Ocular Pharmacology and Toxicology of TRPV1 Antagonist SAF312 (Libvatrep).

Purpose: To evaluate the pharmacology and toxicology of SAF312, a transient receptor potential vanilloid 1 (TRPV1) antagonist. Methods: TRPV1 expression in human ocular tissues was evaluated with immunohistochemistry. Inhibition of calcium influx in Chinese hamster ovary (CHO) cells expressing human TRPV1 (hTRPV1) and selectivity of SAF312 were assessed by a fluorescent imaging plate reader assay. Ocular tissue and plasma pharmacokinetics (PK) were assessed following a single topical ocular dose of SAF312 (0.5%, 1.0%, 1.5%, 2.5%) in rabbits. Safety and tolerability of SAF312 were evaluated in rabbits and dogs. Effects of SAF312 on corneal wound healing after photorefractive keratectomy (PRK) surgery were assessed in rabbits. Results: TRPV1 expression was noted in human cornea and conjunctiva. SAF312 inhibited calcium influx in CHO-hTRPV1 cells induced by pH 5.5 (2-[N-morpholino] ethanesulfonic acid), N-arachidonoylethanolamine, capsaicin, and N-arachidonoyl dopamine, with IC50 values of 5, 10, 12, and 27 nM, respectively, and inhibition appeared noncompetitive. SAF312 demonstrated high selectivity for TRPV1 (>149-fold) over other TRP channels. PK analysis showed highest concentrations of SAF312 in cornea and conjunctiva. SAF312 was found to be safe and well tolerated in rabbits and dogs up to the highest feasible concentration of 2.5%. No delay in wound healing after PRK was observed. Conclusions: SAF312 is a potent, selective, and noncompetitive antagonist of hTRPV1 with an acceptable preclinical safety profile for use in future clinical trials. Translational Relevance: SAF312, which was safe and well tolerated without causing delay in wound healing after PRK in rabbits, may be a potential therapeutic agent for ocular surface pain.

Licogliflozin for nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled, phase 2a study.

Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease that may advance to fibrosis and lead to mortality; however, no pharmacotherapy is currently available. We tested the hypothesis that inhibition of both the sodium-glucose cotransporters 1 and 2 with licogliflozin would lead to improvement in NASH. A total of 107 patients with phenotypic or histologic NASH were randomized (1:2:2) to receive oral administration of either placebo (n = 21), licogliflozin 30 mg (n = 43) or 150 mg (n = 43) once daily for 12 weeks. Licogliflozin 150 mg showed a significant 32% (80% confidence interval (CI): 21-43%; P = 0.002) placebo-adjusted reduction in serum alanine aminotransferase after 12 weeks of treatment, the primary endpoint of the study. However, the 30 mg dose of licogliflozin did not meet the primary endpoint (placebo-adjusted reduction 21% (80% CI: 7-32%; P = 0.061)). Diarrhea occurred in 77% (33 of 43), 49% (21 of 43) and 43% (9 of 21) of patients treated with licogliflozin 150 mg, 30 mg and placebo, respectively, which was mostly mild in severity. No other major safety concerns were identified. Treatment with 150 mg licogliflozin led to reductions in serum alanine aminotransferase in patients with NASH. Studies of longer duration and in combination with drugs that have different mechanisms of action are needed to validate these findings and to define a role of licogliflozin as a therapeutic option for NASH. ClinicalTrials.gov identifier: NCT03205150.

Glucosuric, renal and haemodynamic effects of licogliflozin, a dual inhibitor of sodium-glucose co-transporter-1 and sodium-glucose co-transporter-2, in patients with chronic kidney disease: A randomized trial.

AIM: To investigate the glucosuric, renal and haemodynamic effects of licogliflozin, a dual sodium-glucose co-transporter-1 and sodium-glucose co-transporter-2 inhibitor, in patients with chronic kidney disease (CKD). METHODS: This multiple-dose, parallel-group, phase II mechanistic study randomized 53 participants (aged 18-78 years, body mass index ≤ 50 kg/m2 ) with varying degrees of CKD or normal renal function to treatment with licogliflozin (50 mg once daily) or placebo for 7 days. The effects of licogliflozin on 24-h urinary glucose excretion (UGE24 ), renal function, haemodynamics, pharmacokinetics and safety were assessed. RESULTS: Licogliflozin treatment for 7 days significantly (p < .01) increased UGE24 from baseline in participants with normal renal function (adjusted mean change: 41.8 [33.6, 49.9] g) or with mild (32.6 [24.1, 41.0] g), moderate A (35.7 [28.6, 42.9] g) or moderate B (20.3 [13.1, 27.5] g) CKD, but not in severe (6.2 [-0.71, 13.18] g) CKD. Licogliflozin reduced urinary electrolytes (sodium, potassium and chloride), blood pressure and urinary volume to varying extents among different groups. Significant increases in renin (p < .05), angiotensin II (p < .05) and aldosterone (p < .01) levels were observed. Adverse events were generally mild, and most commonly included diarrhoea (94%), flatulence (68%) and abdominal pain (21%). CONCLUSION: Licogliflozin treatment results in significantly increased UGE and favourable changes in urinary electrolytes and haemodynamics in patients with varying degrees of CKD (estimated glomerular filtration rate ≥ 45 mL/min/1.73 m2 ).

