Jeffrey G. Suico

Effects of the cholesteryl ester transfer protein inhibitor evacetrapib on lipoproteins, apolipoproteins and 24-h ambulatory blood pressure in healthy adults.

We investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of evacetrapib.

Determining Pharmacological Selectivity of the Kappa Opioid Receptor Antagonist LY2456302 Using Pupillometry as a Translational Biomarker in Rat and Human

Background: Selective kappa opioid receptor antagonism is a promising experimental strategy for the treatment of depression. The kappa opioid receptor antagonist, LY2456302, exhibits ~30-fold higher affinity for kappa opioid receptors over mu opioid receptors, which is the next closest identified pharmacology. Methods: Here, we determined kappa opioid receptor pharmacological selectivity of LY2456302 by assessing mu opioid receptor antagonism using translational pupillometry in rats and humans. Results: In rats, morphine-induced mydriasis was completely blocked by the nonselective opioid receptor antagonist naloxone (3mg/kg, which produced 90% mu opioid receptor occupancy), while 100 and 300mg/kg LY2456302 (which produced 56% and 87% mu opioid receptor occupancy, respectively) only partially blocked morphine-induced mydriasis. In humans, fentanyl-induced miosis was completely blocked by 50mg naltrexone, and LY2456302 dose-dependently blocked miosis at 25 and 60mg (minimal-to-no blockade at 4–10mg). Conclusions: We demonstrate, for the first time, the use of translational pupillometry in the context of receptor occupancy to identify a clinical dose of LY2456302 achieving maximal kappa opioid receptor occupancy without evidence of significant mu receptor antagonism.

A Multidose Study to Examine the Effect of Food on Evacetrapib Exposure at Steady State

Purpose: To determine the effect of a high-fat meal on evacetrapib exposure at steady state in healthy participants. Methods: This was a randomized, 2-period, 2-sequence, open-label, crossover study. Patients were randomly assigned to 1 of the 2 treatment sequences in which they received evacetrapib 130 mg/d for 10 days following a 10-hour fast each day or following a high-fat breakfast each day. Plasma samples collected through 24 hours were analyzed for evacetrapib concentrations and pharmacokinetic parameter estimates including area under the concentration–time curve during a dosing interval (AUCτ), maximum observed concentration (Cmax), and time of Cmax (tmax) were calculated. Pharmacodynamic parameters, including cholesteryl ester transfer protein (CETP) activity, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides, were also assessed. Results: A total of 34 males and 6 females, mean age 41.5 years and mean body mass index 26.6 kg/m2, were enrolled. Statistical analysis showed AUCτ was 44% higher (90% confidence interval [CI]: 29%-62%) and Cmax was 51% higher (90% CI: 28%-79%) in the fed state than in the fasted state, indicating an effect of food. Consistent with higher evacetrapib exposure, changes in HDL-C, LDL-C, and CETP activity appeared to be greater in the fed state than in the fasted state. There were no notable changes in total cholesterol or triglycerides following administration in the fed and fasted states. The 130-mg doses of evacetrapib were well tolerated with and without food. Conclusion: A high-fat meal increased evacetrapib mean exposure at steady state by 44% in healthy participants.

Absolute bioavailability of evacetrapib in healthy subjects determined by simultaneous administration of oral evacetrapib and intravenous [13C8]-evacetrapib as a tracer

