Midazolam microdosing applied in early clinical development for drug-drug interaction assessment.

AIMS: We aimed to incorporate a pharmacologically inactive midazolam microdose into early clinical studies for the assessment of CYP3A drug-drug interaction liability. METHODS: Three early clinical studies were conducted with substances (Compounds A, B and C) which gave positive CYP3A perpetrator signals in vitro. A 75 µg dose of midazolam was administered alone (baseline CYP3A activity) followed by administration with the highest dose groups tested for each compound on Day 1/3 and Day 14 or Day 17. Midazolam exposure (AUC0-∞ , Cmax ) during administration with the test substances was compared to baseline data via an analysis of variance on log-transformed data. Partial AUC2-4 ratios were also compared to AUC0-∞ ratios using linear regression on log-transformed data. RESULTS: Test compound Cmax values exceeded relevant thresholds for drug-drug interaction liability. Midazolam concentrations were quantifiable over the full profiles for all subjects in all studies. Point estimates of the midazolam AUC0-∞ gMean ratios ranged from 108.3 to 127.1% for Compound A, from 93.3 to 114.5% for Compound B, and from 92.0 to 96.7% for the two highest dose groups of Compound C. Cmax gMean ratios were in the same range. Thus, no relevant drug-drug interactions were evident, based on the results of midazolam microdosing. AUC2-4 ratios from these studies were comparable to the AUC0-∞ ratios. CONCLUSION: Midazolam microdosing incorporated into early clinical studies is a feasible tool for reducing dedicated drug-drug interaction studies, meaning reduced subject burden. Limited sampling could further reduce subject burden, costs and needed resources.

Effects of Single and Multiple Ascending Doses of BI 1358894 in Healthy Male Volunteers on Safety, Tolerability and Pharmacokinetics: Two Phase I Partially Randomised Studies.

INTRODUCTION: The transient receptor potential canonical (TRPC) ion channels have been implicated in the pathophysiology of major depressive disorder (MDD), and TRPC inhibition has been shown to reduce depressive-like behaviour in rodent models of depression. BI 1358894, a small-molecule inhibitor of TRPC ion channels, is currently being developed for the treatment of MDD. OBJECTIVE: Two phase I studies assessed the safety, tolerability, and pharmacokinetics (PK) of oral BI 1358894 in fed and fasted states following a single ascending dose (SAD) [NCT03210272/1402-0001] and multiple ascending doses (MAD) [NCT03754959/1402-0002] in healthy male volunteers. In addition, any potential food effect was evaluated after a single dose. METHODS: In both studies, eligible healthy male volunteers (aged 18-45 years; body mass index of 18.5-29.9 kg/m2) were allocated to receive BI 1358894 or placebo. In the SAD study (1402-0001), volunteers were randomised 3:1 to receive BI 1358894 or placebo in fasted (3, 6, 10, 25, 50, 100, or 200 mg) and fed states (200 mg). The food effect part was conducted as an open-label, randomised, two-way crossover study at doses of 50 and 100 mg in fasted and fed states (high-calorie, high-fat breakfast). For the MAD study (1402-0002), volunteers were randomised 4:1 to receive BI 1358894 (10, 25, 50, 100, or 200 mg) or placebo once daily for 14 days under fed conditions. Primary endpoint (both studies): number of volunteers with drug-related adverse events (DRAEs). Secondary PK endpoints for study 1402-0001: area under the concentration-time curve (AUC) from time zero extrapolated to infinity (AUC∞), maximum plasma concentration (Cmax), and AUC from time zero to the last quantifiable data time point (AUC0-tz). Secondary PK endpoints for study 1402-0002: AUC over 0-24 h (AUC0-24), Cmax after the first dose, and steady-state AUC and Cmax over a uniform dosing interval (AUCτ,ss and Cmax,ss, respectively) after the last dose. RESULTS: BI 1358894 was well tolerated at doses ≤ 200 mg under all tested conditions and no dose dependency was observed in DRAE frequency for either study. In the SAD study, BI 1358894 exposure increased dose proportionally across 3-50 mg in the fasted state and across 50-200 mg in the fed state. A positive food effect was observed at the tested doses. In the MAD study, BI 1358894 exposure increased less than dose proportionally across 10-200 mg. CONCLUSIONS: These studies demonstrate that BI 1358894 is well tolerated in healthy male volunteers following single and multiple doses, with no dose dependency observed in DRAE frequency. BI 1358894 exposure increased dose dependently in both the SAD and MAD studies, with higher exposure of BI 1358894 observed in the fed state. CLINICALTRIALS REGISTRATION: These trials have been registered on ClinicalTrials.gov: NCT03210272/1402-0001 (registered on 6 July 2017) and NCT03754959/1402-0002 (registered on 27 November 2018).

Effect of BI 1358894 on Cholecystokinin-Tetrapeptide (CCK-4)-Induced Anxiety, Panic Symptoms, and Stress Biomarkers: A Phase I Randomized Trial in Healthy Males.

