Sanofi-Aventis SA fell the most in a year in Paris trading on renewed concern that the French drugmaker’s Lantus diabetes treatment may be linked to an increased risk of cancer.
Sanofi dropped 2.91 euros, or 5.7 percent, to 48.20 euros at 11:40 a.m. The stock slid as much as 8.1 percent, the biggest intraday drop since June 26, 2009.
A study published this week in the journal Diabetes Care linked insulin glargine, as Lantus also is known, to an increased risk of cancer, according to a note today from Hobart Capital Markets, a London brokerage. Sanofi in the past has said the drug is safe and it’s doing additional studies.
In the study, researchers compared the health records of 1,340 people with diabetes who developed cancer to a group of patients matched for age, sex and weight to see if they could tease out any differences that may have contributed to tumor development. During the six-year review, people diagnosed with cancer had taken significantly higher daily doses of Lantus, according to the report in Diabetes Care. No association between new cancer and other forms of insulin were found.