Updated Version 2 - Acadia's drug for treating psychosis symptoms associated with Alzheimer's disease failed to meet the primary endpoint in mid-stage study

Added executive's comments in paragraph 6

Sahil Pandey

Reuters, September 24 - Acadia Pharmaceuticals (ACAD.O) said on Thursday that its experimental drug for treating psychosis associated with Alzheimer's disease failed to meet the main goal of a mid-stage study, causing the company's shares to fall by about 11%.

Patients who received a daily 60-milligram dose of remlifanserin showed a greater improvement in reducing hallucinations and delusions compared to those in the placebo group, but the difference was not enough for the study to meet its primary endpoint.

The lower 30-milligram dose group did not show significant efficacy on any of the study measures, while the higher dose group met a key secondary goal assessing the overall severity of psychosis symptoms in Alzheimer's disease.

Despite the setback, Acadia said it will continue to enroll patients in two ongoing late-stage clinical trials and will discontinue the 30-milligram dose group. The company still expects that remlifanserin's peak sales potential in Alzheimer's disease psychosis and Lewy body dementia psychosis could reach about $4 billion.

Additionally, analysis results indicated that patients with more severe psychotic symptoms may benefit more from the drug, and the company is considering fine-tuning its patient screening criteria as a result.

"The purpose of this phase 2 study was to gain information to help design the phase 3 program. In that regard, I believe it has met our expectations," said Acadia's head of R&D, Elizabeth H.Z. Thompson.

BMO Capital Markets analyst Evan Seigerman said that while the study narrowly missed its primary endpoint, it achieved positive results on a key secondary measure, which may help guide Acadia in adjusting the design of its ongoing late-stage studies.

Acadia said that the rates of side effects, serious side effects, and treatment discontinuations were comparable to the placebo group, with no apparent impairment of motor or cognitive function and no deaths among treated patients.

Alzheimer's disease psychosis affects about 30% of patients diagnosed with Alzheimer's, leading to hallucinations and delusions that increase the burden on caregivers and the need for nursing home placement. There are currently no approved therapies for this condition.

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