Pharmacokinetics,safety, and simulated efficacy of an influenza treatment,baloxavir marboxil,in Chinese individuals

Baloxavir marboxil is an endonuclease inhibitor indicated for the treatment of influenza in patients ≥12 years. No data exist for Chinese patients in global studies. This randomized, open‐label, phase I study evaluated the pharmacokinetics (PK) and safety of baloxavir marboxil in healthy Chinese volunteers and was used to anticipate efficacy in Chinese patients. Patients received a single oral dose of baloxavir marboxil (40 or 80 mg [1:1]). Serial blood samples were collected predose and at various timepoints up to 14 days postdose. Baloxavir marboxil and acid plasma concentrations were determined by liquid chromatography tandem mass spectrometry. PK parameters of baloxavir acid were estimated by noncompartmental analysis. Adverse events (AEs) were recorded. Time to alleviation of symptoms (TTAS) was simulated for otherwise healthy (OwH) and high‐risk (HR) Chinese and Asian patients. Thirty‐two male patients received baloxavir marboxil. Baloxavir acid plasma concentration peaked 4 h postdose. Mean maximum concentration (C_max) was 107.6 and 206.9 ng/ml, and mean area under the plasma concentration‐time curve from zero to infinity (AUC_0–inf) was 6955 and 9643 ng·h/ml in the 40 and 80 mg cohorts, respectively. AEs were mild and transient; no new safety signals were identified. Simulated median TTAS for OwH and HR Chinese patients agreed with simulated values in Asian patients. PK parameters were similar to Asian populations in other studies. The globally adopted baloxavir marboxil dosing strategy was consistent with the established safety profile of baloxavir marboxil in this population. Simulated efficacy indicated Chinese patients could benefit from similar efficacy to Asian patients.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Baloxavir marboxil, the prodrug of baloxavir acid, is indicated for the treatment of influenza virus infection and is to be administered within 48 h of symptom onset. At the time of this study, baloxavir marboxil was not approved for the treatment of influenza in China, and there were no clinical data available in Chinese populations.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study characterized baloxavir acid pharmacokinetics (PK) and safety in healthy Chinese volunteers, and simulated efficacy (time to alleviation of symptoms) in Chinese patients. The aim of this study was to determine if the PK, safety, and efficacy of baloxavir marboxil would be similar between a Chinese population and other Asian patients from global phase III studies.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study indicates that no meaningful differences in the safety and efficacy of baloxavir marboxil are anticipated between Chinese patients and other Asian patients.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Findings from this investigation were used to support a new drug application in China, which was subsequently approved.     

Pharmacokinetics and safety of cenobamate,a novel antiseizure medication,in healthy Japanese,and an ethnic comparison with healthy non‐Japanese

Cenobamate (XCOPRI and ONTOZRY) is a novel antiseizure medication for the treatment of focal‐onset seizures. Nonetheless, there is limited information on the pharmacokinetics (PKs), safety, and efficacy of cenobamate in Asian people, including Japanese people. This study aimed to evaluate the PKs and safety of cenobamate after a single oral dose in healthy Japanese subjects and to compare the PKs with that reported in non‐Japanese subjects. A randomized, double‐blind, placebo‐controlled, single ascending dose study was conducted at four dose levels of 50, 100, 200, and 400 mg. Subjects were randomly assigned to cenobamate or placebo in a 6:2 ratio. Cenobamate was rapidly absorbed, reaching its maximum plasma concentration (C_max) in 0.75 to 2.25 h, and was eliminated with a mean half‐life of 37.0 to 57.7 h. The C_max increased dose proportionally, whereas area under the concentration‐time curve increased more than dose proportionally, which was consistent with the findings in non‐Japanese subjects. The systemic exposure of cenobamate was comparable between Japanese and non‐Japanese subjects at all dose levels evaluated. All adverse events were mild in severity, and their incidence did not show dose‐dependent trends. Furthermore, there were no clinically significant issues in safety parameters, including sedation tests, neurologic examinations, and Columbia Suicide Severity Rating Scale interviews. In conclusion, the systemic exposure of cenobamate after a single dose in Japanese subjects increased by dose, which was similar to the pattern in non‐Japanese subjects. In addition, a single dose of cenobamate was well‐tolerated in the dose range of 50 to 400 mg in healthy Japanese subjects.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Cenobamate is a novel antiseizure medication newly approved for the treatment of focal‐onset seizures in the United States and Europe. To date, properties of cenobamate including pharmacokinetics (PKs) have not been extensively studied in Asian people including Japanese people.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study evaluated the PKs and safety of a single oral dose of cenobamate in healthy Japanese subjects and compared the PKs with that in non‐Japanese subjects previously reported.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Cenobamate showed similar PK profiles in Japanese and non‐Japanese subjects, which suggests its negligible ethnic sensitivity. In addition, a single dose of cenobamate was well‐tolerated in healthy Japanese subjects. Our results indicate that the currently approved dosing regimen of cenobamate may also be applicable to Japanese patients with reasonable exposure and tolerability profiles.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Our study bridged the clinical pharmacology gap between ethnicities by providing new findings on the ethnic sensitivity as well as the PKs and safety of cenobamate in Asian people including Japanese people.     

Pharmacokinetics and tolerability of apremilast in healthy Korean adult men

We performed a two‐part study to evaluate the pharmacokinetics, safety, and tolerability of oral apremilast, a phosphodiesterase 4 inhibitor indicated for the treatment of psoriasis, in healthy Korean adult men. In part 1, there were 12 subjects who randomly received a single oral dose of apremilast at 20, 30, or 40 mg in each of 3 periods in a crossover fashion. In part 2, there were 16 subjects who randomly received 30 mg of apremilast or its matching placebo in a ratio of 3:1 twice daily for 14 days. Apremilast was rapidly absorbed (maximum concentration: ~2–3 h postdose), and eliminated according to a monoexponential pattern with a terminal‐phase elimination half‐life of 8–9 h. The exposure to apremilast increased in a dose‐proportional manner and accumulation was 1.6‐fold at steady‐state. Apremilast was well‐tolerated after a single oral administration and multiple oral administrations in Korean adult men; all of the treatment‐emergent adverse events were mild and recovered without sequelae. In conclusion, apremilast was safe and well‐tolerated in healthy Korean adult men when administered single oral doses of 20, 30, or 40 mg or when administered multiple oral doses of 30 mg b.i.d. for 14 days. Overall exposures increased in an approximate dose proportional manner in healthy Korean adult men.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Apremilast, a phosphodiesterase 4 inhibitor, has been approved to treat patients with psoriasis in many countries, including the United States, Canada, and Japan. Although apremilast has shown a linear pharmacokinetic (PK) profile and little ethnic sensitivity, apremilast has never been studied specifically in Koreans.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This two‐part study evaluated differences in PKs and tolerability of apremilast between healthy Korean adult men and previously studied ethnic populations.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Our results clearly showed that apremilast was safe and well‐tolerated after single and multiple oral administrations in healthy Korean adult men. Linear PK profiles of apremilast were consistently observed in healthy Korean adult men.

