Canagliflozin

Canagliflozin is transported by P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP).

Inhibition of BCRP by canagliflozin cannot be excluded at an intestinal level and increased exposure may therefore occur for medicinal products transported by BCRP, e.g. certain statins like rosuvastatin and some anti-cancer medicinal products.

The metabolism of canagliflozin is primarily via glucuronide conjugation mediated by UDP glucuronosyl transferase 1A9 (UGT1A9) and 2B4 (UGT2B4). Canagliflozin is transported by P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP).

Enzyme inducers (such as St. John’s wort [Hypericum perforatum], rifampicin, barbiturates, phenytoin, carbamazepine, ritonavir, efavirenz) may give rise to decreased exposure of canagliflozin. Following co-administration of canagliflozin with rifampicin (an inducer of various active transporters and medicinal product-metabolising enzymes), 51% and 28% decreases in canagliflozin systemic exposure (AUC) and peak concentration (C_max) were observed. These decreases in exposure to canagliflozin may decrease efficacy.

If a combined inducer of these UGT enzymes and transport proteins must be co-administered with canagliflozin, monitoring of glycaemic control to assess response to canagliflozin is appropriate. If an inducer of these UGT enzymes must be co-administered with canagliflozin, increasing the dose to 300 mg once daily may be considered if patients are currently tolerating canagliflozin 100 mg once daily, have an eGFR ≥60 mL/min/1.73 m² or CrCl ≥60 mL/min, and require additional glycaemic control. In patients with an eGFR 45 mL/min/1.73 m² to <60 mL/min/1.73 m² or CrCl 45 mL/min to <60 mL/min taking canagliflozin 100 mg who are receiving concurrent therapy with a UGT enzyme inducer and who require additional glycaemic control, other glucose-lowering therapies should be considered.

For treatment of diabetic kidney disease as add on to standard of care (eg ACE-inhibitors or ARBs), a dose of 100 mg canagliflozin once daily should be used. Because the glycaemic lowering efficacy of canagliflozin is reduced in patients with moderate renal impairment and likely absent in patients with severe renal impairment, if further glycaemic control is needed, the addition of other anti-hyperglycaemic agents should be considered. For dose adjustment recommendations according to eGFR refer to the following table.

Dose adjustment recommendations:

^a If further glycaemic control is needed, the addition of other anti hyperglycaemic agents should be considered
^b With urinary albumin/creatinine ratio ˃300 mg/g
^c Continue dosing until dialysis or renal transplantation.

Canagliflozin has not been studied in patients with severe hepatic impairment and is not recommended for use in these patients.

Insulin and insulin secretagogues, such as sulphonylureas, can cause hypoglycaemia. Therefore, a lower dose of insulin or an insulin secretagogue may be required to reduce the risk of hypoglycaemia when used in combination with canagliflozin.

The combination of canagliflozin 300 mg once daily for 7 days with a single dose of digoxin 0.5 mg followed by 0.25 mg daily for 6 days resulted in a 20% increase in AUC and a 36% increase in C_max of digoxin, probably due to inhibition of P-gp. Canagliflozin has been observed to inhibit P-gp in vitro. Patients taking digoxin or other cardiac glycosides (e.g. digitoxin) should be monitored appropriately.

Canagliflozin may add to the effect of diuretics and may increase the risk of dehydration and hypotension.

Cholestyramine may potentially reduce canagliflozin exposure. Dosing of canagliflozin should occur at least 1 hour before or 4-6 hours after administration of a bile acid sequestrant to minimise possible interference with their absorption.

The effect of concomitant administration of canagliflozin (a weak P-gp inhibitor) on dabigatran etexilate (a P-gp substrate) has not been studied. As dabigatran concentrations may be increased in the presence of canagliflozin, monitoring (looking for signs of bleeding or anaemia) should be exercised when dabigatran is combined with canagliflozin.

