News from the FDA/CDC

SGLT inhibitor still possible for T1DM, despite FDA committee vote


Sanofi hasn’t given up on its SGLT1/2 inhibitor sotagliflozin (Zynquista) for type 1 diabetes mellitus despite a recent 8-to-8 split decision on recommendation for approval from the Food and Drug Administration’s Endocrinologic and Metabolic Drugs Advisory Committee.

Dr. Peter Wilson, Emory University, Atlanta

Dr. Peter Wilson

In the company’s three trials, involving about 3,000 insulin-dependent adults treated for up to a year, the drug lowered hemoglobin A1c a respectable 0.5% without increasing hypoglycemia risk; reduced glucose variability; and increased time in range, with some modest benefits in both weight loss and lower blood pressure. There was no sign of the increased amputation risk that has bedeviled the sodium-glucose cotransporter 2 (SGLT2) inhibitor canagliflozin (Invokana), already on the market for type 2 diabetes mellitus.

The fly in the ointment was diabetic ketoacidosis (DKA); the drug increased the risk eightfold versus placebo, and, although there were no DKA deaths and over 60% of patients resumed sotagliflozin after recovering, the cases were serious and sometimes occurred in patients with glucose levels as low as 150 mg/dL. Younger people and women seemed to be at higher risk, according to the data.

DKA risk was 4 cases per 100 patients/year, a 4% risk, and that was in the ideal setting of a trial, not everyday practice. The annual background risk of DKA is 1% or less in type 1 diabetes mellitus (T1DM).

“It’s got to be safer than this,” said committee chair Peter Wilson, MD, professor of cardiology and public health at Emory University, Atlanta.

Dr. Wilson voted to recommend approval but with the major caveat that Sanofi have a strong risk mitigation program in place, perhaps based on ketone monitoring to catch emerging DKA before people end up in the ED. That was a universal request among others who voted for recommendation; among those who voted against, the concern in large part was that, even with such a program, the risk of DKA was still too high.

“If they had already developed a mitigation program that had been piloted, and they showed us some data, there would have been more enthusiasm, but we didn’t have that,” he said in an interview after the hearing.

Sanofi did suggest possible risk mitigation strategies during the meeting. In a statement afterwards, spokesman Nicolas Kressmann said, “While we acknowledge the increase in incidence of DKA observed with the addition of sotagliflozin to insulin, we believe that the risks may be mitigated and managed with proper patient selection and education regarding appropriate ketone monitoring. We will continue to work with the FDA to ensure the agency has the data it needs to evaluate the safety and efficacy of sotagliflozin when used as an oral treatment together with insulin by adults with T1DM. We are confident in the data of our T1DM clinical program.”

Meanwhile, the company’s development for T2DMs is ongoing, with results from a number of trials expected later in 2019. Sotagliflozin would join canagliflozin and two other SGLT2 inhibitors already on the market for T2DM, none of which have been approved for T1DM disease. The approved drugs work by increasing renal glucose excretion.

Dr. Cecilia Low Wang of the University of Colorado, Aurora

Dr. Cecilia Low Wang

A significant proportion of DKA cases in sotagliflozin’s T1DM trials were preceded by infections and other well-known triggers, “but there were a proportion of patients where they couldn’t identify the cause; it just kind of came out of the blue. Something about the medication lowers the threshold,” said panelist and endocrinologist Cecilia Low Wang, MD, director of the glucose management team at the University of Colorado Anschutz Medical Campus, Aurora, who voted against recommending approval.

“There’s definitely an increased risk” with other SGLT2 inhibitors, as well, when used off label for T1DM. “No one really knows why,” she said.

Dr. Wilson was also concerned that insulin wasn’t more tightly titrated in the placebo groups, which might have led to the 0.5% improvement seen with sotagliflozin, but “they wanted to have trials that were likely to be beneficial, so it’s reasonable to do what they did,” he said.

Overall, “we don’t really have many options for type 1, and many of us were sympathetic to the idea of increasing options.” In T1DM, “you can lose your concentration” on insulin dosing for a couple hours, “and the next thing you know you are going too high or too low and going off the road. These pills help smooth out your ups and downs. I would like to think [sotagliflozin] might be approved for a restricted group, for which we’ve really sorted out the ketone data,” he said.

Dr. Wilson and Dr. Low Wang did not have any disclosures.

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