Chelsea Therapeutics (NASDAQ:CHTP), regrouping from orphan drug Northera’s failure to secure regulatory approval, now plans to resubmit a new drug application in early 2013 with data from a modified phase 3 study.
The Charlotte, North Carolina drug developer announced the plans following its meeting with the U.S. Food and Drug Administration to discuss the complete response letter received in March for Northera, a compound developed to treat dizziness and fainting in Parkinson’s disease patients.
The company initially said that it understood the FDA’s concerns were about the drug’s durability — how long its effect lasts over a two- to three-month period. But Chelsea said that after subsequent discussions with the agency, it was clearer that the FDA was concerned that most of the data submitted in the drug application came from one study site, which “mitigated the persuasiveness of that study and prevented the FDA from accepting Study 301 alone as adequate evidence of effectiveness.” On a conference call to discuss the Northera plans, CEO Simon Pedder said that the FDA was the results from that site were “too good to be true.” That site, which was outside of the United States, accounted for a disproportionate number of patients with positive results from the drug.
Northera was developed to treat neurogenic orthostatic hypotension, or NOH, a condition in which patients experience dizziness and fainting upon standing due to low blood pressure. Though rare, NOH can be found in patients with Parkinson’s disease, multiple systems atrophy and pure autonomic failure. Patients who have NOH have few treatment options. Shire‘s (NASDAQ:SHPGY) ProAmatine, currently the only FDA-approved NOH treatment, has a black box warning and Shire must conduct additional studies to confirm the drug’s clinical benefit.
Chelsea’s Northera was already in another late-stage trial, Study 306B, studying the compound’s effect preventing falls in Parkinson’s patients with NOH. Chelsea now plans to change the endpoint of that study to evaluate orthostatic hypotension symptoms. The study will also increase in size from about 160 to 200. Fall prevention will be a secondary endpoint, though Pedder said that the goal of this trial is now to study dizziness and fainting in patients with NOH.
The 306B trial will enroll only patients with Parkinson’s disease unlike previous studies which also included patients who have multiple systems atrophy. The study currently has 161 patients enrolled. The FDA still has to review Chelsea’s proposal. But Pedder said that by continuing enrollment now, the company will shorten the timeline for another new drug application filing. The company expects to complete enrollment in the fourth quarter, giving it enough time to get topline data to resubmit its drug filing in the first quarter of 2013. That’s important because the company finished the first quarter with $51.7 million in cash and cash equivalent — enough money to carry Chelsea through the second quarter of 2013. If Chelsea does file a drug application in the first quarter, a regulatory decision could come six months later.
A Deep-dive Into Specialty Pharma
A specialty drug is a class of prescription medications used to treat complex, chronic or rare medical conditions. Although this classification was originally intended to define the treatment of rare, also termed “orphan” diseases, affecting fewer than 200,000 people in the US, more recently, specialty drugs have emerged as the cornerstone of treatment for chronic and complex diseases such as cancer, autoimmune conditions, diabetes, hepatitis C, and HIV/AIDS.
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