Lantus, a synthetic form of insulin, is the subject of an Early Communication from the Food & Drug Administration (FDA). According to the agency, it has learned of four recently-published observational studies that looked at the use of Lantus (insulin glargine) and possible risk for cancer in patients with diabetes. Three of the four studies suggest an increased risk for cancer associated with use of Lantus.
Similar to human insulin, Lantus is used to control blood sugar in people with Type 1 and Type 2 diabetes. Lantus, however, is a modified version of human insulin (an insulin analogue) that allows for the control of blood sugar for extended periods of time (a long-acting insulin). Lantus is approved for once-a-day dosage by subcutaneous injection (injection under the skin).
The FDA Early Communication said that the four observational studies – all conducted in Europe – evaluated large patient databases and all reported some level of association between the use of Lantus, and other insulin products, and various types of cancer. The FDA duration of patient follow-up in all four studies was shorter than what is generally considered necessary to evaluate for cancer risk from drug exposure. Further, the agency pointed out that inconsistencies in findings within and across individual studies raise concerns as to whether an association between the use of insulin glargine and cancer truly exists. Additionally, differences in patient characteristics across the treatment groups may have contributed to a finding of increased cancer risk, the FDA said.
The FDA said it is currently reviewing many sources of safety data for Lantus, including these newly published observational studies, data from all completed controlled clinical trials, and information about ongoing controlled clinical trials, to better understand the risk, if any, for cancer associated with use of Lantus. The agency said it will communicate the results on its ongoing review to the public, as appropriate, as our review continues.
Based on the currently available data, the FDA recommends that patients should not stop taking their insulin therapy without consulting a physician, since uncontrolled blood sugar levels can have both immediate and long-term serious adverse effects. Patients should also contact their healthcare professional if they have concerns about the medicines they are taking.