Exposure?response modelling for empagliflozin,a sodium glucose cotransporter 2 (SGLT2) inhibitor,in patients with type 2 diabetes

Aims

To provide model-based clinical development decision support including dose selection guidance for empagliflozin, an orally administered sodium glucose cotransporter 2 inhibitor, through developed exposure−response (E−R) models for efficacy and tolerability in patients with type 2 diabetes mellitus (T2DM).

Methods

Five randomized, placebo-controlled, multiple oral dose studies of empagliflozin in patients with T2DM (n = 974; 1–100 mg once daily, duration ≤12 weeks) were used to develop E−R models for efficacy (glycosylated haemoglobin [HbA_1c], fasting plasma glucose [FPG] and urinary glucose excretion). Two studies (n = 748, 12 weeks) were used to evaluate tolerability E−R.

Results

The efficacy model predicted maximal decreases in FPG and HbA_1c of 16% and 0.6%, respectively, assuming a baseline FPG concentration of 8 mm (144 mg dl⁻¹) and 10–25 mg every day empagliflozin targeted 80–90% of these maximums. Increases in exposure had no effect on incidence rates of hypoglycaemia (n = 4), urinary tract infection (n = 17) or genital/vulvovaginal-related (n = 16) events, although low prevalence rates may have precluded more accurate evaluation.

Conclusions

E−R analyses indicated that 10 and 25 mg once daily empagliflozin doses achieved near maximal glucose lowering efficacy.     

Safety,pharmacokinetics and pharmacodynamics of multiple oral doses of apixaban,a factor Xa inhibitor,in healthy subjects

Aim

Apixaban is an oral factor Xa inhibitor approved for stroke prevention in atrial fibrillation and thromboprophylaxis in patients who have undergone elective hip or knee replacement surgery and under development for treatment of venous thromboembolism. This study examined the safety, pharmacokinetics and pharmacodynamics of multiple dose apixaban.

Method

This double-blind, randomized, placebo-controlled, parallel group, multiple dose escalation study was conducted in six sequential dose panels – apixaban 2.5, 5, 10 and 25 mg twice daily and 10 and 25 mg once daily– with eight healthy subjects per panel. Within each panel, subjects were randomized (3:1) to oral apixaban or placebo for 7 days. Subjects underwent safety assessments and were monitored for adverse events (AEs). Blood samples were taken to measure apixaban plasma concentration, international normalized ratio (INR), activated partial thromboplastin time (aPTT) and modified prothrombin time (mPT).

Results

Forty-eight subjects were randomized and treated (apixaban, n = 36; placebo, n = 12); one subject receiving 2.5 mg twice daily discontinued due to AEs (headache and nausea). No dose limiting AEs were observed. Apixaban maximum plasma concentration was achieved ∼3 h post-dose. Exposure increased approximately in proportion to dose. Apixaban steady-state concentrations were reached by day 3, with an accumulation index of 1.3–1.9. Peak : trough ratios were lower for twice daily vs. once daily regimens. Clotting times showed dose-related increases tracking the plasma concentration–time profile.

Conclusion

Multiple oral doses of apixaban were safe and well tolerated over a 10-fold dose range, with pharmacokinetics with low variability and concentration-related increases in clotting time measures.     

An open-label, single-dose bioavailability study of the pharmacokinetics of CAT-354 after subcutaneous and intravenous administration in healthy males

AIM

To assess the bioavailability and pharmacokinetics of CAT-354, an anti-IL-13 human monoclonal IgG4 antibody, following subcutaneous (s.c.) and intravenous (i.v.) administration.

METHODS

This was a single-dose, randomized, open-label, parallel-group bioavailability study. Healthy male subjects aged 20–54 years were randomly assigned to one of three dose groups (n= 10/group) to receive CAT-354: 150 mg i.v.; 150 mg s.c. or 300 mg s.c. (two 150 mg injections). Serum pharmacokinetics, adverse events (AEs), vital signs, electrocardiograms and laboratory parameters were assessed.

RESULTS

CAT-354 showed bioavailability of 62% and 60% after 150 mg and 300 mg s.c. doses, respectively, and linear pharmacokinetics over the dose range tested. Peak serum concentrations in the s.c. groups occurred after 3–9 (median 5) days, with a mean elimination half-life of 19.2 ± 3.1 days (150 mg) and 19.4 ± 3.59 days (300 mg) after s.c. and 21.4 ± 2.46 days after i.v. administration. Volume of distribution at steady state (V_ss) was 4960 ± 1440 ml kg⁻¹ after i.v. (slightly greater than plasma volume). Average apparent clearances (CL/F) were 292 ± 82.3 and 307 ± 109 ml day⁻¹ after 150 and 300 mg s.c., respectively; systemic CL of 188 ± 84.0 ml day⁻¹ after i.v. dosing was consistent with endogenous IgG and reticuloendothelial elimination. No severe or serious AEs occurred. Among 40 reported AEs, 25 were headache, sinus disorders/respiratory symptoms and changes in body temperature perception.

CONCLUSIONS

CAT-354 exhibited bioavailability of approximately 60% when given s.c. to healthy male subjects.     

Effects of the moderate CYP3A4 inhibitor, fluconazole, on the pharmacokinetics of fesoterodine in healthy subjects

AIMS

To assess the effects of fluconazole, a moderate CYP3A4 inhibitor, on the pharmacokinetics (PK) and safety/tolerability of fesoterodine.

METHODS

In this open-label, randomized, two-way crossover study, 28 healthy subjects (18–55 years) received single doses of fesoterodine 8 mg alone or with fluconazole 200 mg. PK endpoints, including the area under the plasma concentration–time curve from 0 to infinity (AUC(0,∞)), maximum plasma concentration (C_max), time to C_max (t_max), and half-life (t_1/2), were assessed for 5-hydroxymethyl tolterodine (5-HMT), the active moiety of fesoterodine.

RESULTS

Concomitant administration of fesoterodine with fluconazole increased AUC(0,∞) and C_max of 5-HMT by approximately 27% and 19%, respectively, with corresponding 90% confidence intervals of (18%, 36%) and (11%, 28%). There was no apparent effect of fluconazole on 5-HMT t_max or t_½. Fesoterodine was generally well tolerated regardless of fluconazole co-administration, with no reports of death, serious adverse events (AEs) or severe AEs. Following co-administration of fesoterodine with fluconazole, 13 subjects (48%) experienced a total of 40 AEs; following administration of fesoterodine alone, six subjects (22%) experienced a total of 19 AEs. The majority of AEs were of mild intensity. There were no clinically significant changes in laboratory or physical examination parameters.

CONCLUSION

Fesoterodine 8 mg single dose was well tolerated when administered alone or with fluconazole. Based on the observed increase in 5-HMT exposures being within the inherent variability of 5-HMT pharmacokinetics, adjustment of fesoterodine dose is not warranted when co-administered with a moderate CYP3A4 inhibitor provided they are not also inhibitors of transporters.     

Tolerance and pharmacokinetics of single-dose intravenous hemoporfin in healthy volunteers

Aim:

To investigate the safety, tolerability and pharmacokinetics of intravenous hemoporfin, a novel photosensitive drug for the treatment of port-wine stain (PWS), in healthy Chinese volunteers following single-dose administration.

Methods:

Thirty-six healthy Chinese subjects were enrolled. The subjects were administered hemoporfin (2.5, 5, 7.5 or 10 mg/kg) via single-dose intravenous infusion. Pharmacokinetics of the drug were studied in the groups with doses of 2.5, 5 and 7.5 mg/kg, and tolerability was studied in all the 4 groups. Safety and tolerance were evaluated by monitoring adverse events and laboratory parameters, and pharmacokinetics were assessed by determining hemoporfin content with a validated high-performance liquid chromatography with fluorescence detection (HPLC/FLD) method.

Results:

Mild and transient adverse events occurred in the trial (n=10), but none were serious, and no subjects were withdrawn from the trial. The gastrointestinal tract adverse events, such as nausea, stomach upset, abdominal pain and vomiting, were observed in the groups with doses of 7.5 and 10 mg/kg. Increased alanine aminotransferase (ALT) concentration was found in 3 subjects, and increased alkaline phosphatase (ALP) concentration in one subject. The half-life of hemoporfin for doses of 2.5, 5, and 7.5 mg/kg was 1.26 h, 1.31 h, and 1.70 h, respectively. C_max and AUC increased with dose for intravenous single-dose administration of hemoporfin in the 2.5, 5, and 7.5 mg/kg groups. Urinary excretion of hemoporfin within 12 h was less than 0.2%.

Conclusion:

Hemoporfin is safe and well-tolerated in healthy Chinese volunteers at a single intravenous dose of up to 10 mg/kg. It was rapidly cleared from the blood and had a short half-life, which insures a short light-avoidance period.     

Pharmacokinetics and safety of calcium L-threonate in healthy volunteers after single and multiple oral administrations

Aim:

To evaluate the pharmacokinetics of L-threonate after single or multiple oral administrations and its safety profile in healthy Chinese volunteers.

