The FDA has approved donislecel-jujn (Lantidra – CellTrans), an allogeneic pancreatic islet cellular therapy, for use in conjunction with immunosuppression for treatment of adults with type 1 diabetes who are unable to approach target HbA1c because of current repeated episodes of severe hypoglycemia despite intensive diabetes management and education. Donislecel is the first cell-based treatment to be approved in the US for type 1 diabetes.

Insulin glargine-aglr (Rezvoglar – Lilly), which was approved by the FDA as a biosimilar to the reference product Lantus in 2021 and received interchangeability status with Lantus in 2022, will become available in the US on April 1, 2023. It is the second biosimilar insulin product to be designated as interchangeable with Lantus; Semglee was the first. Rezvoglar did not receive interchangeability status with Lantus at the time of its initial approval because the manufacturer of Semglee had exclusivity for 12 months.

Teplizumab-mzwv (Tzield – Provention Bio), an anti-CD3 monoclonal antibody, has been approved by the FDA to delay the onset of stage 3 type 1 diabetes in patients ≥8 years old who have stage 2 type 1 diabetes. It is the first drug to become available in the US that delays the onset of type 1 diabetes.

Diet, exercise, and weight loss can improve glycemic control, but almost all patients with type 2 diabetes require antihyperglycemic drug therapy. Treating to a target A1C of <7% while minimizing hypoglycemia is recommended to prevent microvascular complications of diabetes (retinopathy, nephropathy, and neuropathy). An A1C target of <8% may be appropriate for some older patients.

The FDA has approved tirzepatide (Mounjaro – Lilly), a peptide hormone with activity at both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors, to improve glycemic control in adults with type 2 diabetes. Tirzepatide, which is injected subcutaneously once weekly, is the first dual GIP/GLP-1 receptor agonist to become available in the US. Selective GIP receptor agonists are not available in the US; GLP-1 receptor agonists have been available for years.

Insulin glargine-yfgn (Semglee – Viatris), a follow-on insulin glargine product, has now received interchangeability status with the reference product Lantus from the FDA. It is the first biosimilar insulin product to receive this designation in the US. Now a pharmacist can substitute Semglee for Lantus as a lower-cost alternative without permission from the prescriber.

The FDA has approved Semglee (Mylan), an insulin glargine product similar to Lantus, for treatment of type 1 diabetes in children and adults and type 2 diabetes in adults. Semglee is the second "follow-on" insulin glargine product to become available in the US; Basaglar, which is also similar to Lantus, was the first. Lantus is a recombinant analog of human insulin that forms microprecipitates in subcutaneous tissue, prolonging its duration of action to a mean of about 24 hours with no pronounced peak effect.

The FDA has approved insulin lispro-aabc (Lyumjev – Lilly), a faster-acting formulation of insulin lispro (Humalog), for treatment of type 1 and type 2 diabetes in adults. Fiasp, a faster-acting formulation of insulin aspart (Novolog), was approved in 2017.

The FDA has approved Trijardy XR (Boehringer Ingelheim/Lilly), a fixed-dose combination of the sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin, and extended-release metformin, for oral treatment of type 2 diabetes in adults. Empagliflozin and linagliptin have been available in a fixed-dose combination as Glyxambi since 2015, and both have been available in 2-drug combinations with extended-release metformin for years (see Table 1).

Diet, exercise, and weight loss can improve glycemic control, but almost all patients with type 2 diabetes eventually require drug therapy. Treating to a glycated hemoglobin (A1C) concentration of <7% can prevent microvascular complications (retinopathy, nephropathy, and neuropathy), but whether it prevents macrovascular complications and death is unclear. An A1C target of <8% may be appropriate for older patients and those with underlying cardiovascular disease (CVD), a history of severe hypoglycemia, diabetes-related complications, a limited life expectancy, or a long duration of disease.

The goal of drug therapy for type 2 diabetes is to achieve and maintain a near-normal glycated hemoglobin (A1C) concentration without inducing hypoglycemia; for most patients, the target A1C is <7%. Metformin is the preferred first-line treatment, but most patients with type 2 diabetes eventually require multidrug therapy and/or insulin to achieve glycemic control.

