New data analyses and a nod from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) have enriched the profile of Merck & Co’s Januvia (sitagliptin) as a broad-spectrum treatment for diabetes with the capacity for sustained glycaemic control.

The data, which showed that Januvia could lower blood sugar significantly over a two-year period either as monotherapy or in combination with the standard therapy metformin, were presented at the 45th Annual Meeting of the European Association for the Study of Diabetes (EASD) in Vienna, Austria.

They came at the same time as the CHMP’s positive opinion on Januvia and Janumet, a fixed-dose combination of sitagliptin and metformin not currently available in some countries including the UK, as add-ons to insulin therapy for type 2 diabetes when diet and exercise plus stable doses of insulin do not provide adequate glycaemic control.

In the EASD presentations, a post-hoc analysis of pooled data found that in 32 type 2 diabetes patients who completed the course of treatment, sitagliptin monotherapy led to a mean reduction of 1.4% in HbA1c levels versus baseline (mean HbA1c reduction from 8.3% to 6.9%) over a 104-week period. HbA1c or glycated haemoglobin levels are a standard marker of blood sugar concentrations.

More than half (54%) of the 147 participating patients who received sitagliptin alone did not require any additional glycaemic medication or discontinuation of treatment, Merck & Co noted.

In the same analysis, adding sitagliptin to ongoing metformin (347 completers) resulted in an HbA1c reduction of 0.8% versus baseline (mean HbA1c reduction from 7.7% to 6.9%) over the two-year span. Among the 852 participants overall, 67% of those given sitagliptin in combination with metformin did not require additional glycaemic medication or discontinuation of therapy due to lack of efficacy.

Additional data presented at the EASD meeting showed that initial combination therapy with sitagliptin and pioglitazone (Takeda’s Actos/Glustin) produced a 2.4% fall in HbA1c levels from baseline (251 participants) over a 24-week period, compared with a 1.5% reduction on pioglitazone alone (246 participants). Initial therapy with a combination of pioglitazone and sitagliptin is not currently licensed in the UK or Europe.

Another study looked at the impact of initial treatment with the fixed-dose combination of sitagliptin and metformin (also not currently licensed in the UK/Europe) on blood sugar control in patients with type 2 diabetes, compared with metformin alone, over an 18-week period.

The outcome was a mean HbA1c reduction of 2.4% following treatment with sitagliptin/metformin (626 participants) versus a 1.8% fall on metformin alone (624 participants), Merck & Co reported.

Commenting on the CHMP recommendation, John Wilding, professor of medicine and honorary consultant physician at University Hospital Aintree in Liverpool, UK, said it was “an important development because insulin treatment alone or in combination with metformin often fails to provide adequate glycaemic control, especially as escalation of insulin doses may lead to weight gain”.

In the future, Wilding added, “this will enable more flexible use of sitagliptin, from the additional recent indication for first-line use in patients who cannot tolerate metformin to today’s CHMP opinion for add-on to insulin”, opening the gate to use of the DPP-4 inhibitor “across the entire treatment pathway”.