The concomitant use of an SGLT2 inhibitor with lithium may decrease serum lithium concentrations. Monitor serum lithium concentration more closely during treatment with canagliflozin, especially during initiation and dosage changes.

The combination of canagliflozin 300 mg once daily for 6 days with a single dose of simvastatin (CYP3A4 substrate) 40 mg resulted in a 12% increase in AUC and a 9% increase in C_max of simvastatin and an 18% increase in AUC and a 26% increase in C_max of simvastatin acid. The increases in simvastatin and simvastatin acid exposures are not considered clinically relevant.

Careful monitoring in patients with already elevated haematocrit is warranted.

Caution should be exercised in patients for whom a canagliflozin-induced drop in blood pressure could pose a risk, such as patients with known cardiovascular disease, patients with an eGFR <60 mL/min/1.73 m², patients on anti-hypertensive therapy with a history of hypotension, patients on diuretics, or elderly patients (≥65 years of age).

For patients receiving canagliflozin, in case of intercurrent conditions that may lead to volume depletion (such as a gastrointestinal illness), careful monitoring of volume status (e.g., physical examination, blood pressure measurements, laboratory tests including renal function tests), and serum electrolytes is recommended. Temporary interruption of treatment with canagliflozin may be considered for patients who develop volume depletion while on canagliflozin therapy until the condition is corrected. If interrupted, consideration should be given to more frequent glucose monitoring.

There are no data from the use of canagliflozin in pregnant women. Studies in animals have shown reproductive toxicity.

Canagliflozin should not be used during pregnancy. When pregnancy is detected, treatment with canagliflozin should be discontinued.

It is unknown whether canagliflozin and/or its metabolites are excreted in human milk. Available pharmacodynamic/toxicological data in animals have shown excretion of canagliflozin/metabolites in milk, as well as pharmacologically mediated effects in breast-feeding offspring and juvenile rats exposed to canagliflozin. A risk to newborns/infants cannot be excluded. Canagliflozin should not be used during breast-feeding.

Fertility

The effect of canagliflozin on fertility in humans has not been studied. No effects on fertility were observed in animal studies.

Canagliflozin has no or negligible influence on the ability to drive and use machines. However, patients should be alerted to the risk of hypoglycaemia when canagliflozin is used as add-on therapy with insulin or an insulin secretagogue, and to the elevated risk of adverse reactions related to volume depletion, such as postural dizziness.

Summary of the safety profile

The safety of canagliflozin was evaluated in 22,645 patients with type 2 diabetes, including 13,278 patients treated with canagliflozin and 9,367 patients treated with comparator in 15 double-blind, controlled phase 3 and phase 4 clinical studies. A total of 10,134 patients were treated in two dedicated cardiovascular studies for a mean exposure duration of 149 weeks (223 weeks in CANVAS and 94 weeks in CANVAS-R), and 8,114 patients were treated in 12 double blind, controlled phase 3 and phase 4 clinical studies, for a mean exposure duration of 49 weeks. In a dedicated renal outcomes study, a total of 4,397 patients with type 2 diabetes and diabetic kidney disease had a mean exposure duration of 115 weeks.

The primary assessment of safety and tolerability was conducted in a pooled analysis (n=2,313) of four 26-week placebo-controlled clinical studies (monotherapy and add-on therapy with metformin, metformin and a sulphonylurea, and metformin and pioglitazone). The most commonly reported adverse reactions during treatment were hypoglycaemia in combination with insulin or a sulphonylurea, vulvovaginal candidiasis, urinary tract infection, and polyuria or pollakiuria (i.e., urinary frequency). Adverse reactions leading to discontinuation of ≥0.5% of all canagliflozin-treated patients in these studies were vulvovaginal candidiasis (0.7% of female patients) and balanitis or balanoposthitis (0.5% of male patients). Additional safety analyses (including long-term data) from data across the entire canagliflozin programme (placebo- and active-controlled studies) were conducted to assess reported adverse reactions in order to identify adverse reactions (table 1).

