A pill that potentially offered a chance to reduce the number of daily insulin injections for people with Type 1 diabetes was rejected for sale in the U.S.

The Food and Drug Administration on Friday issued a complete response letter, which indicates that a new drug application cannot be approved in its present form, for Zynquista.

French drugmaker Sanofi SA and Lexicon Pharmaceuticals Inc., a small biopharmaceutical company based in a Houston suburb, sought approval for Zynquista for use in combination with insulin to help people manage their blood-sugar levels.

The companies didn’t indicate why the FDA rejected their application Friday, but an agency advisory panel in January cast a split vote on whether the benefits of Zynquista, which contains the active substance sotagliflozin, outweighed its risks to support approval.

Concerns focused on the “consistent and clinically meaningful increase in the risk of diabetic ketoacidosis,” a life-threatening complication caused by a lack of insulin in the body, according to a panel report. A similar panel in Europe also noted the higher risk of diabetic ketoacidosis but ultimately recommended approval for overweight or obese patients.