Avanir Pharmaceuticals Inc said its drug was more effective in reducing agitation associated with Alzheimer's, compared with a placebo, sending the company's shares up 55 percent to an over eight-year high.
The company said based on the mid-stage trial data it planned to request a meeting with both the U.S. Food and Drug Administration and the European Medicines Agency.
Alzheimer's is the most common form of dementia and is a progressive neurodegenerative disease, which eventually leads to death.
There are no FDA-approved therapies to treat Alzheimer's-related agitation, Avanir said on Monday.
The drug, AVP-923, is already approved for treatment of pseudobulbar affect since October 2010 under the trade name Nuedexta.
The drug is also being tested for a range of disorders including Parkinson's disease, depression, autism and Bulbar function.
The most common adverse reactions observed in the trial were falls, diarrhea and urinary tract infection, which occurred in less than 10 percent of patients, the company said.
AVP-923 is a combination of two well-known drugs, dextromethorphan hydrobromide, a common ingredient used in cough suppressants, and low-dose quinidine sulfate used to treat irregular heartbeat.
An estimated six million Americans have Alzheimer's, a number that has doubled since 1980 and is expected to be as high as 16 million by 2050, the company said.