Pharmacokinetics, metabolism, and excretion of licogliflozin, a dual inhibitor of SGLT1/2, in rats, dogs, and humans.

Absorption, metabolism, and excretion (AME) of licogliflozin, a sodium-glucose co-transporters (SGLTs) 1 and 2 inhibitor, were studied in male rats, dogs, and healthy male volunteers and reported.Oral absorption of licogliflozin was rapid (tmax < 1 h) with absorption estimated at 87%, 100% and 77% in rats, dogs and humans, respectively.Excretion of licogliflozin-related radioactivity was rapid and nearly complete following oral administration with total radioactivity recovery ranging from 73% in dogs, 92.5% in humans, to 100% in rats. Dose-related radioactivity was excreted in both urine and faeces with urinary excretion playing a slightly more important role in humans (∼56%) than in animal species (∼19-41%).Elimination of licogliflozin was predominantly via metabolism with the majority of the radioactivity dose (∼54-74%) excreted as metabolites across species.The principal biotransformation pathways involved direct glucuronidation and oxidation across all species. In humans, direct glucuronidation to M17 and M27 was the major pathway observed, accounting for ∼38% of the dose in excreta while oxidative metabolism also contributed to >29% of the dose in excreta. Oxidative pathways were predominant in animal species.

Investigation and Management of Stool Frequency and Consistency Associated With SGLT1 Inhibition by Reducing Dietary Carbohydrate: A Randomized Trial.

Treatment with licogliflozin, a dual sodium-glucose co-transporter (SGLT)1/2-inhibitor, is associated with increased stool frequency and loose stools, attributed to SGLT1 inhibition. To investigate the effect of carbohydrate content and supplements on licogliflozin-induced stools, a randomized, open-label, two-part (N = 24/part), three-period crossover study was carried out in overweight or obese adults. Significantly higher (P < 0.01) change from baseline in 3-day total number of bowel movements was observed following 3 days of licogliflozin treatment (50 mg q.d.) together with a 50% carbohydrate meal compared with a 25% and 0% carbohydrate meal. The number of stools with Bristol Stool Chart score of 6 or 7 was also significantly lower following a 0% carbohydrate meal. Supplementation with psyllium 6 g or calcium carbonate 1 g had no effect on stool changes following treatment. Licogliflozin was generally safe and well-tolerated. Loose stool associated with licogliflozin treatment and ingestion of meals can be managed by reducing the carbohydrate content of meals taken with licogliflozin.

The effects of licogliflozin, a dual SGLT1/2 inhibitor, on body weight in obese patients with or without diabetes.