This open‐label, single‐period study in healthy subjects estimated evacetrapib absolute bioavailability following simultaneous administration of a 130‐mg evacetrapib oral dose and 4‐h intravenous (IV) infusion of 175 µg [13C8]‐evacetrapib as a tracer. Plasma samples collected through 168 h were analyzed for evacetrapib and [13C8]‐evacetrapib using high‐performance liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameter estimates following oral and IV doses, including area under the concentration‐time curve (AUC) from zero to infinity (AUC[0‐∞]) and to the last measureable concentration (AUC[0‐tlast]), were calculated. Bioavailability was calculated as the ratio of least‐squares geometric mean of dose‐normalized AUC (oral : IV) and corresponding 90% confidence interval (CI). Bioavailability of evacetrapib was 44.8% (90% CI: 42.2–47.6%) for AUC(0‐∞) and 44.3% (90% CI: 41.8–46.9%) for AUC(0‐tlast). Evacetrapib was well tolerated with no reports of clinically significant safety assessment findings. This is among the first studies to estimate absolute bioavailability using simultaneous administration of an unlabeled oral dose with a 13C‐labeled IV microdose tracer at about 1/1000th the oral dose, with measurement in the pg/mL range. This approach is beneficial for poorly soluble drugs, does not require additional toxicology studies, does not change oral dose pharmacokinetics, and ultimately gives researchers another tool to evaluate absolute bioavailability.

Evacetrapib: in vitro and clinical disposition, metabolism, excretion, and assessment of drug interaction potential with strong CYP3A and CYP2C8 inhibitors.

Evacetrapib is an investigational cholesteryl ester transfer protein inhibitor (CETPi) for reduction of risk of major adverse cardiovascular events in patients with high‐risk vascular disease. Understanding evacetrapib disposition, metabolism, and the potential for drug–drug interactions (DDI) may help guide prescribing recommendations. In vitro, evacetrapib metabolism was investigated with a panel of human recombinant cytochromes P450 (CYP). The disposition, metabolism, and excretion of evacetrapib following a single 100‐mg oral dose of 14C‐evacetrapib were determined in healthy subjects, and the pharmacokinetics of evacetrapib were evaluated in the presence of strong CYP3A or CYP2C8 inhibitors. In vitro, CYP3A was responsible for about 90% of evacetrapibs CYP‐associated clearance, while CYP2C8 accounted for about 10%. In the clinical disposition study, only evacetrapib and two minor metabolites circulated in plasma. Evacetrapib metabolism was extensive. A mean of 93.1% and 2.30% of the dose was excreted in feces and urine, respectively. In clinical DDI studies, the ratios of geometric least squares means for evacetrapib with/without the CYP3A inhibitor ketoconazole were 2.37 for area under the curve (AUC)(0–∞) and 1.94 for Cmax. There was no significant difference in evacetrapib AUC(0–τ) or Cmax with/without the CYP2C8 inhibitor gemfibrozil, with ratios of 0.996 and 1.02, respectively. Although in vitro results indicated that both CYP3A and CYP2C8 metabolized evacetrapib, clinical studies confirmed that evacetrapib is primarily metabolized by CYP3A. However, given the modest increase in evacetrapib exposure and robust clinical safety profile to date, there is a low likelihood of clinically relevant DDI with concomitant use of strong CYP3A or CYP2C8 inhibitors.

CYP‐mediated drug–drug interactions with evacetrapib, an investigational CETP inhibitor: in vitro prediction and clinical outcome

Aims Evacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor under development for reducing cardiovascular events in patients with high risk vascular disease. CETP inhibitors are likely to be utilized as ‘add‐on’ therapy to statins in patients receiving concomitant medications, so the potential for evacetrapib to cause clinically important drug–drug interactions (DDIs) with cytochromes P450 (CYP) was evaluated. Methods The DDI potential of evacetrapib was investigated in vitro, followed by predictions to determine clinical relevance. Potential DDIs with possible clinical implications were then investigated in the clinic. Results In vitro, evacetrapib inhibited all of the major CYPs, with inhibition constants (K i) ranging from 0.57 µm (CYP2C9) to 7.6 µm (CYP2C19). Evacetrapib was a time‐dependent inhibitor and inducer of CYP3A. The effects of evacetrapib on CYP3A and CYP2C9 were assessed in a phase 1 study using midazolam and tolbutamide as probe substrates, respectively. After 14 days of daily dosing with evacetrapib (100 or 300 mg), midazolam exposures (AUC) changed by factors (95% CI) of 1.19 (1.06, 1.33) and 1.44 (1.28, 1.62), respectively. Tolbutamide exposures (AUC) changed by factors of 0.85 (0.77, 0.94) and 1.06 (0.95, 1.18), respectively. In a phase 2 study, evacetrapib 100 mg had minimal impact on AUC of co‐administered simvastatin vs. simvastatin alone with a ratio of 1.25 (1.03, 1.53) at steady‐state, with no differences in reported hepatic or muscular adverse events. Conclusions Taken together, the extent of CYP‐mediated DDI with the potential clinical dose of evacetrapib is weak and clinically important DDIs are not expected to occur in patients taking concomitant medications.

