Bioequivalence and the food effect of macitentan/tadalafil 10/20 fixed-dose combination tablets versus the use of single-component tablets in healthy subjects.

The primary aim was to demonstrate bioequivalence between the 10/20 mg fixed-dose combination (FDC) of macitentan/tadalafil in a single tablet and the free combination of both drugs, and to evaluate the food effect on the 10/20 mg FDC in healthy participants. In this single-center, randomized, open-label, 3-way crossover, single-dose Phase 1 study in healthy adult participants, macitentan/tadalafil was administered as a 10/20 mg FDC formulation and compared with the free combination of macitentan and tadalafil. The food effect on the FDC was also evaluated. Pharmacokinetic sampling (216 h) was conducted. The 90% confidence intervals (CIs) for the geometric mean ratios of maximum observed plasma analyte concentration (Cmax) and area under the plasma analyte concentration-time curves (AUCs) for Treatment A (FDC, fasted) versus C (free combination, fasted) were within bioequivalence limits demonstrating that the FDC formulation can be considered bioequivalent to the free combination. The 90% CIs for the geometric mean ratios of Cmax and AUC for Treatment B (FDC, fed) versus A (FDC, fasted) were contained within bioequivalence limits demonstrating that there was no food effect. The administration of the 10/20 mg FDC was generally safe and well tolerated in healthy participants. This study demonstrated bioequivalence between the FDC of macitentan/tadalafil (10/20 mg) in a single tablet and the free combination of both drugs in healthy participants, and that the FDC can be taken without regard to food, similarly to the individual components. The FDC was generally safe and well tolerated.

Bioequivalence and food effect of a fixed-dose combination of macitentan and tadalafil: Adaptive design in the COVID-19 pandemic.

The COVID-19 pandemic has forced clinical studies to accommodate imposed limitations. In this study, the bioequivalence part could not be conducted as planned. Thus, the aim was to demonstrate bioequivalence, using an adaptive study design, of tadalafil in fixed-dose combination (FDC) tablets of macitentan/tadalafil with single macitentan and tadalafil (Canadian-sourced) tablets and assess the effect of food on FDC tablets in healthy subjects. This Phase 1, single-center, open-label, single-dose, two-part, two-period, randomized, crossover study enrolled 62 subjects. Tadalafil bioequivalence as part of FDC of macitentan/tadalafil (10/40 mg) with single-component tablets of macitentan (10 mg) and tadalafil (40 mg) was determined by pharmacokinetic (PK) assessment under fasted conditions. The effect of food on FDC was evaluated under fed and fasted conditions. Fasted 90% confidence intervals (CIs) for geometric mean ratios (GMRs) were within bioequivalence limits for tadalafil and macitentan. Fed and fasted 90% CIs for area under the curve (AUC) GMR were within bioequivalence limits. However, 90% CIs for maximum plasma concentration (Cmax ) GMR for macitentan and tadalafil were outside bioequivalence limits. One FDC-treated subject experienced a serious adverse event of transient ischemic attack (bioequivalence part). To address pandemic-imposed limitations, an adaptive study design was implemented to demonstrate that the FDC tablet was bioequivalent to the free combination of macitentan and tadalafil (Canadian-sourced). No clinically significant differences in PK were determined between fed and fasted conditions; the FDC formulation could be taken irrespective of meals. The FDC formulation under fasted and fed conditions was well tolerated with no clinically relevant differences in safety profiles between the treatment groups. NCT Number: NCT04235270.

Capillary microsampling in clinical studies: opportunities and challenges in two case studies.

Aim: Capillary microsampling of 15 µl whole blood from fingersticks or heelsticks was used to collect pharmacokinetic (PK) samples from pediatric subjects in two projects. Results: In a mebendazole multisite study in Ethiopia and Rwanda in subjects between 1 and 16 years old, complete PK profiles (7 timepoints) could be obtained, although some of the fingerstick samples were contaminated by the dosing formulation. In a multisite study with a respiratory syncytial virus drug in children between 1 and 24 months old, sparse PK sampling was done (2 samples). All samples were successfully analyzed even though some capillaries were not properly filled. Conclusion: CMS shows potential for PK sampling in pediatrics but may need further optimization.

Comparison of toxicokinetic parameters of a drug and two metabolites following traditional and capillary microsampling in rat.

