Reductions in liver enzymes are associated with anti-hyperglycaemic and anti-obesity effects of tofogliflozin in people with type 2 diabetes: Post-hoc analyses

AIMS

How the pathology of type 2 diabetes (T2D), including hyperglycaemia and obesity, affects liver enzymes has not been clinically demonstrated. Thus, we compared time courses of gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) with those of fasting plasma glucose (FPG) and body weight (BW) during treatment with the SGLT2 inhibitor tofogliflozin for T2D.

MATERIALS AND METHODS

We post-hoc analysed preexisting data on 1046 people with T2D administered tofogliflozin or placebo for 24 weeks in four tofogliflozin studies. First, time courses of percent changes in variables during the intervention were analysed using a mixed effect model to explore the similarity of the time courses and to evaluate time-treatment interactions. Second, clinical factors related to the percent changes in GGT and ALT were clarified using multivariate analyses.

RESULTS

GGT levels and FPG values rapidly and significantly decreased via tofogliflozin as early as week 4, with decreases maintained until week 24. Conversely, BW and ALT decreased progressively until week 24. Time courses of FPG (p = .365, time-treatment interaction) and GGT (p = .510) reductions were parallel between tofogliflozin and placebo from weeks 4 to 24, while BW and ALT reductions (p < .001, respectively) were not. Reductions in GGT at week 24 were associated with reductions in FPG and BW at week 24, whereas ALT reductions were only associated with reductions in BW.

CONCLUSIONS

Reductions in GGT and ALT were associated with the anti-hyperglycaemic and anti-obesity effects of tofogliflozin, respectively, in people with T2D. Therefore, GGT and ALT may be surrogate markers for hyperglycaemia and obesity in T2D.

Effects of Tofogliflozin and Anagliptin Alone or in Combination on Glucose Metabolism and Atherosclerosis-Related Markers in Patients with Type 2 Diabetes Mellitus

Purpose

In people with type 2 diabetes mellitus (T2DM), both glucose metabolism abnormalities and atherosclerosis risk are significant concerns. This study aims to investigate the effects of the sodium-glucose cotransporter 2 inhibitor tofogliflozin (TOFO) and the dipeptidyl peptidase-4 inhibitor anagliptin (ANA) on markers of glucose metabolism and atherosclerosis when administered individually or in combination.

Methods

Fifty T2DM patients were divided into two groups (receiving either TOFO or ANA monotherapy) and observed for 12 weeks (observation points: 0 and 12 weeks). The TOFO and ANA groups were then further treated with ANA and TOFO, respectively, and the patients were observed for an additional 36 weeks (observation points: 24 and 48 weeks). Therapeutic effects and various biomarkers were compared between the two groups at the observation points.

Results

Combination therapy led to significant improvements in HbA1c levels and atherosclerosis markers. Additionally, the TOFO pretreatment group exhibited significant reductions in sLOX-1 and IL-6 levels.

Conclusion

The increase in sLOX-1 and IL-6 levels, which indicates the response of scavenger receptors to oxidized low-density lipoproteins in people with T2DM, is mitigated following TOFO and ANA combination therapy. TOFO alone or in combination with ANA may be beneficial for preventing atherosclerosis development in people with T2DM, in addition to its effect on improving HbA1c levels.

The Impact of Tofogliflozin on Physiological and Hormonal Function, Serum Electrolytes, and Cardiac Diastolic Function in Elderly Japanese Patients with Type 2 Diabetes Mellitus

