Effect of Daridorexant on the Pharmacokinetics of Midazolam, and on the Pharmacokinetics and Pharmacodynamics of Warfarin in Healthy Male Subjects

BACKGROUND AND OBJECTIVES

Daridorexant, a dual orexin receptor antagonist was recently approved for the treatment of insomnia at doses up to 50 mg once per night. This study investigated the effect of single-dose and multiple-dose daridorexant 50 mg at steady state on the pharmacokinetics (PK) of the cytochrome P450 (CYP) 3A4-sensitive substrate midazolam, and the effect of single-dose daridorexant 50 mg on the PK and pharmacodynamics (PD) of the CYP2C9-sensitive substrate warfarin.

METHODS

In this prospective, single-center, open-label, fixed-sequence, phase I, drug-drug interaction study, 18 healthy male subjects sequentially received Treatment A, B, and C in three periods. Treatment A consisted of a single oral concomitant administration of midazolam 2 mg and warfarin 25 mg on day 1 of the first period. Treatment B consisted of one oral administration of daridorexant 50 mg followed 1 h later by a single oral dose of midazolam 2 mg concomitantly with a single oral dose of warfarin 25 mg on day 1 and a once-daily oral administration of daridorexant 50 mg for 6 days of the second period. Treatment C consisted of a single oral administration of daridorexant 50 mg at steady state followed 1 h later by a single oral administration of midazolam 2 mg on day 1 of the third period. Blood samples were assessed for midazolam and S-warfarin PK, and PD (international normalized ratio and factor VII). Noncompartmental  PK parameters and PD variables were evaluated with geometric mean ratios and 90% confidence intervals of Treatment B/A versus C/A for midazolam, and treatment B/A for warfarin. Safety and tolerability of each treatment were also assessed.

RESULTS

Midazolam maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from 0 to 24 h (AUC0-24) were 1.13- and 1.42-fold higher, respectively, after single-dose administration of daridorexant 50 mg compared to administration of midazolam alone, while Cmax and AUC0-24 were 1.12- and 1.35-fold higher, respectively, after administration of daridorexant 50 mg once daily at steady state. Terminal half-life and time to maximum plasma concentration were comparable between treatments. Daridorexant had no influence on the PK and PD of warfarin. All treatments were safe and well tolerated.

CONCLUSIONS

Daridorexant at 50 mg is classified as a weak CYP3A4 inhibitor after single- and multiple-dose administration once daily at steady state. Daridorexant 50 mg did not induce CYP3A4 activity or inhibit CYP2C9 activity.

CLINICAL TRIAL REGISTRATION

This trial (NCT05480488) was registered on 29 July, 2022.

Population pharmacokinetics of the dual endothelin receptor antagonist aprocitentan in subjects with or without essential or resistant hypertension

Aprocitentan is a novel, potent, dual endothelin receptor antagonist that recently demonstrated efficacy in the treatment of difficult-to-treat (resistant) hypertension. The aim of this study was to develop a population pharmacokinetic (PK) model describing aprocitentan plasma concentration over time, to investigate relationships between subject-specific factors (covariates) and model parameters, and to quantify the influence of the identified covariates on the exposure to aprocitentan via model-based simulations, enabling judgment about the clinical relevance of the covariates.PK data from 902 subjects in ten Phase 1, one Phase 2, and one Phase 3 study were pooled to develop a joint population PK model. The concentration-time course of aprocitentan was described by a two-compartment model with absorption lag time, first-order absorption and elimination, and reduced relative bioavailability following very high doses of 300 and 600 mg.The population PK model described the observed data well. Volume and clearance parameters were associated with body weight. Renal function as reflected by estimated glomerular filtration rate (eGFR), hepatic impairment, and sex were identified as relevant covariates on clearance.The subject-specific characteristics of body weight, eGFR, hepatic impairment, and sex were shown to influence exposure parameters area under the concentration-time curve and maximum concentration in steady state to a limited extent, i.e., not more than 25% different from a reference subject, and therefore do not warrant dose adjustments.

Pharmacokinetics, pharmacodynamics and safety of the novel C-X-C chemokine receptor 3 antagonist ACT-777991: Results from the first-in-human study in healthy adults

AIMS

The C-X-C chemokine receptor 3 (CXCR3) axis is highly upregulated in the tissue of patients with type 1 diabetes. Antagonizing CXCR3 may reduce the migration of CXCR3-expressing cells to the pancreas. The pharmacokinetics (PKs), target engagement (TE) (inhibition of CXCR3 internalization) and safety of single- and multiple-ascending doses (SADs and MADs) of ACT-777991, a novel orally available potent CXCR3 antagonist, were assessed in a double-blind, randomized, placebo-controlled phase 1 study.

METHODS

Doses up to 100 mg (SAD part) and 40 mg twice daily (MAD part) were investigated in a total of 70 male and female healthy participants. Food effect was integrated as an SAD subpart. PK, TE, safety and tolerability data were collected up to 4 days after (last) dosing.

RESULTS

In both SAD and MAD parts, ACT-777991 was rapidly absorbed with a time to reach maximum concentration between 0.5 and 1.5 h post dose, followed by a biphasic disposition with a terminal half-life between 9.7 and 10.3 h. Increase in exposure and maximum concentration of ACT-777991 were dose-proportional. Steady state was reached after 48 h with minimal accumulation. The rate but not the extent of absorption was modified by food intake. A dose-dependent TE was demonstrated in both SAD and MAD parts. ACT-777991 was well tolerated. Neither a treatment-related pattern nor a dose-response relationship was determined for adverse events or any safety variable. No QT prolongation liability of regulatory concern was detected.

CONCLUSIONS

In this first-in-human study, ACT-777991 showed good tolerability for all doses tested and a PK and TE profile suitable for further clinical development.

The orexin story and orexin receptor antagonists for the treatment of insomnia

Insomnia is present in up to one third of the adult population worldwide, and it can present independently or with other medical conditions such as mental, metabolic, or cardiovascular diseases, which highlights the importance of treating this multifaceted disorder. Insomnia is associated with an abnormal state of hyperarousal (increased somatic, cognitive, and cortical activation) and orexin has been identified as a key promotor of arousal and vigilance. The current standards of care for the treatment of insomnia recommend non-pharmacological interventions (cognitive behavioural therapy) as first-line treatment and, if behavioural interventions are not effective or available, pharmacotherapy. In contrast to most sleep medications used for decades (benzodiazepines and 'Z-drugs'), the new orexin receptor antagonists do not modulate the activity of γ-aminobutyric acid receptors, the main inhibitory mechanism of the central nervous system. Instead, they temporarily block the orexin pathway, causing a different pattern of effects, e.g., less morning or next-day effects, motor dyscoordination, and cognitive impairment. The pharmacokinetic/pharmacodynamic properties of these drugs are the basis of the different characteristics explained in the package inserts, including the recommended starting dose. Orexin receptor antagonists seem to be devoid of any dependence and tolerance-inducing effects, rendering them a viable option for longer-term treatment. Safety studies did not show exacerbation of existing respiratory problems, but more real-world safety and pharmacovigilance experience is needed. This review provides an overview of the orexin history, the mechanism of action, the relation to insomnia, and key features of available drugs mediating orexin signalling.

Effect of Daridorexant on the Pharmacokinetics of P-Glycoprotein Substrate Dabigatran Etexilate and Breast Cancer Resistance Protein Substrate Rosuvastatin in Healthy Subjects

BACKGROUND AND OBJECTIVE

The dual orexin receptor antagonist daridorexant was approved in 2022 for the treatment of insomnia at doses up to 50 mg once per night. This study aimed at investigating the effect of daridorexant 50 mg at steady state on the pharmacokinetics of dabigatran, the active moiety of dabigatran etexilate, and rosuvastatin, sensitive substrates of P-glycoprotein and breast cancer resistance protein, respectively.

METHODS

This single-center, open-label, fixed-sequence study enrolled 24 healthy male subjects who were dosed orally with dabigatran etexilate 75 mg on days 1 (Treatment A1) and 9 (Treatment C1) as well as rosuvastatin 10 mg on days 3 (Treatment A2) and 11 (Treatment C2). On days 7-14, daridorexant (50 mg once daily) was administered. Blood samples for the pharmacokinetics of both substrates and the pharmacodynamics of dabigatran, i.e., two coagulation tests, were collected and safety assessments performed. Noncompartmental pharmacokinetic parameters and pharmacodynamic variables were evaluated with geometric mean ratios and 90% confidence intervals of Treatment C1/C2 versus A1/A2.

RESULTS

Geometric mean ratios (90% confidence interval) of dabigatran maximum plasma concentration and area under the plasma concentration-time curve were 1.3 (1.0-1.7) and 1.4 (1.1-1.9), respectively, whereas the time to maximum plasma concentration and terminal half-life were comparable between treatments. Pharmacodynamic variables showed a similar pattern as dabigatran pharmacokinetics in both treatments. Rosuvastatin pharmacokinetics were unchanged upon concomitant daridorexant administration. All treatments were well tolerated.

CONCLUSIONS

A mild inhibition of P-glycoprotein was observed after administration of daridorexant (50 mg once daily) at steady state, whereas breast cancer resistance protein was not affected.

CLINICAL TRIAL REGISTRATION

NCT05480475; date of registration: 29 July, 2022.

Effect of nivasorexant (ACT-539313), a selective orexin-1-receptor antagonist, on multiple cytochrome P450 probe substrates in vitro and in vivo using a cocktail approach in healthy subjects

Nivasorexant, a selective orexin-1-receptor antagonist, has recently been assessed in the treatment of humans with binge-eating disorder. Herein, the inhibitory potential of nivasorexant on cytochromes P450 (CYPs) 2C9, 2C19, and 3A4 was evaluated. Human liver microsomes/recombinant CYP enzymes were evaluated in vitro. In vivo, a single-center, open-label, fixed-sequence study was performed in healthy adults to explore the effect of 100 mg nivasorexant administered twice daily (b.i.d.) on the pharmacokinetics (PK) of flurbiprofen (50 mg, CYP2C9), omeprazole (20 mg, CYP2C19), midazolam (2 mg, CYP3A4) making use of a cocktail approach. Plasma PK sampling was performed over 24 h on Day 1 (Cocktail alone), 8 (Cocktail + nivasorexant), and 15 (Cocktail + nivasorexant at steady state). Genotyping of subjects' CYPs was performed while safety and tolerability were also assessed. In vitro, nivasorexant inhibited CYP2C9, 2C19, and 3A4 in competitive inhibition assays with IC50 values of 8.6, 1.6, and 19-44 μM, respectively, while showing a significant time-dependent CYP2C19 inhibition. In 22 subjects, exposure to flurbiprofen, omeprazole, and midazolam was generally higher during concomitant single- (i.e., area under the plasma concentration-time curve [AUC] ratio increased by 1.04-, 2.05-, and 1.56-fold, respectively) and repeated-dose (i.e., AUC ratio increased by 1.47-, 6.84-, and 3.71-fold, respectively) nivasorexant administration compared with the cocktail substrates administered alone. The most frequently reported adverse event was somnolence. According to regulatory guidance, nivasorexant is classified as a moderate CYP2C19 and weak CYP3A4 inhibitor after 1 day and as a weak CYP2C9, strong CYP2C19, and moderate CYP3A4 inhibitor after 8 days of 100 mg b.i.d. administration. Clinicaltrials.gov ID: NCT05254548.