View the Expanded Table: Some Available Insulins

The FDA has approved Admelog (Sanofi-Aventis), an insulin lispro product similar to Humalog (Lilly), which went off patent in 2013.

Approval of Admelog was based on efficacy data with Humalog and on two 6-month, open-label, randomized, noninferiority trials. In SORELLA 11 in 507 patients with type 1 diabetes and SORELLA 22 in 505 patients with type 2 diabetes, Admelog was noninferior to Humalog in lowering A1C, fasting plasma glucose levels, and self-monitored plasma glucose levels. The incidence of adverse effects, including hypoglycemia, was similar.

Even though Admelog is very similar to Humalog in composition, strength, and structural and biological properties, and appears to produce the same glucose-lowering effects, it was not designated as a biosimilar or an interchangeable biologic product by the FDA because of a regulatory technicality: insulin is classified as a chemical, not a biological, entity, so there is no biologic reference product for insulin lispro. Pharmacists cannot substitute Admelog for Humalog without the permission of the prescriber.  

Admelog is available in 10-mL vials and in packages of five multi-dose SoloStar pens, each prefilled with 3 mL of insulin lispro 100 units/mL. A pen can deliver 1 to 80 units per injection. It should be primed with 2 units of insulin lispro before each injection. Admelog should be injected subcutaneously within 15 minutes before a meal, or immediately after a meal.

Admelog is similar to Humalog in efficacy and safety. Patients could use either one.

1. SK Garg et al. Efficacy and safety of biosimilar SAR342434 insulin lispro in adults with type 1 diabetes also using insulin glargine – SORELLA 1 study. Diabetes Technol Ther 2017; 19:516.
2. KM Derwahl et al. Efficacy and safety of biosimilar SAR342434 insulin lispro in adults with type 2 diabetes, also using insulin glargine: SORELLA 2 study. Diabetes Technol Ther 2018; 20:49.

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The FDA has approved semaglutide (Ozempic – Novo Nordisk), a long-acting injectable GLP-1 (glucagon-like peptide-1) receptor agonist, for once-weekly treatment of adults with type 2 diabetes. It is the sixth GLP-1 receptor agonist to be approved in the US.

The FDA has approved Fiasp (Novo Nordisk), a new formulation of insulin aspart, to improve glycemic control in adults with diabetes. Fiasp is described by the manufacturer as faster-acting than conventional insulin aspart (Novolog).

The FDA has approved Xultophy 100/3.6 (Novo Nordisk), a fixed-ratio combination of insulin degludec and the GLP-1 (glucagon-like peptide-1) receptor agonist liraglutide, for once-daily treatment of adults with type 2 diabetes inadequately controlled on basal insulin (<50 units daily) or liraglutide (≤1.8 mg daily).

For many years, the goal of drug therapy for most patients with type 2 diabetes has been to achieve and maintain an A1C of <7%. Achieving that goal can prevent microvascular complications (diabetic retinopathy, nephropathy, neuropathy), but whether it prevents macrovascular complications (myocardial infarction [MI], stroke) has been less clear. The FDA now requires that cardiovascular safety studies be performed for all new drugs for type 2 diabetes.1 Recent findings that some of the newer second-line drugs for type 2 diabetes have cardiovascular benefits have led to new interest in the cardiovascular efficacy and safety of all antidiabetic drugs.

Per capita spending on prescription drugs in the US is higher than in other industrialized nations, including Canada.

The FDA has approved lixisenatide (Sanofi), a short-acting injectable GLP-1 (glucagon-like peptide-1) receptor agonist, for once-daily treatment of adults with type 2 diabetes, both alone (Adlyxin) and in a fixed-ratio combination with insulin glargine (Soliqua 100/33). Lixisenatide has been available since 2013 in many other countries as Lyxumia. It is the fifth GLP-1 receptor agonist to be approved in the US.

The FDA has approved Basaglar (Lilly/Boehringer Ingelheim), a "follow-on" 100 units/mL insulin glargine product similar to Lantus (Sanofi), which recently went off patent. A 300 units/mL formulation of insulin glargine (Toujeo) was approved in 2015.

