Sitagliptin 100mg tablets (Januvia^Ò) - type 2 diabetes mellitus

SMC recommendation
Advice: following a full submission
Sitagliptin (Januvia^Ò) is accepted for restricted use within NHS Scotland for treatment of patients with type 2 diabetes mellitus to improve glycaemic control in combination with metformin when diet and exercise, plus metformin, do not provide adequate glycaemic control. It should be restricted to use in patients only when the addition of sulphonylureas is not appropriate, and represents an alternative to other agents such as thiazolidinediones.
Efficacy, as assessed by measurement of HbA1c, is similar to sulphonylurea and thiazolidinedione drugs added at this stage in therapy. It appears to have minimal effects on body weight.
Click here for SMC link

• Sitagliptin is the first of a new class of oral antidiabetic agents known as the dipeptidyl peptidase type 4 (DPP-4) inhibitors.  DPP-4 inhibitors increase levels of incretin hormones and thus stimulate insulin release and reduce glucagon secretion, thereby reducing blood glucose levels.  A further DPP-4 inhibitor, vildagliptin, is currently undergoing licensing and is anticipated later this year.
• Sitagliptin is licensed for use in combination with metformin when diet and exercise plus metformin do not provide adequate glycaemic control.  It is also licensed for use in combination with a glitazone, however to date this indication has not been submitted to the SMC.  Note that sitagliptin is not licensed for use as a dual therapy with a sulphonylurea or as part of a triple therapy regimen.
• 52-week comparative data in patients inadequately controlled on metformin alone show similar reductions in HbA1c with the addition of sitagliptin or the sulphonylurea glipizide.  Further data indicate that sitagliptin added to metformin has similar efficacy to a glitazone plus metformin.
• Signficantly fewer patients receiving sitagliptin plus metformin reported hypoglycaemia compared to those receiving glipizide plus metformin.  Unlike sulphonylureas, sitagliptin appears to be weight neutral.  Unlike glitazones, sitagliptin is not contraindicated in patients with heart failure or hepatic impairment.
• Long-term studies are needed to assess whether sitagliptin can prevent or reverse decline in beta-cell function, and to determine the effect of sitagliptin on disease-related morbidity and mortality.
• At a cost of £432 per patient per year, sitagliptin is a similar price to glitazones and considerably more expensive than sulphonylureas.
• Locally, the addition of sitagliptin may be considered as an alternative option to the addition of a glitazone in type 2 diabetic patients who are inadequately controlled on metformin alone and are considered unsuitable for treatment with sulphonylureas.
• In-line with the licence, patients who are unable to achieve glycaemic control on metformin/sitagliptin would be anticipated to move to metformin/glitazone (unless a glitazone is contraindicated).
• Existing  Tayside oral hypoglycaemic drug prescribing guidance will be updated to incorporate the DPP-4 inhibitors in due course.