Methods:

This was an open-label, single- and multiple-dose study. The subjects were assigned to receive a single dose, 675, 2025, or 4050 mg, of calcium L-threonate (n=12) or repeated doses of 2025 mg twice daily for 4 d (n=12). Serial plasma and urine samples were analyzed with HPLC-MS/MS. Pharmacokinetic parameters of L-threonate were calculated using non-compartmental analysis with WinNonlin software.

Results:

In the single dose group, C_max reached at 2.0 h and the mean t_1/2 was approximately 2.5 h. Area under curve (AUC) and C_max increased with dose escalation, but dose proportionality was not observed over the range of 675 to 4050 mg. AUC and C_max in the fasted subjects were lower compared with those in the non-fasted subjects. Cumulative urinary excretion of L-threonate over 24 h represented 5.9% of the administered dose with a mean Cl/r of 0.8 L/h. In the multiple-dose study, no accumulation appeared upon repeated doses of 2025 mg twice daily for 4 d. There were no serious adverse events that occurred during this study.

Conclusion:

Calcium L-threonate was well tolerated in healthy Chinese subjects, with no pattern of dose-related adverse events. Plasma exposure increased with dose escalation, but linear pharmacokinetics were not observed over the studied doses. L-threonate was absorbed rapidly, and its absorption was enhanced by food intake. No systemic accumulation appeared after repeated administrations.     

Ibudilast in healthy volunteers: safety,tolerability and pharmacokinetics with single and multiple doses

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Ibudilast is an oral drug approved in Asia for asthma.
• Tolerability of 10-mg regimens has been described previously.
• Published pharmacokinetics (PK) are limited: single or 7-day repeat oral administration of 10 mg in healthy male Asian volunteers.

WHAT THIS STUDY ADDS

• Safety/tolerability and PK of a single 30-mg dose and a 30-mg twice daily (b.i.d.) 2-week regimen in male and female healthy volunteers.
• Higher-dose regimens are relevant for testing in new neurological indications.
• LC-MS/MS analytics for quantification of plasma and urine levels of ibudilast parent and its primary metabolite (6,7-dihydrodiol-ibudilast).

AIMS

To investigate the safety, tolerability and pharmacokinetics (PK) of ibudilast after a single-dose and a multiple-dose regimen.

METHODS

Healthy adult male (n = 9) and female (n = 9) volunteers were evaluated over a 17-day stay in a Phase 1 unit. Subjects were randomized 1 : 3 to either oral placebo or ibudilast at 30-mg single administration followed by 14 days of 30 mg b.i.d. Complete safety analyses were performed and, for PK, plasma and urine samples were analysed for ibudilast and its major metabolite.

RESULTS

Ibudilast was generally well tolerated. No serious adverse events occurred. Treatment-related adverse events included hyperhidrosis, headache and nausea. Two subjects discontinued after a few days at 30 mg b.i.d. because of vomiting. Although samples sizes were too small to rule out a sex difference, PK were similar in men and women. The mean half-life for ibudilast was 19 h and median T_max was 4–6 h. Mean (SD) steady-state plasma C_max and AUC_0–24 were 60 (25) ng ml⁻¹ and 1004 (303) ng h ml⁻¹, respectively. Plasma levels of 6,7- dihydrodiol-ibudilast were approximately 30% of the parent.

CONCLUSIONS

Ibudilast is generally well tolerated in healthy adults when given as a single oral dose of 30 mg followed by 30 mg b.i.d. (60 mg day⁻¹) for 14 days. Plasma PK reached steady state within 2 days of starting the b.i.d. regimen. Exposure to ibudilast was achieved of a magnitude comparable to that associated with efficacy in rat chronic pain models.     

The interaction of the lipase inhibitor orlistat with ethanol in healthy volunteers