• HOW MIGHT THIS CHANGE DRUG DISCOVERY, DEVELOPMENT, AND/OR THERAPEUTICS?

Our results support the notion that recommended apremilast dose of 30 mg b.i.d., after a first week of titration, would be also appropriate in Koreans.     

Short‐ and long‐term effects of body weight loss following calorie restriction and gastric bypass on CYP3A‐activity – a non‐randomized three‐armed controlled trial

It remains uncertain whether pharmacokinetic changes following Roux‐en‐Y gastric bypass (RYGB) can be attributed to surgery‐induced gastrointestinal alterations per se and/or the subsequent weight loss. The aim was to compare short‐ and long‐term effects of RYGB and calorie restriction on CYP3A‐activity, and cross‐sectionally compare CYP3A‐activity with normal weight to overweight controls using midazolam as probe drug. This three‐armed controlled trial included patients with severe obesity preparing for RYGB (n = 41) or diet‐induced (n = 41) weight‐loss, and controls (n = 18). Both weight‐loss groups underwent a 3‐week low‐energy‐diet (<1200 kcal/day) followed by a 6‐week very‐low‐energy‐diet or RYGB (both <800 kcal/day). Patients were followed for 2 years, with four pharmacokinetic investigations using semisimultaneous oral and intravenous dosing to determine changes in midazolam absolute bioavailability and clearance, within and between groups. The RYGB and diet groups showed similar weight‐loss at week 9 (13 ± 2.4% vs. 11 ± 3.6%), but differed substantially after 2 years (−30 ± 7.0% vs. −3.1 ± 6.3%). At baseline, mean absolute bioavailability and clearance of midazolam were similar in the RYGB and diet groups, but higher compared with controls. On average, absolute bioavailability was unaltered at week 9, but decreased by 40 ± 7.5% in the RYGB group and 32 ± 6.1% in the diet group at year 2 compared with baseline, with no between‐group difference. No difference in clearance was observed over time, nor between groups. In conclusion, neither RYGB per se nor weight loss impacted absolute bioavailability or clearance of midazolam short term. Long term, absolute bioavailability was similarly decreased in both groups despite different weight loss, suggesting that the recovered CYP3A‐activity is not only dependent on weight‐loss through RYGB.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

The current literature indicates an inverse relationship between body mass index (BMI) and CYP3A‐activity, and that systemic clearance of the CYP3A‐probe midazolam increases after Roux‐en‐Y gastric bypass (RYGB). However, the knowledge regarding changes in drug disposition following weight loss in general, and bariatric surgery in particular, is sparse and inconclusive, making drug dosing challenging. In addition, it remains uncertain whether pharmacokinetic changes following bariatric surgery are attributed to the gastrointestinal alterations per se and/or the subsequent weight loss.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Do body weight, weight loss, and RYGB impact CYP3A‐activity in vivo?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study shows that neither short‐term weight loss induced by RYGB or very‐low‐energy‐diet, nor RYGB per se, impact absolute bioavailability or systemic clearance of midazolam.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Our results suggests that dose adjustments of CYP3A substrate drugs, 30–50% of all drugs on the market, may not be necessary following nonsurgical and surgical weight loss neither in a short‐ nor long‐term perspective.     

Imeglimin population pharmacokinetics and dose adjustment predictions for renal impairment in Japanese and Western patients with type 2 diabetes

Imeglimin is an orally administered first‐in‐class drug to treat type 2 diabetes mellitus (T2DM) and is mainly excreted unchanged by the kidneys. The present study aimed to define the pharmacokinetic (PK) characteristics of imeglimin using population PK analysis and to determine the optimal dosing regimen for Japanese patients with T2DM and chronic kidney disease (CKD). Imeglimin plasma concentrations in Japanese and Western healthy volunteers, and patients with T2DM, including patients with mild to severe CKD with an estimated glomerular filtration rate (eGFR) greater than 14 ml/min/1.73 m² were included in a population PK analysis. PK simulations were conducted using a population PK model, and the area under concentration‐time curve (AUC) was extrapolated with power regression analysis to lower eGFR. The influence of eGFR, weight, and age on apparent clearance and of dose on relative bioavailability were quantified by population PK analysis. Simulations and extrapolation revealed that the recommended dosing regimen based on the AUC was 500 mg twice daily (b.i.d.) for patients with eGFR 15–45 ml/min/1.73 m², and 500 mg with a longer dosing interval was suggested for those with eGFR less than 15. Simulations revealed that differences in plasma AUCs between Japanese and Western patients at the same dose were mainly driven by a difference in the eGFR and that the plasma AUC after 1000 and 1500 mg b.i.d. in Japanese and Western patients, respectively, was comparable in the phase IIb studies. These results indicate suitable dosages of imeglimin in the clinical setting of T2DM with renal impairment.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Imeglimin is a first‐in‐class oral agent for the treatment of type 2 diabetes (T2DM) and is excreted unchanged into urine. A Japanese phase IIb study found that 1000 mg b.i.d. was optimal in Japanese population, and phase III studies confirmed significant glucose lowering effect. A Western phase IIb study found an optimal dose of 1500 mg b.i.d.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study addressed the key determinants of imeglimin pharmacokinetics (PKs), recommended doses for patients with renal impairment, and what drives the different optimal doses between Japanese and Western patients with T2DM.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Renal function significantly impacts imeglimin PKs. Recommended doses for patients with renal impairment have been proposed for exposure matching. Differences in estimated glomerular filtration rate (eGFR) comprised the key driver for different optimal doses at which estimated exposures were similar between Japanese and Western patients.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Doses of imeglimin could be reduced based on eGFR. Exposure responses seemed similar between Japanese and Western patients.     