The sodium glucose transporter 2 (SGLT2) inhibitor tofogliflozin is a glucose-lowering drug that causes the excretion of surplus glucose by inhibiting SGLT2. Because of tofogliflozin's osmotic diuresis mechanism, patients' serum electrolytes, body fluid levels, and cardiac function must be monitored. We retrospectively analyzed the cases of 64 elderly Japanese patients with type 2 diabetes mellitus (T2DM) who received tofogliflozin for 3 months. Their HbA1c, serum electrolytes (sodium, potassium, chloride), hematocrit, brain natriuretic peptide (cardiac volume load marker) and renin and aldosterone (RAA; an index of regulatory hormones involved in body fluid retention) were continuously monitored during the investigation period. Renal function and cardiac function (by echocardiography) were assessed throughout the period. HbA1c significantly decreased (β1=-0.341, p<0.0001, linear regression analysis [LRA]). Most of the hormonal, electrolyte, and physiological parameters were maintained throughout the study period. In these circumstances, E/e' tended to decrease (β1=-0.382, p=0.13, LRA). Compared to the baseline, E/e' was significantly decreased at 1 and 3 months (p<0.01, p<0.05). In the higher E/e' group (E/e'≥10, n=34), E/e' decreased significantly (β1=-0.63, p<0.05, LRA). ΔE/e' was correlated with body-weight change during treatment (r=0.64, p<0.01). The 3-month tofogliflozin treatment improved glycemic control and diastolic function represented by E/e' in T2DM patients, without affecting serum electrolytes, renal function, or RAA. No negative impacts on the patients were observed. Three-month tofogliflozin treatment lowered glucose and improved cardiac diastolic function.

Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Effects of tofogliflozin on adrenocorticotropic hormone, renin and aldosterone, and cortisol levels in elderly patients with diabetes mellitus: A retrospective study of a patient cohort

Adrenocorticotropic hormone (ACTH) and cortisol reportedly play a role in glycemic control in patients with type 2 diabetes mellitus (T2DM); however, the underlying mechanism remains controversial. We retrospectively investigated the effect of tofogliflozin on serum ACTH and cortisol levels in elderly patients with T2DM.Patients received 20 mg tofogliflozin daily for 3 months. Serum ACTH and cortisol levels were measured at baseline, as well as after 1 month and 3 months of tofogliflozin therapy.Serum ACTH levels were significantly reduced 3 months after tofogliflozin treatment (P < .01). Additionally, serum cortisol levels were reduced 3 months after tofogliflozin treatment, demonstrating borderline significance (P = .05). The higher body mass index (BMI; ≥25 kg/m2) group showed higher ACTH and cortisol levels than the lower BMI (<25 kg/m2) group, with borderline significance (P = .05). Renin levels were significantly increased 1 month after treatment (P < .05), maintaining serum aldosterone levels in parallel with the extracellular fluid.Our findings suggested that tofogliflozin decreased both serum ACTH and cortisol levels, with higher levels observed in the high BMI group. Tofogliflozin increased serum renin levels while maintaining serum aldosterone and extracellular fluid levels. Collectively, tofogliflozin could affect the hypothalamic-pituitary-adrenal pathway in patients with T2DM, especially in the low BMI group.

A Sodium Glucose Cotransporter 2 Inhibitor Fails to Improve Perivascular Adipose Tissue-Mediated Modulation of Vasodilation and Cardiac Function in Rats With Metabolic Syndrome

Arterial perivascular adipose tissue (PVAT) can elicit vasodilator signals complementary to those elicited by the endothelium in SHRSP.Z-Lepr^fa/IzmDmcr (SHRSP.ZF) rats, an animal model of metabolic syndrome (MetS). Here, we tested whether a glucose cotransporter 2 inhibitor (SGLT2-i; tofogliflozin) increased this PVAT effect to prevent the deterioration of cardiac function in aging SHRSP.ZF rats. Tofogliflozin treatments (1 or 10 mg/kg/day) or vehicle (control) were administered for 10 weeks by oral gavage to SHRSP.ZF rats, starting at 13 weeks of age. At 23 weeks of age, glucose levels in the serum and urine (24 h after the last administration) were determined using commercial kits. Vasodilator responsiveness of PVAT-surrounded or PVAT-free superior mesenteric arteries was determined using acetylcholine with organ-bath methods. Cardiac ventricular function and coronary flow were determined using Langendorff heart preparations. Serum and urine glucose levels in SGLT2-i treatment groups did not differ from those in the controls, but the ratios of glycated to non-glycated albumin were lower than those in the controls. Tofogliflozin treatments did not alter relaxations in the presence of PVAT or affect relaxations of PVAT-free arteries. Left ventricular systolic pressures, maximum rate of pressure decline, and coronary flow in ex vivo hearts did not differ among the treatment groups. PVAT effects and cardiac dysfunction were not altered by tofogliflozin treatment in SHRSP.ZF rats with MetS. These results do not provide strong evidence to support the use of SGLT2-i as a cardiovascular protective therapy in MetS, which occurs prior to the onset of type 2 diabetes.