Objectives: The primary objective was to investigate the possible interference of ethanol on the orlistat effect on inhibition of dietary fat absorption and the possible interference of orlistat on the pharmacokinetics of ethanol. Secondary objectives were to assess the tolerability during concomitant dosing of orlistat and ethanol and to determine the ethanol effect on plasma levels of orlistat. Methods: This was a double-blind, placebo-controlled, parallel, randomized study performed in 30 (three parallel groups of ten subjects each) healthy normal weight male subjects between the ages of 20 and 30 years. A 5-day run-in period to accustom subjects to a standardized diet of 2500?kcal/day (30% fat) and to establish baseline fecal fat excretion was followed by a 6-day treatment period. Subjects were randomly assigned to one of three treatment groups (A?=?orlistat 120?mg t.i.d. and ethanol placebo, B?=?orlistat 120?mg t.i.d. and 40?g ethanol qd on days ?1 and 6, and 40?g bid on days 1–5, and C?=?orlistat placebo tid and 40?g ethanol qd on days ?1 and 6, and 40?g b.i.d. on days 1–5). Serial blood samples were collected for determination of ethanol serum concentrations at specified times over 5?h after each dose of ethanol on days ?1 and 6, and for determination of orlistat plasma concentrations on days 1, 3, 5, and 6. Feces were collected quantitatively on days ?5 through 8 for analysis of fecal fat. Results: The means of baseline-corrected fecal fat excretion values were comparable: 23.7?g for group A (orlistat) and 22.7?g for group B (orlistat and ethanol). No significant difference was found regarding ethanol pharmacokinetic parameters between treatments with orlistat and placebo. No apparent differences existed between the number of plasma samples with measurable orlistat concentrations in groups A and B. Conclusion: Concomitant ingestion of social amounts of ethanol did not alter the inhibitory effect of orlistat on dietary fat absorption during short-term treatment (6 days) with orlistat. Short-term treatment with orlistat had no significant influence on ethanol pharmacokinetics.     

Pharmacokinetics of linagliptin in subjects with hepatic impairment

AIM

To investigate whether hepatic impairment affects linagliptin pharmacokinetics, pharmacodynamics and tolerability.

METHOD

This open label, parallel group, single centre study enrolled patients with mild (n = 8), moderate (n = 9) or severe (n = 8) hepatic impairment and healthy subjects (n = 8). Groups were matched with regard to age, weight and gender. Primary endpoints were linagliptin exposure following 5 mg linagliptin once daily for 7 days in patients with mild and moderate hepatic impairment vs. healthy subjects or after a single 5 mg dose for patients with severe hepatic impairment vs. healthy subjects.

RESULTS

In mild hepatic impairment, steady-state linagliptin exposure was slightly lower than in healthy subjects [AUC_τ,ss geometric mean ratio (GMR) 75.5%, 90% confidence interval (CI) 61.6%, 92.5%, and C_max,ss GMR 64.4%, 90% CI 43.2%, 96.0%]. Exposure also tended to be lower in moderate hepatic impairment (AUC_τ,ss GMR 85.5%, 90% CI 70.2%, 104.2% and C_max,ss GMR 92.3%, 90% CI 62.8%, 135.6%). After a single dose, AUC(0,24 h) in patients with severe hepatic impairment was similar to that in healthy subjects (GMR 100.4%, 90% CI 75.0%, 134.3%) and C_max was lower (GMR 77.0%, 90% CI 44.9%, 132.3%). Accumulation based on AUC or C_max and renal excretion of unchanged linagliptin (≤7%) were comparable across groups. Median plasma DPP-4 inhibition was similar in healthy subjects (91%), and patients with mild (90%) and moderate (89%) hepatic impairment at steady-state trough concentrations, and in patients with severe hepatic impairment 24 h after a single dose (84%). Linagliptin was well tolerated.

CONCLUSION

Mild, moderate or severe hepatic impairment did not result in an increase in linagliptin exposure after single and multiple dosing compared with normal hepatic function. Dose adjustment with linagliptin is not required in patients with hepatic impairment.     

Pharmacokinetics, adverse effects and tolerability of a novel analogue of human pancreatic polypeptide, PP 1420

AIMS

The objectives of this phase 1 study were to confirm the tolerability of single ascending subcutaneous doses of PP 1420 in healthy subjects, to assess its adverse effects and to investigate the drug''s pharmacokinetics and dose proportionality.

METHODS

This was a double-blind, placebo-controlled, randomized study. There were three dosing periods. Each subject (n = 12) was randomized to receive one dose of placebo and two ascending doses of PP 1420, given as a subcutaneous injection. Blood samples were taken over 24 h to assess pharmacokinetics. Standard safety and laboratory data were collected. The primary endpoint was the tolerability of PP 1420. The secondary endpoint was exposure to PP 1420 as assessed by C_max and AUC(0,∞).

RESULTS

PP 1420 was well tolerated by all subjects with no serious adverse effects. Following single subcutaneous doses of PP 1420 at 2, 4 and 8 mg to male subjects, C_max was reached at a median t_max of approximately 1 h post dose (range 0.32–2.00 h). Thereafter, plasma concentrations of PP 1420 declined with geometric mean apparent terminal elimination t_1/2 ranging from 2.42–2.61 h (range 1.64–3.95 h) across all dose levels.

