Vericiguat: a QTc interval study in patients with coronary artery disease

Background

Vericiguat is a soluble guanylate cyclase stimulator developed for the treatment of symptomatic chronic heart failure (HF) in adult patients with ejection fraction less than 45% who had a previous decompensation event. Guidelines on QT studies recommend evaluation of investigational drugs at supratherapeutic exposures in healthy volunteers. We anticipated that supratherapeutic doses of vericiguat would decrease blood pressure. We conducted an adjusted QT study using the therapeutic range of vericiguat in patients with coronary artery disease (CAD), who were expected to be more haemodynamically stable with fewer confounders (e.g., on the electrocardiogram) than a HF population.

Purpose

To assess the effect of vericiguat 10 mg once-daily on placebo-adjusted change from baseline of the Fridericia-corrected QT interval (QTcF) in patients with stable CAD.

Methods

This was a randomised, Phase Ib, placebo-controlled, double blind, double-dummy, multicentre study (NCT03504982). Test drug was vericiguat once-daily (up-titrated from 2.5 mg to 5 mg and then to 10 mg [treatments A, B, C] at 14-day intervals). The positive control was moxifloxacin 400 mg (single dose on Day 8 or Day 50 with placebo on other days [treatment D]; Figure). Patients were randomised to one of two sequences.

We evaluated QTcF interval prolongation potential of vericiguat at increasing doses up to 10 mg, steady state. We investigated the pharmacokinetics, safety and tolerability of vericiguat. A clinically meaningful effect was defined as a QTcF change from baseline >10 ms relative to placebo. Assay sensitivity for moxifloxacin was confirmed by the lower limit of the 90% confidence interval (CI) of the time-matched, baseline-adjusted mean difference to placebo exceeding 5 ms at >1 time point.

Results

A total of 74 patients (66 males and 8 females) with CAD, mean (standard deviation) age 63.4 (8.0) years, were included. Mean difference between vericiguat and placebo in QTcF change from baseline (≤7 h post-dose) was <6 ms; no upper limit of the 90% CIs crossed the threshold of 10 ms. Lower limits of the two-sided 90% CI of the differences between moxifloxacin and placebo in QTcF change from baseline were >5 ms at 3 of 4 time points (Table).

Peak plasma concentration (Cmax) of vericiguat following administration of vericiguat 10 mg was 322 μg/l and median time of maximum concentration (Tmax) was 4.5 h post-dose, in line with concentrations observed following administration of vericiguat 10 mg to patients with HF [1]. For moxifloxacin 400 mg, Cmax was 1960 μg/l and median Tmax was 3 h post-dose, in line with previously reported values [2]. Vericiguat up to 10 mg was generally safe and well tolerated.

Conclusion

This study supports the assessment that administration of vericiguat 10 mg is not associated with clinically meaningful QTc prolongation. These data contribute to the overall safety profile of vericiguat for the treatment of patients with HF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Funding was provided by Bayer AG, Berlin, Germany, and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA QTc study design

Observational study on the tolerability and safety of film-coated tablets containing ivy extract (Prospan® Cough Tablets) in the treatment of colds accompanied by coughing

The only saponin drug currently prescribed in any significant amount in monotherapy medicines is ivy. This post-marketing surveillance study (PMSS) aimed at investigating the tolerability and safety of film-coated tablets containing ivy leaves dry extract (extracting medium: ethanol 30%, DER 5-7.5:1 [Prospan® Cough Tablets]) under practice conditions. Adults and children aged 11-85 years of both genders were included. A total of 330 patients suffering from colds accompanied by coughing or from chronic, inflammatory bronchial diseases were scheduled to undergo treatment for a period of at least seven days. The tolerability of the tablets was rated by means of questionnaires. The results of this PMSS reflect the good to very good tolerability of the tablets in the global assessment by both, the practitioner (98.5%) and by the patient (96.4%). This is one of the reasons for the high acceptance and compliance (rated as 'good' in 98.8% of all cases). The safety not only regarding the administration form but also regarding the active substance is thus underlined once again.

Critical evaluation of the effect of valerian extract on sleep structure and sleep quality

