Fast-Acting Insulin Aspart: The Rationale for a New Mealtime Insulin

Attenuating postprandial hyperglycaemia is a critical factor in the achievement of optimal glucose control. Prandial insulin analogues have been developed to replicate the physiology of normal endogenous insulin secretion and action, with the aim of limiting postprandial glucose excursions. There is still, however, a significant unmet need, with many people failing to achieve desired glycaemic control targets despite the current armamentarium of prandial insulin analogues. Such insulins have a delayed onset and a longer duration of action than endogenous insulin production. There has been considerable focus on attempts to accelerate the time-action profile of prandial exogenous insulin in order to produce a more physiological profile. One such approach is to modify the insulin formulation. Fast-acting insulin aspart is a modified formulation of insulin aspart containing niacinamide and L-arginine. It has an earlier onset of action than aspart. In an extensive trial programme, this faster aspart demonstrated similar HbA1c reductions to those achieved with aspart but superior postprandial glucose reductions, with no increase in hypoglycaemia. Furthermore, administration of faster aspart up to 20 min after the start of a meal permitted similar glucose control to aspart given preprandially. These data, taken in totality, illustrate the potential role of faster insulin aspart in clinical practice.