The sodium-glucose cotransporter 2 inhibitor tofogliflozin prevents diabetic kidney disease progression in type 2 diabetic mice

Trials on cardiovascular and renal outcomes in patients with type 2 diabetes have consistently demonstrated that sodium–glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of diabetic kidney disease (DKD) progression. However, their renal protective mechanisms have yet to be completely understood and the effect on albuminuria reduction in animal models is controversial. We investigated these issues using KK and KK‐A^y mice as a control (CTRL) and as a model for type 2 diabetes (DKD), respectively. KK‐A^y mice were treated with 0.015% tofogliflozin, which is an SGLT2 inhibitor, starting at seven weeks of age for eight weeks. Compared with the CTRL mice, the DKD mice had higher HbA1c levels and albuminuria. Although tofogliflozin treatment significantly lowered HbA1c levels, it did not reverse albuminuria. Tofogliflozin treatment enhanced damage in both the glomerular (i.e., enlarged mesangial area, increased foot process effacement rate, and decreased number of WT‐1‐positive cells) and tubulointerstitial (increased protein levels of KIM‐1 and MCP‐1, increased number of macrophages, and abnormal mitochondrial morphology) areas. Our results suggest that tofogliflozin may prevent glomerular and tubulointerstitial damage, partly by ameliorating hyperglycemia, renal inflammation, and abnormal mitochondrial morphology.

Basal insulin secretion capacity predicts the initial response and maximum levels of beta-hydroxybutyrate during therapy with the sodium-glucose co-transporter-2 inhibitor tofogliflozin, in relation to weight loss

AIMS

To investigate predictors of the initial response of beta-hydroxybutyrate (BHB) and maximum BHB (max-BHB) values during long-term therapy with the sodium-glucose co-transporter-2 inhibitor tofogliflozin (TOFO), and to explore the association of the initial elevation of BHB with subsequent clinical effects in people with type 2 diabetes mellitus.

METHODS

We analysed 774 people receiving TOFO in phase 3 trials in two groups based on measurable BHB change at week 4 (initial response): the top quartile [n = 194] and the three lower quartiles [n = 579]. Multivariate analysis was used to determine baseline predictors of inclusion in the top quartile and the max-BHB values. To investigate the association of the initial response with subsequent clinical effects, adjusted changes in variables in the two groups were compared using an analysis of covariance model.

RESULTS

Of the participants, 66% were men, and the mean age, glycated haemoglobin, body mass index and estimated glomerular filtration rate were 58.5 years, 8.1%, 25.6 kg/m² and 83.9 mL/min/1.73 m² , respectively. Median changes in BHB at week 4 in the top quartile and lower three quartiles were +246.4* and +30.8* μmol/L, respectively (*P < .001 vs baseline). Lower baseline insulin secretion capacity predicted the inclusion in the top quartile and greater max-BHB levels. The top quartile was associated with greater weight loss following greater increases in free fatty acids and greater reductions in fasting C-peptide levels compared with the lower three quartiles.

CONCLUSIONS

Lower basal insulin secretion capacity might predict greater initial BHB elevations and max-BHB levels during long-term TOFO therapy. Greater weight loss through lipid use might be related to high initial BHB elevations.

