SOURCE: Yki-Järvinen H, et al. New insulin glargine 300 units/mL vs glargine 100 units/mL in people with type 2 diabetes using oral agents and basal insulin: Glucose control and hypoglycemia in a 6-month randomized controlled trial (EDITION 2). Diabetes Care 2014;37:3235-3243.

One of the primary reasons for wide-spread clinician endorsement of newer basal insulins (i.e., glargine, detemir) over NPH is the relative “flatness” of insulin levels with the former. The greater curve of NPH than newer basal insulins incurs greater risk for nocturnal hypoglycemia, which may become a limiting factor for insulin titration.

Glargine and detemir are generally regarded as “flat” basal insulins. Traditional glargine is supplied as 100 units/mL. Could there be an advantage to glargine 300 (300 units/mL)?

The EDITION 2 study was an open-label trial comparing traditional glargine (100 units/mL) with a new formulation of glargine (300 units/mL). The more concentrated insulin glargine-300 reportedly has smoother, more stable pharmacokinetics and pharmacodynamics than glargine-100, attributed to its extended release from the subcutaneous depot. Does glargine-300 offer any meaningful advantage?

In a 6-month trial comparing glargine-100 to glargine-300 in type 2 diabetes (n = 811), glargine-300 was similar in efficacy as far as A1c reduction goes, but there was a modest reduction in hypoglycemic events, including both severe hypoglycemia and any hypoglycemic event. Curiously, the dose of glargine-300 required for glycemic control was about 10% higher than that of glargine-100. So, a possible advantage of lesser hypoglycemia and smaller volume of injection with glargine-300 must be counterbalanced with the increased cost of the approximately 10% more glargine-300 needed to achieve the same degree of A1c reduction. For patients incurring problematic episodes of hypoglycemia, an insulin that provides even “flatter” plasma levels may provide an advantage.