with non-selective DOR agonists. TRV250 significantly reduced nitroglycerin-evoked hyperalgesia in rodents, indicating a potential utility in acute migraine without the risk of seizure activity or abuse potential. OBJECTIVE: This trial evaluated the safety, tolerability, and pharmacokinetics of ascending dose levels of TRV250 administered subcutaneously (SC) and the relative bioavailability of TRV250 administered orally compared with SC administration. METHODS: This was a two-part, single ascending dose study. Part A included four cohorts of healthy adults (N = 38). Each cohort was dosed on three occasions (placebo and two different dose levels of TRV250, allocated in randomized order and administered by SC route). In Part B, a single cohort of nine subjects received an oral dose of either TRV250 (n = 7) or placebo (n = 2) in a fed or fasted state. Serial blood samples were obtained for pharmacokinetic determination across a 24-h post-dose period. Safety assessments included clinical laboratory measures, vital signs, 12-lead electrocardiogram (ECG), and electroencephalogram (EEG) pre- and post-dosing. RESULTS: TRV250 was well tolerated. There were no serious adverse events (SAEs), and all AEs were mild in severity. Injection-site reactions and headache were the most common AEs. One subject was withdrawn from the study due to a TRV250-related AE of postural orthostatic tachycardia. There were no clinically relevant changes in physical examination, hematology, clinical chemistry, urinalysis, suicidal ideation, or vital signs, with the exception of orthostatic changes in some subjects. No subject experienced abnormalities in EEGs or experienced a change from baseline in heart-rate-corrected QT interval (QTcF) > 60 ms, or an absolute QTcF interval > 480 ms at any post-dosing observation. Peak and total plasma exposure to TRV250 increased in a dose-proportional manner following 0.1-30 mg SC doses, with the mean half-life ranging from 2.39 to 3.76 h. Oral bioavailability of TRV250 ranged from 14% (fasting) to 19% (fed) relative to SC dosing, while administration with food increased the AUC but decreased the rate of absorption as reflected by a modest delay in median time to maximum concentration and a slight reduction in maximum concentration. CONCLUSION: The findings from the first-in-human study support further evaluation of TRV250, a G-protein selective DOR agonist, in the treatment of acute migraine.

Evaluating the Incidence of Opioid-Induced Respiratory Depression Associated with Oliceridine and Morphine as Measured by the Frequency and Average Cumulative Duration of Dosing Interruption in Patients Treated for Acute Postoperative Pain.

BACKGROUND AND OBJECTIVE: Opioid-induced respiratory depression (OIRD) is a potentially fatal complication associated with conventional opioids. Currently, there is a paucity of validated endpoints available to measure respiratory safety. Oliceridine, an investigational intravenous (IV) opioid, is a G-protein selective µ-agonist with limited activity on ß-arrestin2, a signaling pathway associated with adverse events including OIRD. In controlled phase III trials, oliceridine 0.35 mg and 0.5 mg demand doses demonstrated comparable analgesia to morphine 1 mg with favorable improvements in respiratory safety. In this exploratory analysis, we report dosing interruption (DI) and average cumulative duration of DI (CDDI) for both oliceridine and morphine. METHODS: Patients requiring analgesia after bunionectomy or abdominoplasty were randomized to IV demand doses of placebo, oliceridine (0.1 mg, 0.35 mg, or 0.5 mg), or morphine (1 mg), administered via patient-controlled analgesia (PCA), following a loading dose (oliceridine 1.5 mg, morphine 4 mg, volume-matched placebo) with a 6-min lockout interval. Certified nurse anesthetists monitored each patient and withheld study medication according to the patient's respiratory status. For each patient, the duration of all DIs was summed and reported as CDDI. A zero-inflated gamma mixture model was used to compute the mean CDDI for each treatment. RESULTS: Proportion of patients with DI was lower with oliceridine (0.1 mg: 3.2%, 0.35 mg: 13.9%, 0.5 mg: 15.1%) versus morphine (22%). The CDDI was also lower across all demand doses of oliceridine versus morphine. CONCLUSION: Using DI as a surrogate for OIRD indicates improved respiratory safety with oliceridine versus morphine that merits further investigation.

A First-in-Human Clinical Study With TRV734, an Orally Bioavailable G-Protein-Biased Ligand at the µ-Opioid Receptor.

TRV734 is an orally bioavailable G-protein-biased ligand at the µ-opioid receptor. In nonclinical studies it was potently analgesic while causing less gastrointestinal dysfunction than morphine, suggesting unique benefits in acute pain management. A 2-part, first-in-human study was conducted with ascending doses of TRV734 to explore its tolerability, pharmacokinetics, and pharmacodynamics in healthy volunteers. TRV734 was well tolerated over the dose range 2 to 250 mg when administered orally. Plasma TRV734 maximum concentration and area under the plasma concentration-time curve generally increased with dose, while time to maximum concentration was similar across doses (0.5-1.3 h). The half-life increased with dose from 10 mg through 150 mg (0.75-2.28 h) but was similar from 150 mg through 250 mg. Pupil constriction, confirming central nervous system µ-opioid receptor engagement, correlated with higher plasma TRV734 concentrations; the greatest reductions in pupil diameter occurring between 0 and 4 hours after dosing (-2.9 mm/h, with reduction peaking at 1 hour, and returning to baseline by 8 hours). Following administration of TRV734 125 mg under fasted or fed conditions, there was no significant difference in bioavailability when given as a solution or drug in capsule to fasted subjects. When drug in capsule was given to subjects following a high-fat meal, absorption was slowed, resulting in decreased peak concentrations, but area under the plasma concentration-time curve was not affected.