AstraZeneca's Farxiga follows rival Zynquista to FDA rejection in Type 1 diabetes

Turns out, the FDA’s March rejection of Sanofi and Lexicon Pharmaceuticals’ Zynquista was just a preview of what would come for the SGLT class in Type 1 diabetes.

The agency shot down a second drug from the group, AstraZeneca’s Farxiga, the British drugmaker said Monday. Regulators issued a complete response letter for the drug as an add-on to insulin in Type 1 adults whose insulin therapy isn't enough to control their blood sugar levels.

AstraZeneca didn’t provide any details about the denial or a timeline for resubmitting its application, saying only that it would work closely with the FDA to discuss next steps.

RELATED: AZ's Farxiga nabbed its Type 1 nod in EU. But after Zynquista's rebuff, how will it fare at FDA?

The FDA’s decision is hardly a shocking one, despite a thumbs-up for Farxiga—called Forxiga in Europe—from regulators across the pond earlier this year. The European Commission greenlighted the drug in overweight Type 1 patients, and an AstraZeneca spokesperson said at the time that “We remain confident in the positive benefit-risk profile of dapagliflozin and dapagliflozin-containing products, as outlined in the prescribing information.”

The thing is, the European watchdogs also waved through SGLT 1/2 Zynquista, which the FDA nixed on safety concerns. An increased incidence of diabetic ketoacidosis—a potentially life-threatening complication when the body produces high levels of blood acids—seen among trial patients was enough to turn off some expert panelists at an advisory committee meeting. Farxiga—as well as the rest of its SGLT2 brethren—also bears that risk.

RELATED: EASD: AstraZeneca's Farxiga cuts blood sugar, weight and insulin use in Type 1 diabetes study

AstraZeneca had been looking to build on market-leading sales for Farxiga, which led the SGLT2 class with $1.39 billion in 2018 revenue. Johnson & Johnson’s Invokana, on a major decline for the second straight year, managed just $881 million in 2018, while Eli Lilly and Boehringer Ingelheim’s Jardiance put up $658.3 million.

AZ’s drug could have used a boost in the U.S., though, where Farxiga isn’t ahead of the pack. Invokana last year churned out $711 million in stateside sales versus Farxiga’s $591 million.