BACKGROUND: There is an unmet need for a safer and more effective treatment for obesity. This study assessed the effects of licogliflozin, a dual inhibitor of sodium-glucose co-transporter (SGLT) 1/2, on body weight, metabolic parameters and incretin hormones in patients with type 2 diabetes mellitus (T2DM) and/or obesity. METHODS: Patients with obesity (BMI, 35-50 kg/m2 ) were enrolled into a 12-week study (N = 88; licogliflozin 150 mg q.d.). Patients with T2DM were enrolled into a second, two-part study, comprising a single-dose cross-over study (N = 12; 2.5 - 300 mg) and a 14-day dosing study (N = 30; 15 mg q.d). Primary endpoints included effects on body weight, effects on glucose, safety and tolerability. Secondary endpoints included urinary glucose excretion (UGE24 ) and pharmacokinetics, while exploratory endpoints assessed the effects on incretin hormones (total GLP-1, PYY3-36 , and GIP), insulin and glucagon. RESULTS: Treatment with licogliflozin 150 mg q.d. for 12 weeks in patients with obesity significantly reduced body weight by 5.7% vs placebo (P < 0.001) and improved metabolic parameters such as significantly reduced postprandial glucose excursion (21%; P < 0.001), reduced insulin levels (80%; P < 0.001) and increased glucagon (59%; P < 0.001). In patients with T2DM, a single dose of licogliflozin 300 mg in the morning prior to an oral glucose tolerance test (OGTT) remarkably reduced glucose excursion by 93% (P < 0.001; incremental AUC0-4h ) and suppressed insulin by 90% (P < 0.01; incremental AUC0-4h ). Treatment with licogliflozin 15 mg q.d. for 14 days reduced 24-hour average glucose levels by 26% (41 mg/dL; P < 0.001) and increased UGE24 to 100 g (P < 0.001) in patients with T2DM. In addition, this treatment regimen significantly increased total GLP-1 by 54% (P < 0.001) and PYY3-36 by 67% (P < 0.05) post OGTT vs placebo, while significantly reducing GIP levels by 53% (P < 0.001). Treatment with licogliflozin was generally safe and well tolerated. Diarrhea (increased numbers of loose stool) was the most common adverse event in all studies (90% with licogliflozin vs 25% with placebo in the 12-week study), while a lower incidence of flatulence, abdominal pain and abdominal distension (25%-43% with licogliflozin vs 9%-11% with placebo in the 12-week study) were among the other gastrointestinal events reported. CONCLUSION: Licogliflozin treatment (1-84 days) leads to significant weight loss and favourable changes in a variety of metabolic parameters and incretin hormones. Dual inhibition of SGLT1/2 with licogliflozin in the gut and kidneys is an attractive strategy for treating obesity and diabetes.

Evaluation of safety and tolerability, pharmacokinetics, and pharmacodynamics of BMS-820836 in healthy subjects: a placebo-controlled, ascending single-dose study.

RATIONALE: BMS-820836, a novel triple monoamine reuptake inhibitor, is an experimental monotherapy for sufferers of major depressive disorder who have had an inadequate response to an existing antidepressant treatment. OBJECTIVES: This study was conducted to evaluate the safety and tolerability, pharmacokinetics (PK), and serotonin transporter (SERT) and dopamine transporter (DAT) occupancy for single doses of BMS-820836 in healthy subjects. METHODS: Healthy subjects were assigned to seven BMS-820836 dose panels (0.025, 0.1, 0.5, 1, 2, 3, and 5 mg; n = 8 each), in which subjects were randomly allocated 3:1 to a single BMS-820836 dose or matched placebo. Serial blood samples were collected on Days 1, 2, 3, 4, 7, and 14 to characterize the PK of BMS-820836. Following evaluation of the maximum tolerated dose, SERT occupancy was determined by applying [(11)C]DASB positron emission tomography (PET) after single-dose BMS-820836 (0.5 or 3 mg; n = 3 each) and DAT occupancy by applying [(11)C]PE2I PET after single-dose BMS-820836 (3 mg; n = 6). RESULTS: Single oral doses of BMS-820836 (0.025-3 mg) were generally safe and well tolerated. BMS-820836 had a median T max of 5.0-7.2 h and a mean apparent terminal T 1/2 of 34-57 h. Mean striatal SERT occupancies were 19 ± 9 % and 82 ± 8 % after single doses of 0.5 and 3 mg BMS-820836, respectively. The mean striatal DAT occupancy was 19 ± 9 % after a single 3 mg BMS-820836 dose. CONCLUSIONS: Single doses of BMS-820836 have meaningful SERT and DAT occupancy and demonstrate an acceptable safety and tolerability profile in healthy control subjects.

Bioavailability of valsartan oral dosage forms.

The oral bioavailability of valsartan from extemporaneous suspension and solution formulations were evaluated relative to tablet formulation in two separate open-label, randomized crossover studies in healthy adults. In both studies, the plasma concentrations of valsartan after oral administration were analyzed using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods, and the corresponding pharmacokinetic parameters were estimated using noncompartmental analysis. The peak plasma concentration (Cmax ) and area under the concentration time-curves (AUC(0-∞) ) of valsartan from the extemporaneous suspension were higher by 1.93- and 1.56-fold, respectively, relative to the tablet formulation (P < .001). The Cmax and AUC(0-∞) of valsartan from the oral solution were higher by 2.21- and 1.74-fold, respectively, relative to the tablet formulation (P < .001). These results indicate that both rate and extent of absorption of valsartan are higher in the two liquid dosage forms (extemporaneous suspension and solution formulations) relative to the solid oral dosage form (tablet formulation).

The concentration of cyclosporine metabolites is significantly lower in kidney transplant recipients with diabetes mellitus.