Mind the Gap: Model-Based Switching from Selatogrel to Maintenance Therapy with Oral P2Y12 Receptor Antagonists

Background: The P2Y12 receptor antagonist selatogrel is being developed for subcutaneous self-administration with a ready-to-use autoinjector at the onset of acute myocardial infarction (AMI) symptoms. The unique pharmacological profile of selatogrel (fast, potent, and short-acting) can bridge the time gap between the onset of AMI and first medical care. A clinical Phase 1 study showed a time-dependent pharmacodynamic interaction between selatogrel and loading doses of clopidogrel and prasugrel. As treatment switching is a common clinical practice, the assessment of subsequent switching from a clopidogrel loading dose to the first maintenance dose of oral P2Y12 receptor antagonists is highly relevant. Objectives: Model-based predictions of inhibition of platelet aggregation (IPA) for the drugs triggering pharmacodynamic interactions were to be derived to support clinical guidance on the transition from selatogrel to oral P2Y12 receptor antagonists. Methods: Scenarios with selatogrel 16 mg administration or placebo followed by a clopidogrel loading dose and, in turn, prasugrel or ticagrelor maintenance doses at different times of administration were studied. Population pharmacokinetic/pharmacodynamic modeling and simulations of different treatment scenarios were used to derive quantitative estimates for IPA over time. Results: Following selatogrel/placebo and a clopidogrel loading dose, maintenance treatment with ticagrelor or a prasugrel loading dose followed by maintenance treatment quickly achieved sustained IPA levels above 80%. Prior to maintenance treatment, a short time span from 18 to 24 h was identified where IPA levels were predicted to be lower with selatogrel than with placebo if clopidogrel was administered 12 h after selatogrel or placebo. Predicted IPA levels reached with placebo alone and a clopidogrel loading dose at 4 h were consistently lower than with selatogrel administration, followed by a clopidogrel loading dose at 12 h. If a clopidogrel loading dose is administered at 12 h, selatogrel maintains higher IPA levels up to 16 h. IPA levels are subsequently lower than on the placebo until the administration of the first maintenance dose. Conclusions: Model-based predictions informed the transition from selatogrel subcutaneous administration to oral P2Y12 therapy. The application of modeling techniques illustrates the value of employing pharmacokinetic and pharmacodynamic modeling for the simulation of various clinical scenarios of switching therapies.

Modeling time-delayed concentration-QT effects with ACT-1014-6470, a novel oral complement factor 5a receptor 1 (C5a1 receptor) antagonist

The novel oral complement factor 5a receptor 1 antagonist ACT-1014-6470 was well tolerated in single- and multiple-ascending dose studies, including 24 h Holter electrocardiogram (ECG) recordings evaluating its cardiodynamics based on data from single doses of 30-200 mg and twice-daily (b.i.d.) dosing of 30-120 mg for 4.5 days. By-time point, categorical, and morphological analyses as well as concentration-QT modeling and simulations were performed. No relevant effect of ACT-1014-6470 on ECG parameters was observed in the categorical and morphological analyses. After single-dose administration, the by-time point analysis indicated a delayed dose-dependent increase in placebo-corrected change from baseline in QT interval corrected with Fridericia's formula (ΔΔQTcF) at >6 h postdose. After b.i.d. dosing, ΔΔQTcF remained elevated during the 24-h recording period, suggesting that the effect was not directly related to ACT-1014-6470 plasma concentration. The concentration-QT model described change from baseline in QTcF (ΔQTcF)-time profiles best with a 1-oscillator model of 24 h for circadian rhythm, an effect compartment, and a sigmoidal maximum effect model. Model-predicted ΔΔQTcF was derived for lower doses and less-frequent dosing than assessed clinically. Median and 90% prediction intervals of ΔΔQTcF for once-daily doses of 30 mg and b.i.d. doses of 10 mg did not exceed the regulatory threshold of 10 ms but would achieve ACT-1014-6470 plasma concentrations enabling adequate target engagement. Results from cardiodynamic assessments identified dose levels and dosing regimens that could be considered for future clinical trials, attempting to reduce QT liability.

Clinical pharmacology of selatogrel for self-administration by patients with suspected acute myocardial infarction

INTRODUCTION

P2Y12 receptor antagonists (P2Y12 inhibitors) are well established for the treatment of coronary artery disease. The P2Y12 inhibitors currently commercially available present either pharmacokinetic limitations (due to delayed absorption, bioactivation requirement via CYP enzymes, or need of intravenous administration), pharmacodynamic (PD) limitations (limited % inhibition of platelet aggregation (IPA) or relevant PD interactions) or safety limitations (major bleeding in specific populations).

AREAS COVERED

Selatogrel, a 2-phenylpyrimidine-4-carboxamide analog, is a potent, reversible, and selective P2Y12 inhibitor administered subcutaneously that is under development for the treatment of acute myocardial infarction (AMI) in patients with a recent history of AMI. In this review, the authors summarize the results from preclinical, phase 1, and phase 2 trials which showed that selatogrel provides rapid, pronounced, and reversible P2Y12 receptor inhibition with a favorable safety profile.

EXPERT OPINION

These unique characteristics added to the limited potential to interact with co-medications and manageable PD interactions with other P2Y12 inhibitors provide a clear rationale for investigating the benefit of selatogrel as an emergency treatment to improve clinical outcomes in patients with AMI.

Evaluation of the cytochrome P450 2C19 and 3A4 inhibition potential of the complement factor 5a receptor antagonist ACT-1014-6470 in vitro and in vivo

ACT-1014-6470 is an orally available complement factor 5a receptor 1 antagonist and a novel treatment option in autoinflammatory diseases. The in vitro inhibition potential of ACT-1014-6470 on cytochrome P450 isozymes (CYPs) and its effect on the pharmacokinetics (PK) of the CYP2C19 and CYP3A4 substrates omeprazole and midazolam, respectively, in humans were assessed. In vitro assays were conducted with isoform-specific substrates in human liver microsomes. In an open-label, two-period, fixed-sequence cocktail study, single doses of 20 mg omeprazole and 2 mg midazolam were administered concomitantly to 20 healthy male subjects alone (Treatment A) and after a single dose of 100 mg ACT-1014-6470 (Treatment B) under fed conditions. Safety and PK assessments were performed. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) of noncompartmental PK parameters of Treatment B vs Treatment A were calculated. In vitro, no time-dependent inhibition was observed and the lowest inhibition constant of 4.3 μM ACT-1014-6470 was recorded for CYP2C19. In humans, GMRs (90% CI) of omeprazole PK were 1.9 (1.5-2.5) for maximum plasma concentration (C_max ) and 1.9 (1.5-2.3) for area under the plasma concentration-time curve (AUC) from 0 to 12 h. Midazolam PK showed GMRs (90% CI) of 1.1 (1.1-1.2) for C_max and 1.5 (1.4-1.6) for AUC from 0 to 24 h. All treatments were well tolerated. In line with in vitro results and regulatory risk factor calculation, the increased exposure to omeprazole and midazolam in humans after concomitant administration with a single dose of 100 mg ACT-1014-6470 reflected a weak inhibition of CYP2C19 and CYP3A4.

Effect of Severe Renal Impairment on Pharmacokinetics, Safety, and Tolerability of ACT-1014-6470, a Novel Oral Complement Factor 5a Receptor 1 Antagonist

The aim of this study was to examine the safety and the effect of severe renal impairment (RI) on the pharmacokinetics of ACT-1014-6470, a novel oral complement factor 5a receptor 1 antagonist. A phase 1 single-center, open-label, single-dose, parallel-group study was conducted in subjects with severe RI (n = 8) compared to demographically pairwise matched subjects with normal renal function (n = 8). Plasma levels of ACT-1014-6470 were measured up to 120 hours following an oral 40-mg dose. Safety evaluations included adverse events (AEs), vital signs, hematology, coagulation, clinical chemistry tests, and electrocardiograms. All 16 subjects completed the study. Relative to subjects with normal renal function, ACT-1014-6470 time to maximum plasma concentration was delayed with a median of differences of 3 hours. The maximum plasma concentration and the area under the plasma concentration-time profile from time zero to infinity were comparable indicated by geometric mean ratios (90%CI) of 0.85 (0.53-1.37) and 1.17 (0.73-1.85), respectively. Four transient and mild AEs in three subjects with severe RI were reported; three AEs were considered not related to ACT-1014-6470. These results support the use of ACT-1014-6470 in subjects with mild to severe RI without the need of dose adjustment.

Multiple-ascending doses of ACT-1014-6470, an oral complement factor 5a receptor 1 (C5a1 receptor) antagonist: Tolerability, pharmacokinetics and target engagement

AIMS

Targeting the complement factor 5a receptor 1 (C5a1 receptor) offers potential to treat various autoimmune diseases. The C5a1 receptor antagonist ACT-1014-6470 was well tolerated in a single-ascending dose study in healthy subjects. This double-blind, randomized, placebo-controlled study aimed to investigate the safety, tolerability, pharmacokinetics (PK) and target engagement of multiple-ascending doses of ACT-1014-6470.

METHODS

Per dose level, 10 healthy male and female subjects of nonchildbearing potential (1:1 sex ratio) were enrolled to assess 30, 60 and 120 mg ACT-1014-6470 administered twice daily for 4.5 days under fed conditions. Adverse events, clinical laboratory data, vital signs, electrocardiogram and PK blood samples were collected up to 120 h post last dose and ex vivo stimulated matrix metalloproteinase 9 was quantified as target engagement biomarker. At the 60-mg dose level, PK samples were collected until 8 weeks post last dose.

RESULTS

The total adverse event number was 57 and no treatment-related safety pattern was apparent. At steady state, ACT-1014-6470 reached maximum plasma concentrations after 2-3 h and the half-life estimated up to Day 10 was 115-146 h across dose levels. Exposure parameters increased dose-proportionally, steady state was attained between Day 3-5, and ACT-1014-6470 accumulated 2-fold. At the 60-mg dose level, ACT-1014-6470 was quantifiable until 8 weeks after the last dose. Matrix metalloproteinase 9 release was suppressed to endogenous background concentrations up to the last sampling time point, confirming sustained target engagement of ACT-1014-6470.