Aim: Following the request of a regulatory authority, a rat study was conducted to compare pharmacokinetic parameters from traditional large volume sampling and capillary microsampling. Materials & methods: Rats were dosed with a proprietary compound in three dose groups and blood samples were collected via capillary microsampling (32 µl), immediately followed by traditional large volume sampling (300 µl) up to 24 h postdose. Resulting plasma samples were analyzed for parent drug and two metabolites. AUCs were compared between sampling techniques. Results: There was no statistical difference between AUCs from traditional and microsampling across different doses and analytes. Conclusion: Toxicokinetic parameters generated from plasma collected as a capillary microsample or traditional large volume sample are highly comparable.

The application of capillary microsampling in GLP toxicology studies.

AIM: Capillary microsampling (CMS) to collect microplasma volumes is gradually replacing traditional, larger volume sampling from rats in GLP toxicology studies. METHODOLOGY: About 32 µl of blood is collected with a capillary, processed to plasma and stored in a 10- or 4-µl capillary which is washed out further downstream in the laboratory. CMS has been standardized with respect to materials, assay validation experiments and application for sample analysis. CONCLUSION: The implementation of CMS has resulted in blood volume reductions in the rat from 300 to 32 µl per time point and the elimination of toxicokinetic satellite groups in the majority of the rat GLP toxicology studies. The technique has been successfully applied in 26 GLP studies for 12 different projects thus far.

In Vitro and In Vivo Drug-Drug Interaction Studies to Assess the Effect of Abiraterone Acetate, Abiraterone, and Metabolites of Abiraterone on CYP2C8 Activity.

Abiraterone acetate, the prodrug of the cytochrome P450 C17 inhibitor abiraterone, plus prednisone is approved for treatment of metastatic castration-resistant prostate cancer. We explored whether abiraterone interacts with drugs metabolized by CYP2C8, an enzyme responsible for the metabolism of many drugs. Abiraterone acetate and abiraterone and its major metabolites, abiraterone sulfate and abiraterone sulfate N-oxide, inhibited CYP2C8 in human liver microsomes, with IC50 values near or below the peak total concentrations observed in patients with metastatic castration-resistant prostate cancer (IC50 values: 1.3-3.0 µM, 1.6-2.9 µM, 0.044-0.15 µM, and 5.4-5.9 µM, respectively). CYP2C8 inhibition was reversible and time-independent. To explore the clinical relevance of the in vitro data, an open-label, single-center study was conducted comprising 16 healthy male subjects who received a single 15-mg dose of the CYP2C8 substrate pioglitazone on day 1 and again 1 hour after the administration of abiraterone acetate 1000 mg on day 8. Plasma concentrations of pioglitazone, its active M-III (keto derivative) and M-IV (hydroxyl derivative) metabolites, and abiraterone were determined for up to 72 hours after each dose. Abiraterone acetate increased exposure to pioglitazone; the geometric mean ratio (day 8/day 1) was 125 [90% confidence interval (CI), 99.9-156] for Cmax and 146 (90% CI, 126-171) for AUClast Exposure to M-III and M-IV was reduced by 10% to 13%. Plasma abiraterone concentrations were consistent with previous studies. These results show that abiraterone only weakly inhibits CYP2C8 in vivo.

Profiling the dynamics of CSF and plasma Aß reduction after treatment with JNJ-54861911, a potent oral BACE inhibitor.

OBJECTIVES: Safety, tolerability, pharmacokinetics, and pharmacodynamics of a novel ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor, JNJ-54861911, were assessed after single and multiple dosing in healthy participants. METHODS: Two randomized, placebo-controlled, double-blind studies were performed using single and multiple ascending JNJ-54861911 doses (up to 14 days) in young and elderly healthy participants. Regular blood samples and frequent CSF samples, up to 36 hours after last dose, were collected to assess the pharmacokinetic and pharmacodynamic (Aß, sAPPα,ß,total levels) profiles of JNJ-54861911. RESULTS: JNJ-54861911 was well-tolerated, adverse events were uncommon and unrelated to JNJ-54861911. JNJ-54861911 showed dose-proportional CSF and plasma pharmacokinetic profiles. Plasma- and CSF-Aß and CSF-sAPPß were reduced in a dose-dependent manner. Aß reductions (up to 95%) outlasted exposure to JNJ-54861911. APOE ε4 carrier status and baseline Aß levels did not influence Aß/sAPPß reductions. CONCLUSION: JNJ-54861911, a potent brain-penetrant BACE1 inhibitor, achieved high and stable Aß reductions after single and multiple dosing in healthy participants.