Tabulated list of adverse reactions

Adverse reactions in table 1 are based on the pooled analysis of the placebo- and active-controlled studies described above. Adverse reactions reported from world-wide postmarketing use of canagliflozin are also included in this tabulation. Adverse reactions listed below are classified according to frequency and system organ class. Frequency categories are defined according to the following convention: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000), very rare (<1/10,000), not known (cannot be estimated from the available data).

Table 1. Tabulated list of adverse reactions (MedDRA) from placebo^e and active-controlled studies^e and from postmarketing experience:

^a Related to volume depletion; see description of adverse reaction (AR) below.
^b See description of AR below.
^c See description of AR below.
^e Safety data profiles from individual pivotal studies (including studies in moderately renally impaired patients; older patients [≥55 years of age to ≤80 years of age]; patients with increased CV- and renal-risk) were generally consistent with the adverse reactions identified in this table.
^f Thirst includes the terms thirst, dry mouth, and polydipsia.
^g Rash includes the terms rash erythematous, rash generalised, rash macular, rash maculopapular, rash papular, rash pruritic, rash pustular, and rash vesicular.
^h Related to bone fracture; see description of AR below.
ⁱ Polyuria or pollakiuria includes the terms polyuria, pollakiuria, micturition urgency, nocturia, and urine output increased.
^j Vulvovaginal candidiasis includes the terms vulvovaginal candidiasis, vulvovaginal mycotic infection, vulvovaginitis, vaginal infection, vulvitis, and genital infection fungal.
^k Balanitis or balanoposthitis includes the terms balanitis, balanoposthitis, balanitis candida, and genital infection fungal.
^l Mean percent increases from baseline for canagliflozin 100 mg and 300 mg versus placebo, respectively, were total cholesterol 3.4% and 5.2% versus 0.9%; HDL-cholesterol 9.4% and 10.3% versus 4.0%; LDL-cholesterol 5.7% and 9.3% versus 1.3%; non-HDL-cholesterol 2.2% and 4.4% versus 0.7%; triglycerides 2.4% and 0.0% versus 7.6%.
^m Mean changes from baseline in haematocrit were 2.4% and 2.5% for canagliflozin 100 mg and 300 mg, respectively, compared to 0.0% for placebo.
ⁿ Mean percent changes from baseline in creatinine were 2.8% and 4.0% for canagliflozin 100 mg and 300 mg, respectively, compared to 1.5% for placebo.
° Mean percent changes from baseline in blood urea nitrogen were 17.1% and 18.0% for canagliflozin 100 mg and 300 mg, respectively, compared to 2.7% for placebo.
^p Mean percent changes from baseline in blood potassium were 0.5% and 1.0% for canagliflozin 100 mg and 300 mg, respectively, compared to 0.6% for placebo.
^q Mean percent changes from baseline in serum phosphate were 3.6% and 5.1% for canagliflozin 100 mg and 300 mg, compared to 1.5% for placebo.

Description of selected adverse reactions

Diabetic ketoacidosis

In a long-term renal outcomes study in patients with type 2 diabetes and diabetic kidney disease, incidence rates of adjudicated events of diabetic ketoacidosis (DKA) were 0.21 (0.5%, 12/2,200) and 0.03 (0.1%, 2/2,197) per 100 patient-years of follow-up with canagliflozin 100 mg and placebo, respectively; of the 14 patients with DKA, 8 (7 on canagliflozin 100 mg and 1 on placebo) had a pretreatment eGFR of 30 to ˂45 mL/min/1.73 m².

Lower limb amputation

In patients with type 2 diabetes who had established cardiovascular disease or at least two risk factors for cardiovascular disease, canagliflozin was associated with an increased risk of lower limb amputation as observed in the Integrated CANVAS Program comprised of CANVAS and CANVAS-R, two large, long-term, randomised, placebo-controlled trials evaluating 10,134 patients. The imbalance occurred as early as the first 26 weeks of therapy. Patients in CANVAS and CANVAS-R were followed for an average of 5.7 and 2.1 years, respectively. Regardless of treatment with canagliflozin or placebo, the risk of amputation was highest in patients with a baseline history of prior amputation, peripheral vascular disease, and neuropathy. The risk of lower limb amputation was not dose-dependent. The amputation results for the Integrated CANVAS Program are shown in table 2.

