The drug company Merck & Co said on Wednesday that the US Food and Drug Administration (FDA) has approved new uses of its diabetes drug Januvia in combination with other medicines but also reported the drug can cause serious allergic reactions to some patients.
Januvia (sitagliptin) received FDA approval in October 2006 as a prescription medicine for use as part of a treatment programme (including diet and exercise) to lower blood sugar in patients with type 2 diabetes. That approval was granted for the drug to be used on its own or as adjunctive therapy with certain other drugs, such as metformin and thiazolidinediones (eg Takeda’s Actos and GlaxoSmithKline’s Avandia).
Since then over 2 million prescriptions have been filled for the drug in the US.
The FDA has now approved a follow-up application to allow use of the drug as an adjunctive therapy in combination with another family of diabetes drugs called sulfonylureas, when these are not enough to control blood sugar.
The drugmaker said Januvia could also be used in combination with sulfonylurea and metformin, in cases when the two are not enough to control blood sugar, and they also said that it could be used with metformin as an initial therapy.
The follow-up application was supported by findings of three studies on the efficacy and safety of Januvia. These included one where Januvia was combined with metformin as an initial therapy, another where the drug was used with patients whose blood sugar was not being sufficiently controlled on metformin, and a third in patients who were being treated with a sulfonylurea (glimepiride), with and without metformin.
Januvia is a DPP-4 inhibitor: it inhibits glucagon production (the enzyme that increases blood sugar), and stimulates insulin (the enzyme that decreases blood sugar).
The drug label has been updated to include reports “hypersensitivity reactions” which have been received since the drug was launched. These reactions include anaphylaxis (serious acute allergic response), angioedema (rapid swelling of the mucosa, moist tissue that lines organs and body cavities, eg respiratory and digestive tracts) and exfoliating skin conditions, including a potentially life-threatening one called Stevens-Johnson syndrome.
However, Merck said that because these reactions were reported “voluntarily”, that is not monitored as part of a trial, and from a population of an uncertain size, it is not possible to make a reliable estimate of the risk or the strength of any causal link between Januvia and these potential side effects.
The drug should not be used to treat type 1 diabetes or diabetic ketoacidosis (a condition where the body breaks down amino acids and fats to obtain energy in the absence of blood sugar). The drugmaker said the drug has not been studied in combination with insulin. And Januvia is not approved for use with children under 18.
The FDA said the level of concern about the adverse reactions was “not great” and it was normal for the label to be updated to reflect potential symptoms that emerge after a drug is launched.
Click here for full drug company press release on the new FDA approval.
Written by: Catharine Paddock