CONCLUSION

The compound was generally safe and well tolerated at all dose levels, warranting further clinical investigations.

Lack of Effect of Cenerimod, a Selective S1P1 Receptor Modulator, on the Pharmacokinetics of a Combined Oral Contraceptive

Cenerimod, a sphingosine-1-phosphate 1 receptor modulator, is in development for the treatment of systemic lupus erythematosus, a disease mainly affecting women of childbearing potential. The effect of cenerimod on the pharmacokinetics (PK) of a combined oral contraceptive (COC, 100 µg levonorgestrel and 20 µg ethinylestradiol (EE)) was investigated. A randomized, double-blind, parallel-group study was performed in 24 healthy male and female subjects. A single oral dose of COC was administered alone and after 35 days of once daily (o.d.) administration of cenerimod 0.5 (n = 10) or 4 (n = 14) mg. Exposure to EE alone or in combination with cenerimod was comparable as reflected by the geometric mean ratios and the respective 90% confidence intervals, while a slight increase in exposure (approximately 10-25%) to levonorgestrel was observed at clinically relevant concentrations of cenerimod. Overall, COC alone or in combination with cenerimod was safe and well tolerated. Two subjects reported one adverse event each (one headache after COC alone, and gastroenteritis in combination with cenerimod 4 mg). In conclusion, cenerimod does not affect the PK of levonorgestrel or EE to a clinically relevant extent. Therefore, COC can be selected as method of contraception during and after cenerimod therapy without the risk of interaction.

Population pharmacokinetic modeling of daridorexant, a novel dual orexin receptor antagonist

The analysis aimed at identifying subject-specific characteristics (covariates) influencing exposure to daridorexant and quantification of covariate effects to determine clinical relevance. Data from 13 phase I, two phase II, and two phase III studies were pooled to develop a population pharmacokinetic model describing daridorexant concentration over time. Covariate effects were quantified based on model predictions. A two-compartment model with dose-dependent bioavailability, absorption lag time, linear absorption, and nonlinear elimination described the data best. Statistically significant covariates were food status on absorption (lag time and rate constant), time of drug administration (morning, bedtime) on absorption rate constant, lean body weight on central volume of distribution and elimination, fat mass on peripheral volume of distribution and intercompartmental drug transfer, and age and alkaline phosphatase on elimination. Age, lean body weight, fat mass, and alkaline phosphatase influence exposure (area under the curve, time of maximum concentration after dose administration, maximum plasma concentration, and next-morning concentration) to a limited extent, that is, less than 20% difference from a typical subject. Morning administration is not relevant for daridorexant use by insomnia patients. The food effect with simultaneous intake of a high-fat, high-calorie food is an extreme-case scenario unlikely to occur in clinical practice. Body composition, alkaline phosphatase, and age showed clinically negligible effects on exposure to daridorexant. Lean body weight and fat mass described the pharmacokinetics of daridorexant better than other body size descriptors (body weight, height, body mass index), suggesting a convenient physiological alternative to reduce the number of covariates in population pharmacokinetic models. The results indicate that differences between subjects do not require dose adjustments.

Driving Performance after Bedtime Administration of Daridorexant, Assessed in a Sensitive Simulator

Use of hypnotics is often associated with next‐morning residual effects and a higher risk of motor vehicle accidents. Measuring next‐morning effects on driving performance is therefore advised by regulatory agencies. Here, we examined driving performance following administration of daridorexant, a new dual orexin receptor antagonist developed to treat insomnia. Sixty healthy male and female subjects (50–79 years of age) were randomized in a placebo‐ and active‐controlled, four‐way cross‐over study. Each subject received evening administration of daridorexant 50 and 100 mg, zopiclone 7.5 mg, and placebo, in separate treatment phases of 4 days. Simulated driving performance was assessed after initial (day 2) and repeated dosing (day 5), 9 hours postdose. Standard deviation of the lateral position (SDLP) was the main outcome. On both days, with zopiclone, SDLP increased significantly compared with placebo, which confirmed sensitivity of the simulator. With daridorexant, on day 2, the placebo‐corrected mean (97.5% confidence interval) SDLP increased by 2.19 cm (0.46–3.93) and 4.43 cm (2.72–6.15) for 50 and 100 mg, respectively. On day 5, SDLP values for both daridorexant doses were significantly below the prespecified threshold of impairment (2.6 cm) and statistically not different from placebo. Daridorexant showed a lower self‐rated driving quality and higher effort compared to placebo on day 2 but not on day 5. In non‐insomnia subjects, daridorexant impaired simulated driving after initial but not after repeated dosing. Subjects should be cautioned about driving until they know how daridorexant affects them.

First-in-human study with ACT-1014-6470, a novel oral complement factor 5a receptor 1 (C5aR1) antagonist, supported by pharmacokinetic predictions from animals to patients

Aberrantly controlled activation of the complement system contributes to inflammatory diseases. Safety, tolerability, and pharmacokinetics of single-ascending doses of ACT-1014-6470, a novel orally available complement factor 5a receptor 1 antagonist, were assessed in a randomized, double-blind, placebo-controlled Phase 1 study. Six ACT-1014-6470 doses (0.5-200 mg) were selected after predictions from a Complex Dedrick plot. In each group, ACT-1014-6470 or matching placebo was administered to six and two healthy male individuals under fed conditions, respectively, including a cross-over part with 10 mg administered also under fasted conditions. Pharmacokinetic blood sampling and safety assessments (adverse events, clinical laboratory, vital signs, 12-lead electrocardiogram, and QT telemetry) were performed. ACT-1014-6470 was absorbed with a time to maximum plasma concentration (t_max ) of 3 h across dose levels and eliminated with a terminal half-life of 30-46 h at doses ≥ 2.5 mg. Exposure increased approximately dose proportionally. Under fed compared to fasted conditions, ACT-1014-6470 exposure was 2.2-fold higher and t_max delayed by 1.5 h. Pharmacokinetic modelling predicted that twice-daily oral administration is warranted in a subsequent multiple-dose study. No clinically relevant findings were observed in safety assessments. ACT-1014-6470 was well tolerated at all doses and could provide a novel therapy with more patient-friendly administration route compared to biologicals.

Influence of hepatic impairment on the pharmacokinetics and pharmacodynamics of the P2Y12 receptor antagonist selatogrel

Selatogrel is a potent and selective reversible P2Y12 receptor antagonist in development for early treatment of acute myocardial infarction via subcutaneous (s.c.) self‐injection. Selatogrel is almost exclusively eliminated via the hepatobiliary route. Hepatic impairment is associated with reduced drug clearance and primary hemostasis. This single‐center, open‐label study investigated the effect of mild and moderate hepatic impairment on pharmacokinetics (PK) and pharmacodynamics (PD) of a single s.c. dose of selatogrel (16 mg). The study included groups of eight subjects with mild and moderate hepatic impairment, and matched healthy control subjects. Compared to healthy subjects, exposure to selatogrel in subjects with mild and moderate hepatic impairment was 30% and 108% (maximum plasma concentration [C_max]) and 47% and 212% (area under the concentration‐time curve from zero to infinity [AUC_0–∞]) higher, respectively. Hepatic impairment was associated with lower clearance and volume of distribution, whereas plasma protein binding was not affected. Marked inhibition of platelet aggregation (IPA > 80%) was attained within 30 min in all subjects and hepatic impairment prolonged IPA duration. Area under the effect curve was 60% and 160% higher in subjects with mild and moderate hepatic impairment, respectively. PK/PD modeling identified a change in the relationship between exposure and IPA, with a steeper concentration‐effect relationship in healthy subjects compared to subjects with hepatic impairment. The combination of higher exposure and lower half‐maximum inhibitory concentration resulted in longer lasting effect. In conclusion, hepatic impairment alters the PK/PD relationship leading to prolonged effects. Therefore, dose adjustments may be warranted in subjects with moderate hepatic impairment.

Absorption, Metabolism, and Excretion of ACT-1004-1239, a First-In-Class CXCR7 Antagonist: In Vitro, Preclinical, and Clinical Data

ACT-1004-1239 is a potent, selective, first-in-class CXCR7 antagonist, which shows a favorable preclinical and clinical profile. Here we report the metabolites and the metabolic pathways of ACT-1004-1239 identified using results from in vitro and in vivo studies. Two complementary in vitro studies (incubation with human liver microsomes in the absence/presence of cytochrome P450- [CYP] specific chemical inhibitors and incubation with recombinant CYPs) were conducted to identify CYPs involved in ACT-1004-1239 metabolism. For the in vivo investigations, a microtracer approach was integrated in the first-in-human study to assess mass balance and absorption, distribution, metabolism, and excretion (ADME) characteristics of ACT-1004-1239. Six healthy male subjects received orally 100 mg non-radioactive ACT-1004-1239 together with 1 μCi ¹⁴C-ACT-1004-1239. Plasma, urine, and feces samples were collected up to 240 h post-dose and ¹⁴C-drug-related material was measured with accelerator mass spectrometry. This technique was also used to construct radiochromatograms of pooled human samples. Metabolite structure elucidation of human-relevant metabolites was performed using high performance liquid chromatography coupled with high resolution mass spectrometry and facilitated by the use of rat samples. CYP3A4 was identified as the major CYP catalyzing the formation of M1 in vitro. In humans, the cumulative recovery from urine and feces was 84.1% of the dose with the majority being eliminated via the feces (69.6%) and the rest via the urine (14.5%). In human plasma, two major circulating metabolites were identified, i.e., M1 and M23. Elimination via M1 was the only elimination pathway that contributed to ≥25% of ACT-1004-1239 elimination. M1 was identified as a secondary amine metabolite following oxidative N-dealkylation of the parent. M23 was identified as a difluorophenyl isoxazole carboxylic acid metabolite following central amide bond hydrolysis of the parent. Other metabolites observed in humans were A1, A2, and A3. Metabolite A1 was identified as an analog of M1 after oxidative defluorination, whereas both, A2 and A3, were identified as a reduced analog of M1 and parent, respectively, after addition of two hydrogen atoms at the isoxazole ring. In conclusion, CYP3A4 contributes to a relevant extent to ACT-1004-1239 disposition and two major circulating metabolites were observed in humans. Clinical Trial Registration: (https://clinicaltrials.gov/ct2/show/NCT03869320) ClinicalTrials.gov Identifier NCT03869320.

