Clinical Pharmacology Perspective on Development of Adeno-Associated Virus Vector-Based Retina Gene Therapy.

Adeno-associated virus (AAV) vector-based gene therapy is an innovative modality being increasingly investigated to treat diseases by modifying or replacing defective genes or expressing therapeutic entities. With its unique anatomic and physiological characteristics, the eye constitutes a very attractive target for gene therapy. Specifically, the ocular space is easily accessible and is generally considered "immune-privileged" with a low risk of systemic side effects following local drug administration. As retina cells have limited cellular turnover, a one-time gene delivery has the potential to provide long-term transgene expression. Despite the initial success with voretigene neparvovec (Luxturna), the first approved retina gene therapy, there are still challenges to be overcome for successful clinical development of these products and scientific questions to be answered. The current review paper aims to integrate published experience learned thus far for AAV-based retina gene therapy related to preclinical to clinical translation; first-in-human dose selection; relevant bioanalytical assays and strategies; clinical development considerations including trial design, biodistribution and vector shedding, immunogenicity, transgene expression, and pediatric populations; opportunities for model-informed drug development; and regulatory perspectives. The information presented herein is intended to serve as a guide to inform the clinical development strategy for retina gene therapy with a focus on clinical pharmacology.

Preclinical and clinical characterization of the RORγt inhibitor JNJ-61803534.

The nuclear receptor retinoid-related orphan receptor gamma t (RORγt) plays a critical role in driving Th17 cell differentiation and expansion, as well as IL-17 production in innate and adaptive immune cells. The IL-23/IL-17 axis is implicated in several autoimmune and inflammatory diseases, and biologics targeting IL-23 and IL-17 have shown significant clinical efficacy in treating psoriasis and psoriatic arthritis. JNJ-61803534 is a potent RORγt inverse agonist, selectively inhibiting RORγt-driven transcription versus closely-related family members, RORα and RORß. JNJ-61803534 inhibited IL-17A production in human CD4+ T cells under Th17 differentiation conditions, but did not inhibit IFNγ production under Th1 differentiation conditions, and had no impact on in vitro differentiation of regulatory T cells (Treg), nor on the suppressive activity of natural Tregs. In the mouse collagen-induced arthritis model, JNJ-61803534 dose-dependently attenuated inflammation, achieving ~ 90% maximum inhibition of clinical score. JNJ-61803534 significantly inhibited disease score in the imiquimod-induced mouse skin inflammation model, and dose-dependently inhibited the expression of RORγt-regulated genes, including IL-17A, IL-17F, IL-22 and IL-23R. Preclinical 1-month toxicity studies in rats and dogs identified doses that were well tolerated supporting progression into first-in-human studies. An oral formulation of JNJ-61803534 was studied in a phase 1 randomized double-blind study in healthy human volunteers to assess safety, pharmacokinetics, and pharmacodynamics. The compound was well tolerated in single ascending doses (SAD) up to 200 mg, and exhibited dose-dependent increases in exposure upon oral dosing, with a plasma half-life of 164 to 170 h. In addition, dose-dependent inhibition of ex vivo stimulated IL-17A production in whole blood was observed, demonstrating in vivo target engagement. In conclusion, JNJ-61803534 is a potent and selective RORγt inhibitor that exhibited acceptable preclinical safety and efficacy, as well as an acceptable safety profile in a healthy volunteer SAD study, with clear evidence of a pharmacodynamic effect in humans.

Dynamic population pharmacokinetic-pharmacodynamic modelling and simulation supports similar efficacy in glycosylated haemoglobin response with once or twice-daily dosing of canagliflozin.

AIM: Canagliflozin is an SGLT2 inhibitor approved for the treatment of type-2 diabetes. A dynamic population pharmacokinetic-pharmacodynamic (PK/PD) model relating 24-h canagliflozin exposure profiles to effects on glycosylated haemoglobin was developed to compare the efficacy of once-daily and twice-daily dosing. METHODS: Data from two clinical studies, one with once-daily, and the other with twice-daily dosing of canagliflozin as add-on to metformin were used (n = 1347). An established population PK model was used to predict full 24-h profiles from measured trough concentrations and/or baseline covariates. The dynamic PK/PD model incorporated an Emax relationship between 24-h canagliflozin exposure and HbA1c-lowering with baseline HbA1c affecting the efficacy. RESULTS: Internal and external model validation demonstrated that the model adequately predicted HbA1c-lowering for canagliflozin once-daily and twice-daily dosing regimens. The differences in HbA1c reduction between the twice-daily and daily mean profiles were minimal (at most 0.023% for 100 mg total daily dose [TDD] and 0.011% for 300 mg TDD, up to week 26, increasing with time and decreasing with TDD) and not considered clinically meaningful. CONCLUSIONS: Simulations using this model demonstrated the absence of clinically meaningful between-regimen differences in efficacy, supported the regulatory approval of a canagliflozin-metformin immediate release fixed-dose combination tablet and alleviated the need for an additional clinical study.

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.