A phase I study to evaluate the safety,tolerability, pharmacodynamic and pharmacokinetic profiles of ocular GLH8NDE in healthy male adults

GLH8NDE, a derivative of eupatilin, is currently under development to treat dry eye disease. We conducted a randomized, double‐masked, placebo‐controlled, single‐ and multiple‐day study to evaluate safety, tolerability, pharmacodynamics, and pharmacokinetics of ocular GLH8NDE in healthy male adults. Subjects randomly received topical ocular dosing of GLH8NDE or its matching placebo for a day, then for 7 consecutive days with a 62‐h washout at one of the following daily doses: 9, 18, 36 (Koreans), and 36 mg (Whites). The study drug was administered in divided doses over 10 h with 2‐ or 5‐h intervals. Thirty‐nine (97.5%) out of 40 subjects completed the study. A total of 17 subjects experienced 31 treatment‐emergent adverse events, all of which were mild in severity and recovered without sequelae. Neither pathological changes in eye compartments nor clinically significant systemic effects were observed. GLH8NDE was rapidly absorbed reaching the peak concentration within 0.25–0.75 h postdose. The systemic exposure as measured by area under the concentration‐time curve from time of administration up to the time of the last quantifiable concentration (AUC_last) after single‐day administration of the same dose was 109% higher in Koreans than in Whites. In conclusion, GLH8NDE was safe and well‐tolerated in healthy Korean and White male adults at 9–36 mg/day after single‐ and multiple‐day administrations.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

GLH8NDE (7‐carboxymethyloxy‐3′,4′,5′‐trimethoxy flavone) is a derivative of eupatilin, which is currently under clinical development to treat dry eye disease (DED). GLH8NDE has been effective in various experimentally induced DED animal models. Ocular GLH8NDE has never been studied in humans.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This phase I study evaluated the safety, tolerability, pharmacodynamic, and pharmacokinetic profiles of ocular GLH8NDE in humans. In addition, the ethnic difference in the systemic exposure to GLH8NDE was assessed between Korean and White healthy male adults.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Ocular doses of GLH8NDE from 9 to 36 mg per day after single‐ and multiple‐day administrations were safe and well‐tolerated in Korean and White healthy male adults. GLH8NDE was rapidly absorbed in a dose‐proportional manner. The systemic exposure to GLH8NDE was higher in Koreans than in Whites. GLH8NDE at 9 and 36 mg per day increased tear break‐up time (TBUT) from baseline whereas TBUT was decreased in the placebo group.

• HOW MIGHT THIS CHANGE DRUG DISCOVERY, DEVELOPMENT, AND/OR THERAPEUTICS?

This study shows that GLH8NDE is safe and well‐tolerated in healthy Korean and White male adults over the dose range of 9–36 mg per day. GLH8NDE has a potential to be developed as a useful treatment option for DED. Further research should take account the ethnic differences in the systemic exposure to GLH8NDE.     

Population pharmacokinetics and exposure‐response analyses of teduglutide in adult and pediatric patients with short bowel syndrome

Teduglutide is a recombinant analog of human glucagon‐like peptide‐2 that regulates the functional and structural integrity of the cells lining the gastrointestinal tract. Teduglutide is approved for the treatment of patients with short bowel syndrome (SBS) who are dependent on parenteral support (PS). Population pharmacokinetic (PK) and exposure‐response analyses were performed to support teduglutide dosing in patients with SBS. The analysis included 219 patients with SBS (aged <1 year, 5 patients; 1–11 years, 86 patients; 12–17 years, 8 patients; 18–79 years, 120 patients), and 259 non‐SBS subjects (including healthy volunteers and subjects with renal or liver impairment). A one‐compartment model with first‐order absorption and linear elimination adequately characterized the PKs of teduglutide. In patients with SBS, the apparent clearance (CL/F), volume of distribution (V/F), and elimination half‐life of teduglutide were 16.0 L/h, 33.9 L, and 1.47 h, respectively. CL/F depended on body weight and renal function, and V/F depended on body weight and age. Maximum concentration (C _max) of teduglutide was similar in adult and pediatric patients, and in Japanese and non‐Japanese patients. A time‐ and exposure‐response model dependent on the C _max of teduglutide adequately characterized the reduction in PS over more than 2 years of treatment. Daily dosing of 0.05 mg/kg teduglutide resulted in a maximum reduction in PS of 5.76 L/week. Higher C _max values were associated with a more important reduction in PS over time. Adult and pediatric patients with SBS presented similar PKs and response to teduglutide.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Short bowel syndrome (SBS) is a malabsorption disorder that usually results from surgical resection of bowel but can also occur as a congenital condition. It manifests as a collection of signs and symptoms, such as malabsorption, diarrhea, fluid and electrolyte disturbances, and malnutrition, and patients with SBS may require long‐term parenteral support (PS). Teduglutide is a recombinant analog of naturally occurring human glucagon‐like peptide‐2, approved for the treatment of PS‐dependent patients with SBS in the United States, Canada, and Europe.

• WHAT QUESTION DID THIS STUDY ADDRESS?

What the population pharmacokinetic (PK) properties are of teduglutide and exposure‐response relationship in Japanese and non‐Japanese adult (18–79 years) and pediatric (4 months–17 years) patients with SBS, and how teduglutide exposure is related to the treatment response.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

PK properties and exposure parameters of teduglutide in Japanese adult and pediatric patients with SBS are similar to those observed in non‐Japanese adult and pediatric patients with SBS. Teduglutide clearance is dependent on body weight and renal function, and volume of distribution is dependent on body weight and age. The exposure‐response model shows that higher maximum concentrations of teduglutide are associated with a greater reduction in PS volume over time.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

The population PK properties and exposure‐response relationship of teduglutide support the selection of 0.05 mg/kg daily treatment as the effective dose regimen in adult and pediatric patients with SBS.     

Safety,tolerability, and pharmacokinetics of oral baicalein tablets in healthy Chinese subjects: A single‐center,randomized, double‐blind,placebo‐controlled multiple‐ascending‐dose study

Baicalein is a biologically important flavonoid in extracted from the Scutellaria baicalensis Georgi, which can effectively inhibit the influenza virus. This study aimed to analyze the safety and pharmacokinetic (PK) characteristics of baicalein tablets in healthy Chinese subjects and provide more information for phase II clinical trials. In this multiple‐ascending‐dose placebo‐controlled trial, 36 healthy subjects were randomized to receive 200, 400, and 600 mg of baicalein tablet or placebo once daily on day 1 and day 10, 3 times daily on days 4–9. All groups were intended to produce safety and tolerability outcomes (lowest dose first). Blood and urine samples were collected from subjects in the 600 mg group for baicalein PK analysis. Our study had shown that Baicalein tablet was generally safe and well‐tolerated. All adverse events were mild and resolved without any intervention except one case of fever reported in the 600 mg group, which was considered as moderate but not related with baicalein as judged by the investigator. Oral baicalein tablets were rapidly absorbed with peak plasma levels being reached within 2 h after multiple administration. The highest urinary excretion of baicalein and its metabolites peaked in 2 h, followed by 12 h, with a double peak trend.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Many studies have shown that baicalin has an anti‐influenza effect in cell and animal experiments. The primary mechanism of action is that baicalein has a strong inhibitory effect on the sialidase of the influenza virus.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study aimed to analyze the safety and pharmacokinetic (PK) characteristics of baicalein tablets in healthy Chinese subjects and provide more information for phase II clinical trials.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Our study results have shown that baicalein tablets were administered multiple times within the studied dose range were safe and well‐tolerated in healthy Chinese subjects with no serious or severe adverse effects. The highest urinary excretion of baicalein and its metabolites peaked in 2 h, followed by 12 h, with a double peak trend. Oral baicalein tablets were rapidly absorbed with peak plasma levels reached within 2 h after multiple administration.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Our study addresses the safety outcomes of baicalein tablets and emphasizes the PKs of baicalein, which provides a better understanding and a scientific basis of the clinical application of baicalein for further evaluation.     