Transition from Syringe to Autoinjector Based on Bridging Pharmacokinetics and Pharmacodynamics of the P2Y12 Receptor Antagonist Selatogrel in Healthy Subjects

BACKGROUND AND OBJECTIVES

Selatogrel is a potent, reversible, and selective antagonist of the platelet P2Y₁₂ receptor currently developed for the treatment of acute myocardial infarction (AMI). In the completed Phase I/II studies, selatogrel was subcutaneously (s.c.) administered as a lyophilizate-based formulation by syringe by a healthcare professional. In the Phase III study, selatogrel will be self-administered s.c. as a liquid formulation with an autoinjector at the onset of AMI symptoms to shorten treatment delay. This clinical bridging study compared the pharmacokinetics (PK) of selatogrel between the different formulations.

METHODS

This was a single-center, randomized, open-label, three-period, cross-over Phase I study in 24 healthy subjects. In each period, a single subcutaneous dose of 16 mg selatogrel was administered as (1) a Phase III liquid formulation by autoinjector (Treatment A), (2) a Phase III liquid formulation by prefilled syringe (Treatment B), or (3) a Phase I/II reconstituted lyophilizate-based formulation by syringe (Treatment C). PK parameters including area under the plasma concentration-time curve from zero to infinity (AUC_0-∞), maximum plasma concentration (C_max), time to reach C_max(t_max), and terminal half-life (t_1/2) were determined using noncompartmental analysis. Pharmacodynamic (PD) parameters were estimated using PK/PD modeling, including the time of first occurrence of inhibition of platelet aggregation (IPA) ≥ 80% (t_onset), duration of IPA above 80% (t_duration), and responder rate defined as the percentage of subjects with t_onset ≤ 30 min and t_duration ≥ 3 h. Safety and tolerability were also assessed.

RESULTS

Comparing Treatment A to Treatment C, the exposure (AUC_0-∞) was bioequivalent with a geometric mean ratio (GMR) (90% confidence interval) of 0.95 (0.92-0.97) within the bioequivalence range (0.80-1.25). Absorption following Treatment A was slightly slower with a t_max occurring approximately 30 min later and a 20% lower C_max. The autoinjector itself had no impact on the PK of selatogrel, as similar values of C_max and AUC_0-∞ were determined after administration as a Phase III liquid formulation by autoinjector or by prefilled syringe (i.e., GMR [90% confidence interval] of 1.06 [0.97-1.15] and 0.99 [0.96-1.03] for C_max and AUC_0-∞, respectively). PK/PD modeling predicted that the median t_onset will occur slightly later for Treatment A (7.2 min) compared to Treatment C (4.2  min), while no relevant differences in t_duration and responder rate were estimated between the two treatments. Selatogrel was safe and well tolerated following all three treatments.

CONCLUSIONS

PK and simulated PD effects of selatogrel were similar across treatments.

CLINICAL TRIAL REGISTRATION

NCT04557280.

Target engagement of the first-in-class CXCR7 antagonist ACT-1004-1239 following multiple-dose administration in mice and humans

Antagonism of the chemokine receptor CXCR7 has shown promising effects in diverse disease areas through modulation of its ligands, CXCL11 and CXCL12. Preclinical data of the first-in-class CXCR7 antagonist, ACT-1004-1239, showed efficacy in animal models of multiple sclerosis and acute lung injury. In healthy humans, single-dose administration of ACT-1004-1239 revealed a favorable clinical profile. Here, we report the target engagement of ACT-1004-1239 in healthy mice and humans after multiple doses using CXCL11 and CXCL12 as biomarkers. In addition, safety/tolerability, concentration-QTc relationship, and pharmacokinetics (PK) were assessed in a randomized, double-blind, placebo-controlled Phase 1 clinical study. Multiple-dose ACT-1004-1239 dose-dependently increased CXCL12 plasma concentration across the investigated dose range in mice and humans (mice: 1-100 mg/kg b.i.d.; humans: 30-200 mg o.d.) when compared to vehicle/placebo demonstrating target engagement. Mouse and human PK/PD models predicted that CXCL12 concentration approached a plateau within these dose ranges. In humans, ACT-1004-1239 was rapidly absorbed (t_max: 1.75-3.01 h) and the terminal t_1/2 was approximately 19 h. Steady-state conditions were reached by Day 3 with an accumulation index of 1.2. Female subjects had overall higher exposure compared to males. Multiple-dose ACT-1004-1239 was well tolerated up to 200 mg once daily in humans. There was no evidence of ACT-1004-1239-mediated QTc interval prolongation. Overall, multiple oral doses of ACT-1004-1239 showed target engagement with CXCR7 in healthy mice and humans, therefore, assessment of CXCL12 as translational tool for further investigations in patients is warranted. Favorable safety/tolerability and PK profiles allow for further clinical development.

Pharmacokinetic and pharmacodynamic interactions between daridorexant, a dual orexin receptor antagonist, and citalopram in healthy subjects

Daridorexant (ACT-541468) is a new dual orexin receptor antagonist being evaluated for the treatment of insomnia, which is a common comorbidity of depression and anxiety. Therefore, daridorexant is likely to be administered concomitantly with agents (e.g., citalopram) used to treat these disorders. In this single-centre, single-blind, randomized, placebo-controlled, sequential design Phase 1 study with the inclusion of two double-blind crossover parts, the pharmacokinetic (PK; blood sampling at regular intervals) and pharmacodynamic (PD; battery of objective and subjective PD tests performed at regular intervals) interactions between daridorexant (50 mg) and citalopram (20 mg, single dose and at steady state) as well as the safety/tolerability in healthy subjects were investigated. There were no relevant effects of citalopram (single dose/steady state) on daridorexant exposure and vice versa. PD variables measured after morning administration of daridorexant alone showed effects consistent with a sleep-promoting compound. Only co-administration of daridorexant with citalopram at steady state led to relevant changes in objective (unstable tracking) and subjective (visual analogue scale alertness and Karolinska Sleepiness Scale) PD endpoints compared to daridorexant alone. No serious or severe adverse events were reported, while no clinically relevant treatment-emergent effects on ECG parameters, clinical laboratory, or vital signs were observed. In conclusion, the co-administration of daridorexant and citalopram lead to only minor changes in PK parameters, while performance of PD assessments following co-administration were mainly driven by the expected central nervous system effects of daridorexant. Doses up to 50 mg daridorexant can be safely co-administered with citalopram.

Pharmacokinetics and Pharmacodynamics of Approved and Investigational P2Y12 Receptor Antagonists

Coronary artery disease remains the major cause of mortality worldwide. Antiplatelet drugs such as acetylsalicylic acid and P2Y12 receptor antagonists are cornerstone treatments for the prevention of thrombotic events in patients with coronary artery disease. Clopidogrel has long been the gold standard but has major pharmacological limitations such as a slow onset and long duration of effect, as well as weak platelet inhibition with high inter-individual pharmacokinetic and pharmacodynamic variability. There has been a strong need to develop potent P2Y12 receptor antagonists with more favorable pharmacological properties. Prasugrel and ticagrelor are more potent and have a faster onset of action; however, they have shown an increased bleeding risk compared with clopidogrel. Cangrelor is highly potent and has a very rapid onset and offset of effect; however, its indication is limited to P2Y12 antagonist-naïve patients undergoing percutaneous coronary intervention. Two novel P2Y12 receptor antagonists are currently in clinical development, namely vicagrel and selatogrel. Vicagrel is an analog of clopidogrel with enhanced and more efficient formation of its active metabolite. Selatogrel is characterized by a rapid onset of action following subcutaneous administration and developed for early treatment of a suspected acute myocardial infarction. This review article describes the clinical pharmacology profile of marketed P2Y12 receptor antagonists and those under development focusing on pharmacokinetic, pharmacodynamic, and drug-drug interaction liability.

Abuse potential assessment of the new dual orexin receptor antagonist daridorexant in recreational sedative drug users as compared to suvorexant and zolpidem

STUDY OBJECTIVES

Abuse potential properties have been reported for the dual orexin receptor antagonists (DORAs) suvorexant and lemborexant. Daridorexant is a new DORA currently in late-stage clinical development. This randomized, double-blind, double-dummy, placebo- and active-controlled 6-period crossover study assessed its abuse potential in healthy recreational sedative drug users (n=63).

METHODS

In each study period, a single, oral, morning dose of either daridorexant (50, 100, 150 mg), placebo, or active control, i.e., suvorexant (150 mg) or zolpidem (30 mg), was administered. Primary pharmacodynamic endpoint was the Emax of the Drug-liking visual analog scale (VAS) assessed over 24 h. Several secondary subjective and objective pharmacodynamic endpoints were also assessed.

RESULTS

Study validity was confirmed based on drug-liking of suvorexant and zolpidem greater than placebo applying a pre-defined 15-point validity margin (p<0.0001). Drug-liking VAS Emax (mean; 95% CI) of daridorexant at 50 mg (73.2; 69.0-77.5) was significantly lower compared to suvorexant (80.7; 77.0-84.5) and zolpidem (79.9; 76.2-83.5) (p<0.001), but similar at 100 mg (79.1; 75.0-83.3) and 150 mg (81.3; 77.7, 84.8). Such dose-related patterns were also observed for most secondary endpoints. At each daridorexant dose, Drug-liking VAS scores were greater than placebo. Both control drugs and daridorexant were safe and the pharmacokinetics of daridorexant was consistent with earlier trials indicating quick absorption and elimination.

CONCLUSIONS

In this large, valid human abuse potential study, daridorexant showed dose-related drug-liking among recreational sedative drug users with lower effects at the highest phase-3 dose, and similar effects at higher doses compared to supratherapeutic doses of suvorexant and zolpidem.

Effect of gastric pH and of a moderate CYP3A4 inducer on the pharmacokinetics of daridorexant, a dual orexin receptor antagonist

AIM

Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia. The solubility of daridorexant is pH dependent and daridorexant has been shown to be a sensitive CYP3A4 substrate when co-administered with moderate CYP3A4 inhibitors. The purpose of this study was to assess the effect of an increased gastric pH on daridorexant pharmacokinetics (PK) and the extent of interaction when daridorexant is co-administered with a moderate CYP3A4 inducer.

METHODS

In this prospective, single-centre, randomized, open-label study, 24 male subjects consecutively received four treatments, i.e., daridorexant 50 mg single dose; famotidine 40 mg single dose + daridorexant 50 mg single dose; efavirenz 600 mg once a day (o.d.) during 10 days; and daridorexant 50 mg single dose + efavirenz 600 mg o.d. for 2 days. Plasma PK parameters of daridorexant were derived by noncompartmental analysis. Standard safety and tolerability evaluations were analysed descriptively.

