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San Diego’s Acadia Pharmaceuticals Updates Plans for Experimental Parkinson’s Drug

Xconomy San Diego — 

Acadia Pharmaceuticals of San Diego and its Canadian partner Biovail are continuing to move ahead with pimavanserin. The experimental drug, you might recall, failed last September in a trial testing it as a treatment for Parkinson’s disease-related psychosis.

Pimavanserin is Acadia’s lead drug candidate, which may help explain why Acadia (NASDAQ: ACAD) and its partner aren’t willing to give up on it.

The companies now say they expect to meet with the FDA before the end of June to discuss plans for again testing the drug in Parkinson’s disease patients with psychotic symptoms stemming from their illness. They are planning a 200-patient late-stage trial comparing pimavanserin to a placebo. The companies say they anticipate making changes to the trial design that will increase the odds of success.

Under the partnership agreement between Acadia and Biovail, Acadia will run the trial and Biovail (NYSE: BVF) will pick up the initial costs. If the trial fails, Acadia must reimburse Biovail for 50 percent of the study costs. If successful, half of the trial costs will be deducted from the milestone payment due Acadia from Biovail.

The companies also are planning a late-stage study evaluating pimavanserin alone and in combination with risperidone in 600 patients with schizophrenia. The companies anticipate the drug combination, which uses a low dose of risperidone, will have comparable efficacy but fewer side effects of a higher dose of risperidone, which is approved for schizophrenia and bipolar disorder.  Biovail is responsible for the costs and conduct of the study, which the company expects to discuss with the FDA during this quarter.

In addition, Acadia is planning anexploratory trial in Alzheimer’s disease psychosis. If successful, Biovail will reimburse the costs.

As I reported last year, pimavanserin blocks a serotonin receptor on brain cells that appear to have a role in psychotic conditions. There are no approved drugs for psychosis related to Parkinson’s disease; up to 40 percent of 1.5 million Americans with Parkinson’s disease experience hallucinations or delusions of varying severity. An estimated 3 million Americans have schizophrenia. Drugs approved for the illness vary in effectiveness and carry severe side effects.

Pimavanserin was invented internally by Acadia, so if the trials succeed, the upside could be substantial. Needham & Co. analyst Alan Carr, in a research note today, said he viewed the Parkinson’s disease program as “high risk” but continued to favor the schizophrenia program, which showed promise in earlier studies.

Acadia provided the update Tuesday during its fourth quarter conference call. As noted at Briefing.com, the company’s performance was worse than expected. Acadia reported a loss of 23 cents a share after restructuring charges compared to the 19 cent loss expected by First Call. Revenues were $1.8 million versus a First Call census estimate of $2.5 million. Acadia’s shares took a hit today, falling nearly 3 percent to close around $1.37.