Renal effects of a sodium-glucose cotransporter 2 inhibitor, tofogliflozin, in relation to sodium intake and glycaemic status

AIMS

Little is known about whether sodium intake is associated with the clinical effects of SGLT2 inhibitors (SGLT2is); however, SGLT2is may increase urinary sodium excretion. Thus, we investigated the impact of daily sodium intake on the estimated glomerular filtration rate (eGFR) via an SGLT2i, tofogliflozin (TOFO), in patients with type 2 diabetes (T2D).

METHODS

Individual-level data on 775 T2D patients in TOFO Phase 3 trials were analysed. Adjusted changes in variables during 52 weeks of TOFO therapy were compared according to basal daily salt intake (DSI), which was measured based on estimated daily urinary sodium excretion using the Tanaka formula. Multivariable analysis was used to investigate the impact of basal DSI on changes in eGFR at Weeks 4 and 52.

RESULTS

Sixty-six percent of participants were men; mean age, HbA1c, body mass index, eGFR_MDRD and median DSI were 58.5 years, 8.0%, 25.6 kg/m² , 83.9 mL/min/1.73 m² and 9.3 g/d, respectively. In all participants, eGFR_MDRD sharply dipped during Week 4, and gradually increased by Week 52, showing a significant increase overall from baseline to Week 52. Multivariable analysis showed that basal DSI and HbA1c levels were independently correlated with eGFR_MDRD changes at Weeks 4 and 52. Additionally, lower baseline HbA1c and DSI levels were significantly correlated with a greater increase in eGFR_MDRD at Week 52.

CONCLUSIONS

Dietary salt intake, in addition to glycaemic control, correlates with changed eGFR_MDRD via TOFO. Thus, an appropriate dietary approach to therapy should be considered before treatment of T2D patients with an SGLT2i.

Inhibition of sodium glucose cotransporter 2 (SGLT2) delays liver fibrosis in a medaka model of nonalcoholic steatohepatitis (NASH)

The rise in the incidence of nonalcoholic steatohepatitis (NASH) has necessitated the development of an effective prevention methodology. An antidiabetic drug, belonging to the group of sodium glucose cotransporter 2 (SGLT2) inhibitors, has been tested for its therapeutic effect on NASH; however, no studies to date have demonstrated the preventive effect of an SGLT2 inhibitor on the histological progression of steatosis and fibrosis in a sequential manner in animal models. In the present study, we examined the effect of the SGLT2 inhibitor, tofogliflozin (Tofo), on NASH liver tissue using medaka as an animal model, maintaining a feeding amount and drug concentration in all animal bodies. We generated a medaka NASH model by feeding d‐rR/Tokyo medaka a high‐fat diet and administered Tofo by dissolving the drug directly in the water of the feeding tank. Thereafter, the effects of Tofo on body weight (BW), liver weight, hepatotoxicity, fatty infiltration, and fibrotic changes in the liver were examined. We report here that SGLT2 is expressed in medaka fish and that Tofo inhibits the accumulation of fatty tissue and delays the progression of liver fibrosis in the medaka NASH model by inhibiting increases in blood sugar, serum lipids, and transaminase, irrespective of changes in BW. These results suggest that Tofo is effective for treating NASH and that the medaka model may be useful for developing new therapeutic drugs for this disease.

Tofogliflozin Salt Cocrystals with Sodium Acetate and Potassium Acetate

We investigated the salt cocrystals formed by tofogliflozin with sodium acetate and potassium acetate by determining the crystal structures of the salt cocrystals and characterizing the solid states. The salt cocrystal screening using the slurry method and the liquid-assisted grinding method resulted in the formation of tofogliflozin-sodium acetate 1 : 1 and tofogliflozin-potassium acetate 1 : 1 salt cocrystals. Single-crystal X-ray diffraction revealed that, although each salt cocrystal belongs to a different space group, both of the salt cocrystals have almost similar structural features, including the conformation of tofogliflozin molecules, the coordination to Na⁺/K⁺ ions, and hydrogen bonds. The salt cocrystals exhibited extreme hygroscopicity with deliquescence, which is also a property of sodium acetate and potassium acetate. In addition, tofogliflozin-potassium acetate salt cocrystal had two polymorphs, which were enantiotropically related.