BACKGROUND: Diabetes mellitus is prevalent among kidney transplant recipients. The activity of drug metabolizing enzymes or transporters may be altered by diabetes leading to changes in the concentration of parent drug or metabolites. This study was aimed to characterize the effect of diabetes on the concentration of cyclosporine (CsA) and metabolites. METHODS: Concentration-time profiles of CsA and metabolites (AM1, AM9, AM4N, AM1c, AM19, and AM1c9) were characterized over a 12-hour dosing interval in 10 nondiabetic and 7 diabetic stable kidney transplant recipients. All patients were male, had nonfunctional CYP3A5*3 genotype, and were on combination therapy with ketoconazole. RESULTS: The average daily dose (±SD) of CsA was 65 ± 21 and 68 ± 35 mg in nondiabetic and diabetic subjects, respectively (P = 0.550). Cyclosporine metabolites that involved amino acid 1 (AM1, AM19, AM1c) exhibited significantly lower dose-normalized values of area under the concentration-time curve in patients with diabetes. Moreover, during the postabsorption phase (≥3 hours after dose), metabolite-parent concentration ratios for all metabolites, except AM4N, was significantly lower in diabetic patients. The pharmacokinetic parameters of ketoconazole were similar between the 2 groups thus excluding inconsistent ketoconazole exposure as a source of altered CsA metabolism. CONCLUSIONS: This study indicates that diabetes mellitus significantly affects the concentration of CsA metabolites. Because CsA is eliminated as metabolites via the biliary route, the decrease in the blood concentration of CsA metabolites during postabsorption phase would probably reflect lower hepatic cytochrome P450 3A4 enzyme activity. However, other mechanisms including altered expression of transporters may also play a role. Results of cyclosporine therapeutic drug monitoring in diabetic patients must be interpreted with caution when nonspecific assays are used.

Blood and plasma pharmacokinetics of ciclosporin in diabetic kidney transplant recipients.

BACKGROUND AND OBJECTIVES: Long-term diabetes mellitus may affect the absorption, distribution and metabolism of immunosuppressive agents used after organ transplantation. The aims of this study were to characterize ciclosporin pharmacokinetics in blood and plasma and to compare the ciclosporin unbound concentration and the blood : plasma concentration (B : P) ratio in diabetic kidney transplant recipients. PATIENTS AND METHODS: Ciclosporin 12-hour steady-state pharmacokinetics were studied in eight diabetic and nine nondiabetic patients. Ciclosporin concentrations in whole blood and in plasma were measured using liquid chromatography-tandem mass spectrometry, and the ciclosporin fraction unbound (f(u)) was determined by an equilibrium dialysis method utilizing [(3)H]ciclosporin as a tracer. Oral absorption of paracetamol (acetaminophen) was used as a marker for gastric emptying. RESULTS: In diabetic patients, the time to the peak blood ciclosporin concentration at steady state (t(max)(,ss)) was prolonged (128 minutes vs 93 minutes in nondiabetic patients, p < 0.01) and, on average, the paracetamol t(max) was prolonged by 30 minutes. The whole-blood dose-normalized area under the concentration-time curve from 0 to 12 hours (AUC(12)) was marginally lower in diabetic patients (p = 0.09) and the plasma AUC(12) was significantly lower (p = 0.03). The ciclosporin f(u) was numerically higher in diabetic patients (1.20 +/- 0.65% vs 0.72 +/- 0.28% in nondiabetic patients, p = 0.066); however, the unbound concentration values were essentially similar in the two groups (0.58 +/- 0.76 microg/L in diabetic patients and 0.52 +/- 0.48 microg/L in nondiabetic patients; p = 0.59). No difference was observed in the ciclosporin B : P ratio between the two groups. CONCLUSION: This study indicates that diabetes delays ciclosporin absorption, reduces ciclosporin exposure and increases the ciclosporin f(u) but not the pharmacologically active unbound concentration.

Tacrolimus in diabetic kidney transplant recipients: pharmacokinetics and application of a limited sampling strategy.