The FDA has approved the Minimed 670G (Medtronic), a hybrid closed-loop insulin delivery system for use in patients ≥14 years old with type 1 diabetes. The system uses an algorithm to automatically adjust basal insulin doses based on readings from a continuous glucose monitor (CGM). It fully automates basal insulin delivery in "auto" mode, but is considered a "hybrid" system (not a true "artificial pancreas") because it requires some action by the patient. The 670G system is expected to become available in Spring 2017.

The FDA has approved insulin degludec (Tresiba – Novo Nordisk) for treatment of adults with type 1 or type 2 diabetes. Insulin degludec is the third long-acting human insulin analog to be approved by the FDA; insulin detemir (Levemir) and insulin glargine (Lantus, Toujeo) were approved earlier.

The FDA has approved Toujeo (Sanofi), a more concentrated form of insulin glargine containing 300 IU/mL compared to the 100 IU/mL in Lantus (Sanofi). Lantus is nearing the end of its patent protection in the US, and biosimilars are expected to become available.

The FDA has approved an inhaled, rapid-acting, dry-powder formulation of recombinant human insulin (Afrezza – Mannkind/Sanofi) for treatment of adults with type 1 or type 2 diabetes. In patients with type 1 diabetes, the drug must be used in combination with long-acting insulin. Another inhaled, rapid-acting insulin (Exubera) was approved in 2006 for the same indication, but was withdrawn from the market the following year.

Two new injectable GLP-1 (glucagon-like peptide-1) receptor agonists, dulaglutide (Trulicity [trū li si tee] – Lilly) and albiglutide (Tanzeum [tan' zee um] – GSK), have been approved by the FDA for once-weekly treatment of type 2 diabetes. Other available GLP-1 receptor agonists include exenatide, which is approved for injection twice daily (Byetta) or once weekly (Bydureon), and liraglutide (Victoza), which is injected once daily.

Empagliflozin (Jardiance – Boehringer Ingelheim/Lilly), an SGLT2 inhibitor, has been approved by the FDA for oral treatment of type 2 diabetes. It is the third SGLT2 inhibitor to be approved for this indication.

The goal of drug therapy for type 2 diabetes is to achieve and maintain a near-normal A1C concentration without inducing hypoglycemia; the target is generally an A1C of <7.0%. Treating to this target has been shown to prevent the microvascular complications of retinopathy and nephropathy, but whether it prevents macrovascular outcomes remains unclear. Three large trials found that intensive glucose control did not reduce the incidence of macrovascular events. One of these trials (ACCORD) in >10,000 patients with type 2 diabetes, with or at high-risk for cardiovascular disease, found that treating patients intensively with antihyperglycemic drugs to an A1C target of 6.0% for a mean of 3.7 years did not significantly reduce the incidence of major cardiovascular events (the primary endpoint) and was associated with increased all-cause mortality compared to patients treated to an A1C target of 7.0-7.9%. An A1C target of 7-8% may be prudent in older patients and in those with underlying cardiovascular disease, severe hypoglycemia, or multiple diabetes-related complications or co-morbidities.

Dapagliflozin (dap" a gli fl oe' zin; Farxiga – Bristol-Myers Squibb/AstraZeneca), an SGLT2 (sodium-glucose co-transporter 2) inhibitor, has been approved by the FDA for oral treatment of type 2 diabetes. Dapagliflozin is the second SGLT2 inhibitor to be approved for this indication; canagliflozin (Invokana) was the first .

The FDA has approved the MiniMed 530G (Medtronic), an insulin pump used in combination with a continuous glucose monitoring sensor (Enlite) that can stop delivery of insulin when interstitial glucose reaches a prespecified low level. It is the only sensoraugmented insulin pump available in the US with this capability.

Omalizumab (Xolair) is a recombinant humanized monoclonal anti-IgE antibody currently approved by the FDA for treatment of moderate to severe persistent allergic asthma. It has been used off-label for treatment of allergic rhinitis and food allergies. Recently the results of a phase III clinical trial indicated that omalizumab may be effective in treating chronic urticaria as well.

Canagliflozin (kan" a gli floe' zin; Invokana – Janssen), a sodium-glucose co-transporter 2 (SGLT2) inhibitor, has been approved by the FDA for oral treatment of type 2 diabetes.

