Background and Aims
Since the majority of people with T1D do not achieve target A1cs (<7 or 6.5%) and more than 2/3 of the patients with T1D are getting overweight or obese, it is important to find adjunctive therapies for patients with T1D, which might help achieving target A1cs without any increase in weight[1]. Several molecules (like metformin, GLP analogs, coleselvelam, and DPP-4 inhibitors) have been evaluated as adjunctive therapeutic options for T1D[2],[3]. Unfortunately, none of them have been successful in significantly improving glucose control or weight loss; and thus, are not approved for their use in patients with T1D. The only FDA-approved option for adjunctive therapy for patients with T1D is pramlintide, which is rarely used because of GI side-effects and risk of severe hypoglycemia[4].
Background and Aims
Since the majority of people with T1D do not achieve target A1cs (<7 or 6.5%) and more than 2/3 of the patients with T1D are getting overweight or obese, it is important to find adjunctive therapies for patients with T1D, which might help achieving target A1cs without any increase in weight[1]. Several molecules (like metformin, GLP analogs, coleselvelam, and DPP-4 inhibitors) have been evaluated as adjunctive therapeutic options for T1D[2],[3]. Unfortunately, none of them have been successful in significantly improving glucose control or weight loss; and thus, are not approved for their use in patients with T1D. The only FDA-approved option for adjunctive therapy for patients with T1D is pramlintide, which is rarely used because of GI side-effects and risk of severe hypoglycemia[4].
Methods
SGLT 2 inhibitors have been successfully used for patients with T2D with a significant reduction in cardiovascular disease and renal failure. Since this class of drugs have insulin-independent effect and in early phase 1 and 2 clinical trials for patients with T1D showed significant benefits. Several Phase 3 trials were reported in the last two years with SGLT 1 and/or 2 inhibitors used adjunctively with insulin in patients with T1D[1]. DEPICT[2] (dapagliflozin) in T1D showed improvement in A1c, Time-in-Range (TIR), and weight loss with a small but significant increase in diabetic ketoacidosis (DKA). The second trial (replicating real-life use) using a dual SGLT 1 and 2 inhibitor (inTandem 3-Sotagliflozin in T1D)[3] showed significant reduction in A1c, hypoglycemia, especially severe (<55mg/dL) and weight loss. The other two large trials done in the USA and Europe using Sotagliflozin (in Tandem 1 and in Tandem 2) also showed similar results[4],[5]. Similarly, there was a small, but significant, increase DKA, which is now known with all SGLT 2 inhibitors. It’s important to keep in mind that the background risk of DKA is ~5% in the USA (T1D Exchange data—see reference 3) and is increasing significantly in Europe with or without the use of these medications[1]. Lastly, EASE 2 and 3 trials[2] using Empagliflozin in T1D and showed similar benefits and risks like Dapa and Sota except the authors recommended a smaller dose of 2.5mg a day to be considered for T1D (due to no increase in DKA risk, but efficacy on A1c was about 50%) based on a small sample size in EASE 3.
Methods
SGLT 2 inhibitors have been successfully used for patients with T2D with a significant reduction in cardiovascular disease and renal failure. Since this class of drugs have insulin-independent effect and in early phase 1 and 2 clinical trials for patients with T1D showed significant benefits. Several Phase 3 trials were reported in the last two years with SGLT 1 and/or 2 inhibitors used adjunctively with insulin in patients with T1D[1]. DEPICT[2] (dapagliflozin) in T1D showed improvement in A1c, Time-in-Range (TIR), and weight loss with a small but significant increase in diabetic ketoacidosis (DKA). The second trial (replicating real-life use) using a dual SGLT 1 and 2 inhibitor (inTandem 3-Sotagliflozin in T1D)[3] showed significant reduction in A1c, hypoglycemia, especially severe (<55mg/dL) and weight loss. The other two large trials done in the USA and Europe using Sotagliflozin (in Tandem 1 and in Tandem 2) also showed similar results[4],[5]. Similarly, there was a small, but significant, increase DKA, which is now known with all SGLT 2 inhibitors. It’s important to keep in mind that the background risk of DKA is ~5% in the USA (T1D Exchange data—see reference 3) and is increasing significantly in Europe with or without the use of these medications[1]. Lastly, EASE 2 and 3 trials[2] using Empagliflozin in T1D and showed similar benefits and risks like Dapa and Sota except the authors recommended a smaller dose of 2.5mg a day to be considered for T1D (due to no increase in DKA risk, but efficacy on A1c was about 50%) based on a small sample size in EASE 3.