CONCLUSIONS

Subcutaneous PP 1420 was well tolerated in healthy human subjects at single doses between 2–8 mg, with no tolerability issues arising. Where observed, adverse events were not serious, and there was no evidence of a dose-relationship to frequency of adverse events. The results therefore support the conduct of clinical trials to investigate efficacy, tolerability and pharmacokinetics during repeated dosing.     

Pharmacokinetic–pharmacodynamic studies of the 11β-hydroxysteroid dehydrogenase type 1 inhibitor MK-0916 in healthy subjects

Aims

To characterize pharmacokinetic parameters of MK-0916 and its safety and tolerability in lean, healthy male subjects following single and multiple oral doses. To assess (by stable-isotope labelling) the in vivo inhibition of cortisone-to-cortisol conversion following oral MK-0916.

Methods

Data are presented from two randomized, controlled, double-blind, rising-dose phase I studies. In the first study, subjects received single oral doses of 0.4–100 mg MK-0916 (n = 16). In the second study, subjects received 0.2–225 mg MK-0916 followed by daily doses of 0.2–100 mg for 13 days beginning on day 2 or day 15 (n = 80). Plasma and urine drug concentrations were measured for pharmacokinetic analysis. For pharmacodynamic analysis, concentrations of plasma [¹³C₄]cortisol were measured by high-pressure liquid chromatography and tandem mass spectrometry following a single oral dose of 5 mg [¹³C₄]cortisone.

Results

Doses ≥3 mg were rapidly absorbed (time at which maximal concentration was achieved in plasma, 1.1–1.8 h). Exposure (measured as the area under the concentration–time curve from 0 to 168 h) increased approximately in proportion to dose. Values for the maximal plasma concentration and the plasma concentration at 24 h increased in excess of dose proportionality at doses <6 mg and roughly in proportion to dose at doses >6 mg. In subjects dosed with 6 mg MK-0916 once daily for 14 days, the mean trough plasma concentration was 240 nm and in vivo cortisone-to-cortisol conversion was inhibited by 84%. The relationship between plasma MK-0916 and hepatic 11β-hydroxysteroid dehydrogenase type 1 inhibition was well represented by a simple E_max model with an IC₅₀ of 70.4 nm. Exposure to MK-0916 was generally well tolerated.

Conclusions

These findings indicate that 11β-hydroxysteroid dehydrogenase type 1 is effectively inhibited in human subjects by doses of MK-0916 that are well tolerated.     

Bile pigment pharmacokinetics and absorption in the rat: therapeutic potential for enteral administration

BACKGROUND AND PURPOSE

Bilirubin and biliverdin possess antioxidant and anti-inflammatory properties and their exogenous administration protects against the effects of inflammation and trauma in experimental models. Despite the therapeutic potential of bile pigments, little is known about their in vivo parenteral or enteral absorption after exogenous administration. This study investigated the absorption and pharmacokinetics of bile pigments after i.v., i.p. and intraduodenal (i.d.) administration in addition to their metabolism and routes of excretion.

EXPERIMENTAL APPROACH

Anaesthetized Wistar rats had their bile duct, jugular and portal veins cannulated. Bile pigments were infused and their circulating concentrations/biliary excretion were measured over 180 min.

KEY RESULTS

After i.v. administration of unconjugated bilirubin, biliverdin and bilirubin ditaurate, their plasma concentrations decreased exponentially over time. Subsequently, native and metabolized compounds appeared in the bile. When administered i.p., their absolute bioavailabilities equalled 14.0, 16.1 and 33.1%, respectively, and correspondingly 38, 28 and 34% of the same bile pigment doses were excreted in the bile. Administration of unconjugated bilirubin and bilirubin ditaurate i.d. increased their portal and systemic concentrations and their systemic bioavailability equalled 1.0 and 2.0%, respectively. Correspondingly, 2.7 and 4.6%, of the doses were excreted in the bile. Biliverdin was rapidly metabolized and these products were absorbed and excreted via the urine and bile.

CONCLUSIONS AND IMPLICATIONS

Bile pigment absorption from the peritoneal and duodenal cavities demonstrate new routes of administration for the treatment of inflammatory and traumatic pathology. Oral biliverdin administration may lead to the production of active metabolite that protect from inflammation/complement activation.     

Single dose pharmacokinetics, pharmacodynamics, tolerability and safety of BAY 60-5521, a potent inhibitor of cholesteryl ester transfer protein

AIMS

To determine pharmacokinetics (PK), pharmacodynamics (PD), tolerability and safety of BAY 60–5521, a potent inhibitor of cholesteryl ester transfer protein (CETP).

