NEW YORK (AP) — Canadian biotechnology company Biovail Corp. and Acadia Pharmaceuticals Inc. said Tuesday they will continue to develop pimavanserin as a potential Parkinson's disease treatment, despite failures in one late-stage study. In September, the companies said pimavanserin failed to meet key goals in a study of Parkinson's disease psychosis patients. Symptoms associated with Parkinson's disease psychosis include visual hallucinations and delusions. The drug is still in another Phase III, or late-stage, clinical trial. The companies said they will design a third late-stage study using positive secondary results from the previous study, along with data from the ongoing late-stage study. The third study is expected to begin in the first half of 2010 and Biovail will be responsible for costs. Meanwhile, Biovail said it plans to pursue a development program for pimavanserin as an adjunctive therapy for schizophrenia.