Source: European Medicines Agency (EU) Revision Year: 2023 Publisher: Janssen-Cilag International NV, Turnhoutseweg 30, B-2340 Beerse, Belgium
Lactic acidosis, a very rare but serious metabolic complication, most often occurs at acute worsening of renal function or cardiorespiratory illness or sepsis. Metformin accumulation occurs at acute worsening of renal function and increases the risk of lactic acidosis.
In case of dehydration (severe diarrhoea or vomiting, fever or reduced fluid intake), Vokanamet should be temporarily discontinued and contact with a healthcare professional is recommended.
Medicinal products that can acutely impair renal function (such as antihypertensives, diuretics and non-steroidal anti-inflammatory drugs [NSAIDs]) should be initiated with caution in Vokanamet-treated patients. Other risk factors for lactic acidosis are excessive alcohol intake, hepatic insufficiency, inadequately controlled diabetes, ketosis, prolonged fasting and any conditions associated with hypoxia, as well as concomitant use of medicinal products that may cause lactic acidosis (see sections 4.3 and 4.5).
Patients and/or care-givers should be informed of the risk of lactic acidosis. Lactic acidosis is characterised by acidotic dyspnoea, abdominal pain, muscle cramps, asthenia and hypothermia followed by coma. In case of suspected symptoms, the patient should stop taking Vokanamet and seek immediate medical attention. Diagnostic laboratory findings are decreased blood pH (<7.35), increased plasma lactate levels (>5 mmol/L) and an increased anion gap and lactate/pyruvate ratio.
The risk of lactic acidosis must be considered in the event of non-specific signs such as muscle cramps with digestive disorders as abdominal pain and severe asthenia.
Decreased renal function in elderly patients is frequent and asymptomatic. Special caution should be exercised in situations where renal function may become impaired; for example, when initiating antihypertensive or diuretic therapy and when starting treatment with a NSAID.
The efficacy of canagliflozin for glycaemic control is dependent on renal function, and efficacy is reduced in patients who have moderate renal impairment and likely absent in patients with severe renal impairment (see section 4.2).
In patients with an eGFR <60 mL/min/1.73 m² or CrCl <60 mL/min, a higher incidence of adverse reactions associated with volume depletion (e.g., postural dizziness, orthostatic hypotension, hypotension) was reported, particularly with the 300 mg dose. In addition, in such patients more events of elevated potassium and greater increases in serum creatinine and blood urea nitrogen (BUN) were reported (see section 4.8).
Therefore, the canagliflozin dose should be limited to 100 mg daily in patients with eGFR <60 mL/min/1.73 m² or CrCl <60 mL/min and canagliflozin should not be used for the purpose of glycaemic control in patients with an eGFR persistently <45 mL/min/1.73 m² or CrCl <45 mL/min (see section 4.2).
Intravascular administration of iodinated contrast agents may lead to contrast induced nephropathy, resulting in metformin accumulation and an increased risk of lactic acidosis. Vokanamet should be discontinued prior to, or at the time of the imaging procedure and not restarted until at least 48 hours after, provided that renal function has been re-evaluated and found to be stable (see sections 4.2 and 4.5).
As Vokanamet contains metformin, Vokanamet must be discontinued at the time of surgery under general, spinal, or epidural anaesthesia. Therapy may be restarted no earlier than 48 hours following surgery or resumption of oral nutrition and provided that renal function has been re-evaluated and found to be stable.
Metformin may reduce vitamin B12 serum levels. The risk of low vitamin B12 levels increases with increasing metformin dose, treatment duration, and/or in patients with risk factors known to cause vitamin B12 deficiency. In case of suspicion of vitamin B12 deficiency (such as anaemia or neuropathy), vitamin B12 serum levels should be monitored. Periodic vitamin B12 monitoring could be necessary in patients with risk factors for vitamin B12 deficiency. Metformin therapy should be continued for as long as it is tolerated and not contra-indicated and appropriate corrective treatment for vitamin B12 deficiency provided in line with current clinical guidelines.
Due to its mechanism of action, canagliflozin, by increasing urinary glucose excretion (UGE), induces an osmotic diuresis, which may reduce intravascular volume and decrease blood pressure (see section 5.1). In controlled clinical studies of canagliflozin, increases in adverse reactions related to volume depletion (e.g., postural dizziness, orthostatic hypotension, or hypotension) were seen more commonly with a daily dose of 300 mg canaliflozin and occurred most frequently in the first three months (see section 4.8).
