The FDA has pushed the pause button on Sanofi’s and Lexicon’s diabetes treatment Zynquista (sotagliflozin) two months after an advisory committee panel deadlocked over the drug’s safety profile.

The agency issued a complete response letter telling the companies that the application can’t be approved in its present form, Sanofi announced.

In a Jan. 17 meeting, the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee balked at data indicating that the Type 1 diabetes treatment increased the risk that diabetic patients could suffer from a dangerous spike of acid in the blood. Trial data showed that patients in the Zynquista group suffered from the potentially fatal complication at a rate eight times that of patients in the placebo group. In the end, the committee’s vote was 8-8.

Sanofi was one of the few big drugmakers to post a loss last year and at least one analyst had predicted big things for Zynquista—with estimated peak sales of more than $1 billion.