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

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: [[ticker: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: [[ticker: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 an