Chelsea Therapeutics International Ltd. shares plunged below a dollar in premarket trading Tuesday after the drug developer said regulators recommended another trial for its drug candidate Northera.
The Food and Drug Administration told the Charlotte, N.C., company that an ongoing study is unlikely to provide enough evidence to support an application for approval of the treatment, which is intended to prevent falling in patients with conditions like Parkinson's disease.
Chelsea said it is "evaluating several scenarios that may provide the supportive data the FDA is seeking while minimizing any delays" to its resubmission of the Northera application for approval.
Chelsea had said in late May it might have to make changes to a clinical trial of Northera that could delay its approval. Northera is Chelsea Therapeutics' most advanced drug candidate. The company has no drugs approved for sale.
Northera is designed to treat neurogenic orthostatic hypotension, which is a drop in blood pressure on standing. It's a common symptom of Parkinson's disease, and can make patients get dizzy and fall.
Chelsea also said in May it was ending studies of a potential treatment for rheumatoid arthritis, and it planned to focus resources on Northera.
Company shares have tumbled more than 70 percent so far in 2012, after the stock closed 2011 at $5.13. The stock closed at $1.46 Monday and then sank another 75 cents, or 51 percent, to 71 cents Tuesday before markets opened.