Single-dose Pharmacokinetics and Pharmacodynamics of Canagliflozin, a Selective Inhibitor of Sodium Glucose Cotransporter 2, in Healthy Indian Participants.

PURPOSE: Canagliflozin, an orally active selective inhibitor of sodium glucose cotransporter 2, has been approved in several countries for the treatment of type 2 diabetes mellitus. This study assessed the pharmacokinetic (PK) and pharmacodynamic (PD) properties and tolerability of single-dose canagliflozin 200 or 300 mg in healthy Indian participants. METHODS: In this Phase 1, single-center, open-label, 2-period crossover study, healthy adult participants were randomly assigned to receive a single dose of canagliflozin 200 mg in period 1, followed by canagliflozin 300 mg in period 2, or vice versa. The 2 periods were separated by a washout interval of 14 days. The PK and PD properties and tolerability of canagliflozin were assessed at prespecified time points. FINDINGS: Of 15 randomized participants, 14 completed the study. After the administration of single doses of 200 and 300 mg, the mean (SD) Cmax values were 1792 (430) ng/mL and 2789 (941) ng/mL, respectively; AUC0-∞, values were 18,706 (3818) ng·h/mL and 28,207 (5901) ng·h/mL, respectively. The Tmax and t½ of canagliflozin were independent of dose (Tmax, 1.5 hours at both doses; t½, 13.0 and 12.6 hours with 200 and 300 mg). Over the first 4 hours, mean (SD) renal threshold for glucose (RTG) values were 60.8 (8.90) and 61.2 (7.04) mg/dL with the 200- and 300-mg doses, respectively. No effect on plasma glucose concentrations over 0 to 4 hours relative to baseline was observed with either dose. The only treatment-emergent adverse event (TEAE) reported in >1 participant was dizziness (2 participants with the 200-mg dose). None of the participants in the 300-mg group reported any TEAEs. No deaths, discontinuations due to TEAEs, or hypoglycemic episodes were reported. IMPLICATIONS: The mean plasma exposure (Cmax and AUC) to canagliflozin increased in a dose-dependent manner after the administration of single-dose oral canagliflozin 200 and 300 mg in these healthy Indian participants. The Tmax and t½ of canagliflozin appeared to be independent of dose. Overall, PK characteristics were consistent with previous findings in other ethnic populations. The reductions in RTG with canagliflozin were similar to those reported in Western participants, whereas the amount of urinary glucose excretion was somewhat less than those previously observed in studies in Western participants. Canagliflozin was generally well tolerated in these healthy Indian participants. ClinicalTrials.gov identifier: NCT01748526.

Food effects on abiraterone pharmacokinetics in healthy subjects and patients with metastatic castration-resistant prostate cancer.

Food effect on abiraterone pharmacokinetics and safety on abiraterone acetate coadministration with low-fat or high-fat meals was examined in healthy subjects and metastatic castration-resistant prostate cancer (mCRPC) patients. Healthy subjects (n = 36) were randomized to abiraterone acetate (single dose, 1000 mg) + low-fat meal, + high-fat meal, and fasted state. mCRPC patients received repeated doses (abiraterone acetate 1000 mg + 5 mg prednisone twice daily; days 1-7) in a modified fasting state followed by abiraterone acetate plus prednisone within 0.5 hours post-low-fat (n = 6) or high-fat meal (n = 18; days 8-14). In healthy subjects, geometric mean (GM) abiraterone area under plasma concentration-time curve (AUC) increased ∼5- and ∼10-fold, respectively, with low-fat and high-fat meals versus fasted state (GM [coefficient of variation], 1942 [48] and 4077 [37] ng · h/mL vs 421 [67] ng · h/mL, respectively). In mCRPC patients, abiraterone AUC was ∼2-fold higher with a high-fat meal and similar with a low-fat meal versus modified fasting state (GM [coefficient of variation]: 1992 [34] vs 973 [58] ng · h/mL and 1264 [65] vs 1185 [90] ng · h/mL, respectively). Adverse events (all grade ≤ 3) were similar, with high-fat/low-fat meals or fasted/modified fasting state. Short-term dosing with food did not alter abiraterone acetate safety.