METHODS

The first in man (FIM) study investigated the safety, tolerability, pharmacodynamics and pharmacokinetics in healthy male subjects following administration of single oral doses. The study was performed using a randomized, single-blind, placebo-controlled, single dose-escalation design. Thirty-eight young healthy male subjects (aged 20–45 years) received an oral dose of 5, 12.5, 25 or 50 mg BAY 60–5521 (n = 28) or were treated with a placebo (n = 10).

RESULTS

In all four dose steps, only one adverse event (25 mg; mild skin rash) was considered drug related. Clinical laboratory parameters showed no clinically relevant changes. A clear dose-dependent CETP inhibition could be demonstrated starting at a dose of 5 mg. At a dose of 25 mg, a CETP inhibition >50% over 18 h was observed. After 50 mg, CETP inhibition >50% lasted more than 50 h. Twenty-four h after administration mean HDL-C-values showed a nearly dose-proportional increase. Following administration of 50 mg, a significant HDL-C increase of about 30% relative to baseline values was found. BAY 60–5521 was slowly absorbed reaching maximum concentrations in plasma after 4 to 6 h. The disposition in plasma was multi-exponential with an estimated mean terminal half-life of 76 to 144 h.

CONCLUSIONS

BAY 60–5521 was clinically safe and well tolerated. No effects on heart rate, blood pressure and ECG recordings were observed during the study. A clear pharmacodynamic effect on CETP inhibition and HDL could be demonstrated.     

AQW051, a novel,potent and selective α7 nicotinic ACh receptor partial agonist: pharmacological characterization and phase I evaluation

Background and Purpose

Activation of the α7 nicotinic ACh receptor (nACh receptor) is considered an attractive target for the treatment of cognitive impairment associated with neurological disorders. Here we describe the novel α7-nACh receptor agonist AQW051 as a promising drug candidate for this indication.

Experimental Approach

AQW051 was functionally characterized in vitro and cognitive effects evaluated in rodent behavioural models. Pharmacokinetics and tolerability were evaluated in three phase I placebo-controlled studies in 180 healthy subjects.

Key Results

In vitro, AQW051 bound with high affinity to α7-nACh receptors and stimulated calcium influx in cells recombinantly expressing the human α7-nACh receptor. In vivo, AQW051 demonstrated good oral bioavailability and rapid penetration into the rodent brain. AQW051 administered over a broad dose range facilitated learning/memory performance in the object recognition and social recognition test in mice and the water maze model in aged rats. Clinically, AQW051 was well tolerated in healthy young and elderly subjects, with an adverse event (AE) profile comparable with placebo. No serious AEs were reported and all AEs were either mild or moderate in severity at single oral doses up to 200 mg and multiple daily doses up to 75 mg. Once-daily oral administration of AQW051 resulted in continuous exposure and a two- to threefold accumulation compared with steady state was achieved by 1 week.

Conclusions and Implications

These data support further development of AQW051 as a cognitive-enhancing agent, as a therapeutic, for example, in Alzheimer''s disease or schizophrenia.     

A randomized trial of the safety,pharmacokinetics and pharmacodynamics of edoxaban,an oral factor Xa inhibitor,following a switch from warfarin

Aims

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of edoxaban, an oral direct factor Xa inhibitor, in healthy subjects switching from warfarin.

Methods

Seventy-two subjects were randomized to edoxaban 60 mg once daily (n = 48) or matching placebo (n = 24) for 5 days at 24 h after the last dose of warfarin treatment (INR 2.0 to 3.0). Safety/tolerability was the primary outcome measure. Pharmacokinetics, INR, aPTT, anti-FXa, thrombin generation and other coagulation assays were assessed.

Results

Seventy-two subjects were randomized and 64 subjects received at least one dose of edoxaban (n = 43) or placebo (n = 21) after achieving a target INR of 2.0 to 3.0 on warfarin treatment. Edoxaban 60 mg administered 24 h post-warfarin appeared to be safe and well tolerated. Adverse events were similar across treatments. For bleeding-related adverse events, eight subjects tested positive for faecal occult blood, five subjects during warfarin treatment and three subjects during edoxaban treatment. The mean (SD) baseline (post-dose of warfarin) INR was 2.31 (0.193) which increased to 3.84 (0.744) over 2 h during the edoxaban treatment (P < 0.0001 vs. placebo), returning to post-warfarin baseline within 12 h. A similar time course of effects for the other coagulation assays was observed in accordance with the drugs'' mechanisms of action.