Population Pharmacokinetic Modeling of Canagliflozin in Healthy Volunteers and Patients with Type 2 Diabetes Mellitus.

BACKGROUND AND OBJECTIVES: Canagliflozin is an orally active, reversible, selective sodium-glucose co-transporter-2 inhibitor. A population pharmacokinetic (popPK) model of canagliflozin, including relevant covariates as sources of inter-individual variability, was developed to describe phase I, II, and III data in healthy volunteers and in patients with type 2 diabetes mellitus (T2DM). METHODS: The final analysis included 9061 pharmacokinetic (PK) samples from 1616 volunteers enrolled in nine phase I, two phase II, and three phase III studies and was performed using NONMEM(®) 7.1. Inter-individual variability was evaluated using an exponential model and the residual error model was additive in the log domain. The first-order conditional estimation method with interaction was applied and the model was parameterized in terms of rate constants. Covariate effects were explored graphically on empirical Bayes estimates of PK parameters, as shrinkage was low. Clinical relevance of statistically significant covariates was evaluated. The predictive properties of the model were illustrated by prediction-corrected visual predictive checks. RESULTS: A two-compartment PK model with lag-time and sequential zero- and first-order absorption and first-order elimination best described the observed data. Sex, age, and weight on apparent volume of distribution of the central compartment, body mass index on first-order absorption rate constant, and body mass index and over-encapsulation on lag-time, and estimated glomerular filtration rate (eGFR, by MDRD equation), dose, and genetic polymorphism (carriers of UGT1A9*3 allele) on elimination rate constant were identified as statistically significant covariates. The prediction-corrected visual predictive checks revealed acceptable predictive performance of the model. CONCLUSION: The popPK model adequately described canagliflozin PK in healthy volunteers and in patients with T2DM. Because of the small magnitude of statistically significant covariates, they were not considered clinically relevant. However, dosage adjustments are recommended for T2DM patients with renal impairment (eGFR ≥60 mL/min/1.73 m(2): 100 or 300 mg/day; eGFR of 45 to <60 mL/min/1.73 m(2): 100 mg/day).

Clinical Pharmacokinetic, Pharmacodynamic, and Drug-Drug Interaction Profile of Canagliflozin, a Sodium-Glucose Co-transporter 2 Inhibitor.

The sodium-glucose co-transporter 2 (SGLT2) inhibitors represent novel therapeutic approaches in the management of type 2 diabetes mellitus; they act on kidneys to decrease the renal threshold for glucose (RTG) and increase urinary glucose excretion (UGE). Canagliflozin is an orally active, reversible, selective SGLT2 inhibitor. Orally administered canagliflozin is rapidly absorbed achieving peak plasma concentrations in 1-2 h. Dose-proportional systemic exposure to canagliflozin has been observed over a wide dose range (50-1600 mg) with an oral bioavailability of 65 %. Canagliflozin is glucuronidated into two inactive metabolites, M7 and M5 by uridine diphosphate-glucuronosyltransferase (UGT) 1A9 and UGT2B4, respectively. Canagliflozin reaches steady state in 4 days, and there is minimal accumulation observed after multiple dosing. Approximately 60 % and 33 % of the administered dose is excreted in the feces and urine, respectively. The half-life of orally administered canagliflozin 100 or 300 mg in healthy participants is 10.6 and 13.1 h, respectively. No clinically relevant differences are observed in canagliflozin exposure with respect to age, race, sex, and body weight. The pharmacokinetics of canagliflozin remains unaffected by mild or moderate hepatic impairment. Systemic exposure to canagliflozin is increased in patients with renal impairment relative to those with normal renal function; however, the efficacy is reduced in patients with renal impairment owing to the reduced filtered glucose load. Canagliflozin did not show clinically relevant drug interactions with metformin, glyburide, simvastatin, warfarin, hydrochlorothiazide, oral contraceptives, probenecid, and cyclosporine, while co-administration with rifampin modestly reduced canagliflozin plasma concentrations and thus may necessitate an appropriate monitoring of glycemic control. Canagliflozin increases UGE and suppresses RTG in a dose-dependent manner, thereby lowering the plasma glucose levels and reducing the glycosylated hemoglobin levels through an insulin-independent mechanism of action. The 300-mg dose provides near-maximal effects on RTG throughout the full 24-h dosing interval, whereas the effect of the 100-mg dose on RTG is near-maximal for approximately 12 h and is modestly attenuated during the overnight period. The observed pharmacokinetic/pharmacodynamic profile of canagliflozin in patients with type 2 diabetes mellitus supports a once-daily dosing regimen.

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.

In vitro metabolism of canagliflozin in human liver, kidney, intestine microsomes, and recombinant uridine diphosphate glucuronosyltransferases (UGT) and the effect of genetic variability of UGT enzymes on the pharmacokinetics of canagliflozin in humans.