Safety,tolerability, pharmacokinetics,and pharmacodynamics of HBM9161, a novel FcRn inhibitor,in a phase I study for healthy Chinese volunteers

Blockade of the binding between neonatal Fc receptor and IgG‐Fc reduces circulating IgG, and thus emerges as a potential therapy for IgG‐mediated autoimmune conditions. This was a double blind, randomized, single ascending dose study to evaluate the safety, pharmacokinetics, and pharmacodynamics of HBM9161 (a fully humanized Fc receptor monoclonal antibody) in healthy Chinese volunteers. Subjects were randomized to receive a single s.c. dose of HBM9161 or placebo in a 3:1 ratio in 3 dosing cohorts (340 mg, 510 mg, or 680 mg, respectively), and then followed up for 85 days. Study end points included incidence of adverse event (AE), serum drug concentration, IgG and its subclasses, and anti‐drug antibodies (ADAs). Twenty‐four subjects were randomized. Dose‐dependent reduction of total IgG occurred rapidly from baseline to reach nadir at day 11, then recovered steadily from day 11 to day 85. The mean maximum percentage reductions from baseline total IgG were 21.0 ± 9.3%, 39.8 ± 5.13%, and 41.2 ± 10.4% for subjects receiving HBM9161 340 mg, 510 mg, and 680 mg, respectively. The exposure of HBM9161 (areas under the curve [AUCs] and peak plasma concentration [C_max]) increased in a more than dose‐proportional manner at the dose examined. All reported AEs were mild in severity. The most reported AEs in the HBM9161 groups were influenza‐like illness and rash. Two subjects developed ADA during the study period. A single s.c. dose of HBM9161 results in sustained and dose‐dependent IgG reduction, and was well‐tolerated at a dose up to 680 mg in Chinese subjects. The data warrant further investigation of its effects in IgG‐mediated autoimmune disorders.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Animal studies and recent human data from White populations showed that treatment with neonatal Fc receptor (FcRn) inhibitor reduces circulating IgG levels and is well‐tolerated. Data of FcRn inhibitors in Asians is relatively limited.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study investigated the pharmacokinetics (PKs), pharmacodynamics (PDs), and safety profile of HBM9161 (an FcRn inhibitor) in healthy Chinese volunteers.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Subcutaneous HBM9161 is safe and effective in IgG reduction in Chinese subjects. The PKs, PDs, and safety characteristics in Chinese are similar to the first‐in‐human study in the White population.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

HBM9161 can be a potential treatment for IgG‐mediated autoimmune disorders and organ transplant rejection.     

First‐in‐human study of the safety,tolerability, pharmacokinetics,and pharmacodynamics of ALPN‐101, a dual CD28/ICOS antagonist,in healthy adult subjects

ALPN‐101 (ICOSL vIgD‐Fc) is an Fc fusion protein of a human inducible T cell costimulatory ligand (ICOSL) variant immunoglobulin domain (vIgD) designed to inhibit the cluster of differentiation 28 (CD28) and inducible T cell costimulator (ICOS) pathways simultaneously. A first‐in‐human study evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of ALPN‐101 in healthy adult subjects. ALPN‐101 was generally well‐tolerated with no evidence of cytokine release, clinically significant immunogenicity, or severe adverse events following single subcutaneous (SC) doses up to 3 mg/kg or single intravenous (IV) doses up to 10 mg/kg or up to 4 weekly IV doses of up to 1 mg/kg. ALPN‐101 exhibited a dose‐dependent increase in exposure with an estimated terminal half‐life of 4.3–8.6 days and SC bioavailability of 60.6% at 3 mg/kg. Minimal to modest accumulation in exposure was observed with repeated IV dosing. ALPN‐101 resulted in a dose‐dependent increase in maximum target saturation and duration of high‐level target saturation. Consistent with its mechanism of action, ALPN‐101 inhibited cytokine production in whole blood stimulated by Staphylococcus aureus enterotoxin B ex vivo, as well as antibody responses to keyhole limpet hemocyanin immunization, reflecting immunomodulatory effects upon T cell and T‐dependent B cell responses, respectively. In conclusion, ALPN‐101 was well‐tolerated in healthy subjects with dose‐dependent PK and PD consistent with the known biology of the CD28 and ICOS costimulatory pathways. Further clinical development of ALPN‐101 in inflammatory and/or autoimmune diseases is therefore warranted.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

ALPN‐101 is an Fc fusion protein of a human inducible T cell costimulatory ligand variant immunoglobulin domain designed to block the cluster of differentiation 28 CD28) and inducible T cell costimulator (ICOS) simultaneously, thereby inhibiting two key costimulatory pathways in T lymphocytes. Although inhibitors of each pathway alone have been studied in humans, this is the first assessment of a dual antagonist in humans.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This first‐in‐human study assessed the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of ALPN‐101 in healthy subjects. The PK‐PD relationship was evaluated.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

ALPN‐101 demonstrated favorable safety and tolerability profiles and dose‐dependent PK and PD in healthy subjects. The dose‐PK‐PD analysis showed that the target saturation of ALPN‐101 can be well‐predicted based on PK data and the observed PD effects are consistent with the known biology of the CD28 and ICOS pathways.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

The results support further clinical development of ALPN‐101 and the PK‐PD relationship will guide dosing regimens in autoimmune and inflammatory diseases.     

