Neurocrine hits the brakes on its genetic disease drug

Neurocrine Biosciences ($NBIX) suspended a pair of studies on its latest endocrinology treatment, flagging a preclinical safety signal but downplaying its potential to derail the program.

The San Diego biotech paused development of NBI-77860, a treatment for a potentially deadly disorder called congenital adrenal hyperplasia. Prior to enrollment, Neurocrine discovered some undisclosed preclinical findings inconsistent with its earlier animal studies, and, "out of an abundance of caution," halted the trials before they began dosing, Chief Medical Officer Dr. Chris O'Brien said in a statement.

The FDA has since put a partial clinical hold on NBI-77860, Neurocrine said, creating another hurdle for the drug.

"We intend to work closely with the FDA to elucidate these findings and determine the next steps for NBI-77860 in congenital adrenal hyperplasia," O'Brien said.

The news sent Neurocrine's shares down as much as 14%, but the biotech made up ground overnight and traded about 5% off its previous close by Tuesday morning.

Neurocrine's key asset is the AbbVie ($ABBV)-partnered elagolix, a Phase III endometriosis treatment analysts say could be a blockbuster in the making. Behind that is NBI-98854, a wholly owned drug for tardive dyskinesia and Tourette syndrome that has shown promise in Phase II.

- read the statement