Pharmacokinetics, Pharmacodynamics, and Safety of Single-Dose Canagliflozin in Healthy Chinese Subjects.

PURPOSE: Canagliflozin, an orally active sodium-glucose cotransporter 2 inhibitor, is approved in many countries as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. The recommended dose of canagliflozin is 100 or 300 mg once daily. This Phase I study was conducted to evaluate the pharmacokinetics, pharmacodynamics, and safety profile of canagliflozin in healthy Chinese subjects. METHODS: In this double-blind, single-dose, 3-way crossover study, 15 healthy subjects were randomized (1:1:1) to receive single oral doses of canagliflozin 100 mg, canagliflozin 300 mg, or placebo. Pharmacokinetic, pharmacodynamic, and safety assessments were made at prespecified time points. FINDINGS: All participants are healthy Chinese adults. Mean AUC and Cmax of canagliflozin increased in a dose-dependent manner after single-dose administration (AUC0-∞, 10,521 ng · h/mL for 100 mg, 33,583 ng · h/mL for 300 mg; Cmax, 1178 ng/mL for 100 mg, 4113 ng/mL for 300 mg). The mean apparent t½ and the median Tmax of canagliflozin were independent of dose (t½, 16.0 hours for 100 mg, 16.2 hours for 300 mg; Tmax, ~1 hour). Mean CL/F and renal clearance of canagliflozin were comparable between the 2 doses. Mean plasma metabolite to parent molar ratios for Cmax and AUC0-∞ were similar with both doses. Canagliflozin decreased the 24-hour mean renal threshold for glucose, calculated by using measured creatinine clearance to estimate the glomerular filtration rate (67.9 and 60.7 mg/dL for canagliflozin 100 and 300 mg, respectively) and 24-hour increased urinary glucose excretion (33.8 and 42.9 g for canagliflozin 100 and 300 mg, respectively) in a dose-dependent manner; the 24-hour plasma glucose profile remained largely unchanged. No deaths, hypoglycemic events, or discontinuations due to adverse events were observed. IMPLICATIONS: Pharmacokinetics (AUC and Cmax) of canagliflozin increased in a dose-dependent manner after single oral doses of canagliflozin (100 and 300 mg) in these healthy Chinese subjects. Tmax and t½ of canagliflozin were independent of the dose. Canagliflozin decreased the 24-hour mean renal threshold for glucose and increased urinary glucose excretion in a dose-dependent manner; these results are consistent with those observed in other patient populations. Canagliflozin was generally safe and well tolerated in these healthy Chinese subjects. ClinicalTrials.gov identifier: NCT01707316.

Pharmacokinetics and pharmacodynamics of once- and twice-daily multiple-doses of canagliflozin, a selective inhibitor of sodium glucose co-transporter 2, in healthy participants.

AIMS: Assess the steady-state pharmacokinetics, pharmacodynamics and safety of once-daily (q.d.) versus twice-daily (b.i.d.) dosing with canagliflozin at the same total daily doses of 100 and 300 mg in healthy participants. METHODS: 34 participants (17 in each cohort) were enrolled in this single-center, open-label, multiple-dose, 2-cohort, 2-way crossover study. Participants in each cohort received a total daily dose of either 100 or 300 mg canagliflozin for 5 days with q.d. then b.i.d. dosing or vice versa. Pharmacokinetics and pharmacodynamics were assessed on day 5 of each period. RESULTS: The canagliflozin Cmax,ss of 100 and 300 mg q.d. dosing were higher by 66% and 72% than corresponding morning Cmax,ss of the 50 mg and 150 mg b.i.d. regimen, respectively. The geometric mean ratios (90% CI) of b.i.d./q.d. for AUC0-24h,ss at total doses of 100 and 300 mg were 97.08 (94.08; 99.62) and 99.32 (94.71; 104.16) respectively. Median tmax and mean t1/2 were independent of dose and regimen. Mean (SE) 24-h mean renal glucose threshold values for b.i.d. and q.d. regimens were 59.2 (1.03) and 60.2 (1.03) mg/dL for the 100 mg daily doses and 51.0 (1.04) and 52.5 (1.04) mg/dL for the 300 mg daily doses. Mean (SE) values of 24-h urinary glucose excretion for b.i.d. and q.d. regimens were 52.8 (1.94) and 48.6 (1.94) g for the 100 mg daily doses and 58.6 (3.81) and 57.8 (3.81) g for the 300 mg daily doses. Both doses were safe and well tolerated. CONCLUSION: Pharmacokinetics and pharmacodynamics of canagliflozin administered q.d. relative to b.i.d. at the same 100 and 300 mg total daily doses were comparable. Overall, canagliflozin was well tolerated.