Evaluation of drug‐drug interaction potential between omecamtiv mecarbil and rosuvastatin,a BCRP substrate,with a clinical study in healthy subjects and using a physiologically‐based pharmacokinetic model

Omecamtiv mecarbil (OM) is a novel cardiac myosin activator in development for the treatment of heart failure. In vitro, OM is an inhibitor of BCRP. Rosuvastatin, a BCRP substrate, is one of the most commonly prescribed medications in patients with heart failure. The potential for a pharmacokinetic (PK) drug‐drug interaction (DDI) was investigated, specifically to determine whether a single 50 mg dose of OM would impact the PKs of a single 10 mg dose of rosuvastatin in an open‐label study in 14 healthy subjects. The ratios of the geometric least‐square means (90% confidence intervals [CIs]) of rosuvastatin co‐administered with OM compared to rosuvastatin alone were 127.1% (90% CI 113.8–141.9), 132.8% (90% CI 120.7–146.1), and 154.2% (90% CI 132.8–179.1) for area under the plasma‐concentration time curve from time zero to infinity (AUC_inf), area under the plasma‐concentration time curve from time zero to time of last quantifiable concentration (AUC_last), and maximum observed plasma concentration (C_max), respectively. Whereas the DDI study with rosuvastatin was conducted with the co‐administration of a single dose of OM, in the clinical setting, patients receive OM at doses of 25, 37.5, or 50 mg twice daily (b.i.d.). Hence, to extrapolate the results of the DDI study to a clinically relevant scenario of continuous b.i.d. dosing with OM, physiologically‐based pharmacokinetic (PBPK) modeling was performed to explore the potential of BCRP inhibition following continuous b.i.d. dosing of OM at the highest 50 mg dose. Modeling results indicated that following 50 mg b.i.d. dosing of OM, the predicted ratios of the geometric means (90% CIs) for rosuvastatin AUC_inf and C_max were 1.18 (90% CI 1.16–1.20) and 2.04 (90% CI 1.99–2.10), respectively. Therefore, these results suggest that OM, following multiple dose administration, is a weak inhibitor of BCRP substrates and is in accordance with that observed in the single dose OM DDI clinical study.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Omecamtiv mecarbil (OM) is a cardiac myosin activator and is currently under investigation for the treatment of heart failure with reduced ejection fraction.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study investigated the drug‐drug interaction (DDI) potential of OM on the pharmacokinetics of rosuvastatin, a BCRP substrate, using a clinical study and a physiologically‐based pharmacokinetic (PBPK) modeling approach.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

The clinical study and PBPK modeling analyses confirm that OM is expected to be a weak inhibitor of BCRP in the clinical setting.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

This study highlights the DDI potential of single doses of OM for BCRP substrates from a clinical study and demonstrates the importance of the PBPK modeling approach to investigate DDI effects following multiple doses of OM at therapeutic concentrations.     

First‐in‐human study of milvexian,an oral,direct, small molecule factor XIa inhibitor

Milvexian (BMS‐986177/JNJ‐70033093) is a small molecule, active‐site inhibitor of factor XIa (FXIa) being developed to prevent and treat thrombotic events. The safety, tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of milvexian were assessed in a two‐part, double‐blind, placebo‐controlled, sequential single ascending dose (SAD) and multiple ascending dose (MAD) study in healthy adults. Participants in SAD panels (6 panels of 8 participants; n = 48) were randomized (3:1) to receive milvexian (4, 20, 60, 200, 300, or 500 mg) or placebo. The 200‐ and 500‐mg panels investigated the pharmacokinetic impact of a high‐fat meal. Participants in MAD panels (7 panels of 8 participants; n = 56) were randomized (3:1) to receive milvexian (once‐ or twice‐daily) or placebo for 14 days. All milvexian dosing regimens were safe and well‐tolerated, with only mild treatment‐emergent adverse events and no clinically significant bleeding events. In SAD panels, maximum milvexian plasma concentration occurred 3 h postdose in all fasted panels. The terminal half‐life (T_1/2) ranged from 8.3 to 13.8 h. In fasted panels from 20 to 200 mg, absorption was dose‐proportional; results at higher doses (300 and 500 mg) were consistent with saturable absorption. Food increased milvexian bioavailability in a dose‐dependent fashion. In MAD panels, steady‐state milvexian plasma concentration was reached within 3 and 6 dosing days with once‐ and twice‐daily dosing, respectively. Renal excretion was less than 20% in all panels. Prolongation of activated partial thromboplastin time was observed and was directly related to drug exposure. These results suggest that the safety, tolerability, PK, and PD properties of milvexian are suitable for further clinical development.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Factor XI (FXI) amplifies thrombin generation and has a limited role in hemostasis. Targeted FXI inhibition may reduce the burden of vascular and thromboembolic diseases while preserving hemostasis.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study evaluated the safety/tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of the selective, direct, small molecule FXIa inhibitor milvexian.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Single and multiple ascending doses of milvexian up to 500 mg were generally safe and well‐tolerated, with no clinically significant bleeding events. Milvexian plasma concentration was dose proportional at doses up to 200 mg q.d. The milvexian half‐life is suitable for q.d. or b.i.d. dosing. Milvexian exhibited low renal excretion and low overall variability in PK and PD parameters.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

These results can inform the future clinical development of milvexian.     

Absence of effect of steady state bempedoic acid on cardiac repolarization: Results of a thorough QT/QTc study in healthy volunteers

Bempedoic acid is an inhibitor of adenosine triphosphate–citrate lyase approved for use in adults with hypercholesterolemia. Nonclinical studies assessed binding to the human ether‐a‐go‐go–related gene (hERG) potassium channel in vitro and the effect of bempedoic acid on QT/QTc in cynomolgus monkeys. A randomized, double‐blind, parallel‐design clinical study assessed the effects of steady‐state bempedoic acid at a supratherapeutic dose (240 mg/day, 33.3% higher the180 mg/day therapeutic dose), placebo, and moxifloxacin (400 mg) in healthy subjects. In vitro binding potency for bempedoic acid to the hERG potassium channel was weak, with half‐maximal inhibition (IC₅₀) estimated at greater than 1000 μM (>1670‐fold the bempedoic acid 180 mg/day steady‐state unbound maximum concentration). In monkeys, individual rate‐corrected QT intervals showed no time‐ or dose‐dependent changes up to 100 mg/kg of bempedoic acid. In human subjects, the upper 90% confidence interval (CI) for the difference in QTc interval, corrected using Fridericia’s formula (QTcF), between bempedoic acid and placebo was less than 5 msec at all time points. Concentration‐QTcF analysis showed that maximum bempedoic acid concentration at steady‐state was attained at a median 2.1 h postdose, and the predicted mean change (90% CI) in QTcF at the observed mean bempedoic acid concentration 2 h postdose was −0.5 (−5.0, 4.0) msec. The lower bound of the moxifloxacin 90% CI exceeded 5 msec at prespecified time points, establishing study sensitivity. Steady‐state bempedoic acid at a supratherapeutic dose of 240 mg was generally well‐tolerated and not associated with QTc prolongation in healthy subjects.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Drug‐induced QT prolongation is associated with a rare and potentially fatal ventricular arrhythmia known as torsades de pointes. As a result, it is now a standard regulatory requirement for drug candidates to undergo assessment of QT prolongation risk.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Bempedoic acid is an inhibitor of adenosine triphosphate (ATP)–citrate lyase that is chronically administered to patients at risk for or with cardiovascular disease for the treatment of hypercholesterolemia. This phase I study assessed whether steady‐state concentrations of bempedoic acid at a supratherapeutic dose of 240 mg is associated with increased risk of prolongation of ventricular repolarization.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study demonstrated that steady‐state concentrations of bempedoic acid and its active metabolite {"type":"entrez-protein","attrs":{"text":"ESP15228","term_id":"556126718"}}ESP15228 were not associated with QT/QTc interval prolongation in 54 healthy subjects who received bempedoic acid 240 mg once daily for 9 days. This study adds supportive cardiac safety information for the safe and efficacious use of bempedoic acid in patients with cardiovascular disease.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