There was no difference in risk of lower limb amputations associated with the use of canagliflozin 100 mg relative to placebo (1.2 vs 1.1 events per 100 patient-years, respectively [HR: 1.11; 95% CI 0.79, 1.56]) in CREDENCE, a long-term renal outcomes study of 4,397 patients with type 2 diabetes and diabetic kidney disease. In other type 2 diabetes studies with canagliflozin, which enrolled a general diabetic population of 8,114 patients, no difference in lower limb amputation risk was observed relative to control.

Table 2. Integrated analysis of amputations in CANVAS AND CANVAS-R:

Note: Incidence is based on the number of patients with at least one amputation, and not the total number of amputation events. A patient’s follow-up is calculated from Day 1 to the first amputation event date. Some patients had more than one amputation. The percentage of minor and major amputations is based on the highest level amputation for each patient.
^* Toe and midfoot
^† Ankle, below knee and above knee

Of the subjects, within the CANVAS Program, who had an amputation, the toe and midfoot were the most frequent sites (71%) in both treatment groups (table 2). Multiple amputations (some involving both lower limbs) were observed infrequently and in similar proportions in both treatment groups.

Lower limb infections, diabetic foot ulcers, peripheral arterial disease, and gangrene, were the most common medical events associated with the need for an amputation in both treatment groups.

Adverse reactions related to volume depletion

In the pooled analysis of the four 26-week, placebo-controlled studies, the incidence of all adverse reactions related to volume depletion (e.g., postural dizziness, orthostatic hypotension, hypotension, dehydration, and syncope) was 1.2% for canagliflozin 100 mg, 1.3% for canagliflozin 300 mg, and 1.1% for placebo. The incidence with canagliflozin treatment in the two active-controlled studies was similar to comparators.

In one of the dedicated long-term cardiovascular studies (CANVAS), where patients were generally older with a higher rate of diabetes complications, the incidence rates of adverse reactions related to volume depletion were 2.3 with canagliflozin 100 mg, 2.9 with canagliflozin 300 mg, and 1.9 with placebo, events per 100 patient-years.

To assess risk factors for these adverse reactions, a larger pooled analysis (N = 12,441) of patients from 13 controlled phase 3 and phase 4 studies including both doses of canagliflozin was conducted.

In this pooled analysis, patients on loop diuretics, patients with a baseline eGFR 30 mL/min/1.73 m² to <60 mL/min/1.73 m², and patients ≥75 years of age had generally higher incidences of these adverse reactions. For patients on loop diuretics, the incidence rates were 5.0 on canagliflozin 100 mg and 5.7 on canagliflozin 300 mg compared to 4.1 events per 100 patient-years of exposure in the control group. For patients with a baseline eGFR 30 mL/min/1.73 m² to <60 mL/min/1.73 m², the incidence rates were 5.2 on canagliflozin 100 mg and 5.4 on canagliflozin 300 mg compared to 3.1 events per 100 patient-years of exposure in the control group. In patients ≥75 years of age, the incidence rates were 5.3 on canagliflozin 100 mg and 6.1 on canagliflozin 300 mg compared to 2.4 events per 100 patient-years of exposure in the control group.

In a long-term renal outcomes study in patients with type 2 diabetes and diabetic kidney disease, incidence rate of events related to volume depletion was 2.84 and 2.35 events per 100 patient-years for canagliflozin 100 mg and placebo, respectively. The incidence rate was observed to increase with decreasing eGFR. In subjects with eGFR 30 to <45 mL/min/1.73 m², the incidence rate of volume depletion was higher in the canagliflozin group (4.91 events per 100 patient-years) compared to the placebo group (2.60 events per 100 patient-years); however, in the subgroups eGFR ≥45 to <60 and eGFR 60 to <90 mL/min/1.73 m², the between-group incidence rate was similar.

