This review examined the safety and efficacy of a new basal insulin, PEGylated insulin Lispro.

Insulin is a hormone that controls blood glucose (sugar) levels. Insulin therapy is used for both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) to replace the insulin the body cannot make or is resistant to. Fast-acting insulin therapies can often lead to weight gain or hypoglycemia (dangerously low blood glucose). The ideal insulin therapy would be as close as possible to the insulin the body normally produces, which peaks just after meals, with smaller releases throughout the day. New basal insulins more closely mimic human insulin release. Three basal insulins are currently in use: insulin glargine (Lantus), insulin detemir (Levemir) and insulin degludec (Tresiba). A fourth, PEGylated insulin Lispro (LY), is currently in clinical trials. The present review explores what is known about the safety and efficacy of LY.

LY has a slow duration of action (measured as the time of effectiveness following injection), lasting for 36 hours, compared to 24 hours for insulin glargine (GL). Clinical trials in patients with T2DM found no difference in blood glucose (BG) levels in patients using LY or GL, or in the number of hypoglycemic episodes. At the end of a 12-week study, patients taking LY saw a significant weight loss, which was not seen in GL patients. This weight loss is thought to be due to a decrease in glucose production by the liver. However, LY also led to a rise in blood pressure, which was not seen in the GL patients.

In patients with T1DM, LY led to significantly lower BG levels than did GL (8.01 mmol/L versus 8.43 mmol/L, respectively). Also, the mealtime insulin doses were 24% lower following 8 weeks of LY compared to the beginning of the study. LY patients also saw an average weight loss of 1.2 kg, whereas GL patients saw a 0.69 kg weight gain. Hypoglycemic events were, overall, 12% higher for LY compared to GL, but nighttime hypoglycemic events specifically were 25% lower.

Patients with kidney failure often have to use adjusted doses of insulin. LY, however, was found to be well-tolerated by patients with both DM and kidney failure when taken at normal doses, including patients on dialysis (artificial replacement of lost kidney function).

In summary, this review found LY to be a generally safe and effective insulin therapy with a slow duration of action, similar to GL. While LY was more effective than GL at lowering BG in T1DM, they were equally effective in T2DM. LY led to weight loss in both T1DM and T2DM, but also increased daily hypoglycemia in T1DM and increased blood pressure in T2DM, side effects which need to be addressed in future research.

Discuss with your physician which insulin therapy is most appropriate for your situation.