Effects of sodium-glucose cotransporter 2 inhibitor, tofogliflozin, on the indices of renal tubular function in patients with type 2 diabetes

AIMS

Little is known of the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the renal tubules. We investigated the effect of the SGLT2 inhibitor, tofogliflozin (TOFO) on renal tubular indices, according to the degree of albuminuria, in type 2 diabetes mellitus (T2DM) patients with preserved renal function.

MATERIALS AND METHODS

A total of 988 patients, receiving TOFO, were enroled and divided into 3 groups, based on the urine albumin-to-creatinine ratio (UACR). The tubular indices (urinary N-acetyl-beta-d-glucosaminidase [NAG]-to-creatinine and urinary beta-2 microglobulin [beta2MG]-to-creatinine ratios) and UACR were log-transformed in the correlation analysis.

RESULTS

Treatment with TOFO led to similar reductions in glycated haemoglobin (HbA1c) levels, from baseline to week 24, across all groups. The NAG level increased in the normoalbuminuria group and decreased in the macroalbuminuria group significantly (P < .001, both), but did not change in the microalbuminuria group. Significant reductions in the UACR were observed in both microalbuminuria and macroalbuminuria groups (P < .001, both). Significant negative correlations between changes in the NAG and beta2MG levels and their corresponding baseline values were observed in all participants. The reduction in the UACR was negatively correlated with baseline levels. The changes in the tubular indices were positively correlated with reductions in the UACR across groups.

CONCLUSIONS

Logarithmic reductions in the renal tubular indices, via SGLT2 inhibition, were observed in patients with T2DM. TOFO may not only improve the degree of albuminuria but may also have protective effects on the tubules.

Uric acid lowering in relation to HbA1c reductions with the SGLT2 inhibitor tofogliflozin

An integrated analysis was performed with data from 4 phase 2 and phase 3 studies of tofogliflozin in which patients with type 2 diabetes mellitus received the sodium-glucose cotransporter 2 inhibitor tofogliflozin for up to 24 weeks. Sex differences, baseline haemoglobin A1c (HbA1c) and serum uric acid (UA) levels, and log₁₀ -transformed urinary N-acetyl-β-D-glucosaminidase ratio were significantly correlated with the reduction in serum UA levels at both 4 and 24 weeks in multivariate analysis (respectively, P < .0001). The decrease in HbA1c levels was greatest in the group with the highest baseline HbA1c level (quartile 4; HbA1c > 8.6%) and lowest in the group with the lowest baseline HbA1c level (quartile 1; HbA1c ≤ 7.4%). The decrease in serum UA levels was greatest in the quartile 1 group and lowest in the quartile 4 group. In most groups, the maximum decrease in serum UA levels was seen in the first 4 weeks, while the maximum decrease in HbA1c was seen at week 24. Thus, serum UA levels were significantly decreased in patients with moderate HbA1c levels.

Tofogliflozin, a selective inhibitor of sodium-glucose cotransporter 2, suppresses renal damage in KKAy/Ta mice, obese and type 2 diabetic animals

OBJECTIVE

Inhibitors of sodium-glucose cotransporter 2 ameliorate hyperglycaemia in diabetes by increasing urinary glucose excretion. However, the effects of sodium-glucose cotransporter 2 inhibitors on tubulointerstitial damage in diabetic nephropathy are not fully elucidated. We examined whether tofogliflozin, an inhibitor of sodium-glucose cotransporter 2, suppressed renal damage in KKAy/Ta mice, obese and type 2 diabetic animals.

MATERIALS AND METHODS

Male 8-week-old KKAy/Ta mice or control C57BL/6J mice were kept on a standard diet with or without 0.015% tofogliflozin for 5 weeks. Blood glucose and blood pressure, body and kidney weight, urinary N-acetyl-β-d-glucosaminidase activity and albumin excretion levels were monitored.

