According to researchers, people who had prediabetes (elevated blood sugar levels at risk of developing diabetes), the anti-inflammatory drug canakinumab did not affect rates of newly diagnosed. Since diabetes is thought to be related to inflammatory processes like those involved in heart disease, researchers hypothesized that the drug might help slow or prevent the progression from prediabetes to diabetes.

The research is a key secondary endpoint from the CANTOS study, a large trial that last year reported canakinumab significantly reduced major adverse cardiovascular outcomes in patients with a history of heart attack and elevations in the inflammatory marker high-sensitivity C-reactive protein (hsCRP).

Patients with prediabetes at the start of the study initially showed a reduction in blood sugar levels (as indicated by a drop from 5.8 to 5.6 in median hemoglobin A1c, a measure of average blood sugar over the previous three months) after six months of taking canakinumab.

Canakinumab is designed to disable interleukin-1 beta, a protein that plays a role in inflammation. The drug is approved for several autoimmune disorders and is being investigated for the management of heart disease. The CANTOS trial enrolled more than 10,000 patients.

Of those, about 4,000 had diabetes at the start of the trial and 1,000 had normal blood glucose levels. The new analysis focuses on the remaining 4,960 patients, who had prediabetes at the start of the trial. In general, people with prediabetes are likely to progress to diabetes unless they adopt substantial lifestyle changes such as losing weight and getting more exercise.

Participants were randomly assigned to receive either a placebo or canakinumab in one of three dosing levels (50, 150 or 300 milligrams per dose). Patients were given injections of the drug every three months for a median of more than 3.5 years.  After the study ended and all participants stopped receiving injections, researchers continued to follow those who had prediabetes at baseline for an additional six months.

"Canakinumab is an effective therapy to prevent major cardiovascular events in patients with and without diabetes," Everett said. "It seems to prevent cardiovascular events without increasing the development of Type 2 diabetes among patients who are at risk for the disorder."

In a secondary analysis, the investigators examined the effect of canakinumab on blood glucose in patients with diabetes at the start of the study. In these patients, canakinumab led to similar changes in glucose levels as was seen in patients with prediabetes.

However, patients assigned to take canakinumab still required a similar number of diabetes medications, including insulin, as the patients taking the placebo. One potential area for future research could be to investigate whether canakinumab may contribute to glucose management among people who already have Type 2 diabetes.