Shares of Chelsea Therapeutics Sink Ahead of FDA Review


Shares of Chelsea Therapeutics (NASDAQ:CHTP) fell Friday ahead of a Food and Drug Administration panel to review the company’s leading drug in development, Northera. A panel briefing released by the regulator expressed skepticism and concerns about both the safety and effectiveness of the drug. According to Reuters, Chelsea Therapeutics is down 27.8 percent, to $2.55, as a result of the FDA document, which contained several negative comments about the medicine.

The drug, dropxidopa, is used to treat dizziness and fainting in patients with nervous system disorders like Parkinson’s disease, multiple system atrophy, and pure autonomic failure. The medicine has been approved for use at lower doses in Japan and other Asian countries since 1989, and it is currently in Phase III clinical trials in the United States, where it has been branded under the name Northera by Chelsea.

Northera’s history with the FDA now stretches back to 2007, when Chelsea was given Orphan Drug Status for the medicine, a designation granted to therapies that affect less than 200,000 people per year, and which allows the company seven years of exclusivity in the United States. Five years later, the company submitted its first New Drug Application for Northera to the FDA, which was rejected. The government agency then requested that the company provide positive data from additional studies before resubmitting an NDA. Chelsea responded with a resubmitted application for the drug in mid-August.

In the briefing released Friday, regulators cited various concerns, primarily in regards to the company’s three clinical trials of the drug. The FDA’s briefing notes that due to problems with the way two of the three clinical trials of the drug were carried out, only one of the trials can be considered “truly successful.” The regulator cites “lack of sufficient evidence of efficacy” as the primary reason against approval, saying it is difficult for the agency to approve the drug based on one successful trial alone.

Other criticisms referenced include a lack of data regarding the drug’s long-term effectiveness and potential side effects as a result of continued exposure: “This paucity of long-term exposure combined with low patient exposure at the highest dose make it difficult to evaluate properly the long term safety of droxidopa,” the FDA briefing reads. ”There has been no durable effect (i.e. more than one week) demonstrated for droxidopa.”

The FDA also cited concerns over a neurological condition associated with the drug, which has yet to be fully explained. ”Of upmost concern are reports of neuroleptic malignant syndrome from Japan that aren’t clearly explained,” the FDA briefing reads. “In a review of Japanese postmarketing reports there were 28 cases of neuroleptic malignant syndrome reported while patients were taking droxidopa.”

FDA advisers will meet on Tuesday to discuss whether or not to approve the drug.