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) (see sections 4.2 and 4.8).
Due to volume depletion, generally small mean decreases in eGFR were seen within the first 6 weeks of treatment initiation with canagliflozin. In patients susceptible to greater reductions in intravascular volume as described above, larger decreases in eGFR (>30%) were sometimes seen, which subsequently improved, and infrequently required interruption of treatment with canagliflozin (see section 4.8).
Patients should be advised to report symptoms of volume depletion. Canagliflozin is not recommended for use in patients receiving loop diuretics (see section 4.5) or who are volume depleted, e.g., due to acute illness (such as gastrointestinal illness).
For patients receiving Vokanamet, 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 Vokanamet may be considered for patients who develop volume depletion while on Vokanamet therapy until the condition is corrected. If interrupted, consideration should be given to more frequent glucose monitoring.
Rare cases of diabetic ketoacidosis (DKA), including life-threatening and fatal cases, have been reported in patients treated with SGLT2 inhibitors, including canagliflozin. In a number of cases, the presentation of the condition was atypical with only moderately increased blood glucose values, below 14 mmol/L (250 mg/dL). It is not known if DKA is more likely to occur with higher doses of canagliflozin. Risk of DKA appears to be higher in patients with moderately to severely decreased renal function who require insulin.
The risk of diabetic ketoacidosis must be considered in the event of non-specific symptoms such as nausea, vomiting, anorexia, abdominal pain, excessive thirst, difficulty breathing, confusion, unusual fatigue or sleepiness. Patients should be assessed for ketoacidosis immediately if these symptoms occur, regardless of blood glucose level.
In patients where DKA is suspected or diagnosed, treatment with Vokanamet should be discontinued immediately.
Treatment should be interrupted in patients who are hospitalised for major surgical procedures or acute serious medical illnesses. Monitoring of ketones is recommended in these patients.
Measurement of blood ketone levels is preferred to urine. Treatment with Vokanamet may be restarted when the ketone values are normal and the patient’s condition has stabilised.
Before initiating Vokanamet, factors in the patient history that may predispose to ketoacidosis should be considered.
Diabetic ketoacidosis may be prolonged after discontinuation of Vokanamet in some patients, i.e. it may last longer than expected from the plasma half-life of canagliflozin (see section 5.2). Prolonged glucosuria has been observed along with persistent DKA. Canagliflozin-independent factors might be involved in prolonged periods of DKA. Insulin deficiency may contribute to prolonged diabetic ketoacidosis and has to be corrected when verified.
Patients who may be at higher risk of DKA include patients with a low beta-cell function reserve (e.g., type 2 diabetes patients with low C-peptide or latent autoimmune diabetes in adults (LADA) or patients with a history of pancreatitis), patients with conditions that lead to restricted food intake or severe dehydration, patients for whom insulin doses are reduced and patients with increased insulin requirements due to acute medical illness, surgery or alcohol abuse. SGLT2 inhibitors should be used with caution in these patients.
Restarting SGLT2 inhibitor treatment in patients with previous DKA while on SGLT2 inhibitor treatment is not recommended unless another clear precipitating factor is identified and resolved.
The safety and efficacy of canagliflozin in patients with type 1 diabetes have not been established and Vokanamet should not be used for treatment of patients with type 1 diabetes. Limited data from clinical studies suggest that DKA occurs with common frequency when patients with type 1 diabetes are treated with SGLT2 inhibitors.
In long-term clinical studies of canagliflozin in patients with type 2 diabetes with established cardiovascular disease (CVD) or at least 2 risk factors for CVD, canagliflozin was associated with an increased risk of lower limb amputation versus placebo (0.63 vs 0.34 events per 100 patient-years, respectively), and this increase occurred primarily in the toe and midfoot (see section 4.8). In a long-term clinical study in patients with type 2 diabetes and diabetic kidney disease, no difference in lower limb amputation risk was observed in patients treated with canagliflozin 100 mg relative to placebo. In this study precautionary measures as outlined below were applied. As an underlying mechanism has not been established, risk factors, apart from general risk factors, for amputation are unknown.
Before initiating Vokanamet, consider factors in the patient history that may increase the risk for amputation. As precautionary measures, consideration should be given to carefully monitoring patients with a higher risk for amputation events and counselling patients about the importance of routine preventative foot care and maintaining adequate hydration. Consideration may also be given to stopping treatment with Vokanamet in patients who develop events which may precede amputation such as lower-extremity skin ulcer, infection, osteomyelitis or gangrene.
