US-based pharmaceutical company Cassava Sciences has finished dosing patients in its cognition maintenance study (CMS) of simufilam for the treatment of Alzheimer’s disease and dementia.

The CMS is a double-blind, placebo-controlled six-month trial being conducted in line with a randomised withdrawal study design.

It aims to evaluate the safety and efficacy of simufilam in patients with mild-to-moderate Alzheimer’s disease.

The study enrolled more than 125 patients who had previously completed 12 months of treatment with simufilam or did not respond to open-label treatment.

These patients were randomised into a 1:1 ratio to receive either simufilam or a placebo.

The CMS’ primary outcome measures are patient safety and changes in cognition scores (ADAS-Cog) over six months.

Data obtained from the study will be stored in the CMS dataset and remain locked and blinded. In addition, the dataset will be analysed by outside biostatisticians.

Subgroup analyses could include patients by baseline scores or other crucial shared characteristics, as well as stages of the disease and prior responses to open-label treatment.

Top-line data are expected in the third quarter of this year.

Cassava Sciences president and CEO Remi Barbier said: “We all know that Phase III studies, if successful, provide evidence of efficacy.

“Our cognition maintenance study addresses a flip side of the drug efficacy question: what happens when Alzheimer’s patients who were taking simufilam for a year stop taking the drug for six months?

“Differences that emerge between the group of patients that continued to take simufilam versus the group of patients randomised to placebo may suggest evidence of simufilam’s efficacy.”

Based in Austin, Texas, Cassava Sciences aims to detect and treat neurodegenerative diseases such as Alzheimer’s disease.

The company’s product candidates are not yet approved by any regulatory authority and their safety, efficacy and other desirable attributes have not been established.