Effect of hepatic or renal impairment on the pharmacokinetics of canagliflozin, a sodium glucose co-transporter 2 inhibitor.

PURPOSE: Canagliflozin is a sodium-glucose cotransporter 2 inhibitor approved for the treatment of type 2 diabetes mellitus (T2DM). Because T2DM is often associated with renal or hepatic impairment, understanding the effects of these comorbid conditions on the pharmacokinetics of canagliflozin, and further assessing its safety, in these special populations is essential. Two open-label studies evaluated the pharmacokinetics, pharmacodynamics (renal study only), and safety of canagliflozin in participants with hepatic or renal impairment. METHODS: Participants in the hepatic study (8 in each group) were categorized based on their Child-Pugh score (normal hepatic function, mild impairment [Child-Pugh score of 5 or 6], and moderate impairment [Child-Pugh score of 7-9]) and received a single oral dose of canagliflozin 300 mg. Participants in the renal study (8 in each group) were categorized based on their creatinine clearance (CLCR) (normal renal function [CLCR ≥80 mL/min]; mild [CLCR 50 to <80 mL/min], moderate [CLCR 30 to <50 mL/min], or severe [CLCR <30 mL/min] renal impairment; and end-stage renal disease [ESRD]) and received a single oral dose of canagliflozin 200 mg; the exception was those with ESRD, who received 1 dose postdialysis and 1 dose predialysis (10 days later). Canagliflozin's pharmacokinetics and pharmacodynamics (urinary glucose excretion [UGE] and renal threshold for glucose excretion [RTG]) were assessed at predetermined time points. FINDINGS: Mean maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to infinite (AUC)0-∞ values differed by <11% between the group with normal hepatic function and those with mild and moderate hepatic impairment. In the renal study, the mean Cmax values were 13%, 29%, and 29% higher and the mean AUC0-∞ values were 17%, 63%, and 50% higher in participants with mild, moderate, and severe renal impairment, respectively; values were similar in the ESRD group relative to the group with normal function, however. The amount of UGE declined as renal function decreased, whereas RTG was not suppressed to the same extent in the moderate to severe renal impairment groups (mean RTG, 93-97 mg/dL) compared with the mild impairment and normal function groups (mean RTG, 68-77 mg/dL). IMPLICATIONS: Canagliflozin's pharmacokinetics were not affected by mild or moderate hepatic impairment. Systemic exposure to canagliflozin increased in the renal impairment groups relative to participants with normal renal function. Pharmacodynamic response to canagliflozin, measured by using UGE and RTG, declined with increasing severity of renal impairment. A single oral dose of canagliflozin was well tolerated by participants in both studies. ClinicalTrials.gov identifiers: NCT01186588 and NCT01759576.

Pharmacokinetics of abiraterone in healthy Japanese men: dose-proportionality and effect of food timing.

PURPOSE: Abiraterone acetate (AA) was recently approved for castration-resistant prostate cancer in Japan. Two phase 1 studies were conducted to assess the pharmacokinetics of abiraterone after single-dose administration in Japanese healthy men and to evaluate the effects of food timing on abiraterone pharmacokinetics after single-dose administration of AA in Japanese and Caucasian healthy men. METHODS: In the dose-proportionality study, subjects (n = 30 Japanese) were randomly assigned to receive single doses of 250, 500, and 1,000 mg AA, and in the food-timing study, subjects (n = 22 Japanese and n = 23 Caucasian) randomly received single doses of 1,000 mg AA under fasted (overnight) and three different modified fasting conditions. RESULTS: Mean C(max) and AUC(∞) for abiraterone increased dose-dependently in Japanese healthy men; however, 90 % confidential interval (CI) was outside the predefined dose-proportionality criteria. Based on geometric mean ratios and 90 % CIs (versus overnight fasting condition), abiraterone exposure (AUC) increased significantly with dosing 1 h premeal, 2 h postmeal, or in between two meals 4 h apart by 57 %, 595 %, and 649 %, respectively. CONCLUSION: No clinically meaningful difference was observed in the pharmacokinetics of abiraterone between Caucasian and Japanese subjects.

Effect of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on the pharmacokinetics of oral contraceptives, warfarin, and digoxin in healthy participants.

OBJECTIVE: Drug-drug interactions between canagliflozin, a sodium glucose co-transporter 2 inhibitor approved for the management of type-2 diabetes mellitus, and an oral contraceptive (OC), warfarin, and digoxin were evaluated in three phase 1 studies in healthy participants. METHODS: All studies were open-label; study 1 included a fixed-sequence design, and studies 2 and 3 used a crossover design. Regimens were: study 1: OC (levonorgestrel (150 µg) + ethinyl estradiol (30 µg))/day (day 1), canagliflozin 200 mg/day (days 4 - 8), and canagliflozin with OC (day 9); study 2: canagliflozin 300 mg/day (days 1 - 12) with warfarin 30 mg/day (day 6) in period 1, and only warfarin 30 mg/day (day 1) in period 2, or vice versa; study 3: digoxin alone (0.5 mg/day (day 1) + 0.25 mg/day (days 2 - 7)) in period 1, and with canagliflozin 300 mg/day (days 1 - 7) in period 2, or vice versa. Pharmacokinetics (PK) were assessed at prespecified intervals; OC: days 1 and 9, canagliflozin: days 8 - 9 (study 1); warfarin: days 6 (period 1) and 1 (period 2) (study 2); and digoxin: days 5 - 7 (periods 1 and 2) (study 3). Warfarin's pharmacodynamics (PD; International Normalized Ratio (INR)) was assessed on days 6 (period 1) and 1 (period 2). RESULTS: Canagliflozin increased the plasma exposure of OC (maximum plasma concentration (Cmax): 22%, area under the curve (AUC): 6%) and digoxin (Cmax: 36%, AUC: 20%); but did not alter warfarin'€™s PK and PD. No clinically relevant safety findings (including hypoglycemia) were noted. CONCLUSION: Canagliflozin can be coadministered with OC, warfarin, or digoxin without dose adjustments. All treatments were well-tolerated.

Effects of rifampin, cyclosporine A, and probenecid on the pharmacokinetic profile of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in healthy participants.

OBJECTIVE: Canagliflozin, a sodium-glucose co-transporter 2 inhibitor, approved for the treatment of type-2 diabetes mellitus (T2DM), is metabolized by uridine diphosphate-glucuronosyltransferases (UGT) 1A9 and UGT2B4, and is a substrate of P-glycoprotein (P-gp). Canagliflozin exposures may be affected by coadministration of drugs that induce (e.g., rifampin for UGT) or inhibit (e.g. probenecid for UGT; cyclosporine A for P-gp) these pathways. The primary objective of these three independent studies (single-center, open-label, fixed-sequence) was to evaluate the effects of rifampin (study 1), probenecid (study 2), and cyclosporine A (study 3) on the pharmacokinetics of canagliflozin in healthy participants. METHODS: Participants received; in study 1: canagliflozin 300 mg (days 1 and 10), rifampin 600 mg (days 4-12); study 2: canagliflozin 300 mg (days 1-17), probenecid 500 mg twice daily (days 15-17); and study 3: canagliflozin 300 mg (days 1-8), cyclosporine A 400 mg (day 8). Pharmacokinetics were assessed at prespecified intervals on days 1 and 10 (study 1); on days 14 and 17 (study 2), and on days 2-8 (study 3). RESULTS: Rifampin decreased the maximum plasma canagliflozin concentration (Cmax) by 28% and its area under the curve (AUC) by 51%. Probenecid increased the Cmax by 13% and the AUC by 21%. Cyclosporine A increased the AUC by 23% but did not affect the Cmax. CONCLUSION: Coadministration of canagliflozin with rifampin, probenecid, and cyclosporine A was well-tolerated. No clinically meaningful interactions were observed for probenecid or cyclosporine A, while rifampin coadministration modestly reduced canagliflozin plasma concentrations and could necessitate an appropriate monitoring of glycemic control.