Post-marketing cases of necrotising fasciitis of the perineum, (also known as Fournier’s gangrene), have been reported in female and male patients taking SGLT2 inhibitors. This is a rare but serious and potentially life-threatening event that requires urgent surgical intervention and antibiotic treatment.
Patients should be advised to seek medical attention if they experience a combination of symptoms of pain, tenderness, erythema, or swelling in the genital or perineal area, with fever or malaise. Be aware that either uro-genital infection or perineal abscess may precede necrotising fasciitis. If Fournier’s gangrene is suspected, Vokanamet should be discontinued and prompt treatment (including antibiotics and surgical debridement) should be instituted.
Haematocrit increase was observed with canagliflozin treatment (see section 4.8); therefore, careful monitoring in patients with already elevated haematocrit is warranted.
Elderly patients may be at a greater risk for volume depletion, are more likely to be treated with diuretics, and to have impaired renal function. In patients ≥75 years of age, a higher incidence of adverse reactions associated with volume depletion (e.g., postural dizziness, orthostatic hypotension, hypotension) was reported with canagliflozin therapy. In addition, in such patients greater decreases in eGFR were reported (see sections 4.2 and 4.8).
Consistent with the mechanism of sodium glucose co-transporter 2 (SGLT2) inhibition with increased UGE, vulvovaginal candidiasis in females and balanitis or balanoposthitis in males were reported in clinical studies with canagliflozin (see section 4.8). Male and female patients with a history of genital mycotic infections were more likely to develop an infection. Balanitis or balanoposthitis occurred primarily in uncircumcised male patients which in some instances resulted in phimosis and/or circumcision. The majority of genital mycotic infections were treated with topical antifungal treatments, either prescribed by a healthcare professional or self-treated while continuing therapy with Vokanamet.
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. Temporary interruption of canagliflozin should be considered in patients with complicated urinary tract infections.
Experience in New York Heart Association (NYHA) class III is limited, and there is no experience in clinical studies with canagliflozin in NYHA class IV.
Due to canagliflozin’s mechanism of action, patients taking Vokanamet will test positive for glucose in their urine.
This medicinal product contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium-free’.
Pharmacokinetic drug interaction studies with Vokanamet have not been performed; however, such studies have been conducted with the individual active substances (canagliflozin and metformin). Co-administration of canagliflozin (300 mg once daily) and metformin (2,000 mg once daily) had no clinically relevant effect on the pharmacokinetics of either canagliflozin or metformin.
Canagliflozin may add to the effect of diuretics and may increase the risk of dehydration and hypotension (see section 4.4).
Canagliflozin is not recommended for use in patients receiving loop diuretics.
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 Vokanamet (see sections 4.2 and 4.8).
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 (area under the curve, AUC) and peak concentration (Cmax) 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 Vokanamet containing 150 mg twice daily may be considered if patients are currently tolerating canagliflozin 50 mg twice daily and require additional glycaemic control (see sections 4.2 and 4.4).
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.
Interaction studies suggest that the pharmacokinetics of canagliflozin are not altered by metformin, hydrochlorothiazide, oral contraceptives (ethinyl estradiol and levonorgestrol), ciclosporin, and/or probenecid.
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 Cmax 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.
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 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 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 Cmax of simvastatin and an 18% increase in AUC and a 26% increase in Cmax of simvastatin acid. The increases in simvastatin and simvastatin acid exposures are not considered clinically relevant.
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.
In interaction studies, canagliflozin at steady-state had no clinically relevant effect on the pharmacokinetics of metformin, oral contraceptives (ethinyl estradiol and levonorgestrol), glibenclamide, paracetamol, hydrochlorothiazide, or warfarin.
Increases in urinary glucose excretion with canagliflozin can falsely lower 1,5-anhydroglucitol (1,5-AG) levels and make measurements of 1,5-AG unreliable in assessing glycaemic control. Therefore, 1,5-AG assays should not be used for assessment of glycaemic control in patients on Vokanamet. For further detail, it may be advisable to contact the specific manufacturer of the 1,5-AG assay.
Alcohol intoxication is associated with an increased risk of lactic acidosis (particularly in cases of fasting, malnutrition, or hepatic impairment) due to the metformin active substance of Vokanamet (see section 4.4). Consumption of alcohol and medicinal products containing alcohol should be avoided.