In vitro human ether‐a‐go‐go–related gene (hERG) binding and results in cynomolgus monkeys indicated that bempedoic acid has a favorable cardiac electrocardiographic nonclinical safety profile. These nonclinical results are consistent with the findings of a clinical study in which bempedoic acid at a supratherapeutic dose level was generally well‐tolerated and not associated with QTc prolongation in healthy subjects.     

Intraperitoneal pharmacokinetics of vancomycin in patients on automated peritoneal dialysis

It is unclear if the pharmacokinetics of vancomycin are the same during automated peritoneal dialysis (APD), where cycler exchanges may affect the systemic, peritoneal, and urinary disposition of drug. We conducted a prospective pharmacokinetic study evaluating the pharmacokinetics of vancomycin in plasma, dialysis fluid, and urine in peritonitis‐negative patients on APD. Patients underwent four drug‐free exchanges with 1.5% or 2.5% dextrose following the initial dwell period. Plasma, dialysis fluid, and urine was collected over the course of 7 days for pharmacokinetic analysis. Four patients completed the study with no adverse events. Following a median (range) dwell of 14.6 (14.2–17.6 h), the mean (±SD) observed maximum plasma concentration was 28.7 ± 4.9 mg/L with a mean bioavailability of 98.5 ± 1.4% prior to starting the cycler. The overall mean total plasma clearance estimated from study start to completion was 7.6 ± 1.2 ml/min. Mean total clearance during the dialytic exchange was 13.6 ± 4.9 ml/min. In patients with residual renal function, the mean vancomycin renal clearance was 3.1 ± 1.5 ml/min, representing 21.4%–58.9% of the overall total plasma clearance during the study period. Despite the small sample size, this pilot study suggests that the dwell time has important implications for systemic vancomycin exposure, time to therapeutic plasma concentration, and dosing. Dose is driven by dwell time, whereas the cycler determines the dosing interval. Rapid exchanges from APD will determine the frequency of dosing rather than the adequacy of absorption when vancomycin is given in the peritoneum.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Vancomycin dosing in patients with peritonitis during automated peritoneal dialysis (APD) is empiric and extrapolated from studies in patients on continuous ambulatory peritoneal dialysis (CAPD). Extrapolation of pharmacokinetic data from CAPD to APD may result in substantial under‐ or overdosing due to rapid exchanges and longer dwell times. The impact of residual renal function on vancomycin pharmacokinetics is also unknown.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study assessed the absorption and disposition of vancomycin following an intraperitoneal dose. Disposition of vancomycin was assessed in plasma, dialysis fluid, and urine.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Drug‐dialysis fluid dwell times of up to 15 h achieves adequate therapeutic vancomycin concentrations in plasma. Rapid exchanges from APD increases vancomycin total systemic plasma clearance during the exchange period.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Drug‐dialysis fluid dwell time has direct influence on the systemic bioavailability and therapeutic concentration of vancomycin. Initial and maintenance vancomycin dosing regimens should account for the dwell time, dialytic and renal clearance, and microbial susceptibility.     

REGN1908‐1909 monoclonal antibodies block Fel d 1 in cat allergic subjects: Translational pharmacokinetics and pharmacodynamics

REGN1908‐1909, a 1:1 cocktail of two fully human IgG₄ monoclonal antibodies (mAbs), REGN1908 and REGN1909, is being evaluated for treatment of cat allergy. Both REGN1908 and REGN1909 bind to the dominant cat allergen, Fel d 1. Adults with cat allergy confirmed by skin prick test (SPT) were randomized to single subcutaneous administration of placebo (n = 6) or REGN1908‐1909 at doses of 150 (n = 6), 300 (n = 6), or 600 mg (n = 6). Blood samples were taken at prespecified time points for pharmacokinetic (PK) analysis and exploratory evaluation of biomarkers (IgE and SPT). Safety was assessed. Drug concentration‐time profiles in serum for ascending doses of REGN1908‐1909 were consistent with linear PKs. Noncompartmental analysis showed that maximum concentration (C_max) and exposure increased proportionately with dose, with similar time to maximum concentration (T_max) for REGN1908 and REGN1909 (6.2 to 8.2 days across doses), and a longer terminal half‐life for REGN1908 (~ 30 days) relative to REGN1909 (~ 21 days). Adverse events were not dose dependent; there were no dose‐limiting toxicities. REGN1908‐1909 is characterized by linear and dose‐proportional kinetics of the two individual mAb components. A single 600 mg dose maintains total mAb mean concentrations in serum above the target (mean of ~ 10 mg/L) for 8–12 weeks. Maintaining this mean target concentration resulted in translational pharmacodynamic effects: maximal mast cell degranulation in a passive cutaneous anaphylaxis mouse model, and maintenance of clinical efficacy measured by Total Nasal Symptom Score in a previous proof‐of‐mechanism study.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

REGN1908 and REGN1909 are fully human IgG₄ monoclonal antibodies that demonstrated high affinity, noncompetitive binding to distinct epitopes of Fel d 1 allergen. Whereas a cocktail of these monoclonal antibodies, REGN1908‐1909, is being evaluated as a passive immunization strategy for treatment of cat allergy, its pharmacokinetics (PKs) have not been fully characterized, especially with respect to potential pharmacodynamic (PD) effects.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This first‐in‐human study of REGN1908‐1909 evaluated the PKs and safety of REGN1908‐1909 in cat‐allergic individuals who were otherwise healthy. Translational context is provided by discussing the PK profile with regard to PD effects observed in mouse models and among patients in a proof‐of‐mechanism study.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

The PK profile of subcutaneous administration of REGN1908‐1909 in subjects with cat allergy appeared to be dose‐proportional, with half‐lives of the individual components within the expected range for a typical monoclonal antibody. The concentration‐time curve was consistent with previously reported peak PD effects, including clinical response that temporally coincides with the time of peak concentrations of the drugs in serum.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE

Pharmacokinetic results support REGN1908‐1909 600 mg as the dose that maintains drug concentrations in serum above a mean target concentration required for PD effects, and suggest a prophylactic dosing regimen of every 2–3 months.     