Evacetrapib at a Supratherapeutic Steady State Concentration Does Not Prolong QT in a Thorough QT/QTc Study in Healthy Participants

Purpose: To evaluate whether evacetrapib prolongs QT intervals in healthy participants. Methods: This was a single-center, randomized, active and placebo-controlled, 3-period, 6-sequence, and crossover study. Participants were randomized to 1 of 6 treatment sequences in which they received 1 of 3 treatments: evacetrapib 1200 mg daily for 10 days (supratherapeutic dose), moxifloxacin 400 mg for 1 day (positive control), or placebo for 10 days in each of the 3 separate treatment periods. Electrocardiographic parameters were recorded at time points specified in the protocol. The primary end point was the comparison of evacetrapib effect on the population-corrected QT interval (QTcP) to that of placebo at 7 time points following dosing on day 10. An upper limit of the 2-sided 90% confidence interval (CI) <10 milliseconds confirmed the absence of significant effect. Pharmacokinetic parameters were also calculated. Results: Subjects were predominantly male (73.2%) with a mean age of 43.1 years and a mean body mass index of 25.9 kg/m2. For the primary analysis, the upper bound of the 2-sided 90% CI for the mean difference between evacetrapib and placebo was <10 milliseconds at all time points on day 10. Following administration of moxifloxacin, the QTcP increased by ≥5 milliseconds at all time points (2, 3, and 4 hours postdose). Maximum plasma concentrations of evacetrapib occurred at a median time of approximately 2 hours, and the mean apparent elimination half-life was approximately 41 hours. The area under the curve and Cmax achieved in this study were both ∼5-fold the values that are expected with the dose level being studied in a phase 3 cardiovascular outcome study. A 1200-mg supratherapeutic dose of evacetrapib was considered to be well tolerated after 10 days of daily dosing in healthy participants. Conclusions: Evacetrapib is not associated with QT interval prolongation, even at supratherapeutic doses.

Impact of Increased Gastric pH on the Pharmacokinetics of Evacetrapib in Healthy Subjects

To examine the effect of increased gastric pH on exposure to evacetrapib, a cholesteryl ester transfer protein inhibitor evaluated for the treatment of atherosclerotic heart disease.

Serum Lipid and Protein Changes in Healthy Dyslipidemic Subjects Given a Selective Inhibitor of p70 S6 Kinase‐1

The safety, pharmacokinetic, and pharmacodynamic effects of LY2584702, a selective inhibitor for p70 S6 serine/threonine protein kinase‐1, were evaluated in healthy dyslipidemic volunteers. LY2584702 was tolerated well as a monotherapy and dose‐dependently reduced low‐density lipoprotein cholesterol and triglycerides by up to 60% and 50%, respectively, without significantly changing high‐density lipoprotein cholesterol levels in plasma. LY2584702 also dose‐dependently decreased factor V activity. Alanine aminotransferase elevations were noted in 2 subjects when LY2584702 was given with atorvastatin. We suspect that the formation of 4‐aminopyrazolo[3,4‐d]pyrimidine (4‐APP) during metabolism may have contributed to some of the adverse effects of LY2584702, and the contribution of 4‐APP to the pharmacology merits further investigation. Although clinical investigation of LY2584702 has been terminated because of hepatotoxicity risk, we suggest that a selective inhibitor of p70 S6 serine/threonine protein kinase‐1 with a larger margin of safety and without the possibility of being metabolized to 4‐APP may be useful in the treatment of dyslipidemia.