Lantus Cancer Risk Being Reviewed by FDA

The FDA is reviewing new information about potential Lantus cancer side effects after several observational studies were published that suggest the artificial insulin may be associated with an increased incidence of cancer. However, the agency has expressed doubts about whether a connection between the use of Lantus and cancer truly exists.

In an early communication released by the FDA yesterday, they notified healthcare providers that they are aware of four studies published in the medical journal Diabetologia, which suggested that more in-depth studies need to be done about the potential Lantus cancer risk.

Lantus (insulin glargine) is a once-a-day injection that slowly releases insulin into the blood over time. Manufactured by Sanofi-Aventis, it has the second largest share of the diabetic drug treatment market and brought in $3.45 billion in worldwide sales last year. The drug was approved by FDA for diabetes treatment in 2000.

The studies referenced by the FDA involved analysis of German and Swedish insurance databases, looking at the incidence of cancer among diabetics using Lantus insulin. The study data suggested that low doses of Lantus may increase the risk of cancer 9% and high doses may increase the risk 31%. However, similar databases in Scotland and the U.K. showed no significant cancer risk increases, and the editors of the journal and the European Association for the Study of Diabetes cautioned that the results are inconclusive.

“The 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,” said the FDA in a statement issued July 1, 2009. “Further, 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 indicates that they are reviewing a number of sources for Lantus safety data, including the recent studies and clinical studies, and is also currently working with Sanofi-Aventis to determine whether there need to be additional studies.

Patients have been urged by the FDA to not stop their insulin therapy without consulting a physician. Uncontrolled blood sugar levels can have both immediate and long-term serious adverse effects, and patients are advised to cntact their doctors if they have concerns about the medicines they are taking.