The FDA rejected Lexicon Pharmaceuticals and Sanofi’s Zynquista in March, dashing their hopes of launching the Type 1 diabetes drug this year. Nine months later, the agency has rebuffed Lexicon’s appeal of that decision.
Along the way, Lexicon lost its partner Sanofi, which in 2015 handed over $300 million upfront and committed to as much as $1.4 billion in milestones for a worldwide license to Zynquista. Under the deal, Sanofi picked up the rights to develop and market the drug for Type 2 diabetes worldwide and for Type 1 diabetes outside the U.S.
Sanofi’s decision to dissolve the partnership came after Zynquista fell short of expectations in patients with chronic kidney disease. It announced in July it would exit the deal, but Lexicon wasn’t letting it go without a fight. The biotech said it considered Sanofi’s notice “invalid” and believed the Big Pharma was breaching the partners' contract. The duo buried the hatchet in September, with Sanofi agreeing to pay $260 million (€236 million) to exit the union.
Texas-based Lexicon is undeterred. Although the FDA’s Office of New Drugs “reiterated the FDA’s prior position and denied Lexicon’s appeal of the Complete Response Letter for Zynquista,” the company plans to plead its case to the agency’s Center for Drug Evaluation and Research (CDER) for a second appeal, Lexicon said in a statement on Monday.
Lexicon’s stock dipped 30% in premarket trading on Monday before trending back up.
The original FDA rejection for Zynquista (sotagliflozin), an SGLT1/2 inhibitor, came after an advisory panel deadlocked 8-8 on whether it would recommend the drug for approval. Lexicon and Sanofi sought approval for Zynquista as an oral add-on to insulin, but the panel members flagged a safety concern for the drug: increased risk of diabetic ketoacidosis, a serious complication that results from too little insulin.
Zynquista isn’t the only drug in its class that fell victim to the FDA. Months after Zynquista's rejection, AstraZeneca’s Farxiga met the same fate. The FDA approved the SGLT2 inhibitor for Type 2 diabetes in 2014 and the company had hoped to give it a boost in the U.S. with a Type 1 nod. Like Zynquista, Farxiga is approved in Europe—where it’s known as Forxiga—for the treatment of Type 1 diabetes.