Effects of vancomycin‐induced gut microbiome alteration on the pharmacodynamics of metformin in healthy male subjects

Metformin is a major treatment for type 2 diabetes. This study was conducted to investigate the impact of gut microbiome dysbiosis on the pharmacokinetics and antihyperglycemic effects of metformin. Healthy adult males aged 19–45 years with no defecation abnormalities were recruited for this 4‐period clinical study: baseline; post‐metformin (i.e., multiple oral doses of 1000 mg metformin on days 1–4); post‐vancomycin (i.e., multiple oral doses of 500 mg vancomycin on days 11–17 inducing gut microbiome changes); and post‐metformin + vancomycin (i.e., multiple oral doses of 1000 mg metformin on days 16–19). In each period, serum glucose and insulin concentrations following an oral glucose tolerance test, fecal samples for gut microbiome composition, and safety data were obtained. Following metformin dosing, plasma and urine samples for pharmacokinetics were collected. Nine subjects completed the study. The pharmacokinetics of metformin remained unchanged, and the antihyperglycemic effect was significantly decreased after vancomycin administration (p value = 0.039), demonstrating the weak relationship between the pharmacokinetics and pharmacodynamics of metformin. Relative abundances of some genus were changed after vancomycin administration, and tended to correlate with the antihyperglycemic effects of metformin (p value = 0.062 for Erysipelatoclostridium; p value = 0.039 for Enterobacter; and p value = 0.086 for Faecalibacterium). Adverse events occurred in all subjects and were resolved without sequelae. In conclusion, a decrease in the antihyperglycemic effect of metformin was observed after concomitant administration with vancomycin, without changes in metformin pharmacokinetics. The antihyperglycemic effect was tended to correlate with the relative abundance of several genus, suggesting that the effect of metformin is partly attributable to the gut microbiome (ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT03809260","term_id":"NCT03809260"}}NCT03809260).

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

The relationship between the systemic exposure and antihyperglycemic effect of metformin is weak. The possibility of gut‐mediated effects of metformin has recently emerged.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Is there a relationship between the antihyperglycemic effect of metformin and the gut microbiome?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

When the gut microbiome was altered in healthy male subjects due to oral vancomycin administration, the antihyperglycemic effect of metformin was less pronounced, despite similar metformin pharmacokinetics. The antihyperglycemic effect of metformin tended to correlate with the relative abundance of some genera.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

The results of this study showed that the antihyperglycemic effect of metformin is not related to its systemic exposure, and is likely to be associated with the relative abundance of some gut microbiome, suggesting the possibility that the effect of metformin is partly attributable to the gut microbiome, which may be extrapolated to the use of metformin in patients with type 2 diabetes.     

Safety,tolerability, and pharmacokinetics of single‐ and multiple‐dose administration of islatravir (MK‐8591) in adults without HIV

Islatravir (MK‐8591) is a nucleoside analogue in development for the treatment and prevention of HIV‐1. Two phase 1 trials were conducted during initial evaluation of islatravir: rising single doses (Study 1) and rising multiple doses (Study 2) of oral islatravir in male and female participants without HIV (aged 18–60 years). Safety, tolerability, and pharmacokinetics of islatravir (plasma) and islatravir‐triphosphate (peripheral blood mononuclear cells) were assessed. In Study 1, 24 participants, assigned to 1 of 3 panels, received alternating single doses of islatravir in a fasted state from 5 mg to 400 mg, or placebo, over 3 dosing periods; a 30 mg dose was additionally assessed following a high‐fat meal. In Study 2, 8 participants per dose received 3 once‐weekly doses of 10, 30, or 100 mg islatravir or placebo in a fasted state. For each panel in both trials, 6 participants received active drug and 2 received placebo. Islatravir was generally well‐tolerated, with no serious adverse events or discontinuations due to adverse events. Islatravir was rapidly absorbed (median time to maximum plasma concentration 0.5 hours); plasma half‐life was 49–61 h; intracellular islatravir‐triphosphate half‐life was 118–171 h. Plasma exposure increased in an approximately dose‐proportional manner; there was no meaningful food effect. There was a modest degree of intracellular islatravir‐triphosphate accumulation after multiple weekly dosing. After single oral doses of islatravir greater than or equal to 5 mg, intracellular islatravir‐triphosphate levels were comparable to levels associated with efficacy in preclinical studies. These results warrant continued clinical investigation of islatravir.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

​Current HIV treatment and prevention strategies have limitations, and novel agents that offer improved safety and tolerability, a high barrier to HIV resistance, and more convenient dosing regimens are required.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Two phase 1 studies in participants without HIV assessed safety and pharmacokinetics of rising single and multiple doses of oral islatravir, a nucleoside analogue, to support continued development for the treatment and prevention of HIV‐1 infection.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Islatravir was generally well‐tolerated at single doses up to 400 mg. Oral doses of islatravir greater than or equal to 10 mg resulted in intracellular peripheral blood mononuclear cell levels of the active form, islatravir‐triphosphate, comparable to those associated with antiviral efficacy in preclinical studies.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

These studies provide important safety and pharmacokinetic information about islatravir in adults without HIV, which will be used to support further clinical investigation of islatravir for the treatment and prevention of HIV‐1 infection.     

Pharmacokinetically guided dosing of oral sorafenib in pediatric hepatocellular carcinoma: A simulation study