The intravascular administration of iodinated contrast agents in radiological studies may lead to renal failure, resulting in metformin accumulation and a risk of lactic acidosis. Therefore, Vokanamet must be discontinued prior to, or at the time of the imaging procedure and not restarted until at least 48 hours after, provided that renal function has been re-evaluated and found to be stable (see sections 4.2 and 4.4).
Cationic medicinal products that are eliminated by renal tubular secretion (e.g., cimetidine) may interact with metformin by competing for common renal tubular transport systems. A study conducted in seven normal healthy volunteers showed that cimetidine, administered as 400 mg twice daily, increased metformin AUC by 50% and Cmax by 81%. Therefore, close monitoring of glycaemic control, dose adjustment within the recommended posology and changes in diabetic treatment should be considered when cationic medicinal products that are eliminated by renal tubular secretion are co-administered (see sections 4.4 and 5.1).
Some medicinal products can adversely affect renal function which may increase the risk of lactic acidosis, e.g. NSAIDs, including selective cyclo-oxygenase (COX) II inhibitors, ACE inhibitors, angiotensin II receptor antagonists and diuretics, especially loop diuretics. When starting or using such products in combination with Vokanamet, close monitoring of renal function is necessary.
Glucocorticoids (given by systemic and local routes), beta-2-agonists, and diuretics have intrinsic hyperglycaemic activity. The patient should be informed and more frequent blood glucose monitoring performed, especially at the beginning of treatment with such medicinal products. If necessary, the dose of glucose-lowering medicinal products should be adjusted during therapy with the other medicinal product and on its discontinuation.
Due to their potential to decrease renal function, diuretics (especially loop diuretics) may increase the risk of lactic acidosis associated with metformin.
There are no data from the use of canagliflozin alone or Vokanamet in pregnant women. Studies in animals with canagliflozin have shown reproductive toxicity (see section 5.3).
A limited amount of data from the use of metformin in pregnant women does not indicate an increased risk of congenital malformations. Animal studies with metformin do not indicate harmful effects with respect to pregnancy, embryonic or foetal development, parturition, or postnatal development (see section 5.3).
Vokanamet should not be used during pregnancy. When pregnancy is detected, treatment with Vokanamet should be discontinued.
No studies in lactating animals have been conducted with the combined active substances of Vokanamet. 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 (see section 5.3). Metformin is excreted into human breast milk in small amounts. A risk to newborns/infants cannot be excluded. Vokanamet should not be used during breast-feeding.
The effect of Vokanamet on fertility in humans has not been studied. No effects of canagliflozin or metformin on fertility were observed in animal studies (see section 5.3).
Vokanamet has no or negligible influence on the ability to drive and use machines. However, patients should be alerted to the risk of hypoglycaemia when Vokanamet 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 (see sections 4.2, 4.4, and 4.8).
The safety of canagliflozin was evaluated in 22,645 patients with type 2 diabetes, including the evaluation of canagliflozin in combination with metformin in 16,334 patients. In addition, an 18-week double-blind, placebo-controlled phase 2 study with twice daily dosing (canagliflozin 50 mg or 150 mg as add-on therapy with metformin 500 mg) was conducted in 279 patients in which 186 patients were treated with canagliflozin as add-on therapy with metformin.
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 events in order to identify adverse reactions (see table 2) (see sections 4.2 and 4.4).
