Favourable safety profile of S62798, a potent TAFIa (activated thrombin-activatable fibrinolysis inhibitor) inhibitor, in first-in-man study in healthy subjects

Background

Thromboembolic diseases, such as venous thromboembolic diseases represent a significant public health burden. S62798, a selective and potent inhibitor of activated thrombin-activatable fibrinolysis inhibitor (TAFIa), is being developed as a fibrinolysis enhancer for the treatment of thromboembolic diseases, including pulmonary embolism. TAFIa inhibits the fibrinolysis by limiting plasmin generation.

Objectives

This double-blind, randomised, placebo-controlled first-in-man study was conducted to investigate the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of single ascending doses of S62798 in healthy subjects.

Methods

Young male (18–40 years) subjects were randomised 3:1 to single ascending doses of S62798 ranging from 3.2 mg to 320 mg or placebo, administered as an intravenous bolus followed by a 7 hour 2-step infusion (part 1), or to 30 mg or 40 mg or placebo administered as a 1-min bolus (part 2). Follow-up ranged from 6 to 13 days post S62798 administration depending on cohorts. Exclusion criteria included bleeding disorders, recent bleeding, and abnormal blood coagulation parameters. Anticoagulant/antiplatelet treatments were not allowed for 30 days prior to and during the study. Safety was assessed by recording adverse events (AE), physical examination, vital signs, biochemical, haematological and haemostasis parameters (prothrombin time, activated partial thromboplastin time, thrombin clotting time, D-Dimers and fibrinogen). Plasma and urine samples for PK assessment were collected pre-dose and up to day 13 to assess the full PK profile. In part 1, ex vivo TAFIa inhibition (spiking of purified human TAFIa) and in vitro clot lysis time were assessed at pre-dose, during and after infusion. The study was performed in France in accordance with the declaration of Helsinki revised in Fortaleza. EudraCT number: 2016–002108–25.

Results

A total of 56 subjects were randomized to part 1 and 16 to part 2. Subjects were (mean ± SD) 29.5 ±- 5.7 years old with a BMI of 23.9±2.6 kg/m2 in part 1 and 31.4±5.2 years old with a BMI of 23.9±2.5 kg/m2 in part 2.

All doses of S62798 administered as a bolus and infusion or a single bolus were well tolerated, and no serious adverse events or discontinuations resulting from AEs occurred during the study. No effects of S62798 on haemostasis parameters were observed. Cardiac safety assessed by 12-lead 24h Holter ECG showed no relevant abnormalities. Plasma exposure of S62798 increased proportionally with the dose. S62798 inhibits TAFIa activity and decreases clot lysis time (reflecting TAFIa activity inhibition) rapidly and dose-dependently in all treated groups.

Conclusions

S62798, a potent TAFIa inhibitor, has a favourable safety profile with a linear PK. PD results on TAFIa inhibition and clot lysis assay suggest that S62798 has relevant properties to pursue clinical development as an enhancer of endogenous fibrinolysis for the treatment of thromboembolic diseases

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): IRIS

Evaluation of Levothyroxine Bioavailability after Oral Administration of a Fixed Combination of Soy Isoflavones in Post-menopausal Female Volunteers

BACKGROUND

Post-menopausal women under treatment with levothyroxine for their medical conditions may take concomitantly dietary supplements containing soy isoflavones in combination to treat their post-menopausal symptoms. The aim of this study was to investigate the effect of a fixed combination of soy isoflavones on the oral bioavailability of levothyroxine in post-menopausal female volunteers.

METHODS

12 healthy post-menopausal female, who were on stable oral levothyroxine as replacement/supplementation therapy for hypothyroidism, received a single recommended oral dose of a food supplement containing 60 mg of soy isoflavones (>19% genistin and daidzin) concomitantly with (test) and 6 h later (reference) the administration of levothyroxine in a randomized, open label, crossover fashion. Plasma concentrations of levothyroxine and soy isoflavones (daidzin, daidzein, genistin, genistein, S-equol) were determined by LC-MS/MS. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. No effect of soy isoflavones was assumed if the 90% confidence intervals (CIs) for the estimated ratio test/reference was included in the acceptance limits 0.80-1.25 for PK parameters Cmax and AUCt.

RESULTS

The test/reference ratios Cmax and AUCt of levothyroxine were very close to unity (1.02 and 0.99, respectively) and the corresponding 90% CIs (0.99-1.04 and 0.88-1.12, respectively) fell entirely within the acceptance bioequivalence limits.

CONCLUSION

The combination of soy isoflavones used in the present investigation does not affect the rate and extent of levothyroxine absorption when administered concomitantly in post-menopausal women.

Effects of a 3-month supplementation with a novel soluble highly viscous polysaccharide on anthropometry and blood lipids in nondieting overweight or obese adults

BACKGROUND

High viscosity fibre is known to exert many beneficial effects on appetite and metabolism. It could potentially help in weight management, in dieting or nondieting individuals. The present study investigated the effects of the daily intake of a novel high viscosity polysaccharide (HVP) over 3 months in nondieting obese or overweight men and women.

