Shares in Acorda Therapeutics (NSDQ:ACOR) dropped nearly -30% today after the FDA told the company that the new drug application for its inhaled Parkinson’s disease treatment is incomplete.

The FDA’s refusal to file letter surprised analysts. The note from the regulatory agency had to do with the date when the manufacturing site would be ready for inspection and a question about the submission of the drug master production record, Acorda said.

The move is “surprising, puzzling, disconcerting” and “a very significant surprise,” Leerink analyst Paul Matteis said, according to MarketWatch.

The Ardsley, N.Y.-based company said it believes that the issues are “addressable” and pointed out that the FDA has not asked for more efficacy or safety studies for Acorda’s Inbrija.

In March, the company touted data from 2 ongoing, long-term safety studies of its inhaled Parkinson’s therapy. The trials showed no difference in pulmonary function between the group receiving the inhaled formulation of Parkinson’s drug levodopa and the control group.

Inbrija is being developed as a therapy for people with Parkinson’s disease experiencing “off” periods, or a re-emergence of symptoms.

Shares in Adamas Pharmaceuticals (NSDQ:ADMS), which won approval for its Parkinson’s therapy earlier this month, rose nearly 7% today on the news that the FDA would not review Acorda’s NDA.