RESULTS

When daridorexant administration was preceded by administration of famotidine, daridorexant C_max decreased by 39%, geometric means ratio (GMR) (90% confidence interval (90% CI)): 0.61 (0.50, 0.73). AUC_0-∞ remained unchanged. In the presence of steady-state efavirenz, daridorexant C_max , AUC_0-∞ , and t_½ decreased by approximately 35% (GMR (90% CI)): 0.65 (0.54, 0.78), 61% (0.39 (0.348, 0.44), and 35% (0.65 (0.58, 0.73), respectively. T_max remained unaffected. All treatments containing daridorexant were well tolerated.

CONCLUSION

Daridorexant 50 mg can be administered concomitantly with gastric pH modifiers or with moderate CYP3A4 inducers without dose adaptation based on efficacy observed at lower doses in Phase 3 studies.

Impact of Daridorexant, a Dual Orexin Receptor Antagonist, on Cardiac Repolarization Following Bedtime Dosing: Results from a Thorough QT Study Using Concentration-QT Analysis

BACKGROUND AND OBJECTIVE

Daridorexant is a new dual orexin receptor antagonist currently in late-stage clinical development for the treatment of insomnia. This randomized, double-blind, placebo-controlled, four-period crossover study investigated the effect of daridorexant at a therapeutic and supratherapeutic dose on QT interval duration.

METHODS

Thirty-six healthy subjects received single oral doses of daridorexant (50 mg; 200 mg), moxifloxacin (400 mg; open label), and placebo. All treatments were administered at bedtime to mimic therapeutic practice. The primary analysis was based on linear mixed-effects concentration-QT modelling. Triplicate ECG data were extracted from Holter recordings at baseline and until 24 h post dosing at time points matching those for pharmacokinetic sampling. Plasma concentrations of daridorexant were determined over 24 h.

RESULTS

Assay sensitivity was demonstrated based on mean baseline- and placebo-corrected QT interval using Fridericia's formula (ΔΔQTcF) > 5 ms following moxifloxacin administration (p < 0.01). Following daridorexant administration, mean (90% confidence interval, CI) ΔΔQTcF was 1.40 ms (0.48; 2.32 ms) and 1.84 ms (-0.12; 3.79 ms) at the C_max of 747 ng/mL (50 mg dose) and 1809 ng/mL (200 mg dose), respectively, i.e., the upper bounds of the CIs were < 10 ms defined as threshold of regulatory concern. Lack of relevant QT prolongation was confirmed by secondary by-time point analysis and absence of relevant findings in the categorical outlier analysis. Daridorexant was safe and well tolerated and its pharmacokinetics were consistent with previous data.

CONCLUSION

Daridorexant does not impair cardiac repolarization evidenced by absence of relevant QT prolongation at therapeutic and supratherapeutic doses. Clinical Trials Registration ID: NCT04250506.

Absorption, Distribution, Metabolism, and Excretion of Aprocitentan, a Dual Endothelin Receptor Antagonist, in Humans

BACKGROUND

Aprocitentan is an orally active, dual endothelin receptor antagonist that may offer a new therapeutic option for the treatment of difficult-to-control hypertension.

OBJECTIVE

To investigate safety, tolerability, mass balance, absorption, distribution, metabolism, and excretion of aprocitentan.

METHODS

In this single-center, open-label study, a single oral dose of 25 mg containing 3.7 MBq of ¹⁴C-radiolabeled aprocitentan was administered to 6 healthy male subjects. Metabolites were identified using mass spectrometry and, where possible, confirmed and quantified with reference compounds.

RESULTS

Aprocitentan was well tolerated and there were no clinically significant findings for any safety variable. The geometric mean cumulative recovery of radioactivity from urine and feces over 14 days was 77% of the administered radioactive dose, with 52.1% cumulative recovery from urine and 24.8% from feces. Concentrations of total radioactivity in whole blood were markedly lower compared to plasma. In plasma, 94.3% of total radioactivity was aprocitentan. In urine and feces, 5 and 2, respectively (in feces one being aprocitentan) main products were identified. Metabolism data of aprocitentan identified two main elimination pathways, glucosidation to M3 and hydrolysis to M1, representing approximately 25% and 32% of the radioactive dose, respectively.

CONCLUSIONS

Based on these metabolism data, aprocitentan can be concomitantly administered without dose adjustment with drugs that are inhibitors or inducers of any metabolizing enzyme, specifically cytochrome P450 enzymes.

Effect of the new dual orexin receptor antagonist daridorexant on nighttime respiratory function and sleep in patients with mild and moderate obstructive sleep apnea

In this randomized, double-blind, placebo-controlled, two-period crossover study, the effect of the dual orexin receptor antagonist daridorexant was evaluated on nighttime respiratory function and sleep in 28 patients with mild and moderate obstructive sleep apnea (OSA). In each period, 50 mg daridorexant or placebo was administered every evening for 5 days. The primary endpoint was apnea/hypopnea index (AHI) during total sleep time (TST) after the last dosing. Other endpoints included peripheral oxygen saturation (SpO2), sleep duration, latency to persistent sleep (LPS), wake after sleep onset (WASO), and sleep efficiency index (SEI). Pharmacokinetics, safety, and tolerability were also assessed. The mean treatment difference for AHI during TST (i.e. daridorexant - placebo) after the last dosing was 0.74 events/hour (90% confidence interval [CI]: -1.43, 2.92). The corresponding treatment difference for SpO2 during TST was 0.16% [90% CI: -0.21, 0.53]. Overall, there was no clinically relevant effect of daridorexant on AHI or SpO2-related data after single and repeated dosing irrespective of sleep phase (i.e. rapid eye movement [REM] vs non-REM). Moreover, after single and repeated dosing, daridorexant prolonged TST by 39.6 minutes (90% CI: 16.9, 62.3) and 38.8 minutes (19.7, 57.9), respectively, compared with placebo and favorably modulated other sleep-related endpoints (i.e. increased SEI, decreased WASO, and shortened LPS). It attained expected plasma concentrations and was well tolerated in patients with mild and moderate OSA. These results indicate that single and repeated doses of 50 mg daridorexant do not impair nighttime respiratory function and improve sleep in patients with mild and moderate OSA. Clinical Trial Registration: ClinicalTrials.gov NCT03765294. A study to investigate the effects of ACT-541468 on nighttime respiratory function in patients with mild to moderate obstructive sleep apnea. https://clinicaltrials.gov/ct2/show/ NCT03765294.

Pharmacokinetics of daridorexant, a dual orexin receptor antagonist, are not affected by renal impairment

The aim of this study was to evaluate the impact of renal impairment on the pharmacokinetics (PKs), safety, and tolerability of daridorexant, a dual orexin receptor antagonist intended for the treatment of insomnia. A single‐center, open‐label study evaluated the PKs of daridorexant in patients with severe renal function impairment (SRFI; determined by creatinine clearance using the Cockcroft‐Gault equation; N = 8) not on dialysis, and in matched control subjects (based on sex, age, and body weight; N = 7). A single oral dose of daridorexant 25 mg was orally administered in the morning. Blood samples were collected up to 72 h postdose for PK assessments of daridorexant. In patients with SRFI, maximum plasma concentrations (C_max; geometric mean ratio [GMR] and 90% confidence interval [CI]: 0.94 [0.60–1.46]), time to reach C_max (T_max; median difference [90% CI] of −0.25 h [−0.75 to 0.25]), and half‐life (GMR [90% CI] of 0.99 [0.66–1.48]), were virtually unchanged. Exposure (area under the plasma concentration‐time profile) to daridorexant was slightly higher in patients with SRFI than in control subjects with the GMR (90% CI) being 1.16 (0.63–2.12). No safety issue of concern was detected as all adverse events were transient and of mild or moderate intensity, and no treatment‐related effects on vital signs, clinical laboratory, or electrocardiogram variables were observed following daridorexant administration in patients with SRFI and control subjects. Based on these observations, PK alterations of daridorexant due to renal function impairment are not considered of clinical relevance and no dose adjustment is necessary in these patients.

Pharmacokinetic/pharmacodynamic modeling of drug interactions at the P2Y12 receptor between selatogrel and oral P2Y12 antagonists

Selatogrel is a potent and reversible P2Y₁₂ receptor antagonist developed for subcutaneous self‐administration by patients with suspected acute myocardial infarction. After single‐dose emergency treatment with selatogrel, patients are switched to long‐term treatment with oral P2Y₁₂ receptor antagonists. Selatogrel shows rapid onset and offset of inhibition of platelet aggregation (IPA) to overcome the critical initial time after acute myocardial infarction. Long‐term benefit is provided by oral P2Y₁₂ receptor antagonists such as clopidogrel, prasugrel, and ticagrelor. A population pharmacokinetic (PK)/pharmacodynamic (PD) model based on data from 545 subjects in 4 phase I and 2 phase II studies well described the effect of selatogrel on IPA alone and in combination with clopidogrel, prasugrel, and ticagrelor. The PK of selatogrel were described by a three‐compartment model. The PD model included a receptor‐pool compartment to which all drugs can bind concurrently, reversibly or irreversibly, depending on their mode of action. Furthermore, ticagrelor and its active metabolite can bind to the selatogrel‐receptor complex allosterically, releasing selatogrel from the binding site. The model provided a framework for predicting the effect on IPA of selatogrel followed by reversibly and irreversibly binding oral P2Y₁₂ receptor antagonists for sustained effects. Determining the timepoint for switching from emergency to maintenance treatment is critical to achieve sufficient IPA at all times. Simulations based on the interaction model showed that loading doses of clopidogrel and prasugrel administered 15 h and 4.5 h after selatogrel, respectively, provide sustained IPA with clinically negligible drug interaction.

Effect of Liver Cirrhosis on the Pharmacokinetics, Metabolism, and Tolerability of Daridorexant, A Novel Dual Orexin Receptor Antagonist

BACKGROUND AND OBJECTIVE

Daridorexant is a dual orexin receptor antagonist in clinical development for insomnia. As daridorexant is cleared mainly via cytochrome P450 (CYP) 3A4, the effect of hepatic impairment on the pharmacokinetics (PK), metabolism, and tolerability of daridorexant was evaluated. Sleep disorders are common in patients with liver cirrhosis and, therefore, sleep-promoting drugs with a better tolerability than currently available would be preferable, a premise that dual orexin receptor antagonists may fulfill.

METHODS

This was a single-dose, open-label, phase I study. Subjects with mild (Child-Pugh A, N = 8) or moderate (Child-Pugh B, N = 8) liver cirrhosis and matched healthy control subjects (N = 8) received 25 mg of daridorexant orally. Blood samples were collected for 72 h post-dose for PK assessments of daridorexant and three major metabolites.

