* FDA panel recommends Northera for FDA approval
* Vote follows FDA staff position opposing approval
* Final FDA decision due by March 28
* Shares up 66 percent as trading resumes
By David Morgan
WASHINGTON, Feb 23 (Reuters) - Chelsea Therapeutics International Ltd's hypotension drug Northera should be approved for use in the United States, a committee of independent experts recommended on Thursday, sending the company's shares sharply higher in afterhours trade.
The panel assembled by the Food and Drug Administration voted 7-4 for approval of the drug known generically as droxidopa, despite government concerns about whether the treatment is safe and effective for treating chronic illness. One committee member abstained and another did not cast a vote
The recommendation will now be taken into consideration by the U.S. regulatory agency, which is expected to render a final opinion by March 28. The drug has been in use in Japan since 1989.
Shares in the Charlotte, North Carolina-based biopharmaceutical company, which had been halted on Thursday, zoomed 66 percent to $4 in the afterhours market from their $2.55 close in regular trading on Wednesday.
FDA approval for Northera would guarantee Chelsea Therapeutics marketing exclusivity for seven years, according to analysts.
There is only one currently U.S.-approved drug for symptomatic neurogenic orthostatic hypotension, or NOH, called midodrine hydrochloride, which Shire Plc markets under the brand name ProAmatine. The FDA review document said midodrine may be removed from the market soon because it has never demonstrated clinical effectiveness.
On Tuesday, the FDA released a staff review document in which a government physician recommended against regulatory approval.
NOH is a rare, chronic and often debilitating drop in blood pressure on standing up, associated with Parkinson's disease, multiple-system atrophy and pure autonomic failure.
Symptoms include dizziness, lightheadedness, blurred vision, fatigue and fainting episodes, which often severely limit a person's ability to do daily activities that require standing and walking.
Many committee members said they voted in favor of the drug's approval because research data, though limited, showed it could provide remarkable benefits for some who suffer from a devastating disease for which no other effective treatment is available.
"If there were other treatments available, the answer would be 'no.' But there aren't," added Allan Coukell of Pew Charitable Trusts, the panel's consumer representative.
Several public witnesses provided by Chelsea Therapeutics, including disease sufferers, told panelists that the drug had produced life changing effects and had allowed them to lead relatively normal lives.
"If a wheelchair-bound patient can now stand up and do his day-to-day activities, that's huge for him," said Dr. Vasilios Papademetriou, a cardiologist with the Veterans Affairs Medical Center in Washington.
FDA staff advised the committee that strong evidence that Northera can confer at least one week of benefits on patients with NOH including the raising of standing blood pressure.
But the evidence showed no durable benefits that could compensate for safety concerns stemming from 19 deaths in data too limited to point to a cause, the staff said.
Company data also showed nine cases of life-threatening neuroleptic malignant syndrome over a 10-year period in Japan. The condition, that includes muscle rigidity and fever, is known to be caused by drug use.
But most panelists concluded the safety risks, though little known, were acceptable given the potential quality-of-life benefits for a treatment population with limited life expectancy.
"The safety profile of this is just as good if not better than what we're using right now," said Dr. Jeffrey Cohen, a neurologist at Dartmouth Hitchcock Medical Center.