Several readers have raised questions about the statement in our recent article (Med Lett Drugs Ther 2012; 54:58) that long-acting insulins, like metformin and sulfonylureas, have been shown to decrease long-term cardiovascular risk. Our statement was based on the extension of the UKPDS (RR Holman et al, N Engl J Med 2008; 359:1577), which is the longest prospective trial of drug therapy in patients with type 2 diabetes. Shorter studies in older patients with long-standing diabetes did not find a reduction in cardiovascular risk with these and other drugs (The Action to Control Cardiovascular Risk in Diabetes Study Group. N Engl J Med 2008; 358:2545; The ADVANCE Collaborative Group. N Engl J Med 2008; 358:2560; W Duckworth et al. N Engl J Med 2009; 360:129).

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Most experts agree that lifestyle modifications and metformin (Glucophage, and others) should be used first to treat patients with type 2 diabetes. If metformin alone fails to control hyperglycemia, there is no general agreement on which drug should be added next. A recent article in The Medical Letter offered some support for a sulfonylurea. Three recent trials published in The Lancet favored the long-acting basal insulin glargine, the glucagon-like peptide (GLP-1) analog exenatide, and the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin, respectively. Some of the advantages and disadvantages of these and other available agents are listed in Table 1 on the opposite page.

The development of hyperglycemia in type 2 diabetes results from a combination of metabolic abnormalities that includes insulin resistance, diminished insulin secretion and excess hepatic glucose production. Diet, exercise and weight loss are helpful in improving glucose control, but most patients ultimately require drug therapy.

A variety of continuous glucose monitoring (CGM) devices have been used in an effort to reduce the hypoglycemia and wide glucose excursions that complicate insulin treatment of diabetes. Since the last Medical Letter issue reviewing such devices, some new devices and some new data on old devices have become available. The devices currently marketed in the US for personal use are listed in Table 1.

Liraglutide (Victoza – Novo Nordisk), a glucagon-like peptide-1 (GLP-1) receptor agonist given by subcutaneous injection, has been approved by the FDA for treatment of patients with type 2 diabetes. It can be used alone or in addition to oral antidiabetic drugs such as metformin (Glucophage, and others) or glimepiride (Amaryl, and others). Liraglutide is not recommended for first-line therapy and is not approved for use with insulin.

Three rapid-acting insulin analogs are currently available: insulin lispro, insulin aspart and insulin glulisine. 1-3 All three are approved for use in both type 1 and type 2 diabetes, either by subcutaneous injection, insulin pump or intravenous administration. All three cost more than regular insulin.

Several large European observational studies published on-line this summer have raised questions about whether use of insulin glargine increases the risk of cancer.

Primary hypothyroidism is usually the result of Hashimoto's thyroiditis, thyroidectomy for hyperthyroidism, goiter or cancer, or radioactive iodine therapy for hyperthyroidism.

The goal for drug therapy of type 2 diabetes is achieving and maintaining a near-normal glycated hemoglobin (HbA_1C) concentration without inducing hypoglycemia; the target has generally been an HbA_1C of 6.5-7.0% or lower. Whether treating to this level prevents macrovascular (cardiovascular) events has been unclear. Now, 2 large randomized, double-blind trials in patients with long-standing diabetes and at high risk for cardiovascular disease have found no decrease in macrovascular events with intensive glucose control.

The ACCORD trial in about 10,000 patients found that patients intensively treated with anti-hyperglycemic drugs, including frequent use of thiazolidinediones, mostly rosiglitazone (Avandia), and insulin, with an HbA_1C target of 6.0% (actual median HbA_1C 6.4%) did not obtain a significant reduction in major cardiovascular events (the primary endpoint) over a period of 3.5 years. The trial was stopped early because of an unexpected increase in all-cause mortality (257 deaths vs. 203) in intensively treated patients compared to patients with an HbA_1C target of 7.0-7.9% (actual median HbA_1C 7.5%). The etiology of the higher mortality is unclear.1

The ADVANCE trial in about 11,000 similar patients treated to an HbA_1C target of 6.5% with a sulfonylurea-based regimen, and infrequent use of thiazolidinediones, also found no decrease in macrovascular events, but no increase in all-cause mortality.2

Whether intensive glycemic control would reduce macrovascular events in patients at lower risk has not been established.