In the dedicated cardiovascular study and the larger pooled analysis, as well as in a dedicated renal outcomes study, discontinuations due to adverse reactions related to volume depletion and serious adverse reactions related to volume depletion were not increased with canagliflozin.

Hypoglycaemia in add-on therapy with insulin or insulin secretagogues

The frequency of hypoglycaemia was low (approximately 4%) among treatment groups, including placebo, when used as monotherapy or as an add-on to metformin. When canagliflozin was added to insulin therapy, hypoglycaemia was observed in 49.3%, 48.2%, and 36.8% of patients treated with canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively, and severe hypoglycaemia occurred in 1.8%, 2.7%, and 2.5% of patients treated with canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively. When canagliflozin was added to a sulphonylurea therapy, hypoglycaemia was observed in 4.1%, 12.5%, and 5.8% of patients treated with canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively.

Genital mycotic infections

Vulvovaginal candidiasis (including vulvovaginitis and vulvovaginal mycotic infection) was reported in 10.4% and 11.4% of female patients treated with canagliflozin 100 mg and canagliflozin 300 mg, respectively, compared to 3.2% in placebo-treated female patients. Most reports of vulvovaginal candidiasis occurred during the first four months of treatment with canagliflozin. Among female patients taking canagliflozin, 2.3% experienced more than one infection. Overall, 0.7% of all female patients discontinued canagliflozin due to vulvovaginal candidiasis. In the CANVAS Program, median duration of the infection was longer in the canagliflozin group compared to the placebo group.

Candidal balanitis or balanoposthitis occurred in male patients at a rate of 2.98 and 0.79 events per 100 patient-years on canagliflozin and placebo, respectively. Among male patients taking canagliflozin, 2.4% had more than one infection. Discontinuation of canagliflozin by male patients due to candidal balanitis or balanoposthitis occurred at a rate of 0.37 events per 100 patient-years. Phimosis was reported at a rate of 0.39 and 0.07 events per 100 patient-years on canagliflozin and placebo, respectively. Circumcision was performed at rates of 0.31 and 0.09 events per 100 patient-years on canagliflozin and placebo, respectively.

Urinary tract infections

In clinical studies, urinary tract infections were more frequently reported for canagliflozin 100 mg and 300 mg (5.9% versus 4.3%, respectively) compared to 4.0% with placebo. Most infections were mild to moderate with no increase in the occurrence of serious adverse reactions. In these studies, subjects responded to standard treatments while continuing canagliflozin treatment.

However, post-marketing cases of complicated urinary tract infections including pyelonephritis and urosepsis have been reported in patients treated with canagliflozin, frequently leading to treatment interruption.

Bone fracture

In a cardiovascular study (CANVAS) of 4,327 treated subjects with established or at least two risk factors for cardiovascular disease, the incidence rates of all adjudicated bone fracture were 1.6, 1.8, and 1.1 per 100 patient-years of follow-up to canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively, with the fracture imbalance initially occurring within the first 26 weeks of therapy.

In two other long-term studies and in studies conducted in the general diabetes population, no difference in fracture risk was observed with canagliflozin relative to control. In a second cardiovascular study (CANVAS-R) of 5,807 treated subjects with established or at least two risk factors for cardiovascular disease, the incidence rates of all adjudicated bone fracture were 1.1 and 1.3 events per 100 patient-years of follow-up to canagliflozin and placebo, respectively.

In a long-term renal outcomes study of 4,397 treated subjects with type 2 diabetes and diabetic kidney disease, the incidence rates of all adjudicated bone fracture were 1.2 events per 100 patient-years of follow-up for both canagliflozin 100 mg and placebo. In other type 2 diabetes studies with canagliflozin, which enrolled a general diabetes population of 7,729 patients and where bone fractures were adjudicated, the incidence rates of all adjudicated bone fracture were 1.2 and 1.1 per 100 patient-years of follow-up to canagliflozin and control, respectively. After 104 weeks of treatment, canagliflozin did not adversely affect bone mineral density.