INTRODUCTION: Depression, anxiety, and/or panic disorder are often comorbid and have a complex etiology mediated through the same neuronal network. Cholecystokinin-tetrapeptide (CCK-4), a synthetic analog of the endogenous neuropeptide cholecystokinin (CCK), is thought to be implicated in this network. The CCK-4 challenge model is an accepted method of investigating the pathophysiology of panic and has been shown to mediate neuronal activation via the transient receptor potential canonical (TRPC) ion channels. OBJECTIVES: This study aimed to assess the pharmacodynamic effects of BI 1358894, a small-molecule inhibitor of TRPC ion channel members 4 and 5 (TRPC4/5), on CCK-4-induced anxiety/panic-like symptoms and evaluate circuit engagement. METHODS: Twenty healthy male CCK-4-sensitive volunteers entered a Phase I, double blind, randomized, two-way cross-over, single dose, placebo-controlled trial. Randomization was to oral BI 1358894 100 mg in the fed state followed by oral placebo in the fed state, or vice versa. Treatments were administered 5 h prior to intravenous CCK-4 50 µg. The primary endpoint was maximum change from baseline of the Panic Symptom Scale (PSS) sum intensity score after CCK-4 injection. Further endpoints included the emotional faces visual analog score (EVAS), the Spielberger State-Trait Anxiety Inventory (STAI), plasma adrenocorticotropic hormone (ACTH), and serum cortisol values. The safety and tolerability of BI 1358894 was assessed based on a number of parameters including occurrence of adverse events (AEs). All pharmacodynamic, pharmacokinetic, and safety endpoints were analyzed using descriptive statistics. RESULTS: Single oral doses of BI 1358894 were generally well tolerated by the healthy male volunteers included in this study. Adjusted mean maximum change from baseline in PSS sum intensity score was 24.4 % lower in volunteers treated with BI 1358894 versus placebo, while adjusted mean maximum change from baseline of EVAS was reduced by 19.2 % (BI 1358894 vs placebo). The STAI total score before CCK-4 injection was similar in both groups (placebo: 25.1; BI 1358894: 24.3). Relative to placebo, BI 1358894 reduced CCK-4-induced mean maximum plasma ACTH and serum cortisol values by 58.6 % and 27.3 %, respectively. Investigator-assessed drug-related AEs were reported for 13/20 participants (65.0 %). There were no serious or severe AEs, AEs of special interest, AEs leading to discontinuation of trial medication, or deaths. CONCLUSIONS: Overall, BI 1358894 reduced psychological and physiological responses to CCK-4 compared with placebo, as measured by PSS, subjective EVAS and objectively measured stress biomarkers. BI 1358894 had a positive safety profile, and single oral doses were well tolerated by the healthy volunteers. This trial (NCT03904576/1402-0005) was registered on Clinicaltrials.gov on 05.04.19.

Effects of Cytochrome P450 3A4 Induction and Inhibition on the Pharmacokinetics of BI 425809, a Novel Glycine Transporter 1 Inhibitor.

BACKGROUND AND OBJECTIVE: Increased glycine availability at the synaptic cleft may enhance N-methyl-D-aspartate receptor signalling and provide a promising therapeutic strategy for cognitive impairment associated with schizophrenia. These studies aimed to assess the pharmacokinetics of BI 425809, a potent glycine-transporter-1 inhibitor, when co-administered with a strong cytochrome P450 3A4 (CYP3A4) inhibitor (itraconazole) and inducer (rifampicin). METHODS: In vitro studies using recombinant CYPs, human liver microsomes, and human hepatocytes were conducted to determine the CYP isoforms responsible for BI 425809 metabolism. In addition, two open-label, fixed-treatment period, phase I studies in healthy male volunteers are described. Period 1: participants received oral BI 425809 25 mg (single dose) on day 1; period 2: participants received multiple doses, across 10 days, of oral itraconazole or rifampicin combined with a single dose of oral BI 425809 25 mg on day 4/7 of the itraconazole/rifampicin treatment, respectively. Pharmacokinetic and safety endpoints were assessed in the absence/presence of itraconazole/rifampicin and included area under the concentration-time curve (AUC) over the time interval 0-167 h (AUC0‒167; itraconazole), 0-168 h (AUC0‒168; rifampicin), or 0-infinity (AUC0-∞; rifampicin and itraconazole), maximum measured concentration (Cmax) of BI 425809, and adverse events. RESULTS: In vitro results suggested that CYP3A4 accounted for ≥ 90% of the metabolism of BI 425809. BI 425809 exposure (adjusted geometric mean ratio [%]) was higher in the presence of itraconazole (AUC0‒167: 265.3; AUC0-∞: 597.0; Cmax: 116.1) and lower in the presence of rifampicin (AUC0‒168: 10.3; AUC0-∞: 9.8; Cmax: 37.4) compared with BI 425809 alone. Investigational treatments were well tolerated. CONCLUSIONS: Systemic exposure of BI 425809 was altered in the presence of strong CYP3A4 modulators, corroborating in vitro results that CYP3A4 mediates a major metabolic pathway for BI 425809. TRIAL REGISTRATION NUMBER: NCT02342717 (registered on 15 January 2015) and NCT03082183 (registered on 10 March 2017).