Sanofi’s best-selling diabetes treatment Lantus leads to no increased cancer risk, according to three studies that explored a possible link among patients after one to three years of treatment.
The studies, which analyzed data on more than 615,000 patients, independently compared the use of Lantus with other long-acting insulins in diabetics, the American Diabetes Association said in a statement. The results are being presented today at the organization’s annual meeting in Philadelphia. The studies were conducted by researchers in five northern European countries including Sweden and Denmark, at Kaiser Permanente in California, and at the University of North Carolina.
“The preponderance of evidence suggests that there is no increased risk of cancer associated with relatively short-term use of insulin,” John Buse, director of the Diabetes Center at the University of North Carolina School of Medicine, said in the statement.
Lantus came under the spotlight in 2009 after four studies suggested a possible increased cancer risk following use of the treatment, a long-acting insulin analogue that is Sanofi’s best-selling medicine. Those studies had yielded mixed results. The U.S. Food and Drug Administration said last year it found no conclusive evidence of a link. Another study presented today, dubbed Origin, also showed no increased tumor risk from insulin glargine, the chemical name for Lantus.
“Independently from what region of the world, what methodology you use, what specific type of cancer you look at, the result is simple -- there is no increased cancer risk in patients using glargine,” Riccardo Perfetti, vice president for medical affairs at Sanofi Diabetes, said in telephone interview. Sanofi sponsored the studies, which were the largest analysis on the possible link.
In the three studies, researchers looked at the association between insulin use and all cancers and analyzed the individual risks for breast, colorectal and prostate cancer, the ADA said. Only one study, from Kaiser Permanente, found a “suggestion” of a relationship between Lantus and a “modest” increase in breast cancer risk, but only in new insulin users, according to the statement.
Such results “should be viewed cautiously, given the relatively short duration of glargine use and the large number of associations examined,” Laurel Habel, principal investigator and research scientist at the Kaiser Permanente Northern California Division of Research, said in today’s statement.
None of the other groups found any link. The Kaiser Permanente and University of North Carolina studies examined data on patients with a median duration of 1.2 years of glargine use. The five-country study was based on an average duration of 3.1 years of Lantus use.
“Because the induction period for many carcinogens is years to decades, additional follow-up of the Kaiser cohort and others will be needed to determine whether glargine is associated with an increase in breast, or other forms of cancer,” Habel said.
Concern about a potential cancer link hasn’t slowed Lantus sales, which climbed 12 percent to 3.92 billion euros ($4.9 billion) last year. The medication generates more than three times the revenue of Levemir, a competing product from Bagsvaerd, Denmark-based Novo Nordisk A/S.
“We are expecting a minor positive to sentiment around insulin safety” from the results of studies on Lantus and a potential cancer risk, Jeffrey Holford, an analyst with Jefferies International Ltd. in New York, wrote in a May 29 note to investors. Such concern “has not been a significant commercial issue to date,” he wrote.