O-glucuronidation is the major metabolic elimination pathway for canagliflozin. The objective was to identify enzymes and tissues involved in the formation of 2 major glucuronidated metabolites (M7 and M5) of canagliflozin and subsequently to assess the impact of genetic variations in these uridine diphosphate glucuronosyltransferases (UGTs) on in vivo pharmacokinetics in humans. In vitro incubations with recombinant UGTs revealed involvement of UGT1A9 and UGT2B4 in the formation of M7 and M5, respectively. Although M7 and M5 were formed in liver microsomes, only M7 was formed in kidney microsomes. Participants from 7 phase 1 studies were pooled for pharmacogenomic analyses. A total of 134 participants (mean age, 41 years; men, 63%; white, 84%) were included in the analysis. In UGT1A9*3 carriers, exposure of plasma canagliflozin (Cmax,ss , 11%; AUCτ,ss , 45%) increased relative to the wild type. An increase in exposure of plasma canagliflozin (Cmax,ss , 21%; AUCt,ss , 18%) was observed in participants with UGT2B4*2 genotype compared with UGT2B4*2 noncarriers. Metabolites further delineate the role of both enzymes. The pharmacokinetic findings in participants carrying the UGT1A9*3 and UGT2B4*2 allele implicate that UGT1A9 and UGT2B4 are involved in the metabolism of canagliflozin to M7 and M5, respectively.

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.

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.

Effect of canagliflozin on the pharmacokinetics of glyburide, metformin, and simvastatin in healthy participants.

Drug-drug interactions between canagliflozin, a sodium glucose co-transporter 2 inhibitor, and glyburide, metformin, and simvastatin were evaluated in three phase-1 studies in healthy participants. In these open-label, fixed sequence studies, participants received: Study 1-glyburide 1.25 mg/day (Day 1), canagliflozin 200 mg/day (Days 4-8), canagliflozin with glyburide (Day 9); Study 2-metformin 2,000 mg/day (Day 1), canagliflozin 300 mg/day (Days 4-7), metformin with canagliflozin (Day 8); Study 3-simvastatin 40 mg/day (Day 1), canagliflozin 300 mg/day (Days 2-6), simvastatin with canagliflozin (Day 7). Pharmacokinetic parameters were assessed at prespecified intervals. Co-administration of canagliflozin and glyburide did not affect the overall exposure (maximum plasma concentration [Cmax ] and area under the plasma concentration-time curve [AUC]) of glyburide and its metabolites (4-trans-hydroxy-glyburide and 3-cis-hydroxy-glyburide). Canagliflozin did not affect the peak concentration of metformin; however, AUC increased by 20%. Though Cmax and AUC were slightly increased for simvastatin (9% and 12%) and simvastatin acid (26% and 18%) following coadministration with canagliflozin, compared with simvastatin administration alone; however, no effect on active 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitory activity was observed. There were no serious adverse events or hypoglycemic episodes. No drug-drug interactions were observed between canagliflozin and glyburide, metformin, or simvastatin. All treatments were well-tolerated in healthy participants.

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.

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.

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.

Pharmacodynamic effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, from a randomized study in patients with type 2 diabetes.

INTRODUCTION: This randomized, double-blind, placebo-controlled, single and multiple ascending-dose study evaluated the pharmacodynamic effects and safety/tolerability of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in patients with type 2 diabetes. METHODS: Patients (N = 116) discontinued their antihyperglycemic medications 2 weeks before randomization. Patients received canagliflozin 30, 100, 200, or 400 mg once daily or 300 mg twice daily, or placebo at 2 study centers in the United States and Germany, or canagliflozin 30 mg once daily or placebo at 1 study center in Korea, while maintaining an isocaloric diet for 2 weeks. On Days -1, 1, and 16, urinary glucose excretion (UGE), plasma glucose (PG), fasting PG (FPG), and insulin were measured. The renal threshold for glucose (RTG) was calculated from UGE, PG, and estimated glomerular filtration rate. Safety was evaluated based on adverse event (AE) reports, vital signs, electrocardiograms, clinical laboratory tests, and physical examinations. RESULTS: Canagliflozin increased UGE dose-dependently (,80-120 g/day with canagliflozin $100 mg), with increases maintained over the 14-day dosing period with each dose. Canagliflozin dose-dependently decreased RTG, with maximal reductions to ,4-5 mM (72-90 mg/dL). Canagliflozin also reduced FPG and 24-hour mean PG; glucose reductions were seen on Day 1 and maintained over 2 weeks. Plasma insulin reductions with canagliflozin were consistent with observed PG reductions. Canagliflozin also reduced body weight. AEs were transient, mild to moderate in intensity, and balanced across groups; 1 canagliflozin-treated female reported an episode of vaginal candidiasis. Canagliflozin did not cause hypoglycemia, consistent with the RTG values remaining above the hypoglycemia threshold. At Day 16, there were no clinically meaningful changes in urine volume, urine electrolyte excretion, renal function, or routine laboratory test values. CONCLUSIONS: Canagliflozin increased UGE and decreased RTG, leading to reductions in PG, insulin, and body weight, and was generally well tolerated in patients with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT00963768.