Single- and multiple-dose pharmacokinetics and pharmacodynamics of canagliflozin, a selective inhibitor of sodium glucose co-transporter 2, in healthy participants.

OBJECTIVE: To evaluate the pharmacokinetics of oral canagliflozin and its O-glucuronide metabolites (M7 and M5) after single and multiple doses in healthy adult participants. The pharmacodynamics, safety, and tolerability of canagliflozin were also evaluated. METHODS: In this open-label, single- (day 1) and multiple-dose (days 4-9), parallel-group, phase 1 study, 27 healthy participants were randomized into three groups (1:1:1) to receive 50, 100, or 300 mg canagliflozin. Pharmacokinetics and pharmacodynamics were assessed at pre-pecified timepoints on days 1, 9, and 10. RESULTS: Mean area under the plasma concentration-time curve, and the maximum observed plasma concentration of canagliflozin, M7, and M5 increased in a dose-dependent manner, across all the 3 doses, following single- and multiple-dose administration. The mean apparent elimination half-lives of canagliflozin, M7, and M5 were independent of the dose. Canagliflozin decreased the renal threshold for glucose (RTG) and increased the urinary glucose excretion (UGE) in a concentration- and dose-dependent manner. The relationship between drug concentrations and RTG was described by a sigmoidal relationship with RTGmin (minimum value of RTG) of 37.5 ng/mL (95% confidence interval (CI): 34.3, 40.8) and half-maximal effective concentration (EC50) of 21 ng/mL (95% CI: 18.3, 23.8). No deaths, serious adverse events, hypoglycemic events, or discontinuations due to adverse events were observed. CONCLUSION: Pharmacokinetics of canagliflozin and its metabolites (M7 and M5) were linear, and no time-dependent changes were observed after single- and multiple-dose administration. Similarly, pharmacodynamic effects of canagliflozin on RTG and UGE were found to be dose- and concentration-dependent. Overall, canagliflozin was well-tolerated in healthy participants.

Effect of food on the pharmacokinetics of canagliflozin/metformin (150/1,000 mg) immediate-release fixed-dose combination tablet in healthy participants.

OBJECTIVE: To assess the effect of food on the pharmacokinetics (PK) of canagliflozin and metformin following administration of a canagliflozin/metformin (150/1,000 mg) immediate-release (IR) fixed-dose combination (FDC) tablet. METHODS: A randomized, open-label, singlecenter, single-dose, 2-period, 2-sequence crossover study was conducted in healthy participants. Participants were randomized to 2 sequences of fasted and fed (or vice versa) administration of one 150/1,000 mg canagliflozin/metformin IR FDC, with 10-14 day washout between treatments PK parameters (AUC, Cmax, tmax, t1/2) were assessed for canagliflozin and metformin. Safety was evaluated. RESULTS: When comparing the IR FDC tablet administered with and without food, PK parameters of canagliflozin were bioequivalent as the 90% confidence intervals (CIs) for log-transformed AUClast, AUC∞, and Cmax were within the bioequivalence limits of 80-125%. For metformin, overall exposure was similar under fed and fasted conditions as geometric mean ratios for AUC and associated 90% CI were contained within the bioequivalence limits, but geometric mean Cmax decreased by 16% in the fed compared to fasted state. Both treatments were well tolerated with similar adverse events and most common were gastrointestinal events, generally attributed to metformin. CONCLUSIONS: Food did not affect canagliflozin bioavailability parameters (Cmax and AUCs) or AUCs of metformin. The Cmax of metformin was decreased by 16%, which is not considered clinically meaningful. The canagliflozin/metformin FDC tablet is recommended to be taken with meals to reduce the symptoms of gastrointestinal intolerability associated with metformin.

Impact on abiraterone pharmacokinetics and safety: Open-label drug-drug interaction studies with ketoconazole and rifampicin.