Conclusion

In this study of healthy subjects, edoxaban administered 24 h after the last dose of warfarin was safe and well tolerated with transient increases across the various coagulation assays above post-warfarin baseline levels.     

Relative lung deposition of salbutamol following inhalation from a spacer and a Sidestream jet nebulizer following an acute exacerbation

Background

Studies comparing inhalation methods in acute exacerbations have not assessed lung deposition.

Methods

Five 100-μg salbutamol doses were inhaled from a metered dose inhaler plus spacer (MDI + SP) and 5 mg was nebulized (NEB) following acute exacerbation hospitalization. Urinary salbutamol excretion was determined at 30 min (USAL0.5) and over 24 h (USAL24) postinhalation together with forced expiratory volume in 1 s (FEV₁).

Results

The USAL0.5 mean ratio (90% confidence interval) post MDI + SP and NEB [n = 19 asthma, 11 chronic obstructive pulmonary disease (COPD)] was 1.01 (0.81, 1.26). USAL24 was less (P < 0.001) following MDI + SP, whereas FEV₁ was similar. Only a small difference between asthmatics and COPD patients was observed for the MDI + SP in that the USAL0.5 was higher in the asthmatics for the spacer method.

Conclusion

The relative lung deposition after inhaling 500 μg salbutamol from MDI + SP is similar to 5 mg from a Sidestream nebulizer following an acute exacerbation.

What is already known about this subject

• Studies have shown that a large volume spacer attached to a metered dose inhaler provides similar bronchodilator effects to nebulized dosing during the management of patients following an acute exacerbation.
• Due to the high doses used, these effects could be measured at the top of the dose–response relationship and the response limited due to the patient''s exacerbation.
• Although clinical end-points are the gold standard to show comparability, some indication of similar lung deposition is useful to consolidate any claims.

What this study adds

• The urinary pharmacokinetic method we have used postinhalation provides an index of lung deposition for inhalation methods that can be incorporated into the routine management of patients with an acute exacerbation.
• This is the first study to identify and compare lung deposition and systemic delivery for inhalation methods within the setting of the routine management of asthma and chronic obstructive pulmonary disease patients following hospitalization due to an acute exacerbation.
• The study highlights the comparability of the doses for the two inhalation methods evaluated with respect to lung deposition, systemic delivery and bronchodilator response.

     

The Safety and Tolerability Profile of Vilazodone,A Novel Antidepressant for the Treatment of Major Depressive Disorder

Objective

Vilazodone is a selective serotonin reuptake inhibitor and 5-HT_1A receptor partial agonist approved for the treatment of major depressive disorder (MDD). This report summarizes the safety and tolerability of vilazodone 40 mg/day during short- and long-term treatment of adult MDD.

Methods

Pooled data from two 8-week, double-blind studies of vilazodone (n = 436) vs placebo (n = 433) and data from one 52-week, open-label study (n = 616, vilazodone only) were analyzed. Patients aged 18-70 with DSM-IV-TR-defined MDD received vilazodone or placebo (8-week studies only) once daily, with food, titrated to 40 mg/day over 2 weeks. Safety and tolerability assessments included adverse events (AEs), laboratory tests, vital signs, electrocardiograms, and weight.

Results

The most common AEs in all studies were diarrhea, nausea, and headache. Vilazodone-associated AEs in the two 8-week studies, defined as an incidence rate of ≥5% in the vilazodone group and at least twice that for placebo, were diarrhea (28.0% vs 9.2%), nausea (23.4% vs 5.1%), and insomnia (6.0% vs 2.1%), with the majority reported as mild to moderate and <5% of those patients requiring concomitant (directed) treatment for these conditions. Discontinuation rates due to AEs were 7.1% (vilazodone) and 3.2% (placebo) in the 8-week studies and 20.7% in the 52-week study. Vilazodone had no clinically significant effects on vital signs, laboratory tests, or electrocardiograms.

Conclusion

Vilazodone 40 mg/day was well tolerated during short- and long-term MDD treatment in these trials. Safety profiles associated with 8- and 52-week exposure were consistent.     

Inhibition of capsaicin-driven nasal hyper-reactivity by SB-705498, a TRPV1 antagonist

AIMS

To assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of intranasal SB-705498, a selective TRPV1 antagonist.

METHODS

Two randomized, double-blind, placebo-controlled, clinical studies were performed: (i) an intranasal SB-705498 first time in human study to examine the safety and PK of five single escalating doses from 0.5 to 12 mg and of repeat dosing with 6 mg and 12 mg twice daily for 14 days and (ii) a PD efficacy study in subjects with non-allergic rhinitis (NAR) to evaluate the effect of 12 mg intranasal SB-705498 against nasal capsaicin challenge.

