An experimental treatment in late-stage development hit a bullseye in a clinical trial with Alzheimer's disease patients. Axsome Therapeutics' (NASDAQ:AXSM) lead treatment candidate, AXS-05 significantly reduced symptoms of Alzheimer's disease agitation during the pivotal Advance-1 study.

Around 6 million Americans have Alzheimer's disease, and this figure is expected to reach 14 million by 2050. AXS-05 does not treat dementia directly, but it could alleviate symptoms of agitation that affect around 70% of Alzheimer's disease patients.

Caregiver and elderly patient

Image source: Getty Images.

Alzheimer's disease agitation has been associated with accelerated cognitive decline, decreased functioning, and earlier nursing home placement. Frequent bouts of emotional distress, disinhibition, and disruptive irritability also make life extra difficult for caregivers.

Hitting the mark

AXS-05 is a combination of bupropion, a decades-old old antidepressant, and dextromethorphan, which is the main ingredient in most cough suppressants. 

The Advance-1 trial split 366 patients into groups that received either AXS-05, a placebo, or bupropion alone. Patients treated with a placebo showed less agitation than those treated with bupropion, which was a little surprising.

As hoped, patients in the AXS-05 group were significantly less agitated than both control groups without any serious side effects reported. In fact, there were patient deaths in both control groups, but none among those treated with AXS-05. 

A pivotal trial with AXS-05 as a treatment for treatment-resistant depression failed to meet its primary endpoint in March, but it did succeed in a pivotal major depressive disorder study. An application to treat major depressive disorder will probably reach the FDA in the fourth quarter.