1. The ACCORD Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 2008; 358:2545.
2. The ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med 2008; 358:2560.

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Colesevelam (Welchol - Daiichi Sankyo - Med Lett Drugs Ther 2000; 42:102), a bile-acid sequestrant used to lower LDL cholesterol, has been approved by the FDA as an adjunct to diet and exercise in the treatment of type 2 diabetes. In unpublished studies summarized in the package insert, patients with type 2 diabetes taking metformin (Glucophage, and others), a sulfonylurea or insulin (each as either monotherapy or in combination with other anti-diabetic agents) were given colesevelam 3800 mg per day or placebo; colesevelam significantly reduced glycosylated hemoglobin (A1c) by about 0.5% more than placebo in all three trials. The mechanism is unclear.

Colesevelam can cause constipation, nausea and dyspepsia, increase serum triglyceride concentrations, and interfere with absorption of other oral drugs. One month's treatment with Welchol obtained from drugstore.com would cost about $200. Medical Letter consultants are not enthusiastic about prescribing it for this indication.

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An inhaled, dry-powder formulation of rapid-acting human insulin (Exubera - Pfizer) has been approved by the FDA for treatment of adults with type 1 or type 2 diabetes.

Insulin detemir (Levemir - Novo Nordisk) is the second long-acting basal insulin analog to be marketed in the US for treatment of both type 1 and type 2 diabetes. Detemir differs from human insulin by the elimination of the amino acid threonine in position B30 and the addition of a 14-carbon fatty acid chain at position B29. Insulin glargine (Lantus), the first long-acting insulin analog, has been available since 2001 and is usually given once daily.1 NPH insulin is an intermediate-acting basal insulin given twice daily. Basal insulins are usually combined with prandial doses of a rapid-acting insulin.

Insulin glulisine (Apidra - Sanofi Aventis) is the third rapid-acting insulin analog to be marketed in the US, following insulin lispro (Humalog) and insulin aspart (Novolog). All three have a more rapid onset and shorter duration of action than regular human insulin. Rapid-acting insulin analogs are generally taken immediately before meals and are usually combined with a long-acting basal insulin.

With the 2004 Olympics only weeks away, performance-enhancing drugs will once again be receiving a great deal of attention. The US Anti-Doping Agency has published a list of drugs banned in Olympic sports (www.usantidoping.org) that includes, at least for some sports, all but 2 of the drugs reviewed here.

Bexarotene, a retinoid analog, has been approved by the US Food and Drug Administration for oral treatment of dermatologic manifestations of refractory cutaneous T-cell lymphoma.

Pioglitazone is the third thiazolidinedione ("glitazone") to be marketed in the USA for treatment of type 2 diabetes. Thiazolidinediones decrease resistance to insulin.

Troglitazone (Rezulin - Parke-Davis), the first of a new class of thiazolidinedione derivatives ('glitazones') for diabetes, has been marketed for oral treatment of noninsulin- dependent diabetes mellitus (NIDDM) in patients who take more than 30 units of insulin daily and still have a glycosylated hemoglobin concentration (HbA1c) of 8.5% or higher.

Lispro insulin (Humalog - Lilly), a synthetic insulin analog, has been approved for marketing by the US Food and Drug Administration. Prepared by recombinant DNA methods using E. coli, lispro differs from human insulin in having lysine and proline at positions 28 and 29 on the beta-chain, reversed from their natural position. The new drug has biologic effects similar to unmodified insulin, but is absorbed more rapidly after subcutaneous injection.

The NovolinPen (Squibb - Novo) is a device that uses prefilled cartridges to inject semisynthetic human insulin (Medical Letter, 25:63, 1983). Three formulations are available: regular insulin (Novolin R PenFill), NPH insulin isophane (Novolin N PenFill) and a mixture of 70% NPH and 30% regular (Novolin 70/30 PenFill). The NovolinPen is advertised as more accurate, more convenient and less expensive than conventional syringes and needles. The same device is marketed in Canada as the Novolin-Pen II (Connaught Novo). (An earlier device is also available as the Novolin-Pen in Canada and the NovoPen in the USA.)