RESULTS

Single and repeat dosing with intranasal SB-705498 was safe and well tolerated. The overall frequency of adverse events was similar for SB-705498 and placebo and no dose-dependent increase was observed. Administration of SB-705498 resulted in less than dose proportional AUC(0,12 h) and C_max, while repeat dosing from day 1 to day 14 led to its accumulation. SB-705498 receptor occupancy in nasal tissue was estimated to be high (>80%). Administration of 12 mg SB-705498 to patients with NAR induced a marked reduction in total symptom scores triggered by nasal capsaicin challenge. Inhibition of rhinorrhoea, nasal congestion and burning sensation was associated with 2-to 4-fold shift in capsaicin potency.

CONCLUSIONS

Intranasal SB-705498 has an appropriate safety and PK profile for development in humans and achieves clinically relevant attenuation of capsaicin-provoked rhinitis symptoms in patients with NAR. The potential impact intranasal SB-705498 may have in rhinitis treatment deserves further evaluation.     

Drug-disease interaction: Crohn's disease elevates verapamil plasma concentrations but reduces response to the drug proportional to disease activity

AIM

Inflammation is involved in the pathogenesis of cardiovascular diseases that includes reduced response to pharmacotherapy due to altered pharmacokinetics and pharmacodynamics. It is not known if these effects exist in general in all inflammatory conditions. It also remains unknown whether in a given population the effect is a function of disease severity. We investigated whether pharmacokinetics and pharmacodynamics of a typical calcium channel inhibitor are influenced by Crohn''s disease (CD), a disease for which the disease severity can be readily ranked.

METHODS

We administered 80 mg verapamil orally to (i) healthy control subjects (n = 9), (ii) patients with clinically quiescent CD (n = 22) and (iii) patients with clinically active CD (n = 14). Serial analysis of verapamil enantiomers (total and plasma unbound), blood pressure and electrocardiograms were recorded over 8 h post dose. The severity of CD was measured using the Harvey-Bradshaw Index.

RESULTS

CD substantially and significantly increased plasma verapamil concentration and in a stereoselective fashion (S, 9-fold; R, 2-fold). The elevated verapamil concentration, however, failed to result in an increased verapamil pharmacodynamic effect so that the patients with elevated verapamil concentration demonstrated no significant increase in response measured as PR interval and blood pressure. Instead, the greater the disease severity, the lower was the drug potency to prolong PR interval (r = 0.86, P < 0.0006),

CONCLUSIONS

CD patients with severe disease may not respond to cardiovascular therapy with calcium channel blockers. Reducing the severity increases response despite reduced drug concentration. This observation may have therapeutic implication beyond the disease and the drug studies herein.     

Pharmacokinetics and pharmacodynamics of single and multiple doses of prasugrel in healthy native Chinese subjects

Aim:

To characterize the pharmacokinetics (PKs), pharmacodynamics (PDs), and tolerability of different dose regimens of prasugrel in healthy Chinese subjects.

Methods:

This was a single-centered, open-label, parallel-design study. Subjects received a single loading dose (LD) of prasugrel followed by once-daily maintenance dose (MD) for 10 d. They were enrolled into 3 groups: 60 mg LD/10 mg MD; 30 mg LD/7.5 mg MD; 30 mg LD/5 mg MD. Blood samples were collected after the first and last dose. The serum concentration of the active metabolite of prasugrel was determined using a LC/MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y₁₂ assay.

Results:

Thirty-six healthy native Chinese subjects (19 males) aged 18–45 were enrolled; mean age and body weight were similar across the treatment groups (n=12 for each). The metabolite AUC_0–4 and C_max increased dose-proportionally across the dose range of 5 mg to 60 mg. The median T_max was 0.5 h in all groups. The PD parameters, indicated by the inhibition of ADP-induced platelet aggregation, were met more rapidly in the 60 mg group than the 30 mg group after the LD (94%–98%). This high degree of inhibition of platelet aggregation was maintained following the 10 mg MD (87%–90%) and was lower in the 7.5 mg and 5 mg MD groups (79%–83% and 64%–67%, respectively). Prasugrel was well tolerated in healthy Chinese subjects for single doses up to 60 mg and a MD of 10 mg for 10 d.

Conclusion:

The PKs and PDs of the active metabolite of prasugrel were similar to those in Chinese subjects reported by a previous bridging study, which demonstrated that the exposure to the active metabolite in Chinese subjects was higher than in Caucasians.