We evaluated the impact of a strong CYP3A4 inhibitor, ketoconazole, and a strong inducer, rifampicin, on the pharmacokinetic (PK) exposure of abiraterone in two studies in healthy men. All subjects received 1,000 mg of abiraterone acetate on Days 1 and 14. Study A subjects (n = 20) received 400 mg ketoconazole on Days 11-16. Study B subjects (n = 19) received 600 mg rifampicin on Days 8-13. Serial PK sampling was done on Days 1 and 14. Study A: When given with ketoconazole, abiraterone exposure increased by 9% for maximum plasma concentration (Cmax ) and 15% for area under the plasma concentration-time curve from 0 to time of the last quantifiable concentration (AUClast ) and AUC from time 0 to infinity (AUC∞ ) compared to abiraterone acetate alone. Study B: When given with rifampicin, abiraterone exposure was reduced to 45% for Cmax and AUC∞ and to 42% for AUClast compared to abiraterone acetate alone. Ketoconazole had no clinically meaningful impact on abiraterone exposure. Rifampicin decreased abiraterone exposure by half. Hence, strong CYP3A4 inducers should be avoided or used with careful evaluation of clinical efficacy when administered with abiraterone acetate.

Effect of food on the pharmacokinetics of canagliflozin, a sodium glucose co-transporter 2 inhibitor, and assessment of dose proportionality in healthy participants.

Canagliflozin, an orally active inhibitor of sodium glucose co-transporter 2, is approved for the treatment of type-2 diabetes mellitus. The effect of food on the pharmacokinetics of 300 mg canagliflozin, and dose proportionality of 50, 100, and 300 mg canagliflozin, were evaluated, in two studies, in healthy participants. Study 1 used a randomized, 2-way crossover design: canagliflozin 300 mg/day was administered under fasted (Period-1) and fed (Period-2) conditions or vice versa. Study 2 was a 3-way crossover: participants were randomized to receive three single-doses of canagliflozin (50, 100, and 300 mg), one in each period. In both studies, treatment periods were separated by washout intervals of 10-14 days, and pharmacokinetics assessed up to 72 hours postdose of each treatment period. No clinically relevant food effects on canagliflozin exposure parameters were observed: 90% confidence intervals (CIs) for the fed/fasted geometric mean ratios of AUC∞ (ratio: 100.51; 90% CI: 89.47-112.93) and Cmax (ratio: 108.09; 90% CI: 103.45-112.95) were entirely within bioequivalence limits (80-125%). Plasma canagliflozin exposures were dose-proportional as the 90% CI of the slope of the regression line for dose-normalized AUC∞ and Cmax fell entirely within the prespecified limits of -0.124 to 0.124. No clinically significant safety issues were noted, and canagliflozin was generally well-tolerated.

Absolute oral bioavailability and pharmacokinetics of canagliflozin: A microdose study in healthy participants.

Absolute oral bioavailability of canagliflozin was assessed by simultaneous oral administration with intravenous [(14) C]-canagliflozin microdose infusion in nine healthy men. Pharmacokinetics of canagliflozin, [(14) C]-canagliflozin, and total radioactivity, and safety and tolerability were assessed at prespecified timepoints. On day 1, single-dose oral canagliflozin (300 mg) followed 105 minutes later by intravenous [(14) C]-canagliflozin (10 µg, 200 nCi) was administered. After oral administration, the mean (SD) Cmax of canagliflozin was 2504 (482) ng/mL at 1.5 hours, AUC∞ 17,375 (3555) ng.h/mL, and t1/2 11.6 (0.70) hours. After intravenous administration, the mean (SD) Cmax of unchanged [(14) C]-canagliflozin was 17,605 (6901) ng/mL, AUC∞ 27,100 (10,778) ng.h/mL, Vdss 83.5 (29.2) L, Vdz 119 (41.6) L, and CL 12.2 (3.79) L/h. Unchanged [(14) C]-canagliflozin and metabolites accounted for about 57% and 43% of the plasma total [(14) C] radioactivity AUC∞ , respectively. For total [(14) C] radioactivity, the mean (SD) Cmax was 15,981 (2721) ng-eq/mL, and AUC∞ 53,755 (15,587) ng-eq.h/mL. Renal (34.5% in urine) and biliary (34.1% in feces) excretions were the major elimination pathways for total [(14) C] radioactivity. The absolute oral bioavailability of canagliflozin was 65% (90% confidence interval: 55.41; 76.07). Overall, oral canagliflozin 300 mg coadministered with intravenous [(14) C]-canagliflozin (10 µg) was generally well-tolerated in healthy men, with no treatment-emergent adverse events.