Phase 1 Study of MK-5475, an Inhaled Soluble Guanylate Cyclase Stimulator, in Participants with Pulmonary Hypertension Associated with Chronic Obstructive Pulmonary Disease.

Purpose: This phase 1 study (NCT04370873) evaluated safety and pharmacokinetics/pharmacodynamics (PK/PD) of MK-5475 in participants with pulmonary hypertension associated with COPD (PH-COPD). Methods: Eligible participants were 40-80 years old with COPD (FEV1/FVC <0.7; FEV1 >30% predicted) and PH (mean pulmonary arterial pressure ≥25 mmHg). Participants were randomized 2:1 to MK-5475 or placebo via dry-powder inhaler once daily for 7 days in Part 1 (360 µg) or 28 days in Part 2 (380 µg). Safety was assessed by adverse events (AEs) and arterial blood oxygenation. Part-2 participants had pulmonary vascular resistance (PVR; primary PD endpoint) and pulmonary blood volume (PBV; secondary PD endpoint) measured at baseline and Day 28. A non-informative prior was used to calculate posterior probability (PP) that the between-group difference (MK-5475 - placebo) in mean percent reduction from baseline in PVR was less than -15%. Results: Nine participants were randomized in Part 1, and 14 participants in Part 2. Median age of participants (86.4% male) was 68.5 years (41-77 years); 95.5% had moderate-to-severe COPD. Incidences of AEs were comparable between MK-5475 and placebo: overall (5/14 [36%] versus 5/8 [63%]), drug-related (1/14 [7%] versus 2/8 [25%]), and serious (1/14 [7%] versus 1/8 [13%]). MK-5475 caused no meaningful changes in arterial blood oxygenation or PBV. MK-5475 versus placebo led to numerical improvements from baseline in PVR (-21.2% [95% CI: -35.4, -7.0] versus -5.4% [95% CI: -83.7, 72.9]), with between-group difference in PVR less than -15% and calculated PP of 51%. Conclusion: The favorable safety profile and numerical reductions in PVR observed support further clinical development of inhaled MK-5475 for PH-COPD treatment.

Vericiguat: A Randomized, Phase Ib, Placebo-Controlled, Double-Blind, QTc Interval Study in Patients with Chronic Coronary Syndromes.

BACKGROUND: Vericiguat is indicated for the treatment of symptomatic chronic heart failure in adult patients with reduced ejection fraction who are stabilized after a recent decompensation event. OBJECTIVE: To investigate the effects of vericiguat on QT interval in patients with chronic coronary syndromes (CCS). METHODS: This was a randomized, phase Ib, placebo-controlled, double-blind, double-dummy, multicenter study. Vericiguat once daily was up-titrated from 2.5 mg to 5 mg and then to 10 mg (treatments A, B, and C) at 14-day intervals. Positive control was moxifloxacin 400 mg (single dose on day 8 or day 50; placebo on other days [treatment D]). We evaluated the placebo-adjusted change from baseline of the Frederica-corrected QTc interval (QTcF), pharmacokinetics, safety, and tolerability of vericiguat. RESULTS: In total, 74 patients with CCS, with mean (standard deviation) age 63.4 (8.0) years, were included and 72 patients completed the study. At each timepoint up to 7 h after administration, mean placebo-corrected change in QTcF from baseline was < 6 ms and the upper limit of the two-sided 90% confidence interval of the mean was below the 10-ms threshold for clinical relevance. Moxifloxacin confirmed the assay sensitivity. Median time of maximum concentration of vericiguat was 4.5 h post-dose. The adverse event profile of vericiguat was consistent with its mechanism of action, and the findings did not indicate any safety concerns. CONCLUSIONS: As part of an integrative risk assessment, this study demonstrated no clinically relevant corrected QT prolongation with vericiguat 10 mg once daily at steady state. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov number, NCT03504982.

Vericiguat is approved for treating worsening heart failure with reduced ejection fraction. As part of the safety evaluation of vericiguat, this study assessed its effect on the QT interval of the electrocardiogram. An electrocardiogram measures electrical activity of the heart. The QT interval is the time from the start of the Q wave to the end of the T wave. A longer than normal QT interval indicates an increased chance for abnormal heart rhythms. Usually, a QT study is conducted at high doses in healthy volunteers. Previous studies indicated that high doses of vericiguat may cause increased changes in blood pressure in healthy volunteers. Therefore, this study was performed in patients at a normal therapeutic dose. Patients with chronic coronary syndromes were enrolled rather than patients with heart failure with reduced ejection fraction, because they have fewer electrocardiogram abnormalities. The starting dose of vericiguat was 2.5 mg once daily, and the dose was increased to 5 mg and then to 10 mg at 14-day intervals. Placebo was tested for comparison and moxifloxacin (400 mg), a drug known to increase the QT interval, was tested to confirm that the study could detect a change in the QT interval. An increase in the QT interval of more than 10 ms was considered clinically relevant. Of 74 patients included, 72 completed the study. At each timepoint (up to 7 h after dosing), the difference between the QT change for vericiguat and placebo was less than 10 ms; therefore, vericiguat does not prolong the QT interval to a clinically relevant extent.

Effects of an inhaled soluble guanylate cyclase (sGC) stimulator MK-5475 in pulmonary arterial hypertension (PAH).

BACKGROUND: Novel therapeutics for pulmonary arterial hypertension (PAH) with improved safety/tolerability profiles are needed to address continued high rates of morbidity/mortality. METHODS: This Phase 1 study evaluated efficacy/safety of inhaled single-dose MK-5475, an investigational, small-molecule stimulator of soluble guanylate cyclase designed for inhaled delivery via a dry-powder inhaler device, in participants with PAH (Clinicaltrials.gov: NCT03744637). Eligible participants were 18-70 years of age; body mass index ≤35 kg/m2; diagnosis of PAH (Group 1 pulmonary hypertension). In Part 1, participants received double-blind MK-5475 or placebo for safety assessment (primary outcome). In Part 2, 4 panels participated in ≤3 open-label periods. Part 2/Period 1 assessed safety/tolerability. Part 2/Periods 2 and 3, respectively, involved functional respiratory imaging for measuring pulmonary blood volume (secondary outcome) and right heart catheterization for measuring pulmonary vascular resistance (primary outcome). RESULTS: MK-5475 was generally well tolerated without systemic side effects on blood pressure or heart rate up to 24 h post dose. With respect to the primary pharmacodynamic outcome, mean reductions in pulmonary vascular resistance ranged from 21% to 30% across 120 µg and 360 µg doses. CONCLUSIONS: Treatment with inhaled single-dose MK-5475 showed rapid and sustained reductions in pulmonary vascular resistance and increases in pulmonary blood volume. MK-5475 was generally well tolerated versus placebo without vasodilatory systemic side effects. The promising pulmonary selectivity and favorable safety/tolerability profile of MK-5475 seen in this study of adult participants with PAH lays the foundation for further clinical development.