The effect of diabetes mellitus on the pharmacokinetics of tacrolimus is not well characterized. We have compared tacrolimus 12-hour steady-state concentration-time profiles in diabetic (n = 11) and demographically matched nondiabetic (n = 9) stable kidney transplant recipients and derived a limited sampling strategy for the estimation of tacrolimus area under the concentration-time curve (AUC(0-12)). Tacrolimus concentration was measured by liquid chromatography tandem mass spectrometry and acetaminophen absorption method was used to characterize gastric emptying time. Demographic and biochemical characteristics were comparable between the two groups with the exception of significantly higher glycated hemoglobin levels in patients with diabetes (P = 0.02). Time to maximum concentration (T(max)) of acetaminophen was significantly longer in diabetics [D: 74.1 minute versus nondiabetics (ND): 29.3 minutes, P = 0.02]; however, tacrolimus T(max) was not significantly different (D: 121 minutes versus ND: 87 minutes, P = 0.15). Median (interquartile range) of tacrolimus AUC(0-12) was 114 (101-161) microg*hr/L in patients with diabetes and 113 (87-189) microg*hr/L in nondiabetics (P = 0.62). The following limited sampling equation [AUC(pred) (microg*hr/L) = 18.70 - 1.72 C(1 hr) - 4.09 C(2 hr) + 14.40 C(3 hr)] was derived from a training data set that included 10 patients. The correlation coefficient between model-predicted and observed AUC0-12 values was 0.999. Mean prediction error and root mean square error of the model-predicted values derived from the patients in validation data set were 0.04 and 17.48 microg*hr/L, respectively. In conclusion, it appears that diabetes has a modest effect on the rate but not the extent of tacrolimus absorption, and a three-point abbreviated sampling strategy common to both groups may prove useful for the estimation of tacrolimus exposure in kidney transplant recipients.

Analysis of mycophenolic acid in saliva using liquid chromatography tandem mass spectrometry.

Salivary levels of the immunosuppressive agent, mycophenolic acid (MPA), may provide a convenient and noninvasive method for drug monitoring. An analytical method was developed and validated for quantification of salivary MPA using liquid chromatography tandem mass spectrometry. Sample preparation included addition of 50 microL internal standard solution [500 microg/L indomethacin in methanol] to 100 microL saliva sample, followed by protein precipitation with 200 microL acetonitrile. Supernatants were dried and reconstituted in 100 microL of 85:15% (vol/vol) mixture of methanol and water containing 0.05% formic acid and 20 microL was injected onto the analytical column. The mobile phase comprised a gradient mixture of methanol and 0.05% formic acid, giving a total run time of 7.5 minutes. Chromatograms were obtained using mass transitions of m/z 319.0-->190.8 for MPA and m/z 355.9-->312.2 for indomethacin. The calibration curve was linear over a concentration range of 2.5 to 800 microg/L (r=0.9999) and the recovery of MPA from saliva was >90%. The inaccuracy was <10% and intra- and interday coefficient of variation ranged from 2.8% to 5.2%. Mean+/-SD of MPA concentrations in saliva (n=100) obtained from 11 kidney transplant recipients was 31.4+/-32.3 microg/L (range: 2.6 to 220.4 microg/L) and correlated well with total (r=0.909) and unbound (r=0.910) MPA concentrations in plasma. In conclusion, a simple, sensitive, and specific method was developed and validated for quantification of MPA in saliva. Additional clinical studies are required to establish the usefulness of this specimen in the clinical management of organ transplant recipients.

Determination of total mycophenolic acid and its glucuronide metabolite using liquid chromatography with ultraviolet detection and unbound mycophenolic acid using tandem mass spectrometry.

Two simple, sensitive and reproducible methods for determination of total mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) as well as unbound MPA (fMPA) was developed by the use of HPLC-UV and LC-MS/MS methods, respectively. For the total MPA/MPAG method, the analytes were extracted using Isolute C(2) solid-phase extraction (SPE) cartridges and analyzed at 254 nm over a Zorbax Rx C(8) column (150 mm x 4.6 mm, 5 microm). The mobile phase was a gradient mixture of methanol and water (containing 0.1% (v/v) phosphoric acid). The total run time was 18 min and the extraction recovery was 77% for MPA and 84% for MPAG. The method was precise and accurate with a lower limit of quantification (LLOQ) of 0.5 mg/l for MPA and 5.0 mg/l for MPAG. For the fMPA method, plasma was subjected to ultrafiltration followed by SPE using C(18) cartridges. Analytical column was the same as the HPLC-UV method and the mobile phase was a gradient composition of methanol:0.05% formic acid with a flow rate of 0.6 ml/min for the first 3 min and 0.7 ml for the last 4 min. The chromatographic method separated MPA from its metabolites MPAG and Acyl-MPAG. Mass transitions in negative ionization mode for MPA and the internal standard, indomethacin were m/z: 319-->190.9 and m/z: 356-->312.2, respectively. The assay was linear in the concentration range of 1-1000 microg/l for fMPA with a LLOQ of 1 microg/l and an accuracy of >95%. The two methods reported have an adequate degree of robustness and dynamic concentration range for the measurement of MPA, MPAG and fMPA for therapeutic drug monitoring purposes or pharmacokinetics investigations.