Path Cleared for Potential Parkinson's Treatment as FDA Advises Company to Skip Ph III Study

Posted 12 April 2013 | By Alexander Gaffney, RAC 

If US regulators have a reputation with the pharmaceutical industry, it's generally been for putting up roadblocks to product approval in the way of requiring further clinical studies to assuage concerns over safety or show greater proof of efficacy. But, as the US Food and Drug Administration (FDA) showed with Acadia Pharmaceuticals on Thursday, that's not always the case.


Acadia Pharmaceuticals is a biotechnology company that emphasizes development of small-molecule drugs intended to treat neurological and central nervous system disorders such as Parkinson's disease.

The company's flagship experimental product is pimavanserin, a "potential first-in-class treatment" for patients with Parkinson's disease psychosis (PDP). The chemical drug is an oral, once-a-day tablet that the company says "selectively blocks the activity of the 5-HT2A receptor, a drug target that plays an important role in psychosis."

The product fills a need not yet met by other products, Acadia explained. "Treatment of PDP poses a challenge to physicians as there are no therapies currently approved to treat patients in the United States. Physicians may attempt to address this disorder initially by decreasing the dose of the dopamine replacement drugs, which are administered to manage the motor symptoms of Parkinson's disease. However, this approach is generally not effective in alleviating psychotic symptoms and is often associated with a significant worsening of motor function in these patients."

Pimavanserin, however, holds an edge over such treatments because it does not negatively affect motor control, allowing patients to live a more normal life, the company said.

Based on early-stage positive results, the company said it had been in the process of "continuing preparations for a confirmatory pivotal Phase III trial (-021 Study) to evaluate the efficacy, tolerability and safety of pimavanserin in patients with PDP."

"We plan to use the same optimized trial design in the -021 Study as we did in the -020 Study," it added.

FDA to Company: Apply With What you Have

And while few companies' development plans go as expected, Acadia's has taken an unexpected and serendipitous turn.

On 11 April 2013, the company said that it had received word from FDA that the data from its "-020" study was sufficient, along with its Phase II clinical studies, to support a new drug application (NDA) to the agency. As a result, the company no longer needs to conduct the -021 study, freeing up considerable monetary resources that otherwise would have been spent on the trial, and also clearing a faster path toward market approval.

"We are very pleased with the outcome of our meeting with the FDA, which we expect will reduce substantially both the time and cost of our PDP development program," said Uli Hacksell, CEO of Acadia. "This represents another important step toward our goal of bringing pimavanserin to the market as an innovative therapy for Parkinson's patients who suffer from the psychosis frequently associated with this disease."

Some industry watchers highlighted the move as exceptionally unusual. "How often does FDA tell a drug developer to dispense with a requisite, second late-stage trial-and to proceed with filing a new drug application?" asked Bruce Bigelow of the trade publication Xconomy.

Not very, if investors are to be believed. The stock price of the company has surged around 64% since the announcement to just under $13.00 per share.

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