A carefully designed study assessed the short-term (single dose) and long-term (14 days with multiple dosage) effects of a valerian extract on both objective and subjective sleep parameters. The investigation was performed as a randomised, double-blind, placebo-controlled, cross-over study. Sixteen patients (4 male, 12 female) with previously established psychophysiological insomnia (ICSD-code 1.A.1.), and with a median age of 49 (range: 22 to 55), were included in the study. The main inclusion criteria were reported primary insomnia according to ICSD criteria, which was confirmed by polysomnographic recording, and the absence of acute diseases. During the study, the patients underwent 8 polysomnographic recordings: i.e., 2 recordings (baseline and study night) at each time point at which the short and long-term effects of placebo and valerian were tested. The target variable of the study was sleep efficiency. Other parameters describing objective sleep structure were the usual features of sleep-stage analysis, based on the rules of Rechtschaffen and Kales (1968), and the arousal index (scored according to ASDA criteria, 1992) as a sleep microstructure parameter. Subjective parameters such as sleep quality, morning feeling, daytime performance, subjectively perceived duration of sleep latency, and sleep period time were assessed by means of questionnaires. After a single dose of valerian, no effects on sleep structure and subjective sleep assessment were observed. After multiple-dose treatment, sleep efficiency showed a significant increase for both the placebo and the valerian condition in comparison with baseline polysomnography. We confirmed significant differences between valerian and placebo for parameters describing slow-wave sleep. In comparison with the placebo, slow-wave sleep latency was reduced after administration of valerian (21.3 vs. 13.5 min respectively, p<0.05). The SWS percentage of time in bed (TIB) was increased after long-term valerian treatment, in comparison to baseline (9.8 vs. 8.1% respectively, p<0.05). At the same time point, a tendency for shorter subjective sleep latency, as well as a higher correlation coefficient between subjective and objective sleep latencies, were observed under valerian treatment. Other improvements in sleep structure - such as an increase in REM percentage and a decrease in NREM1 percentage - took place simultaneously under placebo and valerian treatment. A remarkable finding of the study was the extremely low number of adverse events during the valerian treatment periods (3 vs. 18 in the placebo period). In conclusion, treatment with a herbal extract of radix valerianae demonstrated positive effects on sleep structure and sleep perception of insomnia patients, and can therefore be recommended for the treatment of patients with mild psychophysiological insomnia.

Single daily doses of saquinavir achieve HIV-inhibitory concentrations when combined with baby-dose ritonavir

Dual protease inhibitor (PI) therapy has been established either in order to increase plasma concentrations of one PI or to combine synergistic effects of two PI's on viral load. Studies with saquinavir (SQV) and small doses of ritonavir (RTV) as well as experiences from our therapeutic drug monitoring suggest that single daily doses may result in sufficient SQV serum levels throughout an interval of 24 h. A controlled, randomized trial with 20 healthy men was conducted for the comparison of serum levels with 1600 mg SQV (group 1) or 1600 mg SQV/200 mg RTV (group 2). The dosages were selected in order to use RTV as an inhibitor of cytochrome P450 3A4 and SQV as protease inhibitor. The volunteers received single daily doses following a standardized breakfast on 3 consecutive days. Serum samples were analyzed for SQV and RTV employing LC-tandem mass spectrometry. The minimum concentration of saquinavir after 24 hours, the AUC, the maximum concentration and the serum half-lives on day 3 served as target parameters. The minimum SQV concentration amounted to 469.4 ng/ml, when combined with RTV and proved to be significantly higher (p <0.05) than the corresponding concentration with SQV alone (127.3 ng/ml). The SQV maximum concentration was raised approximately 6fold and the AUC 9fold when RTV was coadministered. In combination with 200 mg of RTV the predominant elimination half-life of SQV increased from 2.6 to 6.45 hours. These data prove that under single daily doses of 1600 mg SQV/200 mg RTV HIV-inhibitory concentrations of SQV can be achieved for 24 hours. Due to the high variability of the concentrations, which can be seen with all PI s, we recommend continuous therapeutic drug monitoring of serum trough levels.

The absolute and relative bioavailability of dipyridamole from different preparations and the in vitro-in vivo comparison

The in vitro liberation and the bioavailability (BV) of dipyridamole (D) in three different brands (A, B, C) were determined in a three way cross-over study on 12 healthy subjects. Also, the pharmacokinetics of D given intravenously was investigated. The in vitro liberation of B is only to be achieved by repeated touching. The tmax for the preparations, expressed as mean +/- s mean amounts as follows: A: 0.8 +/- 0.06; B: 1.1 +/- 0.1; C: 0.8 +/- 0.09 hours and is in the case of B significantly different (p less than 0.05) from the others. The cmax values (A: 1.01 +/- 0.25; B: 1.16 +/- 0.15; C: 1.51 +/- 0.3 mumol X l-1) and the AUC values (A: 3.8 +/- 0.9; B: 3.1 +/- 0.5; C: 3.8 +/- 0.7 mumol X h X l-1) are not different. The absolute BV of D is 27 +/- 5.5% (range: 11-44%) independent of the used brand. In 4 subjects a second tmax at the 4th-6th hour is to be observed irrespective of the way of dosing. An enterohepatic circulation is assumed. It is concluded that the determination of the in vitro liberation is a necessary and useful parameter, but cannot be used alone for characterization of the BV in every case, as e.g., for problem drugs.