Results
More recently, a meta-analysis of inTandem studies showed significant reduction in hypoglycemia (<70mg/dL) and severe hypoglycemia (defined as <54mg/dL)[1]. SGLT inhibitors have been approved in Europe and Japan as adjunctive therapy for patients with T1D whose BMI is >27kg/m2 and whose insulin requirements are 0.5 units/kg/day. In the USA, no SGLT inhibitor has been approved for patients with T1D and the FDA has issued a complete response letter (CRL) for both sota- and dapagliflozin. If and when these drugs are approved for patients with T1D in the USA, the risk of DKA will need to be mitigated by proper education for patients and providers following the STICH and STOP DKA protocols[2],[3],[4].Results
More recently, a meta-analysis of inTandem studies showed significant reduction in hypoglycemia (<70mg/dL) and severe hypoglycemia (defined as <54mg/dL)[1]. SGLT inhibitors have been approved in Europe and Japan as adjunctive therapy for patients with T1D whose BMI is >27kg/m2 and whose insulin requirements are 0.5 units/kg/day. In the USA, no SGLT inhibitor has been approved for patients with T1D and the FDA has issued a complete response letter (CRL) for both sota- and dapagliflozin. If and when these drugs are approved for patients with T1D in the USA, the risk of DKA will need to be mitigated by proper education for patients and providers following the STICH and STOP DKA protocols[2],[3],[4].Conclusions
Finally, the use of SGLT inhibitors as adjunctive therapy for T1D may allow many more patients to achieve target A1cs without any further weight gain and may in fact have long-term cardiovascular and renal benefits as have been shown in patients with T2D.
[1] Garg SK, et al. Diabetes Technol Ther. 2019 Feb;21: 66-72. PMID: 30657336.
[2] Garg et al. Endocrine Practice, 2013;19:19-28.
[3] Garg SK et al, Diabetes Obesity and Metabolism, 2011; 13:137-43.
[4] Weyer et al. Diabetes Care 2003; 26:3074–3079.
[5] Garg SK. Diabetes Technol Ther, 19 (10):549-551, 2017. PMID: 28891680.
[6] Dandona P et al. Lancet DE 2017; 5:864-876.
[7] Garg SK, et al. N Engl J Med. 2017;377:2337-2348.
[8] Buse JB, Garg SK et al. Diabetes Care 2018;41:1970−80.
[9] Danne T, et al. Diabetes Care 2018;41:1981−90.
[10] Zhong et al. Diabetes Care 2018;41:1870.
[11] Rosenstock J, et al. Diabetes Care. 2018 Dec;41(12):2560-2569. PMID: 30287422.
[12] Danne T, Garg SK, et al. Diabetes Care Jun 2019 (42). PMID: 31335194.
[13] Garg SK, et al. Diabetes Technol Ther. 2018 (20): 571-575. PMID: 30129772.
[14] Danne T, Garg SK, et al. Diabetes Care Jun 2019 (42). PMID: 31335194.
[15] Goldenberg RM, et al. Diabetes Obes Metab. Jun 2019. ePub ahead of print. PMID: 31183975.
Conclusions
Finally, the use of SGLT inhibitors as adjunctive therapy for T1D may allow many more patients to achieve target A1cs without any further weight gain and may in fact have long-term cardiovascular and renal benefits as have been shown in patients with T2D.
[1] Garg SK, et al. Diabetes Technol Ther. 2019 Feb;21: 66-72. PMID: 30657336.
[2] Garg et al. Endocrine Practice, 2013;19:19-28.
[3] Garg SK et al, Diabetes Obesity and Metabolism, 2011; 13:137-43.
[4] Weyer et al. Diabetes Care 2003; 26:3074–3079.
[5] Garg SK. Diabetes Technol Ther, 19 (10):549-551, 2017. PMID: 28891680.
[6] Dandona P et al. Lancet DE 2017; 5:864-876.
[7] Garg SK, et al. N Engl J Med. 2017;377:2337-2348.
[8] Buse JB, Garg SK et al. Diabetes Care 2018;41:1970−80.
[9] Danne T, et al. Diabetes Care 2018;41:1981−90.
[10] Zhong et al. Diabetes Care 2018;41:1870.
[11] Rosenstock J, et al. Diabetes Care. 2018 Dec;41(12):2560-2569. PMID: 30287422.
[12] Danne T, Garg SK, et al. Diabetes Care Jun 2019 (42). PMID: 31335194.
[13] Garg SK, et al. Diabetes Technol Ther. 2018 (20): 571-575. PMID: 30129772.
[14] Danne T, Garg SK, et al. Diabetes Care Jun 2019 (42). PMID: 31335194.
[15] Goldenberg RM, et al. Diabetes Obes Metab. Jun 2019. ePub ahead of print. PMID: 31183975.