RESULTS

Although tofogliflozin treatment did not affect blood pressure, body weight or serum creatinine values, it improved hyperglycaemia and blocked the elevation of urinary N-acetyl-β-d-glucosaminidase activity in KKAy/Ta diabetic mice at 9, 11 and 13 weeks. Furthermore, compared with control mice, urinary albumin excretion levels and kidney weight were increased in 13-week-old KKAy/Ta mice, both of which were suppressed by the treatment with tofogliflozin.

CONCLUSION

Our present results demonstrated that tofogliflozin could suppress albuminuria and tubulointerstitial injury in obese and type 2 diabetic mice. Inhibition of glucose entry into tubular cells by tofogliflozin may exert renoprotective properties in diabetes.

Impact of the 8-week Administration of Tofogliflozin for Glycemic Control and Body Composition in Japanese Patients with Type 2 Diabetes Mellitus

Objective The adverse effects of selective sodium-glucose co-transporter 2 (SGLT2) inhibitors generally appear within about two or three months after treatment initiation in Japan. Therefore, we investigated the impact of tofogliflozin, a class of SGLT2 inhibitors, on glycemic control and body composition during this period in Japanese patients with type 2 diabetes mellitus. Methods This single-arm open-label study enrolled 20 patients. Patients received tofogliflozin 20 mg once daily for 8 weeks. At week 8, changes from baseline in body weight, serum metabolic markers, and body composition were evaluated. Results A total of 17 patients completed the 8-week administration of tofogliflodin. No serious adverse events were noted. Hemoglobin A1c (HbA1c) decreased significantly, from 7.8% to 7.3% with 8-week administration of tofogliflozin. Both the body weight and body mass index (BMI) also decreased. In addition, a decreased renal function of the boundary zone and hemoconcentration were detected. As for body composition, the free fat mass, total body water, extracellular water and intracellular water were all decreased significantly. Interestingly, the amount of fat mass did not change. The degree of improvement in HbA1c was correlated with the baseline fat mass and BMI. Conclusion An eight-week administration of tofogliflozin improved glycemic control and reduced the body weight and free fat mass in type 2 diabetic patients without affecting the fat mass. In this period, the hematocrit level and renal function should be monitored to guard against hemoconcentration and renal impairment, respectively.

Tofogliflozin, a novel sodium-glucose co-transporter 2 inhibitor, improves renal and pancreatic function in db/db mice

BACKGROUND AND PURPOSE

Although inhibition of renal sodium-glucose co-transporter 2 (SGLT2) has a stable glucose-lowering effect in patients with type 2 diabetes, the effect of SGLT2 inhibition on renal dysfunction in type 2 diabetes remains to be determined. To evaluate the renoprotective effect of SGLT2 inhibition more precisely, we compared the effects of tofogliflozin (a specific SGLT2 inhibitor) with those of losartan (an angiotensin II receptor antagonist) on renal function and beta-cell function in db/db mice.

EXPERIMENTAL APPROACH

The effects of 8-week tofogliflozin or losartan treatment on renal and beta-cell function were investigated in db/db mice by quantitative image analysis of glomerular size, mesangial matrix expansion and islet beta-cell mass. Blood glucose, glycated Hb and insulin levels, along with urinary albumin and creatinine were measured

KEY RESULTS

Tofogliflozin suppressed plasma glucose and glycated Hb and preserved pancreatic beta-cell mass and plasma insulin levels. No improvement of glycaemic conditions or insulin level was observed with losartan treatment. Although the urinary albumin/creatinine ratio of untreated db/db mice gradually increased from baseline, tofogliflozin or losartan treatment prevented this increase (by 50-70%). Tofogliflozin, but not losartan, attenuated glomerular hypertrophy. Neither tofogliflozin nor losartan altered matrix expansion.

CONCLUSIONS AND IMPLICATIONS

Long-term inhibition of renal SGLT2 by tofogliflozin not only preserved pancreatic beta-cell function, but also prevented kidney dysfunction in a mouse model of type 2 diabetes. These findings suggest that long-term use of tofogliflozin in patients with type 2 diabetes may prevent progression of diabetic nephropathy.