A set of new treatment guidelines for treating Type 2 diabetes isn’t likely to lead to a boost in sales for newer classes of drugs like SGLT2 and DPP-4 inhibitors.

The American College of Physicians earlier this month issued new guidelines recommending that healthcare providers first prescribe a cheap generic drug over the newer and more expensive SGLT2 and DPP-4 inhibitors. The American Academy of Family Physicians also endorsed the guidelines.

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The group said patients with Type 2 diabetes should begin treatment with metformin, an inexpensive generic drug that costs about $4 for 60 tablets, after first trying to change their lifestyle habits.

The guidelines said that if clinicians consider adding a second drug, like an SGLT2 inhibitor or DPP-4 inhibitor, they should also take into account that the “increased cost may not always support the added benefit” — such as further lowering of a patient’s blood sugar. 

Johnson & Johnson, Boehringer Ingelheim, and AstraZeneca manufacture SGLT2 inhibitors, Invokana, Jardiance, and Farxiga, respectively; DPP-4 inhibitors include Novartis’ Galvus, Merck’s Januvia, Eli Lilly’s Tradjenta, and AstraZeneca’s Onglyza.

Sanofi, Merck, and Novo Nordisk did not respond to requests for comment by press time.