Chelsea Therapeutics International Ltd. (CHTP: Quote) said Wednesday that the U.S. Food and Drug Administration while reviewing its New Drug Application for Northera has requested more data to assess the efficacy of the drug intended to treat symptomatic neurogenic orthostatic hypotension.
Chelsea said the FDA in its Complete Response Letter, or CRL, has not raised any outstanding concerns for Northera.
Following the news, Chelsea shares initially gained six percent in extended trade on the Nasdaq, but later on pared those gains, dropping about 29 percent.
Chelsea's Northera New Drug Application is indicated in the treatment of symptomatic neurogenic orthostatic hypotension, or NOH - a rare, chronic and often debilitating drop in blood pressure on standing up, most often associated with Parkinson's disease. Chelsea had filed the NDA based on the positive outcome of Study 301.
Chelsea said that in the CRL, the FDA has requested that the company submit data from an additional positive study to support efficacy, and demonstrate durability of effect over a 2- to 3-month period.
The FDA also provided draft recommendations to several sections of the labeling submitted for Northera, with recommendation to include a black box warning related to supine hypertension.
The FDA has also indicated that additional bioequivalence work might be needed to support the approval of Northera 300mg capsule that Chelsea was considering making commercially available in addition to the 100mg and 200mg capsules used in its clinical program.
Meanwhile, Chelsea said that data for Northera from an ongoing Study 306 could potentially meet the efficacy issues raised by the FDA in its letter.
Chelsea said it plans to request a meeting with the FDA to review the Agency's comments, recommendations, and to take measures for securing approval of Northera.
Northera was recommended for approval by a FDA panel in February for the treatment of NOH in primary autonomic failure (Parkinson's disease, multiple system atrophy and pure autonomic failure), dopamine beta hydroxylase deficiency, and non-diabetic autonomic neuropathy.
Neurogenic orthostatic hypotension, or NOH, results from a deficient release of norepinephrine, the neurotransmitter used by autonomic nerves to send signals to the blood vessels and the heart.
Northera, an orally active synthetic precursor of norepinephrine, was granted orphan drug status by the FDA in 2007 for symptomatic NOH. In Japan, Northera has been approved since 1989.
Though there is no FDA-approved treatment specifically for NOH, Shire Pharmaceuticals' Midodrine, approved in 1996, is currently the only FDA-approved therapy for the treatment of orthostatic hypotension.
Northera, in phase III trials 301 and 302, had demonstrated improvement in the symptoms of NOH. The drug has been found to be both safe and very well tolerated.
CHTP closed Wednesday on the Nasdaq at $3.6710, down $0.129 or 3.39%, on a volume of 5.4 million shares. In after hours, the stock lost $1.07 or 29.17%. In the past year, the stock has ranged between $2.18 and $6.06.
by RTT Staff Writer
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