Provention Bio Inc. said the U.S. Food and Drug Administration granted breakthrough-therapy designation to its type 1 diabetes drug PRV-031 for patients who are at risk of developing the disorder.

Oldwick, N.J.-based Provention is developing PRV-031, or teplizumab, for preventing and delaying type 1 diabetes. The drug restores the function of certain cells in the pancreas that synthesize insulin and reduces the need for patients to get it from other means.

The designation is based on results from a study by TrialNet that showed a single 14-day course of PRV-031 delayed diagnosis of type 1 diabetes by an average of at least two years compared to placebo. Participants included children and adults at high risk of developing the disease.

The FDA grants breakthrough-therapy designation to in-development drugs that demonstrate a substantial improvement over existing therapies during early-stage clinical studies. The tag expedites development of the therapy for serious or life-threatening diseases and grants an option for a priority review, subject to certain conditions.

Over 800 patients have received PRV-031 in multiple clinical trials. Provention is conducting a late-stage study of the drug in newly diagnosed patients with type 1 diabetes.

Shares of the pharmaceuticals company spiked at market open but had settled to $10.15, or down 4.69% as of 10:54 a.m. ET on Aug. 5.