The U.S. health regulator has declined to approve a nasal spray that would have been the first needle-free emergency treatment for allergic reactions, a surprise decision that sent shares of its developer ARS Pharmaceuticals down 47% premarket.

Despite concerns regarding neffy’s lack of clinical evidence, the panel of experts voted in favor of the nasal spray’s approval for the emergency treatment of type 1 allergic reactions.

The FDA is kicking off May with three target action dates and three advisory committee meetings, including one for a high-profile investigational gene therapy.