RESULTS

Compared with healthy subjects, patients showed a decrease in total daridorexant area under the plasma concentration-time curve from zero to infinity (AUC_0-inf) and maximum plasma concentration with a geometric mean ratio (GMR, 90% confidence interval [CI]) of 0.51 (0.28-0.92) and 0.50 (0.35-0.72) in Child-Pugh A and 0.74 (0.39-1.41) and 0.42 (0.29-0.60) in Child-Pugh B patients, respectively. Furthermore, the median time to reach maximum plasma concentration was slightly delayed (1.0 h [90% CI 0.0-2.0] in Child-Pugh A patients and 0.5 h [90% CI 0.0-1.5] in Child-Pugh B patients), while for Child-Pugh B patients, a doubling in half-life was observed (GMR [90% CI]: 2.09 [1.32-3.30]). Considering the high plasma protein binding (> 99%) and a 1.9-fold to 2.3-fold increase in the unbound fraction in patients, the PK of unbound daridorexant was also assessed. Compared with healthy subjects, Child-Pugh B patients had a higher AUC_0-inf (GMR [90% CI] 1.60 [0.93-2.73]), a lower apparent plasma clearance (GMR [90% CI] 0.63 [0.37-1.07]), and the same doubling in the half-life observed for total daridorexant, whereas maximum plasma concentration and apparent volume of distribution were not different. Unbound daridorexant PK in Child-Pugh A patients did not differ from healthy subjects. In addition, the metabolic ratios (parent to metabolite), i.e., a marker of CYP 3A4 activity, of the two most abundant daridorexant metabolites were higher in patients with liver cirrhosis compared with healthy subjects. All treatment-emergent adverse events were transient and of mild or moderate intensity and no other treatment-related effects were apparent.

CONCLUSIONS

No safety issue of concern was detected following administration of 25 mg of daridorexant in the study population. Moderate liver cirrhosis causes impaired hepatic clearance of unbound daridorexant, which prolongs the half-life. A 25-mg dose of daridorexant should, therefore, not be exceeded in Child-Pugh B patients. A dose adjustment is not required in Child-Pugh A patients, while avoidance of daridorexant in patients with Child-Pugh C cirrhosis is recommended.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03713242.

357 Daridorexant Does Not Impair Respiratory Function in Patients with Mild/Moderate Obstructive Sleep Apnea Irrespective of Severity

Introduction

Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia. The effect of the highest phase-3 dose of 50 mg daridorexant on nighttime respiratory function was evaluated in patients with mild/moderate obstructive sleep apnea (OSA). This study showed that repeated doses of daridorexant had no clinically meaningful effect on nighttime respiration (i.e., apnea-hypopnea index [AHI] and peripheral oxygen saturation [SpO2]). In the same study, other relevant respiratory endpoints were evaluated.

Methods

In this randomized, double-blind, placebo-controlled, two-period, crossover study, daridorexant or placebo was administered in each period once daily for 5 consecutive nights to 28 patients. Treatment differences (daridorexant – placebo) for total number and mean/longest duration of apneas and hypopneas as well as mean and lowest SpO2 during apnea/hypopnea events in Night 5 were explored using linear mixed-effects modeling. Treatment differences for the above-mentioned endpoints versus AHI during TST at baseline (i.e., OSA severity) was analyzed by linear regression using least square approach.

Results

Of 28 patients enrolled, 25 completed the study and were included in the analysis (n=15/10 with mild/moderate OSA; mean [standard deviation, SD] AHI: 16.3 events/h [8.2]). Compared to placebo, daridorexant increased mean duration of TST and accordingly to a not statistically significant extent the mean number of apneas + hypopneas by 16.4 events (n=103 versus 86.2; 90% confidence interval [CI]: -0.4–33.2]) without difference in mean [SD] AHI between daridorexant (15.1 events/h [7.9] and placebo (14.2 [7.7]). No treatment difference was detected for mean (0.0 sec [-2.6–2.7]) or longest (0.8 sec [-8.9–10.5]) duration of apneas nor for mean (0.2 sec [-2.2–2.5]) or longest (8.3 sec [6.4–23.1]) duration of hypopneas. No treatment difference was observed for mean (0.3% [-0.2–2.1]) and lowest (0.9% [0.3–2.1]) SpO2 during apnea/hypopnea events. Treatment differences for any of the evaluated endpoints did not significantly correlate with AHI at baseline as a marker of OSA severity (r2 ≤ 0.09).

Conclusion

Daridorexant can safely be administered to patients with mild/moderate OSA as treatment differences for respiratory-related endpoints were not of statistical significance and independent of disease severity in the studied population.

Support (if any)

Funded by Idorsia Pharmaceuticals Ltd.

358 Daridorexant Improves Sleep in Patients with Mild/Moderate Obstructive Sleep Apnea

Introduction

Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia. The effect of the highest phase-3 dose of 50 mg daridorexant on nighttime respiratory function was evaluated in patients with mild/moderate obstructive sleep apnea (OSA). This study showed that repeated doses of daridorexant had no clinically meaningful effect on the apnea-hypopnea index (AHI) or on peripheral oxygen saturation. In the same study, the effect on objective sleep parameters was also explored by polysomnography (PSG).

Methods

In this randomized, double-blind, placebo-controlled, two-period, crossover study, daridorexant or placebo was administered in each period once daily for 5 consecutive nights to 28 patients. Treatment difference (daridorexant – placebo) for total sleep time (TST), latency to persistent sleep (LPS), and wake after sleep onset (WASO) was analyzed for Night 5 using linear mixed-effects modeling. In addition, sleep was further explored based on sleep duration during each hour of PSG recording, duration of the different sleep phases (rapid eye movement [REM], non-REM [including N1 to N3 sleep stages]), as well as number and mean/longest duration of awakenings.

Results

Of 28 patients enrolled, 25 completed the study and were included in the analysis (n=15/10 with mild/moderate OSA; mean [standard deviation] AHI: 16.3 [8.2] events/h). One patient had mild insomnia symptoms at baseline. Compared to placebo, daridorexant prolonged mean TST by 38.8 min (90% confidence interval: 19.7–57.9), shortened mean LPS by 17.2 min (-35.5–1.02), and reduced mean WASO by 31.0 min (-47.3 to 14.7). Sleep architecture was maintained as no treatment differences in the duration of the evaluated sleep stages were observed when normalized to TST. Sleep duration was prolonged in the second part of the night. mean and longest duration of awakenings were decreased by a mean (90% CI) of 2.0 min (-3.1 to 0.9) and 16.3 min (-24.1 to -8.6), respectively, without treatment difference for the total number of awakenings.

Conclusion

Daridorexant improved objective sleep parameters in patients with mild to moderate OSA without modifying sleep architecture.

Support (if any)

Funded by Idorsia Pharmaceuticals Ltd.

Clinical Pharmacology of Clazosentan, a Selective Endothelin A Receptor Antagonist for the Prevention and Treatment of aSAH-Related Cerebral Vasospasm

Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm and is associated with significant morbidity and mortality. It represents a major unmet medical need due to few treatment options with limited efficacy. The role of endothelin-1 (ET-1) and its receptor ET_A in the pathogenesis of aSAH-induced vasospasm suggests antagonism of this receptor as promising asset for pharmacological treatment. Clazosentan is a potent ET_A receptor antagonist for intravenous use currently under development for the prevention of aSAH-induced cerebral vasospasm. The pharmacokinetics of clazosentan are characterized by an intermediate clearance, a volume of distribution similar to that of the extracellular fluid volume, dose-proportional exposure, an elimination independent of drug-metabolizing enzymes, and a disposition mainly dependent on the hepatic uptake transporter organic anion transport polypeptide 1B1/1B3. In healthy subjects, clazosentan leads to an increase in ET-1 concentration and prevents the cardiac and renal effects mediated by infusion of ET-1. In patients, it significantly reduced the incidence of moderate or severe vasospasm as well as post-aSAH vasospasm-related morbidity and mortality. Clazosentan is well tolerated up to the expected therapeutic dose of 15 mg/h and, in aSAH patients, lung complications, hypotension, and anemia were adverse events more commonly reported following clazosentan than placebo. In summary, clazosentan has a pharmacokinetic, pharmacodynamic, and safety profile suitable to become a valuable asset in the armamentarium of therapeutic modalities to prevent aSAH-induced cerebral vasospasm.

Effect of Renal Function Impairment on the Pharmacokinetics, Safety, and Tolerability of the Iminosugar Sinbaglustat

Sinbaglustat (ACT-519276), a brain-penetrating inhibitor of glucosylceramide synthase and nonlysosomal glucosylceramidase, is developed as a new therapy for lysosomal storage disorders. In the first-in-human study, sinbaglustat was primarily excreted unchanged in urine. This study was conducted to evaluate the effect of mild, moderate, and severe renal function impairment on the safety, tolerability, and pharmacokinetics (PK) of sinbaglustat. In this single-center, open-label study, 32 subjects (8 per renal function group, assessed by the Cockcroft-Gault formula, and 8 healthy subjects) received a single oral dose of 200 mg sinbaglustat. Plasma PK parameters of sinbaglustat were derived by noncompartmental analysis. Standard safety and tolerability evaluations were analyzed descriptively. When compared with healthy subjects, C_max did not present clinically relevant differences in subjects with impaired renal function, but median t_max was slightly longer in subjects with moderate and severe renal function impairment. Overall, when compared with healthy subjects, exposure to sinbaglustat based on AUC_0-t (geometric mean and 90% confidence interval) increased in subjects with mild, moderate, and severe renal function impairment by 1.2-fold (1.08- to 1.36-fold), 1.8-fold (1.47- to 2.17-fold), and 2.6-fold (2.23- to 3.00-fold), respectively. There were no clinically relevant findings on electrocardiogram, vital signs, and clinical laboratory variables. Headache was reported by 2 of 24 subjects with renal function impairment and by 2 of 8 healthy subjects. In conclusion, 200 mg of sinbaglustat was well tolerated in all groups. In future studies, a 2- and 3-fold dose reduction is needed for subjects with moderate and severe renal function impairment, respectively.