METHODS

The study comprised a double-blind, randomised controlled clinical trial. Participants ingested 5-15 g per day of either HVP (n = 29, experimental group) or inulin (n = 30, control group) for 15 weeks. Changes in anthropometry (weight, waist and hip circumferences), blood lipids and glucose tolerance were studied from the beginning to the end of administration. Compliance and tolerance were examined.

RESULTS

Differences appeared between HVP and inulin supplementation in female participants only. Mean (SD) decreases in body weight [1.6 (3.2) kg; approximately 2% of initial weight] and hip circumference [2.8 (3.6 ) cm] occurred in women of the HVP group but not in controls (Time × Group interactions, P ≤ 0.002). Total, high-density lipoprotein and low-density lipoprotein-cholesterol were lower at the end of supplementation in the women of the HVP group compared to controls (P ≤ 0.021). No effect appeared in waist circumference and triacylglycerol. No difference was noted in the number or severity of the adverse effects reported in both groups. Adverse effects were mild and agreed with commonly reported reactions to intake of dietary fibre.

CONCLUSIONS

Beneficial although modest effects appeared after several weeks of daily HVP intake in nondieting obese or overweight women. The effects of HVP should be investigated in the context of a weight loss programme.

Hydrogen excretion upon ingestion of dairy products in lactose-intolerant male subjects: importance of the live flora

OBJECTIVE

To assess the effects of the ingestion of milk, yoghurt (10(8) bacteria/ml), heat-treated yoghurt (<15 bacteria/ml) and two products obtained by dilution of yoghurt with heat-treated product (10(6) and 10(5) bacteria/ml) on hydrogen production and symptoms of lactose intolerance in lactose malabsorbers.

DESIGN

Double-blind, randomised cross-over design.

SETTING

The study was performed in the phase 1 clinical unit of OPTIMED, Nancy, France.

SUBJECTS

Twenty-four male lactose malabsorbers were selected for the study.

INTERVENTIONS

Hydrogen production and adverse events were followed during 8 h after ingestion of the products.

RESULTS

The results clearly demonstrate that ingestion of yoghurt with 10(8) bacteria/ml leads to lower H(2) excretion and complaints than the other products. Results observed with the products containing a reduced population of live flora remain better than those observed with milk.

CONCLUSIONS

The importance of a high population of the live flora is underlined.

Estradiol pharmacokinetics after transdermal application of patches to postmenopausal women: matrix versus reservoir patches

OBJECTIVE

A new matrix 17 beta-estradiol transdermal patch incorporating lauric acid to improve estradiol skin absorption has been designed for hormone replacement therapy. Estradiol pharmacokinetics obtained with the prototype, its industrial counterpart, a matrix-type, System 50, and a reservoir-type, Estraderm TTS 50, transdermal patch have been compared. Each device delivers 50 micrograms estradiol daily.

METHODS

Twenty postmenopausal women received each of the four formulations for 3 days in a Latin-square design and with a minimum 4-day wash-out period between treatments. Estradiol plasma concentrations were measured by radioimmunoassay at 6, 12, 24, 48 and 72 h after application.

RESULTS

The prototype patch and its industrial counterpart showed no significant difference in estradiol delivery, with 72-h systemic exposure to estradiol similar to that of the reservoir patch but greater than that of the reference matrix formulation, with average baseline-corrected concentrations (SEM) of 35 (4), 32 (3), 32 (2) and 19 (1.8) pg/ml, respectively. In addition, they ensured more stable delivery, with coefficients of variation of plasma estradiol concentrations (12-72 h) of 29, 41, 63 and 84%, respectively. All matrix patches demonstrated the same patients to be poor estradiol absorbers, different from those encountered with the reservoir patch type, despite an improved estradiol bioavailability with the lauric acid-containing matrix patch.

CONCLUSION

Matrix patches incorporating lauric acid led to estradiol plasma levels more stable than with the reference matrix and reservoir patches, and greater than those with the reference matrix patch.

[Effect of low-dose polyethylene glycol 4000 on fecal consistency and dilution water in healthy subjects]

OBJECTIVES

The aim of the study was to assess in normal subjects the changes in stool consistency and dilution water during the ingestion of small doses of polyethylene glycol (PEG) 5.9 g/d. Dilution water is the water located outside solid structures (bacteria and food residue).

METHODS

Each stool passed by 16 non-constipated male volunteers was collected during 3 weeks. PEG was ingested from days 1 to 7, and stools collected during the ingestion of PEG were compared with those collected at least 24 h after the last fecal excretion of PEG (control fecal data). Consistency, fresh and dry weight, dilution water, nitrogen, electrolytes and PEG were quantified in each stool.

RESULTS

Stools were softer during the ingestion of PEG (P < 0.01) and dilution water increased significantly (49.4 +/- 1.7 vs 37.6 +/- 2.6 mL/100 g feces, mean +/- SD, P < 0.02). PEG induced variable effects among individuals according to the consistency and dilution water measured during the control period.

CONCLUSION

Low doses of PEG (5.9 g/d) soften stools particularly when feces are harder. This effect is due to changes in dilution water (water outside fecal solid structures).