Sorafenib improves outcomes in adult hepatocellular carcinoma; however, hand foot skin reaction (HFSR) is a dose limiting toxicity of sorafenib that limits its use. HFSR has been associated with sorafenib systemic exposure. The objective of this study was to use modeling and simulation to determine whether using pharmacokinetically guided dosing to achieve a predefined sorafenib target range could reduce the rate of HFSR. Sorafenib steady‐state exposures (area under the concentration curve from 0 to 12‐h [AUC_0–>12 h]) were simulated using published sorafenib pharmacokinetics at either a fixed dosage (90 mg/m²/dose) or a pharmacokinetically guided dose targeting an AUC_0–>12 h between 20 and 55 h µg/ml. Dosages were either rounded to the nearest quarter of a tablet (50 mg) or capsule (10 mg). A Cox proportional hazard model from a previously published study was used to quantify HFSR toxicity. Simulations showed that in‐target studies increased from 50% using fixed doses with tablets to 74% using pharmacokinetically guided dosing with capsules. The power to observe at least 4 of 6 patients in the target range increased from 33% using fixed dosing with tablets to 80% using pharmacokinetically guided with capsules. The expected HFSR toxicity rate decreased from 22% using fixed doses with tablets to 16% using pharmacokinetically guided dosing with capsules. The power to observe less than 6 of 24 studies with HFSR toxicity increased from 51% using fixed dosing with tablets to 88% using pharmacokinetically guided with capsules. Our simulations provide the rationale to use pharmacokinetically guided sorafenib dosing to maintain effective exposures that potentially improve tolerability in pediatric clinical trials.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Sorafenib pharmacokinetics (PKs) show large interindividual variability given fixed doses (90 mg/m²/dose twice daily). This leads to a wide exposure range, particularly higher exposures, which can lead to hand foot skin reaction (HFSR), withheld doses, and therefore a possible lower antitumor efficacy.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Can PK and pharmacodynamic modeling and simulation approaches provide the rationale to use pharmacokinetically guided sorafenib dosing to maintain effective exposures that potentially improve tolerability in pediatric clinical trials?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study provides evidence, through PK and pharmacodynamic simulations, that it is possible to decrease the variability of sorafenib exposure, increase the percentages of studies in a target range, and reduce the occurrence of HFSR.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

This study provides the rationale to use pharmacokinetically guided sorafenib dosing to maintain effective exposures that potentially improve tolerability in pediatric clinical trials, including our prospective protocol in children with rare solid malignancies.     

Effects of elagolix on the pharmacokinetics of omeprazole and its metabolites in healthy premenopausal women

This study evaluated the effect of repeated doses of elagolix on the pharmacokinetics (PK) of omeprazole and its metabolites in healthy premenopausal female subjects. Adult premenopausal female subjects (N = 20) received a single oral dose of omeprazole (40 mg) on day 1 and day 11 and oral doses of elagolix (300 mg) twice‐daily on days 3–11. Serial blood samples for assay of omeprazole and its metabolites were collected for 24 h after dosing on days 1 and 11. PK parameters were calculated for omeprazole, 5‐hydroxyomeprazole and omeprazole sulfone; and were compared between day 1 and day 11. Pharmacogenetic testing was performed for CYP2C19 variant alleles and the results were used to compare the magnitude of elagolix–omeprazole drug–drug interaction (DDI) between the different genotype subgroups. Administration of elagolix 300 mg twice‐daily for 9 days increased omeprazole exposure by 1.8‐fold and decreased the metabolite‐to‐parent ratio for 5‐hydroxyomeprazole by ~60%. Conversely, there was an increase in the metabolite‐to‐parent ratio for omeprazole sulfone by 25%. Elagolix increased omeprazole exposures by 2‐ to 2.5‐fold in CYP2C19 extensive (EM) and intermediate (IM) metabolizer subjects, but decreased omeprazole exposures by 40% in poor metabolizer subjects. Exposures of 5‐hydroxyomeprazole decreased by 20%–30% in all genotype subgroups, and omeprazole sulfone exposures increased by ~3‐fold in EM and IM subjects. Elagolix is a weak inhibitor of CYP2C19 and exposure of CYP2C19 substrates may be increased upon coadministration with elagolix. Omeprazole may exhibit drug interactions due to multiple mechanisms other than CYP2C19‐mediated metabolism; complicating the interpretation of results from omeprazole DDI studies.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Elagolix is an inhibitor of P‐glycoprotein (P‐gp) and a weak‐to‐moderate inducer of cytochrome P450 3A (CYP3A4). In vitro, elagolix was identified as a possible inhibitor of CYP2C19 with potential to increase plasma concentrations of drugs that are substrates of CYP2C19 if they are coadministered with elagolix.

• WHAT QUESTION DID THIS STUDY ADDRESS?

What are the effects of elagolix on the pharmacokinetics of omeprazole and its metabolites in healthy subjects with different CYP2C19 genotypes and are P‐gp and/or CYP3A4 potentially involved in the interaction between elagolix and omeprazole?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study suggests that elagolix is a weak inhibitor of CYP2C19 and exposure of other CYP2C19 substrates may be increased upon coadministration with elagolix. These results also suggest P‐gp, CYP3A4, and/or another unknown mechanism may also be potential mechanisms for drug interactions with omeprazole.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Future DDI studies with omeprazole as a CYP2C19 substrate should consider that omeprazole may exhibit complex drug interactions due to multiple mechanisms mediating metabolism and transport, which may confound the interpretation of study results.     

A randomized,double‐blind,placebo‐ and positive‐controlled crossover study of the effects of durlobactam on cardiac repolarization in healthy subjects

Durlobactam (formerly ETX2514) is a diazabicyclooctane β‐lactamase inhibitor that inhibits class A, C, and D β‐lactamases. Sulbactam combined with durlobactam has in vitro and in vivo activity against Acinetobacter baumannii including carbapenem‐ and colistin‐resistant isolates and is being developed for treating serious infections due to A. baumannii. The effect of a single supratherapeutic dose of durlobactam on the heart rate corrected QT interval (QTc) was evaluated in healthy subjects in a placebo‐ and active‐controlled, single‐infusion, three‐way crossover study. Subjects were randomized to 1 of 6 sequences that included a single 3‐h i.v. infusion of durlobactam 4 g (supratherapeutic dose), a single 3‐h i.v. infusion of placebo, and a single 3‐h i.v. infusion of placebo plus a single oral dose of moxifloxacin 400 mg given open‐label at the end of the i.v. infusion. In each treatment period, Holter electrocardiogram (ECG) measurements were obtained from predose through 24 h post‐start of infusion. For the primary ECG end point, placebo‐corrected change‐from‐baseline corrected QT Fridericia’s formula (ΔΔQTcF), no significant change was observed with durlobactam. A concentration‐QT analysis demonstrated no significant effect of durlobactam on ECG parameters, including QT interval prolongation. Thus, durlobactam has a low risk for prolonging the QT interval and is unlikely to produce any proarrhythmic effects.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Drug‐induced prolongation of the QT interval has the potential to cause severe, potentially fatal ventricular arrhythmias. A number of antimicrobial agents, including fluoroquinolones and macrolides, are associated with a low, but clinically significant increased risk of QT prolongation.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study evaluated the effect of a single supratherapeutic dose of durlobactam on the heart rate corrected QT interval in healthy subjects to determine if there were any potentials for proarrhythmic effects.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study found that durlobactam had a low risk for prolonging the QT interval and is unlikely to produce any proarrhythmic effects.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Because durlobactam had a low risk for prolonging the QT interval alone and when co‐administered with sulbactam, clinicians should be confident in administering the combination without risk for proarrhythmic effects.