A Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of MK8266 in Hypertensive Men (MK-8266-002)

Assessment of the number of participants with at least one clinical or laboratory AE in those receiving multiple oral doses of MK-8266. An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the sponsor's product, whether or not considered related to the use of the product.

Assessment of the number of participants receiving MK-8266 who discontinued therapy due to an AE over 10 days of treatment. An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the SPONSOR's product, whether or not considered related to the use of the product. The number of participants in any treatment group who discontinued therapy due to an AE was primarily assessed for Days 0-10.

Assessment of the change from baseline in SBP, obtained using a validated, semi-automated oscillometric device. Evaluated for MK-8266 relative to placebo in participants, as measured by the time weighted average change over 24 hours postdose (TWA^0-24hrs) on dosing Day 10. Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this analysis.

Assessment of HR (beats/min) on Day 10 (24-hours postdose) with MK-8266 relative to placebo in participants, as measured by the time weighted average change over 24 hours postdose (TWA^0-24hrs). Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this analysis. Baseline HR values are shown in the Baseline Characteristics section for Panels A, B, C, D, E.

Assessment of the central, ascending aortic blood pressure augmentation index (AIx), based on measurement of central pulse pressure at selected time points on Day 10, as measured by applanation tonometry of the radial artery. This outcome measure assessed the time weighted average change over 24 hours postdose (TWA^0-24hrs) on dosing Day 10. Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this assessment.

Assessment of whole blood samples for cGMP analysis, based on samples obtained predose as well as 4 and 24 hours postdose on Day 1 and Day 10, and predose only on Day 4. The change from baseline in cGMP was assessed at 24 hours postdose on Day 10. Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this assessment.

The percent inhibition of ADP-induced platelet aggregation from Baseline to 5 hours postdose on Day 10 was assessed and is summarized here. Platelet aggregation was initiated by addition of ADP (2.5 µM) to the participant's blood sample. Aggregation was followed for 5 minutes after addition of the agonist, and the maximum percent of light transmission (extent of aggregation) obtained during this period, as well as the instrument-calculated slope (rate of aggregation), were reported. Post treatment platelet aggregation is expressed as a percent of each participant's pretreatment level of aggregation. Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this summary. The data are very limited. On Day 10 only 8 participants received MK-8266 0.8 mg TID and 3 participants received placebo.

The percent inhibition of collagen-induced platelet aggregation from Baseline to 5 hours postdose on Day 10 was assessed and is summarized here. Platelet aggregation was initiated by addition of collagen (2 µg/mL) to the participant's blood sample. Aggregation was followed for 5 minutes after addition of the agonist, and the maximum percent of light transmission (extent of aggregation) obtained during this period, as well as the instrument-calculated slope (rate of aggregation), were reported. Post treatment platelet aggregation is expressed as a percent of each participant's pretreatment level of aggregation. Panel D and Panel E had identical treatments (MK-8266 0.8 mg TID), which were combined for this summary. The data are very limited. On Day 10, only 8 participants received MK-8266 0.8 mg TID and 3 participants received placebo.