Special populations

Elderly (≥65 years old)

In a pooled analysis of 13 placebo-controlled and active-controlled studies, the safety profile of canagliflozin in elderly patients was generally consistent with younger patients. Patients ≥75 years of age had a higher incidence of adverse reactions related to volume depletion (such as postural dizziness, orthostatic hypotension, hypotension) with incidence rates of 5.3, 6.1, and 2.4 events per 100 patient-years of exposure for canagliflozin 100 mg, canagliflozin 300 mg, and in the control group, respectively. Decreases in eGFR (-3.4 and -4.7 mL/min/1.73 m²) were reported with canagliflozin 100 mg and canagliflozin 300 mg, respectively, compared to the control group (-4.2 mL/min/1.73 m²). Mean baseline eGFR was 62.5, 64.7, and 63.5 mL/min/1.73 m² for canagliflozin 100 mg, canagliflozin 300 mg, and the control group, respectively.

Renal impairment in patients with insufficiently controlled type 2 diabetes mellitus

Patients with a baseline eGFR <60 mL/min/1.73 m² had a higher incidence of adverse reactions associated with volume depletion (e.g., postural dizziness, orthostatic hypotension, hypotension) with incidence rates of 5.3, 5.1, and 3.1 events per 100 patient-years of exposure for canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively.

The overall incidence rate of elevated serum potassium was higher in patients with moderate renal impairment with incidence rates of 4.9, 6.1, and 5.4 events per 100 patient-years of exposure for canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively. In general, elevations were transient and did not require specific treatment.

In patients with moderate renal impairment, increases in serum creatinine of 9.2 µmol/L and BUN of approximately 1.0 mmol/L were observed with both doses of canagliflozin.

The incidence rates for larger decreases in eGFR (>30%) at any time during treatment were 7.3, 8.1, and 6.5 events per 100 patient-years of exposure for canagliflozin 100 mg, canagliflozin 300 mg, and placebo, respectively. At the last post-baseline value, incidence rates of such decreases were 3.3 for patients treated with canagliflozin 100 mg, 2.7 for canagliflozin 300 mg, and 3.7 events per 100 patient-years of exposure for placebo.

Patients treated with canagliflozin regardless of baseline eGFR experienced an initial fall in mean eGFR. Thereafter, eGFR was maintained or gradually increased during continued treatment. Mean eGFR returned to baseline after treatment discontinuation suggesting that haemodynamic changes may play a role in these renal function changes.

Renal impairment in patients with diabetic kidney disease in type 2 diabetes mellitus

In a long-term renal outcomes study in patients with type 2 diabetes and diabetic kidney disease, the incidence of renal-related events occurred frequently in both groups but less frequent in the canagliflozin group (5.71 events per 100 patient-years) compared with the placebo group (7.91 events per 100 patient-years). Serious and severe renal-related events were also lower in the canagliflozin group versus placebo. The incidence rates of renal-related events were lower with canagliflozin relative to placebo across all three eGFR strata; the highest incidence rate of renal-related events was seen in the eGFR 30 to <45 mL/min/1.73 m² stratum (9.47 vs 12.80 events per 100 patient-years for canagliflozin versus placebo, respectively).

In the long-term renal outcomes study, no difference in serum potassium, no increase in adverse events of hyperkalaemia, and no absolute (>6.5 mEq/L) or relative (> upper limit of normal and >15% increase from baseline) increases in serum potassium were observed with canagliflozin 100 mg relative to placebo.

In general, there were no imbalances between treatment groups observed for abnormalities of phosphate, overall or in either eGFR category (45 to <60 or 30 to <45 mL/min/1.73 m² [CrCl 45 to <60 or 30 to <45 mL/min]).