Adverse reactions in table 2 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 2. Tabulated list of adverse reactions (MedDRA) from placeboe and active-controlled studiese and from postmarketing experience:
| System organ class Frequency | Adverse reaction |
|---|---|
| Infections and infestations | |
| very common | Vulvovaginal candidiasisb,j |
| common Balanitis or balanoposthitisb,k, Urinary tract infectionc (pyelonephritis and urosepsis have been reported postmarketing) | |
| not known | Necrotising fasciitis of the perineum (Fournier’s gangrene)d |
| Immune system disorders | |
| rare | Anaphylactic reaction |
| Metabolism and nutrition disorders | |
| very common | Hypoglycaemia in combination with insulin or sulphonylureac |
| uncommon | Dehydrationa |
| rare | Diabetic ketoacidosisb |
| Nervous system disorders | |
| uncommon | Dizziness posturala, Syncopea |
| Vascular disorders | |
| uncommon | Hypotensiona, Orthostatic hypotensiona |
| Gastrointestinal disorders | |
| common | Constipation, Thirstf, Nausea |
| Skin and subcutaneous tissue disorders | |
| uncommon | Photosensitivity, Rashg, Urticaria |
| rare | Angioedema |
| Musculoskeletal and connective tissue disorders | |
| uncommon | Bone fractureh |
| Renal and urinary disorders | |
| common | Polyuria or Pollakiuriai |
| uncommon | Renal failure (mainly in the context of volume depletion) |
| Investigations | |
| common | Dyslipidaemial, Haematocrit increasedb,m |
| uncommon | Blood creatinine increasedb,n, Blood urea increasedb,o, Blood potassium increasedb,p, Blood phosphate increasedq |
| Surgical and medical procedures | |
| uncommon | Lower limb amputations (mainly of the toe and midfoot) especially in patients at high risk for heart diseaseb |
a Related to volume depletion; see section 4.4 and description of adverse reaction (AR) below.
b See section 4.4 and description of AR below.
c See description of AR below.
d See section 4.4.
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 cangliflozin 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.
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 3.
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 a long-term renal outcomes study of 4,397 patients with type 2 diabetes and diabetic kidney disease (see section 4.4). 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 3. Integrated analysis of amputations in CANVAS and CANVAS-R:
| Placebo N=4,344 | canagliflozin N=5,790 | |
|---|---|---|
| Total number of subjects with events, n (%) | 47 (1.1) | 140 (2.4) |
| Incidence rate (per 100 patient-years) | 0.34 | 0.63 |
| HR (95% CI) vs. placebo | 1.97 (1.41, 2.75) | |
| Minor amputation, n (%)* | 34/47 (72.3) | 99/140 (70.7) |
| Major amputation, n (%)† | 13/47 (27.7) | 41/140 (29.3) |
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 (see table 3). 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 (see section 4.4).
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 once daily, 1.3% for canagliflozin 300 mg once daily, 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 (see sections 4.2 and 4.4).
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.
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 once daily, canagliflozin 300 mg once daily, and placebo, respectively, and severe hypoglycaemia occurred in 1.8%, 2.7%, and 2.5% of patients treated with canagliflozin 100 mg once daily, canagliflozin 300 mg once daily, 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 once daily, canagliflozin 300 mg once daily, and placebo, respectively (see sections 4.2 and 4.5).
Vulvovaginal candidiasis (including vulvovaginitis and vulvovaginal mycotic infection) was reported in 10.4% and 11.4% of female patients treated with canagliflozin 100 mg once daily and canagliflozin 300 mg once daily, 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 (see section 4.4). 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 (see section 4.4).
In clinical studies, urinary tract infections were more frequently reported for canagliflozin 100 mg and 300 mg once daily (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.
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.
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 once daily, canagliflozin 300 mg once daily, 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 (see sections 4.2 and 4.4).
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 (see sections 4.2 and 4.4).
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 (see section 4.4).
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.
Table 4 presents adverse reactions by SOC and by frequency category reported in patients who received metformin as monotherapy and that were not observed in patients receiving canagliflozin. Frequency categories are based on information available from the metformin Summary of Product Characteristics.
Table 4. The frequency of metformin adverse reactions identified from clinical study and postmarketing data:
| System organ class Frequency | Adverse reaction |
|---|---|
| Metabolism and nutrition disorders | |
| common | Vitamin B12 decrease/deficiencya |
| very rare | Lactic acidosis |
| Nervous system disorders | |
| common | Taste disturbance |
| Gastrointestinal disorders | |
| very common | Gastro-intestinal symptomsb |
| Skin and subcutaneous tissue disorders | |
| very rare | Erythema, Pruritis, Urticaria |
| Hepatobiliary disorders | |
| very rare | Liver function test abnormal, Hepatitis |
a Metformin may commonly reduce vitamin B12 serum levels, which may result in clinically significant vitamin B12 deficiency (e.g., megaloblastic anaemia). The risk of low vitamin B12 levels increases with increasing metformin dose, treatment duration, and/or in patients with risk factors known to cause vitamin B12 deficiency. Periodic monitoring of vitamin B12 levels is recommended in these patients.
b Gastrointestinal symptoms such as nausea, vomiting, diarrhoea, abdominal pain and loss of appetite occur most frequently during initiation of therapy and resolve spontaneously in most cases.
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V.
Not applicable.
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