There are some comments about the carcinogenicity of Lantus. What is your opinion? Does Levemir seem to be safer than Lantus?

The “carcinogenesis” issues of insulin glargine (Lantus) stems from theoretical issues of the anabolic effects (“protein” synthesis) of insulin in general. In addition to acting on the insulin receptor, insulins can cross-react to the insulin-like growth factor receptor. IGF-1 is a compound that has some molecular make up that is similar to insulin. Excess and prolonged exposure to IGF-1 has been implicated in some colon and prostate cancers. Thus, the issue with long-lasting insulin is how there may be ultimate long term effects.

Last I know, insulin glargine, and a similar long-acting synthetic insulin, called insulin detemir (Levimir), have not received FDA approval for use in children under age six. But, be careful in how you interpret this: lack of approval does NOT mean “disapproval.” It means that the manufacturers of these insulins have not submitted to the FDA any formal studies looking at the safety and efficacy. Many clinicians have been swayed to use these insulins in the pediatric-under-six population because of restricted options and the hope to utilize the terrific basal-bolus insulin plans in these younger children as is done in older children and adults. Insulin pump therapy is not approved yet in these younger children either. MANY medicines used in pediatrics do no formally carry FDA-approval because it has previously been thought that clinical trials of medicines in children was “unethical.”

I, personally, try not to use to much glargine or detemir in younger children. But, I certainly have used them, as have many colleagues.

DS
Additional comments from Dr. Andrea Scaramuzza:

In 2000, P. Kurtzhals reported in Correlations of receptor binding and metabolic and mitogenic potencies of insulin analogs designed for clinical use. that detemir (Levemir) has a relatively low insulin receptor binding affinity and metabolic potency than human insulin at equimolar doses. Also, it is less potent in binding to IGF-1 receptor and stimulating mitogenesis, with reduced tumorigenic risk. Even if the long term safety profiles should be studied.

About Glargine (Lantus), I have found only one study published in 2002 (Evaluation of the carcinogenic potential of insulin glargine (LANTUS) in rats and mice.) There was no difference in the incidence of mammary tumors reported in both mice and rats when comparing the insulin glargine groups with the placebo control, or the NPH insulin groups. In rats and mice, the distribution of subcutaneous malignant fibrous histiocytomas found at the injection site were not dose-dependent. These lesions are a rodent-specific event and were related to chronic tissue irritation and inflammation. In rats, neuronal necrosis of the cerebrum was attributed to persistent repeated episodes of hypoglycemia induced by high doses of insulin. In these studies, there were no neoplastic findings to indicate that insulin glargine had a systemic carcinogenic potential in mice or rats. However, no studies were done in humans and we don’t have long follow-up studies to say a definitive word on this issue.

AS
Additional comments from Sanofi Aventis:
The extensive body of evidence provided by Sanofi-Aventis in preclinical models and animal toxicology has established that Lantus� is a safe product, with similar insulin receptor (IR) affinity as human insulin used as the comparator, and that there is no demonstrated carcinogenicity risk associated with Lantus�.

The safety of Lantus was extensively reviewed and evaluated during the registration process in the United States, Europe and Japan; as a result of this process, Lantus� was granted approval by the competent regulatory authorities in the U.S., Europe and Japan.

Throughout a comprehensive clinical trial program and in clinical use since 2000 with an estimated global exposure of over 15 million patient-years, Lantus has been used safely and effectively by adult and pediatric (6 years and older) patients with type 1 diabetes and adult patients with type 2 diabetes.

See also PDF of Sanofi Aventis Statement and Lantus Prescribing Information.