Effect of the novel dual orexin receptor antagonist daridorexant on night-time respiratory function and sleep in patients with moderate chronic obstructive pulmonary disease

In patients with chronic obstructive pulmonary disease (COPD), sleep is often fragmented while, conversely, the use of sleep medications is of concern in these patients due to potential impairment of nocturnal breathing. This randomised, double-blind, placebo-controlled, two-period crossover study was conducted to evaluate the effect of the new dual orexin receptor antagonist daridorexant on night-time respiratory function and sleep in patients with moderate COPD. In each period, the highest Phase-III dose of 50 mg daridorexant or placebo was administered once daily in the evening for 5 consecutive days. The primary endpoint was peripheral oxygen saturation (SpO₂ ) during total sleep time (TST) after last dosing. Night-time respiratory function and sleep were further evaluated based on the apnea-hypopnea index (AHI), sleep duration, and objective sleep parameters. Pharmacokinetics, safety, and tolerability were also assessed. Primary endpoint analysis revealed no significant mean treatment difference (i.e. daridorexant - placebo) for SpO₂ during TST as it was 0.18% (90% confidence interval: -0.21 to 0.57). There was also no difference from placebo for SpO₂ during non-rapid eye movement (REM) and REM sleep at Night 5 and after first dosing. The AHI was slightly increased compared to placebo, but not to a clinically meaningful extent. In addition, daridorexant improved objective sleep parameters (i.e. prolonged TST, increased sleep efficiency, and decreased wake after sleep onset), reached expected plasma concentrations, and was safe and well tolerated. In conclusion, single and multiple doses of 50 mg daridorexant do not impair night-time respiratory function and improves sleep in patients with moderate COPD.

A Multipurpose First-in-Human Study With the Novel CXCR7 Antagonist ACT-1004-1239 Using CXCL12 Plasma Concentrations as Target Engagement Biomarker

The C-X-C chemokine receptor 7 (CXCR7) has evolved as a promising, druggable target mainly in the immunology and oncology fields modulating plasma concentrations of its ligands CXCL11 and CXCL12 through receptor-mediated internalization. This "scavenging" activity creates concentration gradients of these ligands between blood vessels and tissues that drive directional cell migration. This randomized, double-blind, placebo-controlled first-in-human study assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of ACT-1004-1239, a first-in-class drug candidate small-molecule CXCR7 antagonist. Food effect and absolute bioavailability assessments were also integrated in this multipurpose study. Healthy male subjects received single ascending oral doses of ACT-1004-1239 (n = 36) or placebo (n = 12). At each of six dose levels (1-200 mg), repeated blood sampling was done over 144 hours for pharmacokinetic/pharmacodynamic assessments using CXCL11 and CXCL12 as biomarkers of target engagement. ACT-1004-1239 was safe and well tolerated up to the highest tested dose of 200 mg. CXCL12 plasma concentrations dose-dependently increased and more than doubled compared with baseline, indicating target engagement, whereas CXCL11 concentrations remained unchanged. An indirect-response pharmacokinetic/pharmacodynamic model well described the relationship between ACT-1004-1239 and CXCL12 concentrations across the full dose range, supporting once-daily dosing for future clinical studies. At doses ≥ 10 mg, time to reach maximum plasma concentration ranged from 1.3 to 3.0 hours and terminal elimination half-life from 17.8 to 23.6 hours. The exposure increase across the dose range was essentially dose-proportional and no relevant food effect on pharmacokinetics was determined. The absolute bioavailability was 53.0% based on radioactivity data after oral vs. intravenous ¹⁴ C-radiolabeled microtracer administration of ACT-1004-1239. Overall, these comprehensive data support further clinical development of ACT-1004-1239.

Insights from In Vitro and Clinical Data to Guide Transition from the Novel P2Y12 Antagonist Selatogrel to Clopidogrel, Prasugrel, and Ticagrelor

Reduced pharmacodynamic (PD) effects of irreversible oral P2Y₁₂ receptor antagonists have been reported when administered during cangrelor infusion. Therefore, the PD interaction liability of the novel P2Y₁₂ receptor antagonist selatogrel with irreversible (i.e., clopidogrel, prasugrel) and reversible (i.e., ticagrelor) oral P2Y₁₂ receptor antagonists was investigated in vitro and in healthy subjects. In vitro, selatogrel reduced the effects of clopidogrel and prasugrel in a concentration-dependent manner, while additive effects were observed for the combination of selatogrel and ticagrelor. Accordingly, a single-center, randomized, double-blind, two-way crossover study was conducted consisting of six groups. In each group (N = 12), an open-label loading dose of 300 or 600 mg clopidogrel, 60 mg prasugrel, or 180 mg ticagrelor was administered 30 minutes (i.e., at t _max of selatogrel) or 12 hours after a single subcutaneous dose of 16 mg selatogrel or placebo. Inhibition of platelet aggregation (IPA) was assessed at various time points up to 48 hours. Reduced IPA was determined when clopidogrel or prasugrel was administered 30 minutes after selatogrel (∼40 and 70% lower IPA, respectively, at 24 hours postdosing). However, when administering prasugrel 12 hours after selatogrel, IPA was not impacted (>90% IPA) and in the case of clopidogrel reduced effects were partially mitigated. Similar IPA was determined for ticagrelor when administered 30 minutes after selatogrel or placebo. In conclusion, reduced IPA was observed for clopidogrel and prasugrel when administered after selatogrel, which can be mitigated by applying an appropriate time interval. No PD interaction with ticagrelor was observed.

PK/PD modeling of a clazosentan thorough QT study with hysteresis in concentration-QT and RR-QT

Clazosentan's potential QT liability was investigated in a thorough QT study in which clazosentan was administered intravenously as a continuous infusion of 20 mg/h immediately followed by 60 mg/h. Clazosentan prolonged the placebo-corrected change-from-baseline QT interval corrected for RR with Fridericia's formula (ΔΔQTcF) with the maximum QT effect occurring 4 h after the maximum drug concentration, apparently associated with vomiting. The delayed effect precluded the standard linear modeling approach. This analysis aimed at characterizing the concentration-QT relationship in consideration of RR-QT hysteresis, concentration-ΔΔQTcF hysteresis, and the influence of vomiting. Nonlinear mixed-effects modeling was applied to characterize pharmacokinetics and pharmacodynamics, i.e., ΔΔQTcF. Simulations were used to predict ΔΔQTcF for expected therapeutic dose used in Phase 3 clinical development. Correction for RR-QT hysteresis did not influence ΔΔQTcF to a relevant extent. Pharmacokinetics of clazosentan were best described by a linear two-compartment model. The delayed QT prolongation was characterized by an indirect-response model with loglinear drug effect. Vomiting had no statistically significant influence on QT prolongation despite apparent differences between subjects vomiting and not vomiting, probably since vomiting occurred mostly after the main QT prolongation. Following a simulated 3-h infusion of 15 mg/h of clazosentan, the upper bound of the predicted 90% CI for mean ΔΔQTcF was expected to exceed the 10-ms regulatory threshold of concern with maximum effect 3.5 h after end of infusion. TRN: NCT03657446, 05 Sep 2018.

Treatment of Rare Inflammatory Kidney Diseases: Drugs Targeting the Terminal Complement Pathway

The complement system comprises the frontline of the innate immune system. Triggered by pathogenic surface patterns in different pathways, the cascade concludes with the formation of a membrane attack complex (MAC; complement components C5b to C9) and C5a, a potent anaphylatoxin that elicits various inflammatory signals through binding to C5a receptor 1 (C5aR1). Despite its important role in pathogen elimination, priming and recruitment of myeloid cells from the immune system, as well as crosstalk with other physiological systems, inadvertent activation of the complement system can result in self-attack and overreaction in autoinflammatory diseases. Consequently, it constitutes an interesting target for specialized therapies. The paradigm of safe and efficacious terminal complement pathway inhibition has been demonstrated by the approval of eculizumab in paroxysmal nocturnal hematuria. In addition, complement contribution in rare kidney diseases, such as lupus nephritis, IgA nephropathy, atypical hemolytic uremic syndrome, C3 glomerulopathy, or antineutrophil cytoplasmic antibody-associated vasculitis has been demonstrated. This review summarizes the involvement of the terminal effector agents of the complement system in these diseases and provides an overview of inhibitors for complement components C5, C5a, C5aR1, and MAC that are currently in clinical development. Furthermore, a link between increased complement activity and lung damage in severe COVID-19 patients is discussed and the potential for use of complement inhibitors in COVID-19 is presented.

Pharmacological Interactions between the Dual Orexin Receptor Antagonist Daridorexant and Ethanol in a Double-Blind, Randomized, Placebo-Controlled, Double-Dummy, Four-Way Crossover Phase I Study in Healthy Subjects

BACKGROUND

Daridorexant (ACT-541468) is a potent dual orexin receptor antagonist under development for the treatment of sleep disorders. Concomitant intake of ethanol and hypnotics has been shown to result in additive/supra-additive depression of the central nervous system, resulting in pronounced sedation.

OBJECTIVE

The aim of this study was to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) interactions between ethanol and daridorexant.

METHOD

This was a single-center, double-blind, placebo-controlled, randomized, four-way crossover study conducted in 19 healthy male/female subjects. Subjects received the following four treatments: ethanol with daridorexant, daridorexant alone, ethanol alone, and placebo. Daridorexant 50 mg and the matching placebo were administered as single oral tablets. Ethanol was infused intravenously and clamped at a level of 0.6 g/L for 5 h. The PK of ethanol and daridorexant were assessed and a battery of PD tests performed.

RESULTS

Concomitant administration of ethanol prolonged the time to reach maximum plasma concentrations (t_max) of daridorexant (median difference 1.25 h). No other relevant PK interactions were observed. Coadministration with ethanol produced a numerically greater impairment on saccadic peak velocity, body sway, visual analog scale (VAS) alertness, VAS alcohol intoxication, smooth pursuit, and adaptive tracking compared with daridorexant alone. All treatments were generally well tolerated without serious adverse events (AEs). The most commonly reported treatment-emergent AEs following coadministration of daridorexant and ethanol included somnolence, headache, fatigue, sudden onset of sleep, and dizziness.

CONCLUSIONS

Apart from a shift in t_max, no relevant changes in PK parameters were observed following coadministration of daridorexant and ethanol. The coadministration led to reinforced drug actions that were, at most, indicative of infra-additive effects on certain PD markers. Patients will be advised not to consume ethanol with daridorexant.

CLINICAL TRIALS REGISTRATION NUMBER

NCT03609775 (ClinicalTrials.gov Identifier).

Investigation of the effect of the dual orexin receptor antagonist almorexant on ophthalmological, spermatogenic, and hormonal variables in healthy male subjects

BACKGROUND/AIMS

The aim of this single-center, double-blind study was to investigate the effect of a 4-week once daily administration of 200 mg almorexant on tear film break-up time, spermatogenesis, hormone levels, and pancreatic elastase in stool in healthy male subjects.

METHODS

Almorexant 200 mg or matching placebo was administered in the evening for 4 weeks once daily to 56 healthy male subjects. Changes in ophthalmological variables, sperm composition, hormone levels, and pancreatic elastase levels in stool were evaluated periodically up to 8 weeks after discontinuation of drug administration. Blood samples for pharmacokinetic measurements were taken after 4 weeks to confirm compliance to study drug intake.

RESULTS

The results of this study revealed no treatment effects of almorexant, neither on tear film break-up time nor on other ophthalmological variables investigated during this study. Furthermore, spermatogenesis, hormones of the hypothalamic-pituitary-adrenal and -gonadal axes, and endocrine pancreatic secretion were shown to be not affected by a 4-week once daily administration of almorexant.

CONCLUSION

Almorexant was well tolerated and had no effect on the spectrum of pharmacodynamic variables assessed. Ophthalmology and testicular findings detected in preclinical studies were not observed in this clinical study. Therefore, these preclinical findings appear not to be relevant for humans and do not prevent from conducting larger clinical trials with either healthy subjects or patients.

Assessment of Target Engagement in a First-in-Human Trial with Sinbaglustat, an Iminosugar to Treat Lysosomal Storage Disorders

In this first-in-human study, the tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple oral doses of sinbaglustat, a dual inhibitor of glucosylceramide synthase (GCS) and non-lysosomal glucosyl ceramidase (GBA2), were investigated in healthy subjects. The single-ascending dose (SAD) and multiple-ascending dose (MAD) studies were randomized, double-blind, and placebo-controlled. Single doses from 10 to 2,000 mg in men and multiple doses from 30 to 1,000 mg twice daily for 7 days in male and female subjects were investigated. Tolerability, PK, and PD data were collected up to 3 days after (last) treatment administration and analyzed descriptively. Sinbaglustat was well-tolerated in the SAD and MAD studies, however, at the highest dose of the MAD, three of the four female subjects presented a similar pattern of general symptoms. In all cohorts, sinbaglustat was rapidly absorbed. Thereafter, plasma concentrations decreased biphasically. In the MAD study, steady-state conditions were reached on Day 2 without accumulation. During sinbaglustat treatment, plasma concentrations of glucosylceramide (GlcCer), lactosylceramide, and globotriaosylceramide decreased in a dose-dependent manner, reflecting GCS inhibition. The more complex the glycosphingolipid, the more time was required to elicit PD changes. After treatment stop, GlcCer levels returned to baseline and increased above baseline at lowest doses, probably due to the higher potency of sinbaglustat on GBA2 compared to GCS. Overall, sinbaglustat was welltolerated up to the highest tested doses. The PK profile is compatible with b.i.d. dosing. Sinbaglustat demonstrated target engagement in the periphery for GCS and GBA2.

The effect of the glucosylceramide synthase inhibitor lucerastat on cardiac repolarization: results from a thorough QT study in healthy subjects

BACKGROUND

Fabry disease is a rare inherited glycosphingolipid storage disorder caused by deleterious mutations in the GLA gene coding for the lysosomal enzyme α-galactosidase A. The glucosylceramide synthase inhibitor lucerastat is an iminosugar with potential to provide oral substrate reduction therapy in Fabry disease, regardless of the patient´s underlying mutation. Since lucerastat exhibits systemic exposure and many patients with Fabry disease suffer from rhythm and conduction abnormalities its effects on cardiac repolarization were evaluated in a thorough QT study.

METHODS

In Part A of this randomized, double-blind, placebo-controlled phase 1 study, single oral doses of 2000 and 4000 mg lucerastat were investigated to determine the supratherapeutic dose for Part B. The latter was a four-way crossover study to demonstrate that lucerastat at single oral therapeutic and supratherapeutic doses had no effect on the QTc interval > 10 ms using concentration-QTc modeling as primary analysis. The primary ECG endpoint was placebo-corrected change-from-baseline (ΔΔ) in Fridericia-corrected QTc (ΔΔQTcF). Open-label moxifloxacin served as positive control.

RESULTS

The effect of lucerastat on ΔΔQTcF was predicted as 0.39 ms (90% confidence interval [CI] - 0.13 to 0.90) and 1.69 ms (90% CI 0.33-3.05) at lucerastat peak plasma concentration after dosing with 1000 mg (5.2 µg/mL) and 4000 mg (24.3 µg/mL), respectively. A QTcF effect > 10 ms was excluded up to lucerastat plasma concentrations of approximately 34.0 µg/mL. Lucerastat did not exert an effect on other ECG parameters. Across doses, absorption of lucerastat was rapid, its elimination half-life ranged from 8.0 to 10.0 h, and the pharmacokinetics (PK) of lucerastat were dose-proportional. Moxifloxacin PK were in line with published data and assay sensitivity was demonstrated by the moxifloxacin QTc response. Lucerastat was safe and well tolerated.

CONCLUSIONS

Lucerastat up to a dose of 4000 mg has no clinically relevant liability to prolong the QT interval or any clinically relevant effect on other ECG parameters. This will be an important factor in the overall benefit-risk assessment of lucerastat in the potential treatment of Fabry disease. Trial registration The study was registered with the ClinicalTrials.gov identifier NCT03832452 (February 6th, 2019, https://clinicaltrials.gov/ct2/show/NCT03832452 ) and the EudraCT number 2018-004546-42 (December 17th, 2018).

Multiple-Dose Pharmacokinetics, Safety, and Tolerability of Aprocitentan, a Dual Endothelin Receptor Antagonist, in Healthy Japanese and Caucasian Subjects

Aprocitentan is an orally active dual endothelin receptor antagonist currently in development for treatment of difficult-to-control (resistant) hypertension. In phase 1 and 2 studies, aprocitentan has been characterized predominantly in Caucasian subjects. In this bridging, double-blind study, 20 healthy Japanese and Caucasian male and female subjects received 25 mg of aprocitentan or placebo once daily for 10 days and were monitored until 216 hours after the last dosing. The pharmacokinetics of aprocitentan were similar between ethnicities. At steady state, maximum plasma concentration was reached at 4 and 3 hours, and elimination half-life was 49.1 and 48.8 hours for Japanese and Caucasian subjects, respectively. The accumulation index was around 3 for both populations. Geometric means ratios for maximum plasma concentration and area under the plasma concentration-time curve during 1 dosing interval were around 1, with 90% confidence interval ranging from 0.87 to 1.30. Aprocitentan was safe and well tolerated in both groups. As no clinically relevant differences were found between Japanese and Caucasian subjects, it is unlikely that the pharmacokinetics of aprocitentan would differ significantly between Caucasian subjects and other ethnicities. Aprocitentan can therefore be administered at a dose level of up to 25 mg in any ethnicity without dose adjustment.

Effects of the Dual Endothelin Receptor Antagonist Aprocitentan on Body Weight and Fluid Homeostasis in Healthy Subjects on a High Sodium Diet

Aprocitentan is a novel, oral, dual endothelin receptor antagonist (ERA) in development in difficult-to-control hypertension. As fluid retention and edema are concerns with ERAs, we investigated whether aprocitentan causes weight gain in healthy subjects on a high sodium diet and explored potential mechanisms if occurring. This double-blind, randomized, placebo-controlled, crossover study enrolled 28 subjects. Three doses of aprocitentan (10, 25, or 50 mg/day for 9 days) were compared with placebo. Increases in body weight were observed with aprocitentan (placebo-corrected mean weight gains [90% confidence interval]) of 0.43 [0.05-0.80], 0.77 [0.03-1.51], and 0.83 [0.33-1.32] kg at 10 mg, 25 mg, and 50 mg, respectively. Decreases in hemoglobin and uric acid were observed. Plasma volume increased at most by 5.5% without dose-response relationship. Urinary sodium excretion decreased at 10 mg and 25 mg but not at 50 mg. Therefore, aprocitentan produced moderate weight increases in healthy subjects on high sodium diet, without obvious sodium retention.

Pharmacokinetics and Pharmacodynamics of Cenerimod, A Selective S1P1 R Modulator, Are Not Affected by Ethnicity in Healthy Asian and White Subjects

Cenerimod is a sphingosine‐1‐phosphate 1 receptor (S1P₁R) modulator in phase II development for treatment of systemic lupus erythematosus. Its pharmacokinetics (PKs), pharmacodynamics (PDs), as well as safety and tolerability were investigated in white and Asian subjects to allow for recruitment of Asian patients in future studies. A randomized, double‐blind, placebo‐controlled parallel‐group study was performed in 20 healthy male subjects (n = 10 per ethnicity). A single, oral dose of 4 mg cenerimod or placebo (ratio 8:2) was administered under fasted conditions. The PKs of cenerimod were similar in white and Asian subjects indicated by geometric mean ratios (90% confidence interval) of 0.99 (0.80–1.21) for maximum plasma concentration, 0.96 (0.75–1.24) for area under the plasma concentration‐time curve from 0 to infinity, and 1.04 (0.86–1.25) for terminal half‐life. Accordingly, the extent and time course of reduction in lymphocyte count (as PD biomarker) were also similar in white and Asian subjects as compared with placebo. As observed for other S1PR modulators, a transient mean (SD) heart rate reduction in white (15.1 (14.8) bpm) and Asian (11.8 (6.16) bpm) subjects was observed following administration of cenerimod. The drug was safe and well‐tolerated indicated by occurrence of a single adverse event of chemical conjunctivitis in a white subject that was not suspected as study drug related. In conclusion, the determined absence of any relevant PK or PD differences supports using the same doses of cenerimod in white and Asian patients in upcoming late‐phase studies.

Relevance of the CXCR4/CXCR7-CXCL12 axis and its effect in pathophysiological conditions

The impact of the C-X-C receptor (CXCR) 7 and its close co-player CXCR4 in different physiological and pathophysiological processes has been extensively investigated within the last decades. Following activation by their shared ligand C-X-C ligand (CXCL) 12, both chemokine receptors can induce various routes of cell signaling and/or scavenge CXCL12 from the extracellular environment. This contributes to organ development and maintenance of homeostasis. Alterations of the CXCR4/CXCR7-CXCL12 axis have been detected in diseases such as cancer, central nervous system and cardiac disorders, and autoimmune diseases. These alterations include changes of the expression pattern, distribution, or downstream effects. The progression of the diseases can be regulated in preclinical models by the use of various modulators suggesting that this axis serves as a promising therapeutic target. It is therefore of great interest to investigate CXCR4/CXCR7/CXCL12 modulators in clinical development, with several CXCR4 and CXCL12 modulators such as plerixafor, ulocuplumab, balixafortide, and olaptesed pegol having already reached this stage. An overview is presented of the most important diseases whose outcomes can be positively or negatively regulated by the CXCR4/CXCR7-CXCL12 axis and summarizes preclinical and clinical data of modulators of that axis. Contrary to CXCR4 and CXCL12 modulators, CXCR7 modulators have, thus far, not been extensively studied. Therefore, more (pre)clinical investigations are needed.