5-year Study Published in Diabetologia Demonstrated Long-Term Safety of Lantus® Compared to NPH

sanofi-aventisSanofi-aventis (EURONEXT: SAN and NYSE: SNY) has announced that the results of the long-term, 5-year study of Lantus® (insulin glargine [rDNA] injection) versus NPH insulin on progression of retinopathy in patients with type 2 diabetes, published on-line in Diabetologia (DOI 10.1007/s00125-009-1415-7) showed similar effects on retinopathy and overall safety in the two treatment groups. This is the longest controlled study ever reported using insulin glargine.

Diabetic retinopathy is a major cause of blindness in patients with diabetes. It is a progressive disease that results from cellular proliferation within the eye. The stimulation of IGF1 receptors is involved in this process. In the study of patients with retinopathy, the progression of diabetic retinopathy was similar in the two treatment groups over the long-term course of treatment. This indicates that Lantus® does not have mitogenic effects different from the human NPH insulin within the eye.

"This 5-year study is the longest randomized controlled study with insulin glargine versus NPH human insulin," said lead investigator Julio Rosenstock, MD, Director of the Dallas Diabetes and Endocrine Center at Medical City and also Clinical Professor of Medicine, University of Texas Southwestern Medical School. "This study demonstrated no evidence of a greater risk of progression of retinopathy with insulin glargine."

The 5-year open-label study was specifically designed to further characterize the retinal safety profile of Lantus® versus NPH in 1024 patients (Lantus® once daily: 515 patients; NPH twice daily: 509 patients). Retinopathy progression was assessed using serial fundus photography.

Progression was evaluated using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale; the scores at study end were similar in both treatment groups (Lantus®: 14.2%, NPH: 15.7%; 95% CI: -7.02, 3.06). As per protocol, the study aimed to achieve similar levels of glycemic control in both groups, in order to avoid introducing bias on the primary retinopathy end-point that could be related to differences in blood glucose control. Both groups had comparable HbA1c at study end (mean HbA1c improved from a baseline of 8.4% and 8.3% to 7.8% and 7.6% for all patients in the insuline glargine and NPH insulin groups respectively). NPH insulin was associated with a significantly greater incidence of severe hypoglycemia than was insulin glargine (11.1% vs 7.6% respectively, p=0.0439) and mean yearly rates of symptomatic hypoglycemia (7.08+/-16.49 vs 5.13+/-12.79, p=0.0017).

There was no observable trend for a difference in the incidence of serious adverse events including cancer, as well as adverse events leading to study withdrawal. The most common adverse events in the study were: upper respiratory tract infection (glargine 149 [29%], NPH 169 [33.6%]), peripheral edema (glargine 103 [20%], NPH 114 [22.7%]), and arthraralgia (glargine 73 [14.2%], NPH 81 [16.1%]).

About the study
This long-term study was designed to further characterize the retinal safety profile of insulin glargine (glargine) and human neutral protamine Hagedorn insulin (NPH) in patients with type 2 diabetes mellitus.

This was an open-label, 5-year, randomized (1:1), multicentre, stratified, parallel-group study comparing patients treated with either twice-daily NPH (n=509) or once-daily basal glargine (n=515). The main objective of this study was to compare the progression of diabetic retinopathy between treatment groups by analyzing the percentage of patients with ≥3-step progression in the Early Treatment Diabetic Retinopathy Study (ETDRS) retinopathy patient-level severity scale after treatment with either insulin. Masked, centralized grading of seven-field stereoscopic fundus photographs was used.

Main characteristics of the population were the following and well balanced between groups: mean age 55, 54% males, mean baseline HbA1c 8.4 vs 8.3% (glargine vs NPH) diabetes duration 11 years, and about 70% of the population was already treated with insulin prior to study entry.

Similarly sustained glycaemic control was observed in both the glargine and NPH treatment groups. Despite a slightly greater severity of diabetic retinopathy for the glargine-treated group at baseline, ≥3-step progression in ETDRS score from baseline to end-of-study was similar between treatment groups (14.2% [53/374] of glargine-treated patients vs 15.7% [57/363] of NPH-treated patients). Other measures of retinopathy – the development of proliferative diabetic retinopathy and progression to clinically significant macular oedema – occurred to a similar degree in both treatment groups. Rates of symptomatic and clinically important hypoglycaemia were significantly lower in the glargine group: NPH insulin was associated with a significantly greater incidence of severe hypoglycemia than was insulin glargine (11.1% vs 7.6% respectively, p=0.0439) and mean yearly rates of symptomatic hypoglycemia (7.08+/-16.49 vs 5.13+/-12.79, p=0.0017). Body weight gain tended to be greater with NPH insulin compared with insulin glargine treatment, with a baseline to endpoint increase in mean body weight of 3.7 kg for insulin glargine and 4.8 kg for NPH insulin (ITT population; p=0.0505). No other safety issues for either insulin emerged during the 5-year study.

About Lantus®
Lantus® is a truly 24-hour basal insulin without pronounced peak, and therefore efficaciously and safely lowers blood glucose. Lantus® is indicated for once-daily subcutaneous administration in the treatment of adult patients with type 2 diabetes mellitus who require basal (long-acting) insulin for the control of hyperglycemia and for adult and pediatric patients (6 years of age and older) with type 1 diabetes mellitus. Lantus® demonstrates a consistent slow, prolonged absorption and a relatively constant concentration/time profile over 24 hours.

About sanofi-aventis
Sanofi-aventis, a leading global pharmaceutical company, discovers, develops and distributes therapeutic solutions to improve the lives of everyone. Sanofi-aventis is listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY).